MN-S 3D Printers

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3D Printers at Maker Nexus

  • Prusa I3 Mk3S+
  • Prusa XL (can print 360x360x360 mm)
  • FormLabs Form3 Resin Printer


Filament is NOT included in the membership fee.

We have a limited amount of donated filament that you can use. If you make big parts or a lot of small parts, then you should bring your own spool(s) of filament. You might consider buying an extra spool and donating it to the common supply.

Currently all of the 3D Printers owned by Maker Nexus use 1.75mm filament.


General Info

BOSS Class Documents

Materials Recommendations

Prusa has a nice materials guide with interesting information.

Delrin? While it extrudes at typical temperatures, Delrin doesn't stick to any of the heat beds you normally find on FDM printers. Apparently it wants to be printed onto wood or cellulose in a sealed heated chamber. The Prusas have metal heat beds and are open air. There are some hacks for printing Delrin on metal beds, but they involve adhesives, and we don't allow those on our shop machines because they can damage the coatings that are already on the steel build plates.

Carbon fiber-filled PLA or PETG is very strong. It can be printed with one of our Prusas that has the hardened steel nozzle installed.

Changing Filament

Changing filaments is responsible for most clogs. These instructions will help keep our printers printing. Whenever you're changing filaments, always preheat to the highest temperature of the two filaments.

When you approach a 3D printer it will have filament from the previous user in the extruder. If the reel is still there, look to see what the material was and select the appropriate temperature to Unload the Filament.

Often, the previous user will have clipped the filament and taken their reel with them. The only thing you'll see is a pig tail of filament out of the top of the extruder. Trying to Unload the Filament with a temperature too low to melt the filament will not work and may damage the extruder.

The rule is: if you don't know what material was in there before you, pre-heat to 255 which is hot enough to melt any existing filament material and then Unload the Filament. Then load your filament at this high temperature and extrude lots of material to make sure all the old material is gone.

Set the preheat temp to what is appropriate for your filament material and start printing.

If you have enough 3D printers, you might designate one printer for just PETG, to avoid this issue.

Big ball of plastic on the extruder of Prusa

A large ball of plastic attached itself to the nozzle and heat block, and in removal, the wires for the thermistor were damaged. To clean up an issue like that, don't try to remove the plastic while it is cold, you will break things every time. Typically, first thing to do is to remove the filament through a normal filament unload (preheat the nozzle ONLY - no need to preheat bed & unload filament). Then, raise the z axis so you have plenty of room to access the ball'o'plastic. Bring the nozzle temperature up to 30-40 degrees over your printing temperature. Be careful, this is obviously going to have hot plastic all over the place, and it sticks to skin. Wear gloves, use tools, do not try to grab plastic with your bare hand!!!

Once the hot end is at temperature, slowly begin pulling out loose plastic. What is contacting the hot end will get molten. Start scooping/pulling it out, push more plastic against the hot end, repeat. Be very careful of the wires attached to the hot end. There will be two sets, one for the heater cartridge, one for the thermistor. If you damage either, you'll be replacing them. Work the plastic blob into contact with the hot end until it starts to soften (as a blob). You can then try to start working larger chunks free, but again, don't force it, the wrapping for the thermistor, in particular, likes to bond to melted filament because it is a woven wrap. Some time and heat will free up the hot end. Once the majority is gone, cleaning up with a coarse paper towel that won't leave towel fibers is fairly easy. Again, it's HOT, be careful.

So that's what you do if you're at home, if it's one of our printers, ask for staff!

Typically, a failure like this is a first layer adhesion issue. If it failed after the first layer, there are a lot of potential causes. A good takeaway though: get a staff member to deal with it. There are specific ways to clean that up, but if you do it wrong, you'll break wires. In this case, we lost a $9 thermistor. Not a big deal.

Speeding Up Your Print

An article using filtered B-splines algorithms to minimize 3D printer vibrations. The article claimed about a 2x speed improvement. The U of Michigan researchers now have a website looking for beta testers who have a Taz 6 3D printer.

An article about splicer settings to maximize volumetric flow.

Heating Bed

Heated beds can have temperature variance across their surface leading to different adhesion success. One person recommended a hotter bed temperature so that the edges of the bed are at the desired temp. Here is a video evaluating different beds and part 2.

3D Modeling

See our page on 3D Printing and Modeling

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