Quick disclaimer, I’m half way through my build, and i didn’t take photos.
So I decided about 3 months ago I’d print the MPCNC Primo 25.4mm parts out of resin. I’ve got an ELEGOO MARS 2 Pro SLA printer that could print every part except for the Core - I printed that on my Creality CR10 v2.
I always knew this would be an experiment, and was never certain it would work out better or worse. I’ve printed all the parts and have begun putting things together.
I’m going to progress with the build and take photos when I’m done and update you all - it’s entirely possible I’ll have milling crashes when using these parts, so an enclosure and safety precautinos are a must!
SLA Parts Pros:
Faster to print
Firmer/Harder, Far more solid (printed 100% solid SLA Resin though.)
Tolerances are near perfect.
Depending on resin, can tolerate much higher temperatures than FDM plastics.
Cons:
Parts were never designed to be resin.
Parts fail sudden, and crack instead of slow/warp. They are far more prone to cracking and don’t tolerate misalignment or threading well.
Price - Resin is more expensive than plastic, also requires isopropyl alcohol and cleaning equipment.
Overtensioning results in cracking, not crushing.
I’m genuinely interesting to hear if anyone else has attempted this - or wants to, I’ll put my results in this thread in an update.
My current best theory is that SOME parts are probably better printed in SLA, the rails slide very nicely in the SLA parts (Trucks will probably perform much better) and that vibration will be probably worse than if i used PLA plastics.
One part I was particularly concerned about, but didn’t appear to be a problem was the threading tolerances - Endstops on the trucks work just fine being screwed in with the m2.5 screws self-tapping into the plastic.
I did print some core clamps using siraya blu, but they felt too flexy to improve things. My prints with ‘abs like’ resins seemed way too brittle to handle the bumps along the Cnc road, but I figured it might be worth a shot just to see. Glad to see you are giving it a go; interested to see how it turns out long term.
On a side note I have played with mixing resins a bit (like 50/50 blu with abs) and was intrigued by the level of control that it offers over material properties, vs fdm prints. The problem I have had is balancing how much flex resin to use such that the part has good tolerances yet is not too brittle. Adding more flex makes prints warp more while printing, which for some shapes can be a big problem. There is likely a sweet spot where the mix is stronger than pla fdm, and more precise too. I just have not found it yet.
What would be sweet, is seeing some scientific research examining the structural properties of different mix ratios of popular resins vs part accuracy (perhaps using the same set of popular resin printers) and comparing them to fdm materials.
I’ll be watching this, because I just bought a resin printer a little while ago, and so far the parts just don’t seem very durable. I’ve only tried a few resins, though, and none of the fancier materials you mentioned.
Since you have one, I would recommend playing with some of those fancier resins to get a feel where they can be used. Siraya Blu for example, is extremely resilient and for some geometries is plenty stiff. I made a replacement handle screw fitting for my lawn mower for example, that has held
up to extreme abuse better than the molded grp part it replaced. Gears I have made with it work very good… nothing like fdm cogs that barely work. It is also very transparent which makes it good for lighting… also taps well for threading. Only weakness is it’s relatively lower modulus, which makes thinner parts sometimes too flexible… in particular for Cnc where we freak out over 0.001” displacements.
I hear some of the other siraya stuff is even tougher… blue parts feel tough as my nylon fdm stuff already (which is insanely tough vs any other fdm imho… unfortunately nylon fdm is also very challenging when it comes to precision). So I am looking forward to playing with more exotic resins too.
I have. Formlabs Form 2 SLA printer. I printed a few parts using their “Tough” engineering resin. Just some of the smallest possible parts for the older 525 build. They all broke eventually. And at $250 a liter for that resin I gave up on it for the MPCNC.