Better to set the clearance/backlash in the gear data rather than scaling in the slicer. If you're trying to match another gear, pressure angle also matters. If you don't know, you can put the mating gear on a flatbed scanner, make a copy of it, then tweak pressure angle until the tooth profile looks right, and then look if it's close to something commonly used, like 20 or 14.5 degrees. Also, if you're using plain helical gears rather than herringbone, the beta of mating gears should be the same number but opposite sign.
3D printer dimensional accuracy varies quite a bit. Many of the lower end printers will error as much as 1 to 2/10 of a millimeter. Since the people that are downloading the model don't have access to the CAD file, scaling in the slicer is the only option they have. Thanks for the rest of that information though, very helpful.
nice tutorial! I know there should be another rule for the gears which says that the teeth of the wheels at the starting point should not meet, once the compete rotation of the big wheel is performed. meaning the sun and planetary should be different in size / nr of teeth.
Well I have seen several planetary arrangements where the sun and planet gears are the same size and number of teeth. And they seem to work just fine. I just built a dual stacked planetary transmission with a ratio of 16 to 1 and it's smooth as butter. And the planetary and sun gears have the same number and size of teeth.
There are two diameters listed in the data for the gear. Well, three actually. The first two are a diameter to the outer edge of the teeth and then a diameter to the root of the teeth. Those two are the ones you need. You cut them in half to get the radius, and then the distance between the center of the gears is 1 plus the other. The radius out to the end of the teeth on one gear plus the radius to the root of the teeth on the other gear is the distance between the center points.
That's very strange. What slicer are you using.? There's no logical reason that that feature of the geometry would cause that behavior. Unless maybe you set the chamfer too deep and it intersected with the root of the gear teeth? No, That couldn't have been it freeCAD would have failed the chamfer if it crossed edges.
@@loughkb Ok I got it to print but had to come up with my own fix kinda..After trying every slicer I have (Creality,FreeCad,and Cura) I pulled it into TinkerCad and zoomed in you see all the huge holes that were stopping it..I made a new outside ring to go on the outside of the gear teeth and it now prints great 😁...Only problem I have now is trying to keep one for myself..Everyone that sees it wants it LOL
I just went and checked the model file on thingiverse and it was borked. I don't know how that happened! I've fixed the file so nobody else will have trouble with it. I hope.
It is nice to see you feeling well enough to engage in strenuous mental challenges!
thanks for these 3d printing videos, its getting myself back 'in gear' for more printing projects
Hi Kevin, good to see you again!
73…
That really simplifies gears!
Ooooooh, thanks Kevin! Now you've got me looking at getting one of those fancy 3D printers! 😁
Hi Kevin,
Hope your health is still improving. Great explanation on how to make gears in FreeCad. Easily understood. Stay safe. 73 WJ3U
Thanks for your help 😊
Thank you for sharing
Better to set the clearance/backlash in the gear data rather than scaling in the slicer.
If you're trying to match another gear, pressure angle also matters. If you don't know, you can put the mating gear on a flatbed scanner, make a copy of it, then tweak pressure angle until the tooth profile looks right, and then look if it's close to something commonly used, like 20 or 14.5 degrees.
Also, if you're using plain helical gears rather than herringbone, the beta of mating gears should be the same number but opposite sign.
3D printer dimensional accuracy varies quite a bit. Many of the lower end printers will error as much as 1 to 2/10 of a millimeter. Since the people that are downloading the model don't have access to the CAD file, scaling in the slicer is the only option they have.
Thanks for the rest of that information though, very helpful.
nice tutorial! I know there should be another rule for the gears which says that the teeth of the wheels at the starting point should not meet, once the compete rotation of the big wheel is performed. meaning the sun and planetary should be different in size / nr of teeth.
Well I have seen several planetary arrangements where the sun and planet gears are the same size and number of teeth. And they seem to work just fine. I just built a dual stacked planetary transmission with a ratio of 16 to 1 and it's smooth as butter. And the planetary and sun gears have the same number and size of teeth.
Tnx from FarWest of France
Howdy, see ya soon😅
How do you know where to place axles so the gears mesh?
There are two diameters listed in the data for the gear. Well, three actually. The first two are a diameter to the outer edge of the teeth and then a diameter to the root of the teeth. Those two are the ones you need. You cut them in half to get the radius, and then the distance between the center of the gears is 1 plus the other. The radius out to the end of the teeth on one gear plus the radius to the root of the teeth on the other gear is the distance between the center points.
Sadly i can not print the ring gear..Print is being filled in and a top and bottom is on it :/
It's got to be a setting in your slicer.
If you're using Cura, make sure "Remove all holes" is turned off.
@@loughkb I had the same problem, the fix was to remove the chamfers on the outside of the ring gear.
That's very strange. What slicer are you using.? There's no logical reason that that feature of the geometry would cause that behavior. Unless maybe you set the chamfer too deep and it intersected with the root of the gear teeth? No, That couldn't have been it freeCAD would have failed the chamfer if it crossed edges.
@@loughkb Ok I got it to print but had to come up with my own fix kinda..After trying every slicer I have (Creality,FreeCad,and Cura) I pulled it into TinkerCad and zoomed in you see all the huge holes that were stopping it..I made a new outside ring to go on the outside of the gear teeth and it now prints great 😁...Only problem I have now is trying to keep one for myself..Everyone that sees it wants it LOL
I just went and checked the model file on thingiverse and it was borked. I don't know how that happened! I've fixed the file so nobody else will have trouble with it. I hope.
🛵🛵🛵🛵🛵🛵🛵👋🏻