I need to print a few bolts for a project. They are reasonably thick, about 10mm in diameter.
I don’t want to buy a roll of nylon or PC, as I’m not going to use that other than for these, so I’m limited to PLA or PETG, as those I go through like they’re going out of fashion.
It’s particularly the strength in twisting/turning them that will matter. For instance, a test print snapped the head off without much force (it was only 25%, 2 walls, infill, so I wasn’t surprised). So, that is maybe the sheer strength between layers that matters, I’m not sure.
I believe PLA is too brittle, but what about PLA-CF?
So, which would people suggest I use between:
PLA-CF
PETG
PETG-CF
Also, I’m going to make them solid for maximum strength. I’ll do that by using an overly high wall number (I read somewhere that’s better than high infill, though maybe it doesn’t make a difference at 100%). Has anyone got other suggestions for making them strong?
If you want them to provide actual mechanical clamping load, be sure to orient them laying down on the plate. You can cut out the bottom 1/12th of the circle to give a flat surface to print on. It looks real pretty and satisfying to have them pointing with the threads up, but the Z weakness will obliterate your part the moment you apply torque
Since you’ve already worked with CF-filled materials, you know they’re stiff and strong but also highly abrasive. That abrasiveness increases friction in printed threads, and if the fit is even slightly tight, a CF part can bind hard enough to snap the head before the threads ever seat.
Standard PETG avoids that problem. Its smoother surface engages threads cleanly, which is often more important in printed fasteners than the added stiffness from CF.
You mentioned avoiding PC because you don’t want a full spool. A 200g sample roll is a practical way to test it. For printed nuts and bolts, PC is an excellent choice. With high wall count it produces very rugged parts, has a smoother texture than CF composites, and it accepts a tap cleanly because it machines well.
PC prints just fine if you preheat with the heat bed at maximum, and aux fan at 30%. Wait 15-20 minutes until chamber temperature is at least 45°C before starting the print.
I print PC on a P1P enclosed with a pegboard case full of holes. It still works. With an X1’s better-sealed chamber, you should have an easier time.
Key points:
Heat-soak the plate at 95-100C for about 10 minutes.
Bring the chamber to roughly 35C. I tape the bubble wrap from the build-plate packaging (about 400x400 mm) over the open sides to hold heat.
An X1 usually doesn’t need that bubble-wrap trick.
One important note:
Use a glue barrier on the build plate. PC bonds aggressively, and the glue gives you a release layer. Print a small 15x15x15 mm cube in a corner first so you can confirm removal without risking real damage to the surface.
Have you considered Bambu’s PLA tough? Or PLA pro from someone like Overture or Polymaker? They print as easily as regular PLA but are considerably stronger.
Just a reassurance from an amateur like me I have a P1S and, compared to the real experts here, minimal experience. Nevertheless, I spent all of yesterday printing on my PC (my first try) with very satisfactory results (part of it was testing, part of it was printing various models I wanted to try out).
I use the same strategy for the PC as for other “high” materials (till now I printed ASA and PA12) - preheat the printer first. It means set Bed temperature to 100C, Home Position, Aux fan on, and I put an insulated box on the printer (I currently use a modified beer fermentation container - reflective layer on the inside, insulation in the middle, cordura on top… but before that, I successfully used only sweaters and towels on the printer - front, sides, back LEAVE uncovered) …
Within half an hour, the printer reaches 50°C and I can start printing. Then AUX fan is off, of course, I use only Bento fan to ciruclated air inside - it helps. During the entire printing process, the temperature in the printer ranges from 53-59°C, which I consider sufficient… I wouldn’t want it any higher anyway. After printing is complete, I let the printer gradually lower the temperature of the bed… by 5°C every 5 or 10 minutes, so as to avoid rapid cooling… I don’t know if this is necessary for PCs, but it certainly is for ASA and PA… I used to do it manually, but now I have a G code in the printer profile that does it automatically (you can find it online).
At one point, I considered active heating, but after considering the current situation (I can reach a temperature of 50-60°C without it, and I probably wouldn’t want it to be any higher), I gave up on the idea. The initial 30-minute wait is not a problem. Moreover, then the printer is already warmed up for subsequent prints, and the time for the next print is shortened.
I forgot to mention – it is useful to have a reliable thermometer inside the printer – the problem with most cheap ones is that around 55°C they stop showing the temperature and only display “H” Now I use a Bluetooth thermometer for baking – Meater… I had it at home from before and it works perfectly for this… I have temperature information available directly on my computer, including a graph/history.
As for the build plate… for ASA, PA12, and now PC, I’ve had great results with Glacier from Biqu… the materials stick to it when they’re supposed to and can be removed without any problems. Sometimes I use glue, sometimes I don’t… I used glue (Magigoo PC) on yesterday’s PC, so I don’t know how it would be without it… but removing the model was no problem (and it was definitely not always completely cooled down as it should be). But I still remember my first attempt with ASA… back then on Textured PEI (and without glue), when I couldn’t get it off at all… I spent about three hours trying to remove it and even slightly damaged the plate… then I realized that glue can also be used for better release
I had one of the BIQU blue plates. I can’t recall if it was the Glacier or their other cool plate.
Yes, things stuck to it well … really really well … too well. When the print came off, the second time I used it, it took the blue coating with it, leaving bare metal beneath and destroying the plate completely. Given that I only got 2 prints out of it, and they aren’t cheap, I obviously didn’t invest further in their plates.
Now I use a Bluetooth thermometer for baking – Meater… I had it at home from before and it works perfectly for this… I have temperature information available directly on my computer, including a graph/history.