Nonspecific 3D Printer advice

Equipment

  • Get the biggest nozzles possible. Print rate increases proportionally to the square of the nozzle size. 1mm is ideal. Small nozzles can be drilled out to make bigger ones if you can't get them off the shelf.

Material

  • PETG is preferred. It has good mechanical and chemical properties. PLA is hydrophilic and may be hard to sterilise safely, but makes usable single-use parts.

Model file

  • Make sure you're using our modified version of the 3Dverkstan design, with the peg positions adjusted to fit the 4-hole punches available here.
  • Use a layer height of around half the nozzle size. Make it as big as you can get away with.
  • Set the wall thickness to 2mm so that the arms are printed as walls only with no fill.
  • Set the Z seam position to the front and centre of the visor.
  • Turn on ironing for the top layer to seal it and make it easier to sterilise for reuse.
  • The print should involve no travel movements - the part is specifically designed so that you can have the nozzle running continuously and avoid blobs and strings from retraction and travel. If you're not achieving this you need to tweak other settings to get there. We can help with this.
  • Increase the print speeds until the limiting factor is the heater on your extruder. If the nozzle temperature starts falling below the setpoint during printing you're going too fast. If you haven't encountered that problem yet, you can go faster.
  • It may well be necessary to decrease fan speed. Fans can cool the arms of the design very rapidly and cause them to separate from the bed. They can also cool the nozzle and reduce the achievable print speed. You might not need the fans at all.

Rapid / multiple / automatic printing without stacking

If you have a dual extruder machine e.g. Ultimaker 3 or S5, stacking is the best option - print multiple copies of the design on top of each other in PETG/PLA, separated by PVA support. This will keep the machine busy for hours at a time and then you can just pull the copies apart.

With a single extruder machine there are several options to maximise throughput and minimise human attention needed. All of these will need custom G-code added to the print job. We can help with this.

  • You can set the machine to pause when the print is complete, beep and wait for user input. The user then just needs to remove the print from the bed and select to resume. The printer stays hot and immediately starts printing the next copy.
  • If your machine's X/Y axis drives are powerful enough to break the adhesion of the part to the bed, you can push the part off horizontally and resume printing automatically. You may need to print a pusher part that attaches to your print head. If the adhesion is too hard to break, cooling the buildplate or running the fans around the print may help.
  • If your X/Y axis drives are not strong enough to push off but your Z axis drive is strong, you can add a horizontal hole to the front wall of the visor and attach a hook to your print head. The head can then hook the part and pull it upwards off the bed. This is much easier to achieve than pushing sideways but requires a bit more precision to set up.

Stacking

Single extruder:

It's possible to implement stacking with a single extruder, but it may require manual work to pick off the support material inserted between copies, and can leave rough surfaces which may affect comfort or ability to sterilise. It is also difficult to make work with a large nozzle. But it may be a sensible strategy for spare machines with small nozzles that can't be continuously attended.

Detailed how-to of single extruder stacking here

Mutiple extruders:

For stacking you need to have matching print core sizes on both extruders for the Ultimakers when using Cura.

For your stack height you can build the stack to whatever height suits your printer but you may want to strike the balance between how long you want to be able to run the machine per stack and how much material you need on a reel to do so and what your printer does or doesn't do when on of the two reels runs out on you. Some will pause like our S5 but our 3 and 3E's will keep churning away extruding from 1 head only and leaving a mess on top of the stack.

For smaller print heads, we have ended up having to create a hollow profile with a low infill setting, to make sure that we a good solid top layer as the vertical lines were beginning to separate on to many prints and we would have had to throw out more than we could ship if we stuck to the recommended settings. If you are working any printer without a larger print core you may have to do the same and sacrifice a little production time to ensure a better quality finish and by that I mean a usuable quality.