ABS Printed parts and nozzle size

Planning on printing the parts for my MPCNC soon, and i have a VORON to print them on (V003 ftw). Now i have a range of nozzle sizes that will happily be used on the VORON, and it can easily print up to 1mm nozzle with good layer adherence and strength.

While the recommended is 0.4mm, im wondering whether anyone has printed the parts with a larger nozzle size? Im thinking even 0.8mm and 0.2mm layer height with ABS at 230C for optimal adherence.

It will be faster and stronger but I wonder how some fine details will work. Also, the corners are usually quite bad with big nozzles (at least from my own experience with 1.2mm nozzles), so there will be a lot of rework to do, especially for the central carriage, which needs to be very precise. You can try on a few parts and see how it comes up.

There is no point of using a 0.8mm nozzle if you only do 0.2mm layer height. You can do the same layer height without any problem with a .4mm nozzle, so if you use a .8mm nozzle, set up your layer height to 0.35 mm at least.

Also, I recommend you to use PLA for those parts, ABS is too soft, you want something rigid here. Do not even think of using something else (aside from carbon fiber, maybe), you’ll just waste time and material.

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Fair enough on PLA rather than ABS. Was thinkign about the large corner sections though. Centre carriage will be done with an 0.4 or 0.6. But the corner sections are essentially large chunks of plastic and could be rapidly printed at lower resolutions without too much negative effect i would think.

Also a few people have mentioned printing the corners in ABS rather than PLA due to flex needed for clamping. Thoughts there?

The corners are the parts where rigidity is the key, so I really wouldn’t print with an other material than PLA here. They have to support most of the efforts, so they need to be as stiff as possible. Thos parts will determine how rigid your machine will end up being.
I suppose those people were afraid to break the parts during tightening the bolts. If you’re afraid to break the tightening points of the screws (which is something that can happen, if you use too much force), you can just rework the 3D file a bit to put more material there, I think it can be done in 10 minutes on tinkercad.

PLA can flex a little, it is not glass, and since the amount of flex you need to clamp the tubes is minimal, it is more than enough in practice.

There may be a few parts that you could print with ABS if you really want to (the motor supports for instance), but i really don’t think it worth the hassle, considering the facts that ABS is more expensive, harder to print due to a higher probability of warping, and softer. It might worth using ABS if you plan to use your CNC outside under direct UV from sunlight (unlikely) or if you want to make it more impact resistant (but you’re not supposed to bash your CNC with a hammer anyway) or more resistant to high temperatures (the motors never ran hot on my machine so far even after hours of printing, so no need) or maybe if you want to get a better look by acetone polishing the surface (but the CNC, despite its awesome design, is probably not some beautiful piece of art that you want to expose in your living room anyway).

I really don’t see how ABS could be pragmatically justified here, unless maybe you already have a lot of stock of it and don’t want to have to purchase PLA.

Adding two more points:

  1. There are a ton of machines using PLA everywhere, so it’s a good starting point.

  2. There’s nothing to keep you from trying ABS for a part or two once you have an idea how the PLA works. That’s the best part of this machine, it can be constantly tinkered with.