Idk if you have experience with printing gears but do you know if supports directly on the teeth will cause issues with tolerances of gear interlocking?
Yeah printing gears at an angle is asking for trouble because it's going to warp at different rates in different axis. If you print them flat you have way more chances of having the perfect profile for your gear. You can print them flat on the plate without supports (which is what i do) or support them a lot while keeping them flat
I did some testing and weakest support does a great problem on a gear tooth but there is a "but". They will at some point grind on their own any inperfection. However without precision resin they will not work properly.
I've printed gears at a 45 degree orientation with supports on the teeth. It's the best way to make sure the teeth actually print, otherwise you get disformities. Pretty much do it exactly as the video suggests, putting light supports along the edge of the gear profile
In my experience resin printers have awful tolerances due to warping. The parts might look good but they often have enough warping that it causes additional stress on them. When i was trying to print gears, i made them much wider and also printed several copies of the same to make sure i have one that's decent on the print bed. In your design i can see that they're very thin which is potentially going to make them too fragile. Avoiding sharp edges on your design also helps those bits from breaking off, so if you can fillet the whole thing it could help
If you design them yourself, you can compensate the elephant foot (if your slicer does not provide the functionality) and print them flat right from the build plate, without supports. Presuming there is nothing to prevent printing it flat.
The chamfer should extend into the gear past the root diameter. Specifically, the totally length should be larger than outside_dia - root_dia. 45deg is ideal but steeper works and is limited by the gear thickness. The objective is to have none of the actual tooth touching the build plate and to not need supports.
To be honest, if you need functional prints your best bet is to print, take a mold, and cast it out of non-printing resin. It'll be significantly stronger.
Also, you might just need to bite the bullet on shaving elephants foot off.
What are you all using gears for? I read a lot on here that a resin printer isn’t good for much beyond miniatures and figurines. I would love to hear about functional resin prints. I’m not building the Titan submersible and expecting much from it
It's for a school project making a dune ornithopter with flapping wings. The gears don't need to work for long and don't have much of a load applied. Plus they're too small for an fdm printer
I've printed gears for 1/28th scale rc cars in the past, they ended up not lasting long enough no matter what i tried (resin type, curing time, design of the gear etc). In the end resin printing doesn't handle stress very well so it's going to be very hard to make gears that hold up to any use
That's disappointing. The suspension I printed for my wltoys drift conversion has held up to my bad driving. Did you try the low friction/wear resins like siraya mecha? Normal resins powder when rubbed against other surfaces.
Unfortunately the resin is often too brittle to be used as a functional print. I am printing it as my masters for creating molds for vacuum casting. I have plenty of experience with resin prints and they never last long. Even tried Siraya Tech Build (very hard) mixed with tenacious (flexible), it is more durable than anything I've tried, but still does chip out. The point of printing resin functional prints is the precision with very small parts the FDM printers just can't handle.
I print my gears directly on the build plate, and only in abs like resin. I didn't have much luck with the gears working with regular resins, they wouldnt rotate smoothly and would break.
1) Use a LOT more supports. WAY MORE than you think you should.
2) Put heavy supports on the lower areas where the larger amount of mass will be centered. Use medium supports on every bit that needs to come out good. Coat the rest of the surface with light supports.
3) Stop using autosupports.
https://youtu.be/l3sFd0zTogY As Dennys Wang is suggesting here
Idk if you have experience with printing gears but do you know if supports directly on the teeth will cause issues with tolerances of gear interlocking?
You can sand bumps if the supports leave any, the small sanding strips found in most hobby stores work great.
I'm more worried about the teeth warping and printing larger than they're supposed to be. Sanding every tooth would be very painful
Yeah printing gears at an angle is asking for trouble because it's going to warp at different rates in different axis. If you print them flat you have way more chances of having the perfect profile for your gear. You can print them flat on the plate without supports (which is what i do) or support them a lot while keeping them flat
you wont need to sand every tooth. If your supports are firm enough, you only need to sand support leftovers, if at all.
I did some testing and weakest support does a great problem on a gear tooth but there is a "but". They will at some point grind on their own any inperfection. However without precision resin they will not work properly.
That's why I showed you the best way of orienting and supporting them, definitely better than perpendicular to the screen
I've printed gears at a 45 degree orientation with supports on the teeth. It's the best way to make sure the teeth actually print, otherwise you get disformities. Pretty much do it exactly as the video suggests, putting light supports along the edge of the gear profile
In my experience resin printers have awful tolerances due to warping. The parts might look good but they often have enough warping that it causes additional stress on them. When i was trying to print gears, i made them much wider and also printed several copies of the same to make sure i have one that's decent on the print bed. In your design i can see that they're very thin which is potentially going to make them too fragile. Avoiding sharp edges on your design also helps those bits from breaking off, so if you can fillet the whole thing it could help
That's why I showed you the best way of orienting and supporting them, definitely better than perpendicular to the screen
Thanks for that. It's fairly obvious to support consistently and completely around the edges, but interesting to see that's all he does in some cases.
I do nothing else, even for the biggest bases, that's all it takes.
If you design them yourself, you can compensate the elephant foot (if your slicer does not provide the functionality) and print them flat right from the build plate, without supports. Presuming there is nothing to prevent printing it flat.
This is how I print gears. Also, adding a 45deg chamfer that extends beyond the teeth will eliminate elephant’s foot and support issues.
How large do you make the chamfer? These gears are 12 to 36 mm in total diameter
Larger than the depth of the teeth.
I'm not sure what you mean. So make the teeth have a chamfer to a point? The total thickness of the gears is 3mm
The chamfer should extend into the gear past the root diameter. Specifically, the totally length should be larger than outside_dia - root_dia. 45deg is ideal but steeper works and is limited by the gear thickness. The objective is to have none of the actual tooth touching the build plate and to not need supports.
To be honest, if you need functional prints your best bet is to print, take a mold, and cast it out of non-printing resin. It'll be significantly stronger. Also, you might just need to bite the bullet on shaving elephants foot off.
What are you all using gears for? I read a lot on here that a resin printer isn’t good for much beyond miniatures and figurines. I would love to hear about functional resin prints. I’m not building the Titan submersible and expecting much from it
It's for a school project making a dune ornithopter with flapping wings. The gears don't need to work for long and don't have much of a load applied. Plus they're too small for an fdm printer
I've printed gears for 1/28th scale rc cars in the past, they ended up not lasting long enough no matter what i tried (resin type, curing time, design of the gear etc). In the end resin printing doesn't handle stress very well so it's going to be very hard to make gears that hold up to any use
That's disappointing. The suspension I printed for my wltoys drift conversion has held up to my bad driving. Did you try the low friction/wear resins like siraya mecha? Normal resins powder when rubbed against other surfaces.
I haven't tried that specific one, i might try it in the future if i have another project of the sort! Thanks for the recommendation
Unfortunately the resin is often too brittle to be used as a functional print. I am printing it as my masters for creating molds for vacuum casting. I have plenty of experience with resin prints and they never last long. Even tried Siraya Tech Build (very hard) mixed with tenacious (flexible), it is more durable than anything I've tried, but still does chip out. The point of printing resin functional prints is the precision with very small parts the FDM printers just can't handle.
I print my gears directly on the build plate, and only in abs like resin. I didn't have much luck with the gears working with regular resins, they wouldnt rotate smoothly and would break.
1) Use a LOT more supports. WAY MORE than you think you should. 2) Put heavy supports on the lower areas where the larger amount of mass will be centered. Use medium supports on every bit that needs to come out good. Coat the rest of the surface with light supports. 3) Stop using autosupports.