makernexuswiki - User contributions [en]

Particle.io

2021-10-22T19:12:21Z

BobG:

Unfortunately their community pages are long, long conversations that are not trimmed up and easy to read. Once you find a gem of information, post it here.

== Particle.io (formerly Spark.io) ==

This is an "Arduino-like" processor. So far it has run all my Arduino code without a problem. We even brought over some other libraries and they worked. This platform easily connects to WiFi and Particle.io runs a cloud based service that makes talking to your core easy. Once the Particle Core is on WiFi then you can compile your code for it using either a web browser or their Particle Dev application on your local computer. In either case your software is compiled in the Particle Cloud and then pushed down to your Particle Core. This is beautiful. There is no need to be anywhere near your Particle Core when you send it new software.

The Particle firmware contains libraries that let you expose a local variable on your core, or a local function. Then these can be called from any web browser. Thus you can interact with your software on your core from anywhere in the world. Lastly, they offer Spark.publish which your software can call to send short messages through the Particle Cloud service (free) to anywhere. Your own server could monitor the Spark Cloud for alerts from your core(s). IFTTT.com offers a channel for Spark. I've had my core publish events to the cloud that IFTTT picks up and turns into SMS messages to my phone. IFTTT could also add events to a Google Docs spreadsheet.

The original Spark Core cost $35 and was configured via an app on a smart phone. In June 2015 they will ship the new Photon which costs $20 and I believe will be configured via its own WiFi hotspot (like the way Chromecast is configured). In October 2015 they will ship the new Electron which will offer cellular data connectivity for $3/month. In October they are also planning to release a solar power kit for the Electron. With all of this you will be able to put an Electron on the top of any local mountain and interact with it forever. Wow.

== Photon ==

=== String concatenation ===

We found a bit of code that would compile and run on the Spark Core, but not on the Photon. Here's the workaround:
* original code: bufferReadout += Time.timeStr(index);
* revised code: bufferReadout += Time.timeStr(index).c_str();

== Javascript ==
I wanted to interact with my Spark Core through the Spark Cloud. I wanted to do it without having an active web server, so I wrote code to do it in Javascript (a nasty language to work with). The page I wrote will allow you to log on to your Spark account, get information from your core, and then send messages back and forth. To use this you only need the Javascript code to run in your browser. The current version of my code will read the Spark Cloud to get a list of variables and methods that your core firmware exports. It also monitors your core for any Publish events it sends. You can run this from my web site, or go there and download all the code so you can modify it and run it anywhere you want. The download includes a simple sample firmware app to run on your core. But the web site also works with the factory installed firmware. [http://shrimpware.com/SIS http://shrimpware.com/SIS]
== Flashing Green does not connect ==
After much fooling around and Google searching I found that the Spark Core would not connect to my WiFi because I was using WEP encryption. Once I switched to WAP it worked fine. My Spark Core was working fine for weeks sitting next to me in my office (20 feet from the WiFi access point). Then one day it started dropping the WiFi connection and could not recover it. After a lot of searching I decided to move it closer to my WiFi access point (8 feet) and it worked reliably again. Weeks later I moved it back to my office and it worked fine for a few days; then it did not. My assessment: In my office the WiFi signal is strong enough most times, but occasionally someone/thing near by our house starts transmitting (perhaps the police station?) in a way that prevents my Spark Core from connecting when it is 20 feet from the WiFi access point.

== Creating an App to Communicate with a Particle Device ==
Particle provides a REST API (to the Particle Cloud) that allows an app to (1) read out the value of a global variable on the Particle device, at any time, and (2) call a function on the Particle device, also at any time. We have used this API capability to create Android apps in MIT App Inventor 2 that communicate with our Photon and Argon based projects. Complete details can be found at:

https://github.com/TeamPracticalProjects/MIT-App-Inventor-Particle-Photon-test

Particle on-line documentation can be found at:

https://docs.particle.io/reference/device-os/firmware/#cloud-functions

The Particle Cloud functions "Particle.variable()" and "Particle.function()" make it particularly easy to create apps that interact with your Particle-based project. MIT App Inventor 2 is a block-based programming language that is very easy to learn and use, and yet is capable of producing very useful apps. Information about MIT App Inventor 2 can be found at:

http://ai2.appinventor.mit.edu/

MIT App Inventor 2 is currently limited to developing apps for Android. However, MIT is well along in the development of support for iOS. MIT App Inventor 2 is entirely web based (no IDE to install) and is entirely free to use.

The Particle Cloud functions "Particle.publish()" and "Particle.subscribe()" are also particularly useful. The pair can be used for secure device-device communication via the Particle Cloud. Particle.publish() can also be used to fire off Particle Webhooks that can trigger Web APIs for third party cloud services, e.g. Google Sheets. Particle.subscribe() can then be used to receive webhook responses from third party cloud services. We have used these capabilities extensively in the Maker Nexus RFID access control system; for details see:

https://github.com/makernexus/MN_ACL

We have recently learned how to use Google Apps Scripts, in conjunction with Particle.publish() and Particle webhooks, to flexibly log data to Google sheets. We have also learned how to use Google Apps Scripts, in conjunction with Particle.publish() and Particle webhooks, to send e-mail and SMS mobile texts for alarms/alerts from Particle-based projects. Detailed documentation can be found at:

https://github.com/TeamPracticalProjects/Connectivity_Tools_with_Particle_Devices/blob/main/TPP_Connectivity_Tools_Technical_Description.pdf

Particle.io

2021-10-06T16:36:40Z

BobG: Added information about Particle Cloud API and MIT App Inventor 2.

Laser Cutters

2020-11-28T20:20:26Z

BobG:

= Different Machines =

[[Laser Manufacturers]] list (and associated equipment) with any notes we have.

= How To =

* Test to determine the correct focal distance for your laser [https://www.youtube.com/watch?v=Eg6THrEdleo video]

*A [https://www.youtube.com/channel/UCX4wA5KhEX6o8zZkHnPthUQ YouTube channel] with a lot of videos. Specializing in board game enhancements.

= Techniques =

== Wood Staining ==

Use Minwax Water Based Wood Stain to color the wood before cutting. Available everywhere, including Ace Hardware stores. They add tint just like they would with a paint. I ignore the colors in the samples on the shelf. I asked to see the colors in the tint machine, there are about a dozen. For my red, I use the red tint straight, no other colors. The stuff works great. I brush it on with a foam brush, then wipe it with a cotton rag.

== Cut for [[Vacuum_Forming|Vacuum_Forming]] ==

I cut a 3 inch medallion positive to use in laser forming. I cut it out of 6mm Baltic Birch plywood. I set the 3d Stamp mode in the driver to Shoulder 45, Widening 0. This gave great relief. On the 120w laser I used 400 DPI, speed 40, power 90, Stucki, bottom up. I did two passes.

== Fitting Parts to a Sheet ==

=== SVGNest ===

Sometimes you have a lot of irregular shapes you want to cut. Maximizing the use of a piece of material can be tough. The demo on this site is pretty cool: http://svgnest.com/   It's open souce, source found here: https://github.com/Jack000/SVGnest

I haven't tried SVGNest yet, but the sample images on his page are impressive.

== Sudo 3D ==

This web site shows a technique to create nice 3D chess pieces. He cuts the front profile then a bounding box. Then he rotates the piece 90 degrees to cut the other profiles. The results are very interesting. [http://imgur.com/a/Rt8kz http://imgur.com/a/Rt8kz]   Thanks to Bruce for finding this.

== Working with Inkscape and the Epilog Helix ==

* THE KEY CONCEPT: "Objects" in Inkscape can be created in several forms: (1) Object "primitives" (my term) -- the objects that you can draw using the tools on the left hand side of the Inkscape window -- these include rectangles, ovals, polygons, and text strings; (2) "Stroke" objects -- the objects that you create when using the pen tool -- either lines or Bezier curves; and (3) "Path" objects. As far as I know, you cannot create path objects directly, but you can convert other objects to paths using "Path | Object to Path" and "Path | Stroke to Path". If you use "Path | Trace Bitmap" to convert a pixel (raster) image to a vector drawing, the result is a stroke object.

* Now, here is the KEY CONCEPT: you MUST convert all objects that you want the Epilog laser to cut/engrave into "Path" objects. Select the object and use "Path | Object to Path" or "Path | Stroke to Path", as appropriate. If you don't perform these conversions, the objects will be ignored by the laser cutter! You can test that the object has been converted to a path by using the node editor tool (on the left toolbar below the select pointer). You should see a whole bunch of nodes that represent the path around the selected object. Another good test is to select "View | Display Mode | Outline" to clearly see the defined paths. After converting all of your objects to paths, use "Object | Fill and Stroke" to designate vector cutting/engraving (no fill, stroke line width = 0.001") or raster engraving (fill the object with black color and no stroke).

* TECHNIQUES:

To vector cut/engrave an object or text: place the object in the workspace. Select the object with the arrow pointer. Then: "Path | Object to Path". Next, select "Fill and Stroke" and make sure that there is no fill and that lines are solid and 0.001" wide. The difference between vector cutting and vector engraving is in the driver settings and not the Inkscape file.

To raster engrave an object or text: place the object in the workspace. Select the object with the arrow pointer. Then: "Path | Object to Path". Next, select "Fill and Stroke" and make sure that there is a solid fill and no stroke. The depth of the raster engraving is in the driver settings and not the Inkscape file.

To align objects inside of other objects (e.g. to center vertically): "Object | Align and Distribute"

To both vector engrave and vector cut within one project, select different colors for the cut objects and for the engraved objects. Make sure to note the full RGB settings for your color(s). In the Epilog driver, the vector settings will apply to any colors that are not specified in the "Color Mapping" tab. In the Color Mapping tab, put in the settings for the color that you want to engrave. Make sure to check the box to enable color mapping, select the color (double check that the RGB for the selected color are exactly what you set for the object in Inkscape), enter the settings and use the right arrow by the settings to transfer the settings into the color table. Any color that is not set in the color settings will use the default vector/raster settings on the main driver tab.

Settings that work well with 3 mm birch plywood are:

- Raster engraving: raster speed = 30%, raster power = 75%.

- Vector engraving: vector speed = 50%, vector power = 50%, vector frequency = 2500 Hz.

- Vector cutting: vector speed = 20%, vector power = 90%, vector frequency = 2500 Hz.

* MAKING A BOX USING THE INKSCAPE TABBED BOX EXTENSION.
See the document on the MN Member Google Drive, at:
https://drive.google.com/file/d/1btpuTFqOBQuDYE213z-sIyOjfjcpTbVC/view?usp=sharing

= Materials =

[https://www.ponoko.com/blog/materials/10-great-materials-for-laser-cutting/ Ponoko] has a fun list of 10 great materials to laser.

== Baltic Birch Plywood ==
It comes in 5x5 foot sheets 3mm (1/8th inch) for about $18. I have them cut the boards into 24 inch strips so that they fit in my car. I then cut the strips into 24x18 panels at TechShop. The price per panel is about $2.50. It also comes in 6mm sheets. These prices are from 2014 at the now defunct Southern Lumber. We've found a supplier on the web: [http://ocoochhardwoods.com/plywood.php Ocooch Hardwoods] I've found that the glue in this plywood makes it harder to cut than plain wood. There are also some hidden hard spots in the plywood. I have to cut at a slower speed or else I'll have some places that do not cut through.
*Settings for 3mm 45watt: speed 8, power 90, frequency 500. If the laser is really clean then speed can go up to 12.
*Settings for 6mm
Another source for Birch Ply is Mayan Hardwoods In Paso Robles. [http://www.mayanhardwood.com/ http://www.mayanhardwood.com/] Mayan carries a full line of hardwood plywood and regular hardwood lumber by the board foot. They do not have a cutting service for sheets of plywood. They do have a chop saw to cut board down. They have the Baltic Birch in 5' X 5' sheets in both 1/8" (3 mm) and 1/4" (6 mm). They also have Birch Plywood in 4' X 8' sheets. The 5 X 5 sheets are a much better quality than the 4 X 8 sheets. They offer contractor prices 
*Birch 1/8" 5 X 5 sheets for $17.77
*Birch 1/4" 5 X 5 sheets for $21.45
Mayan also has Oak 1/8"; and 1/4" plywood in 4' X 8' sheets.

== Acrylic ==
Also known as Plexiglas. It comes in several thicknesses; usually specified in English units (1/8, 1/4) but actually manufactured in metric (3mm, 6mm). It is easy to laser cut with a nice finish on the cut edges. Etching also produces nice effects. While extruded is cheaper, we highly recommend cast acrylic for your projects.

=== Cast Acrylic ===
Has a paper protective layer stuck to it with rubber cement. You can etch and cut through the paper. Has a very consistent thickness across the sheet. Superior etching results. It can warp if left in the sun on the dashboard of a car.

=== Extruded Acrylic ===
Has a blue plastic protective layer. The protective layer is reported to be laser safe but etching through it may not be ideal. May have slight thickness variation across the sheet. If precise thickness is important to your design, you may want to work in smaller pieces, measuring each with calipers and adjusting your design before cutting. Goes soft at a lower temperature than cast acrylic. Is 15% cheaper than cast acrylic.

=== Mirrored Acrylic ===
Mirrored acrylic has a thin reflective layer on one side. The mirror is seen when looking through the acrylic, the other side is a dull matte finish. You cannot cut or etch mirrored acrylic with the reflective side up (towards the laser). You can, however, cut mirrored acrylic with the dull side towards the laser. You can also get some interesting effects by etching the dull side, which removed the mirrored layer from areas.

=== Cement ===
While many glues may hold acrylic for some time, by far the best option is [https://www.tapplastics.com/product/repair_products/plastic_adhesives/tap_acrylic_cement/130/296?gclid=EAIaIQobChMIt9im_rbB5AIVgv_jBx31xwjwEAQYASABEgLiwvD_BwE acrylic cement]. This is a very thin liquid that wicks into a joint between two pieces of acrylic and dissolves the two pieces to form a very strong molecular bond. The bond requires that the two pieces have good contact between them; the cement does not fill gaps. You should search YouTube for a video on how to use acrylic cement - it is filled with good tips.

You can also use double sided tape or other similar methods.

=== Sources ===
Tap Plastics is a well known supplier of acrylic. They will cut sheets to size while you wait. They also have a scrap bin that is often filled with cheap pieces of acrylic. The scrap bin will also have pieces of other plastics that are not laser safe. If you have a question about the material, ask their helpful staff if the piece you want to by is acrylic.

== Worbla ==

Feels like plastic, but is laser cutter friendly. One side is sticky. You can heat it with a heat gun and form it like clay. Works great to make costume parts. An internet search for warbla will show a plethora of cool examples.

Worbla activates at 90 C.; I dipped in almost boiling water and was able to easily work it by hand. This is great stuff.

You can buy it at [http://www.cosplaysupplies.com/store.php?s=UN4V CosPlay Supplies.]

You can also [[Make_your_own_Worbla|make your own Worbla]]

= Supplies =

Also see the general [[Supply Sources]] page.

== LaserBits ==
[http://www.laserbits.com/ http://www.laserbits.com/] I have not purchased from this company yet. Full line of engraving supplies.  They have Color fills and seals. Engrave a piece of acrylic and then use this stuff to fill the engraving with a different color. [http://www.laserbits.com/laser-supplies/laserbits-pro-color-fill-sealer.html http://www.laserbits.com/laser-supplies/laserbits-pro-color-fill-sealer.html]
== Marking metal and glass ==

=== Thermark ===
You spray this product onto a metal or glass surface, laser it, then wash off the part that was not hit with the laser. I saw this used at TSMP on metal and the result was very good. The woman using it recommended it. I got a 6oz bottle of the spray on Thermark Laser Marking Material LMM14 Black from the manufacturers web site [http://thermark.com Thermark] for $62 plus $11 shipping UPS. Not cheap. My settings: 60W laser, 600 DPI, Stucki, speed 5, power 90.  Anything with less heat left the image susceptible to scratching off.
=== Dry Moly Lube ===

(From [http://www.evilmadscientist.com/2013/laser-moly/ Evil Mad Scientist] web site) A can of "CRC Dry Moly Lube" sells for about $10. Clean your metal with isopropyl alcohol. Spray lube on your metal, let dry. Do this three times. They etched with 20-30% speed (laser power unspecified) which showed a big difference. Clean off the excess lube with alcohol. They say the finished image seems tough. I haven't tried this yet.

[http://www.sawmillcreek.org/showthread.php?163305-Forget-Cermark-and-Plaster-of-Paris-try-this Sawmill Creek] also has a riff on this technique. He used "Sprayon LU200", 2 coats from 4 inches high. 600 DPI, 3% speed and 100% power, air assist and two passes. He cleaned it by spraying with Krud Kutter and letting it sit for a few minutes.

And... one commentator says that Cermark is so easy to use (one coat, water clean up) and fast to laser that the cost of the good stuff is not significant.

== Interesting Projects ==
Things found on the web that would be interesting to try.

[https://www.pinterest.com/richardaky/laser-cut-joint-ideas/ Self locking joints] of all kinds. Good seeds for brainstorming.

Laser Cutters

2020-11-28T20:19:02Z

BobG:

= Different Machines =

[[Laser Manufacturers]] list (and associated equipment) with any notes we have.

= How To =

* Test to determine the correct focal distance for your laser [https://www.youtube.com/watch?v=Eg6THrEdleo video]

*A [https://www.youtube.com/channel/UCX4wA5KhEX6o8zZkHnPthUQ YouTube channel] with a lot of videos. Specializing in board game enhancements.

= Techniques =

== Wood Staining ==

Use Minwax Water Based Wood Stain to color the wood before cutting. Available everywhere, including Ace Hardware stores. They add tint just like they would with a paint. I ignore the colors in the samples on the shelf. I asked to see the colors in the tint machine, there are about a dozen. For my red, I use the red tint straight, no other colors. The stuff works great. I brush it on with a foam brush, then wipe it with a cotton rag.

== Cut for [[Vacuum_Forming|Vacuum_Forming]] ==

I cut a 3 inch medallion positive to use in laser forming. I cut it out of 6mm Baltic Birch plywood. I set the 3d Stamp mode in the driver to Shoulder 45, Widening 0. This gave great relief. On the 120w laser I used 400 DPI, speed 40, power 90, Stucki, bottom up. I did two passes.

== Fitting Parts to a Sheet ==

=== SVGNest ===

Sometimes you have a lot of irregular shapes you want to cut. Maximizing the use of a piece of material can be tough. The demo on this site is pretty cool: http://svgnest.com/   It's open souce, source found here: https://github.com/Jack000/SVGnest

I haven't tried SVGNest yet, but the sample images on his page are impressive.

== Sudo 3D ==

This web site shows a technique to create nice 3D chess pieces. He cuts the front profile then a bounding box. Then he rotates the piece 90 degrees to cut the other profiles. The results are very interesting. [http://imgur.com/a/Rt8kz http://imgur.com/a/Rt8kz]   Thanks to Bruce for finding this.

== Working with Inkscape and the Epilog Helix ==

* THE KEY CONCEPT: "Objects" in Inkscape can be created in several forms: (1) Object "primitives" (my term) -- the objects that you can draw using the tools on the left hand side of the Inkscape window -- these include rectangles, ovals, polygons, and text strings; (2) "Stroke" objects -- the objects that you create when using the pen tool -- either lines or Bezier curves; and (3) "Path" objects. As far as I know, you cannot create path objects directly, but you can convert other objects to paths using "Path | Object to Path" and "Path | Stroke to Path". If you use "Path | Trace Bitmap" to convert a pixel (raster) image to a vector drawing, the result is a stroke object.

* Now, here is the KEY CONCEPT: you MUST convert all objects that you want the Epilog laser to cut/engrave into "Path" objects. Select the object and use "Path | Object to Path" or "Path | Stroke to Path", as appropriate. If you don't perform these conversions, the objects will be ignored by the laser cutter! You can test that the object has been converted to a path by using the node editor tool (on the left toolbar below the select pointer). You should see a whole bunch of nodes that represent the path around the selected object. Another good test is to select "View | Display Mode | Outline" to clearly see the defined paths. After converting all of your objects to paths, use "Object | Fill and Stroke" to designate vector cutting/engraving (no fill, stroke line width = 0.001") or raster engraving (fill the object with black color and no stroke).

* TECHNIQUES:

To vector cut/engrave an object or text: place the object in the workspace. Select the object with the arrow pointer. Then: "Path | Object to Path". Next, select "Fill and Stroke" and make sure that there is no fill and that lines are solid and 0.001" wide. The difference between vector cutting and vector engraving is in the driver settings and not the Inkscape file.

To raster engrave an object or text: place the object in the workspace. Select the object with the arrow pointer. Then: "Path | Object to Path". Next, select "Fill and Stroke" and make sure that there is a solid fill and no stroke. The depth of the raster engraving is in the driver settings and not the Inkscape file.

To align objects inside of other objects (e.g. to center vertically): "Object | Align and Distribute"

To both vector engrave and vector cut within one project, select different colors for the cut objects and for the engraved objects. Make sure to note the full RGB settings for your color(s). In the Epilog driver, the vector settings will apply to any colors that are not specified in the "Color Mapping" tab. In the Color Mapping tab, put in the settings for the color that you want to engrave. Make sure to check the box to enable color mapping, select the color (double check that the RGB for the selected color are exactly what you set for the object in Inkscape), enter the settings and use the right arrow by the settings to transfer the settings into the color table. Any color that is not set in the color settings will use the default vector/raster settings on the main driver tab.

Settings that work well with 3 mm birch plywood are:

- Raster engraving: raster speed = 30%, raster power = 75%.

- Vector engraving: vector speed = 50%, vector power = 50%, vector frequency = 2500 Hz.

- Vector cutting: vector speed = 20%, vector power = 90%, vector frequency = 2500 Hz.

* Making a Box using the Inkscape Tabbed Box Extension.
See the document on the MN Member Google Drive, at:
https://drive.google.com/file/d/1btpuTFqOBQuDYE213z-sIyOjfjcpTbVC/view?usp=sharing

= Materials =

[https://www.ponoko.com/blog/materials/10-great-materials-for-laser-cutting/ Ponoko] has a fun list of 10 great materials to laser.

== Baltic Birch Plywood ==
It comes in 5x5 foot sheets 3mm (1/8th inch) for about $18. I have them cut the boards into 24 inch strips so that they fit in my car. I then cut the strips into 24x18 panels at TechShop. The price per panel is about $2.50. It also comes in 6mm sheets. These prices are from 2014 at the now defunct Southern Lumber. We've found a supplier on the web: [http://ocoochhardwoods.com/plywood.php Ocooch Hardwoods] I've found that the glue in this plywood makes it harder to cut than plain wood. There are also some hidden hard spots in the plywood. I have to cut at a slower speed or else I'll have some places that do not cut through.
*Settings for 3mm 45watt: speed 8, power 90, frequency 500. If the laser is really clean then speed can go up to 12.
*Settings for 6mm
Another source for Birch Ply is Mayan Hardwoods In Paso Robles. [http://www.mayanhardwood.com/ http://www.mayanhardwood.com/] Mayan carries a full line of hardwood plywood and regular hardwood lumber by the board foot. They do not have a cutting service for sheets of plywood. They do have a chop saw to cut board down. They have the Baltic Birch in 5' X 5' sheets in both 1/8" (3 mm) and 1/4" (6 mm). They also have Birch Plywood in 4' X 8' sheets. The 5 X 5 sheets are a much better quality than the 4 X 8 sheets. They offer contractor prices 
*Birch 1/8" 5 X 5 sheets for $17.77
*Birch 1/4" 5 X 5 sheets for $21.45
Mayan also has Oak 1/8"; and 1/4" plywood in 4' X 8' sheets.

== Acrylic ==
Also known as Plexiglas. It comes in several thicknesses; usually specified in English units (1/8, 1/4) but actually manufactured in metric (3mm, 6mm). It is easy to laser cut with a nice finish on the cut edges. Etching also produces nice effects. While extruded is cheaper, we highly recommend cast acrylic for your projects.

=== Cast Acrylic ===
Has a paper protective layer stuck to it with rubber cement. You can etch and cut through the paper. Has a very consistent thickness across the sheet. Superior etching results. It can warp if left in the sun on the dashboard of a car.

=== Extruded Acrylic ===
Has a blue plastic protective layer. The protective layer is reported to be laser safe but etching through it may not be ideal. May have slight thickness variation across the sheet. If precise thickness is important to your design, you may want to work in smaller pieces, measuring each with calipers and adjusting your design before cutting. Goes soft at a lower temperature than cast acrylic. Is 15% cheaper than cast acrylic.

=== Mirrored Acrylic ===
Mirrored acrylic has a thin reflective layer on one side. The mirror is seen when looking through the acrylic, the other side is a dull matte finish. You cannot cut or etch mirrored acrylic with the reflective side up (towards the laser). You can, however, cut mirrored acrylic with the dull side towards the laser. You can also get some interesting effects by etching the dull side, which removed the mirrored layer from areas.

=== Cement ===
While many glues may hold acrylic for some time, by far the best option is [https://www.tapplastics.com/product/repair_products/plastic_adhesives/tap_acrylic_cement/130/296?gclid=EAIaIQobChMIt9im_rbB5AIVgv_jBx31xwjwEAQYASABEgLiwvD_BwE acrylic cement]. This is a very thin liquid that wicks into a joint between two pieces of acrylic and dissolves the two pieces to form a very strong molecular bond. The bond requires that the two pieces have good contact between them; the cement does not fill gaps. You should search YouTube for a video on how to use acrylic cement - it is filled with good tips.

You can also use double sided tape or other similar methods.

=== Sources ===
Tap Plastics is a well known supplier of acrylic. They will cut sheets to size while you wait. They also have a scrap bin that is often filled with cheap pieces of acrylic. The scrap bin will also have pieces of other plastics that are not laser safe. If you have a question about the material, ask their helpful staff if the piece you want to by is acrylic.

== Worbla ==

Feels like plastic, but is laser cutter friendly. One side is sticky. You can heat it with a heat gun and form it like clay. Works great to make costume parts. An internet search for warbla will show a plethora of cool examples.

Worbla activates at 90 C.; I dipped in almost boiling water and was able to easily work it by hand. This is great stuff.

You can buy it at [http://www.cosplaysupplies.com/store.php?s=UN4V CosPlay Supplies.]

You can also [[Make_your_own_Worbla|make your own Worbla]]

= Supplies =

Also see the general [[Supply Sources]] page.

== LaserBits ==
[http://www.laserbits.com/ http://www.laserbits.com/] I have not purchased from this company yet. Full line of engraving supplies.  They have Color fills and seals. Engrave a piece of acrylic and then use this stuff to fill the engraving with a different color. [http://www.laserbits.com/laser-supplies/laserbits-pro-color-fill-sealer.html http://www.laserbits.com/laser-supplies/laserbits-pro-color-fill-sealer.html]
== Marking metal and glass ==

=== Thermark ===
You spray this product onto a metal or glass surface, laser it, then wash off the part that was not hit with the laser. I saw this used at TSMP on metal and the result was very good. The woman using it recommended it. I got a 6oz bottle of the spray on Thermark Laser Marking Material LMM14 Black from the manufacturers web site [http://thermark.com Thermark] for $62 plus $11 shipping UPS. Not cheap. My settings: 60W laser, 600 DPI, Stucki, speed 5, power 90.  Anything with less heat left the image susceptible to scratching off.
=== Dry Moly Lube ===

(From [http://www.evilmadscientist.com/2013/laser-moly/ Evil Mad Scientist] web site) A can of "CRC Dry Moly Lube" sells for about $10. Clean your metal with isopropyl alcohol. Spray lube on your metal, let dry. Do this three times. They etched with 20-30% speed (laser power unspecified) which showed a big difference. Clean off the excess lube with alcohol. They say the finished image seems tough. I haven't tried this yet.

[http://www.sawmillcreek.org/showthread.php?163305-Forget-Cermark-and-Plaster-of-Paris-try-this Sawmill Creek] also has a riff on this technique. He used "Sprayon LU200", 2 coats from 4 inches high. 600 DPI, 3% speed and 100% power, air assist and two passes. He cleaned it by spraying with Krud Kutter and letting it sit for a few minutes.

And... one commentator says that Cermark is so easy to use (one coat, water clean up) and fast to laser that the cost of the good stuff is not significant.

== Interesting Projects ==
Things found on the web that would be interesting to try.

[https://www.pinterest.com/richardaky/laser-cut-joint-ideas/ Self locking joints] of all kinds. Good seeds for brainstorming.

Laser Cutters

2020-11-06T19:41:27Z

BobG: /* Working with Inkscape and the Epilog Helix */

= Different Machines =

[[Laser Manufacturers]] list (and associated equipment) with any notes we have.

= How To =

* Test to determine the correct focal distance for your laser [https://www.youtube.com/watch?v=Eg6THrEdleo video]

*A [https://www.youtube.com/channel/UCX4wA5KhEX6o8zZkHnPthUQ YouTube channel] with a lot of videos. Specializing in board game enhancements.

= Techniques =

== Wood Staining ==

Use Minwax Water Based Wood Stain to color the wood before cutting. Available everywhere, including Ace Hardware stores. They add tint just like they would with a paint. I ignore the colors in the samples on the shelf. I asked to see the colors in the tint machine, there are about a dozen. For my red, I use the red tint straight, no other colors. The stuff works great. I brush it on with a foam brush, then wipe it with a cotton rag.

== Cut for [[Vacuum_Forming|Vacuum_Forming]] ==

I cut a 3 inch medallion positive to use in laser forming. I cut it out of 6mm Baltic Birch plywood. I set the 3d Stamp mode in the driver to Shoulder 45, Widening 0. This gave great relief. On the 120w laser I used 400 DPI, speed 40, power 90, Stucki, bottom up. I did two passes.

== Fitting Parts to a Sheet ==

=== SVGNest ===

Sometimes you have a lot of irregular shapes you want to cut. Maximizing the use of a piece of material can be tough. The demo on this site is pretty cool: http://svgnest.com/   It's open souce, source found here: https://github.com/Jack000/SVGnest

I haven't tried SVGNest yet, but the sample images on his page are impressive.

== Sudo 3D ==

This web site shows a technique to create nice 3D chess pieces. He cuts the front profile then a bounding box. Then he rotates the piece 90 degrees to cut the other profiles. The results are very interesting. [http://imgur.com/a/Rt8kz http://imgur.com/a/Rt8kz]   Thanks to Bruce for finding this.

== Working with Inkscape and the Epilog Helix ==

* THE KEY CONCEPT: "Objects" in Inkscape can be created in several forms: (1) Object "primitives" (my term) -- the objects that you can draw using the tools on the left hand side of the Inkscape window -- these include rectangles, ovals, polygons, and text strings; (2) "Stroke" objects -- the objects that you create when using the pen tool -- either lines or Bezier curves; and (3) "Path" objects. As far as I know, you cannot create path objects directly, but you can convert other objects to paths using "Path | Object to Path" and "Path | Stroke to Path". If you use "Path | Trace Bitmap" to convert a pixel (raster) image to a vector drawing, the result is a stroke object.

* Now, here is the KEY CONCEPT: you MUST convert all objects that you want the Epilog laser to cut/engrave into "Path" objects. Select the object and use "Path | Object to Path" or "Path | Stroke to Path", as appropriate. If you don't perform these conversions, the objects will be ignored by the laser cutter! You can test that the object has been converted to a path by using the node editor tool (on the left toolbar below the select pointer). You should see a whole bunch of nodes that represent the path around the selected object. Another good test is to select "View | Display Mode | Outline" to clearly see the defined paths. After converting all of your objects to paths, use "Object | Fill and Stroke" to designate vector cutting/engraving (no fill, stroke line width = 0.001") or raster engraving (fill the object with black color and no stroke).

* TECHNIQUES:

To vector cut/engrave an object or text: place the object in the workspace. Select the object with the arrow pointer. Then: "Path | Object to Path". Next, select "Fill and Stroke" and make sure that there is no fill and that lines are solid and 0.001" wide. The difference between vector cutting and vector engraving is in the driver settings and not the Inkscape file.

To raster engrave an object or text: place the object in the workspace. Select the object with the arrow pointer. Then: "Path | Object to Path". Next, select "Fill and Stroke" and make sure that there is a solid fill and no stroke. The depth of the raster engraving is in the driver settings and not the Inkscape file.

To align objects inside of other objects (e.g. to center vertically): "Object | Align and Distribute"

To both vector engrave and vector cut within one project, select different colors for the cut objects and for the engraved objects. Make sure to note the full RGB settings for your color(s). In the Epilog driver, the vector settings will apply to any colors that are not specified in the "Color Mapping" tab. In the Color Mapping tab, put in the settings for the color that you want to engrave. Make sure to check the box to enable color mapping, select the color (double check that the RGB for the selected color are exactly what you set for the object in Inkscape), enter the settings and use the right arrow by the settings to transfer the settings into the color table. Any color that is not set in the color settings will use the default vector/raster settings on the main driver tab.

Settings that work well with 3 mm birch plywood are:

- Raster engraving: raster speed = 30%, raster power = 75%.

- Vector engraving: vector speed = 50%, vector power = 50%, vector frequency = 2500 Hz.

- Vector cutting: vector speed = 20%, vector power = 90%, vector frequency = 2500 Hz.

= Materials =

[https://www.ponoko.com/blog/materials/10-great-materials-for-laser-cutting/ Ponoko] has a fun list of 10 great materials to laser.

== Baltic Birch Plywood ==
It comes in 5x5 foot sheets 3mm (1/8th inch) for about $18. I have them cut the boards into 24 inch strips so that they fit in my car. I then cut the strips into 24x18 panels at TechShop. The price per panel is about $2.50. It also comes in 6mm sheets. These prices are from 2014 at the now defunct Southern Lumber. We've found a supplier on the web: [http://ocoochhardwoods.com/plywood.php Ocooch Hardwoods] I've found that the glue in this plywood makes it harder to cut than plain wood. There are also some hidden hard spots in the plywood. I have to cut at a slower speed or else I'll have some places that do not cut through.
*Settings for 3mm 45watt: speed 8, power 90, frequency 500. If the laser is really clean then speed can go up to 12.
*Settings for 6mm
Another source for Birch Ply is Mayan Hardwoods In Paso Robles. [http://www.mayanhardwood.com/ http://www.mayanhardwood.com/] Mayan carries a full line of hardwood plywood and regular hardwood lumber by the board foot. They do not have a cutting service for sheets of plywood. They do have a chop saw to cut board down. They have the Baltic Birch in 5' X 5' sheets in both 1/8" (3 mm) and 1/4" (6 mm). They also have Birch Plywood in 4' X 8' sheets. The 5 X 5 sheets are a much better quality than the 4 X 8 sheets. They offer contractor prices 
*Birch 1/8" 5 X 5 sheets for $17.77
*Birch 1/4" 5 X 5 sheets for $21.45
Mayan also has Oak 1/8"; and 1/4" plywood in 4' X 8' sheets.

== Acrylic ==
Also known as Plexiglas. It comes in several thicknesses; usually specified in English units (1/8, 1/4) but actually manufactured in metric (3mm, 6mm). It is easy to laser cut with a nice finish on the cut edges. Etching also produces nice effects. While extruded is cheaper, we highly recommend cast acrylic for your projects.

=== Cast Acrylic ===
Has a paper protective layer stuck to it with rubber cement. You can etch and cut through the paper. Has a very consistent thickness across the sheet. Superior etching results. It can warp if left in the sun on the dashboard of a car.

=== Extruded Acrylic ===
Has a blue plastic protective layer. The protective layer is reported to be laser safe but etching through it may not be ideal. May have slight thickness variation across the sheet. If precise thickness is important to your design, you may want to work in smaller pieces, measuring each with calipers and adjusting your design before cutting. Goes soft at a lower temperature than cast acrylic. Is 15% cheaper than cast acrylic.

=== Mirrored Acrylic ===
Mirrored acrylic has a thin reflective layer on one side. The mirror is seen when looking through the acrylic, the other side is a dull matte finish. You cannot cut or etch mirrored acrylic with the reflective side up (towards the laser). You can, however, cut mirrored acrylic with the dull side towards the laser. You can also get some interesting effects by etching the dull side, which removed the mirrored layer from areas.

=== Cement ===
While many glues may hold acrylic for some time, by far the best option is [https://www.tapplastics.com/product/repair_products/plastic_adhesives/tap_acrylic_cement/130/296?gclid=EAIaIQobChMIt9im_rbB5AIVgv_jBx31xwjwEAQYASABEgLiwvD_BwE acrylic cement]. This is a very thin liquid that wicks into a joint between two pieces of acrylic and dissolves the two pieces to form a very strong molecular bond. The bond requires that the two pieces have good contact between them; the cement does not fill gaps. You should search YouTube for a video on how to use acrylic cement - it is filled with good tips.

You can also use double sided tape or other similar methods.

=== Sources ===
Tap Plastics is a well known supplier of acrylic. They will cut sheets to size while you wait. They also have a scrap bin that is often filled with cheap pieces of acrylic. The scrap bin will also have pieces of other plastics that are not laser safe. If you have a question about the material, ask their helpful staff if the piece you want to by is acrylic.

== Worbla ==

Feels like plastic, but is laser cutter friendly. One side is sticky. You can heat it with a heat gun and form it like clay. Works great to make costume parts. An internet search for warbla will show a plethora of cool examples.

Worbla activates at 90 C.; I dipped in almost boiling water and was able to easily work it by hand. This is great stuff.

You can buy it at [http://www.cosplaysupplies.com/store.php?s=UN4V CosPlay Supplies.]

You can also [[Make_your_own_Worbla|make your own Worbla]]

= Supplies =

Also see the general [[Supply Sources]] page.

== LaserBits ==
[http://www.laserbits.com/ http://www.laserbits.com/] I have not purchased from this company yet. Full line of engraving supplies.  They have Color fills and seals. Engrave a piece of acrylic and then use this stuff to fill the engraving with a different color. [http://www.laserbits.com/laser-supplies/laserbits-pro-color-fill-sealer.html http://www.laserbits.com/laser-supplies/laserbits-pro-color-fill-sealer.html]
== Marking metal and glass ==

=== Thermark ===
You spray this product onto a metal or glass surface, laser it, then wash off the part that was not hit with the laser. I saw this used at TSMP on metal and the result was very good. The woman using it recommended it. I got a 6oz bottle of the spray on Thermark Laser Marking Material LMM14 Black from the manufacturers web site [http://thermark.com Thermark] for $62 plus $11 shipping UPS. Not cheap. My settings: 60W laser, 600 DPI, Stucki, speed 5, power 90.  Anything with less heat left the image susceptible to scratching off.
=== Dry Moly Lube ===

(From [http://www.evilmadscientist.com/2013/laser-moly/ Evil Mad Scientist] web site) A can of "CRC Dry Moly Lube" sells for about $10. Clean your metal with isopropyl alcohol. Spray lube on your metal, let dry. Do this three times. They etched with 20-30% speed (laser power unspecified) which showed a big difference. Clean off the excess lube with alcohol. They say the finished image seems tough. I haven't tried this yet.

[http://www.sawmillcreek.org/showthread.php?163305-Forget-Cermark-and-Plaster-of-Paris-try-this Sawmill Creek] also has a riff on this technique. He used "Sprayon LU200", 2 coats from 4 inches high. 600 DPI, 3% speed and 100% power, air assist and two passes. He cleaned it by spraying with Krud Kutter and letting it sit for a few minutes.

And... one commentator says that Cermark is so easy to use (one coat, water clean up) and fast to laser that the cost of the good stuff is not significant.

== Interesting Projects ==
Things found on the web that would be interesting to try.

[https://www.pinterest.com/richardaky/laser-cut-joint-ideas/ Self locking joints] of all kinds. Good seeds for brainstorming.

Laser Cutters

2020-10-14T18:45:49Z

BobG: /* Techniques */

= Different Machines =

[[Laser Manufacturers]] list (and associated equipment) with any notes we have.

= How To =

* Test to determine the correct focal distance for your laser [https://www.youtube.com/watch?v=Eg6THrEdleo video]

*A [https://www.youtube.com/channel/UCX4wA5KhEX6o8zZkHnPthUQ YouTube channel] with a lot of videos. Specializing in board game enhancements.

= Techniques =

== Wood Staining ==

Use Minwax Water Based Wood Stain to color the wood before cutting. Available everywhere, including Ace Hardware stores. They add tint just like they would with a paint. I ignore the colors in the samples on the shelf. I asked to see the colors in the tint machine, there are about a dozen. For my red, I use the red tint straight, no other colors. The stuff works great. I brush it on with a foam brush, then wipe it with a cotton rag.

== Cut for [[Vacuum_Forming|Vacuum_Forming]] ==

I cut a 3 inch medallion positive to use in laser forming. I cut it out of 6mm Baltic Birch plywood. I set the 3d Stamp mode in the driver to Shoulder 45, Widening 0. This gave great relief. On the 120w laser I used 400 DPI, speed 40, power 90, Stucki, bottom up. I did two passes.

== Fitting Parts to a Sheet ==

=== SVGNest ===

Sometimes you have a lot of irregular shapes you want to cut. Maximizing the use of a piece of material can be tough. The demo on this site is pretty cool: http://svgnest.com/   It's open souce, source found here: https://github.com/Jack000/SVGnest

I haven't tried SVGNest yet, but the sample images on his page are impressive.

== Sudo 3D ==

This web site shows a technique to create nice 3D chess pieces. He cuts the front profile then a bounding box. Then he rotates the piece 90 degrees to cut the other profiles. The results are very interesting. [http://imgur.com/a/Rt8kz http://imgur.com/a/Rt8kz]   Thanks to Bruce for finding this.

== Working with Inkscape and the Epilog Helix ==

To vector cut/engrave an object or text: place the object in the workspace. Select the object with the arrow pointer. Then: "Path | Object to Path". Next, select "Fill and Stroke" and make sure that there is no fill and that lines are solid and 0.001" wide. The difference between vector cutting and vector engraving is in the driver settings and not the Inkscape file.

To raster engrave an object or text: place the object in the workspace. Select the object with the arrow pointer. Then: "Path | Object to Path". Next, select "Fill and Stroke" and make sure that there is a solid fill and no stroke. The depth of the raster engraving is in the driver settings and not the Inkscape file.

To align objects inside of other objects (e.g. to center vertically): "Object | Align and Distribute"

To both vector engrave and vector cut within one project, select different colors for the cut objects and for the engraved objects. Make sure to note the full RGB settings for your color(s). In the Epilog driver, the vector settings will apply to any colors that are not specified in the "Color Mapping" tab. In the Color Mapping tab, put in the settings for the color that you want to engrave. Make sure to check the box to enable color mapping, select the color (double check that the RGB for the selected color are exactly what you set for the object in Inkscape), enter the settings and use the right arrow by the settings to transfer the settings into the color table. Any color that is not set in the color settings will use the default vector/raster settings on the main driver tab.

Settings that work well with 3 mm birch plywood are:

- Raster engraving: raster speed = 30%, raster power = 75%.

- Vector engraving: vector speed = 50%, vector power = 50%, vector frequency = 2500 Hz.

- Vector cutting: vector speed = 20%, vector power = 90%, vector frequency = 2500 Hz.

= Materials =

[https://www.ponoko.com/blog/materials/10-great-materials-for-laser-cutting/ Ponoko] has a fun list of 10 great materials to laser.

== Baltic Birch Plywood ==
It comes in 5x5 foot sheets 3mm (1/8th inch) for about $18. I have them cut the boards into 24 inch strips so that they fit in my car. I then cut the strips into 24x18 panels at TechShop. The price per panel is about $2.50. It also comes in 6mm sheets. These prices are from 2014 at the now defunct Southern Lumber. We've found a supplier on the web: [http://ocoochhardwoods.com/plywood.php Ocooch Hardwoods] I've found that the glue in this plywood makes it harder to cut than plain wood. There are also some hidden hard spots in the plywood. I have to cut at a slower speed or else I'll have some places that do not cut through.
*Settings for 3mm 45watt: speed 8, power 90, frequency 500. If the laser is really clean then speed can go up to 12.
*Settings for 6mm
Another source for Birch Ply is Mayan Hardwoods In Paso Robles. [http://www.mayanhardwood.com/ http://www.mayanhardwood.com/] Mayan carries a full line of hardwood plywood and regular hardwood lumber by the board foot. They do not have a cutting service for sheets of plywood. They do have a chop saw to cut board down. They have the Baltic Birch in 5' X 5' sheets in both 1/8" (3 mm) and 1/4" (6 mm). They also have Birch Plywood in 4' X 8' sheets. The 5 X 5 sheets are a much better quality than the 4 X 8 sheets. They offer contractor prices 
*Birch 1/8" 5 X 5 sheets for $17.77
*Birch 1/4" 5 X 5 sheets for $21.45
Mayan also has Oak 1/8"; and 1/4" plywood in 4' X 8' sheets.

== Acrylic ==
Also known as Plexiglas. It comes in several thicknesses; usually specified in English units (1/8, 1/4) but actually manufactured in metric (3mm, 6mm). It is easy to laser cut with a nice finish on the cut edges. Etching also produces nice effects. While extruded is cheaper, we highly recommend cast acrylic for your projects.

=== Cast Acrylic ===
Has a paper protective layer stuck to it with rubber cement. You can etch and cut through the paper. Has a very consistent thickness across the sheet. Superior etching results. It can warp if left in the sun on the dashboard of a car.

=== Extruded Acrylic ===
Has a blue plastic protective layer. The protective layer is reported to be laser safe but etching through it may not be ideal. May have slight thickness variation across the sheet. If precise thickness is important to your design, you may want to work in smaller pieces, measuring each with calipers and adjusting your design before cutting. Goes soft at a lower temperature than cast acrylic. Is 15% cheaper than cast acrylic.

=== Mirrored Acrylic ===
Mirrored acrylic has a thin reflective layer on one side. The mirror is seen when looking through the acrylic, the other side is a dull matte finish. You cannot cut or etch mirrored acrylic with the reflective side up (towards the laser). You can, however, cut mirrored acrylic with the dull side towards the laser. You can also get some interesting effects by etching the dull side, which removed the mirrored layer from areas.

=== Cement ===
While many glues may hold acrylic for some time, by far the best option is [https://www.tapplastics.com/product/repair_products/plastic_adhesives/tap_acrylic_cement/130/296?gclid=EAIaIQobChMIt9im_rbB5AIVgv_jBx31xwjwEAQYASABEgLiwvD_BwE acrylic cement]. This is a very thin liquid that wicks into a joint between two pieces of acrylic and dissolves the two pieces to form a very strong molecular bond. The bond requires that the two pieces have good contact between them; the cement does not fill gaps. You should search YouTube for a video on how to use acrylic cement - it is filled with good tips.

You can also use double sided tape or other similar methods.

=== Sources ===
Tap Plastics is a well known supplier of acrylic. They will cut sheets to size while you wait. They also have a scrap bin that is often filled with cheap pieces of acrylic. The scrap bin will also have pieces of other plastics that are not laser safe. If you have a question about the material, ask their helpful staff if the piece you want to by is acrylic.

== Worbla ==

Feels like plastic, but is laser cutter friendly. One side is sticky. You can heat it with a heat gun and form it like clay. Works great to make costume parts. An internet search for warbla will show a plethora of cool examples.

Worbla activates at 90 C.; I dipped in almost boiling water and was able to easily work it by hand. This is great stuff.

You can buy it at [http://www.cosplaysupplies.com/store.php?s=UN4V CosPlay Supplies.]

You can also [[Make_your_own_Worbla|make your own Worbla]]

= Supplies =

Also see the general [[Supply Sources]] page.

== LaserBits ==
[http://www.laserbits.com/ http://www.laserbits.com/] I have not purchased from this company yet. Full line of engraving supplies.  They have Color fills and seals. Engrave a piece of acrylic and then use this stuff to fill the engraving with a different color. [http://www.laserbits.com/laser-supplies/laserbits-pro-color-fill-sealer.html http://www.laserbits.com/laser-supplies/laserbits-pro-color-fill-sealer.html]
== Marking metal and glass ==

=== Thermark ===
You spray this product onto a metal or glass surface, laser it, then wash off the part that was not hit with the laser. I saw this used at TSMP on metal and the result was very good. The woman using it recommended it. I got a 6oz bottle of the spray on Thermark Laser Marking Material LMM14 Black from the manufacturers web site [http://thermark.com Thermark] for $62 plus $11 shipping UPS. Not cheap. My settings: 60W laser, 600 DPI, Stucki, speed 5, power 90.  Anything with less heat left the image susceptible to scratching off.
=== Dry Moly Lube ===

(From [http://www.evilmadscientist.com/2013/laser-moly/ Evil Mad Scientist] web site) A can of "CRC Dry Moly Lube" sells for about $10. Clean your metal with isopropyl alcohol. Spray lube on your metal, let dry. Do this three times. They etched with 20-30% speed (laser power unspecified) which showed a big difference. Clean off the excess lube with alcohol. They say the finished image seems tough. I haven't tried this yet.

[http://www.sawmillcreek.org/showthread.php?163305-Forget-Cermark-and-Plaster-of-Paris-try-this Sawmill Creek] also has a riff on this technique. He used "Sprayon LU200", 2 coats from 4 inches high. 600 DPI, 3% speed and 100% power, air assist and two passes. He cleaned it by spraying with Krud Kutter and letting it sit for a few minutes.

And... one commentator says that Cermark is so easy to use (one coat, water clean up) and fast to laser that the cost of the good stuff is not significant.

== Interesting Projects ==
Things found on the web that would be interesting to try.

[https://www.pinterest.com/richardaky/laser-cut-joint-ideas/ Self locking joints] of all kinds. Good seeds for brainstorming.