This has been real helpful. Thanks for keeping things simple. Been dreading having to go through learning about gears, but your video really made things much more clear. Thanks
Free cad is awesome. It does 99% of what I want in my 3-D print designs and I don’t have to sell my soul to autodesk. It had one weakness compared to fusion 360, the topological naming problem, but the long awaited version 1.0 has made great strides toward fixing it.
Hi, I love the design in this video. I'm interested in learning how to design gears for 3D printing. I was wondering if there are any specs I need to look for in a 3D printer model that provide an accurate result for these type of intricate parts? I might buy one but as a beginner I don't want to spend a lot of money yet.
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.
I have a few more tutorials on my free CAD playlist, also a really good channel to look at is mango jelly. He does some of the best freecad tutorials and has an excellent beginner series.
A great tutorial, thank you! I have one question about the gears workbench. I noticed that in the properties panel for the newly created gear that you can set an axle hole (true/false) and that you can set the axle hole radius. However, when I try this it doesn't create a hole. Do you know if this is a flaw in the gears workbench module or is it not doing what I think it should be doing?
Either I never noticed that, or it didn't exist on that version of the gears workbench I was using making that video. I just went back and looked at the video, there was no section for hole at that time. I know there's been two updates since I made the video. I'm currently on Gears version 1.3.0 and I just tested, the axle hole function does indeed work for me. I set it to true and a hole appeared in the gear as expected.
@@loughkb I'm also on 1.3.0 and restarting everything, I do get a hole in the gear but it stops just at the last surface. That is, it is the same length as the gear thickness but the bottom surface still shows. Strange.
@@loughkb Ah, if I turn off Beta, set it to zero, then the axle hole does go all the way through. Could be a minor bug. The pocket way in your video is still the way to go for now.
First, you would have to scale each gear down so that there is about 0.2 mm clearance between each of them. You could probably do that in the Part workbench. You could duplicate the planet gears as separate parts in part workbench. Then you would have to use transform to position them all in place. Once they're all in place, you could create a compound of them all in Part workbench and export the compound as an STL file.
That's an interesting factoid. Although I had no idea what Citroën was. So I looked it up. 1919 was when he discovered that gear design being used in Poland and bought the patent. That was an interesting read.
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.
I'm finding the Gears work bench very frustrating. It does not play well with paramedic references. For example, if on your first gear, if I make the hole's diameter dependent on the gear's df value by dimensioning the hole diameter as ".df - 2 mm" it at first works but if I then go change the number of teeth, the sketch fails to recompute. I get "Sketch: No planar face in AttachEngine3D::calculateAttachedPlacement()!".
That is the topological naming issue. Most CAD programs suffer from that. When the gear is regenerated the face names have changed, so your sketch references a face name that doesn't exist anymore. A workaround would be to make sure the gear is centered on the origin point and then sketch your circle on the base plane, also centered on the origin point, and reverse the pocket direction to go up through the gear. Since the sketch is attached to the base plane it will no longer fail.
@@loughkb Wow. Thanks that works. Is there somewhere to learn best practices? I have a Spreadsheet which I renamed params after creation. It seems if I create the spreadsheet after the gear, I can't reference the spreadsheet. I need to create the spreadsheet first.
@@loughkb Another issue I'm having is that I want to use a spreadsheet variable to set the total outside diameter so in the gear's base.thickness field I am trying to enter into the equation: .BearingID - outside_diameter This gives me an error about "Unit mismatch" in the expression. The BearingID units are in mm as is outside_diameter. I get the same if I enter: 2 - outside But this case I can change it to: 2mm - outside_diameter and then it works. I can also just enter: .BearingID and that works. I can't reference the Gear in the Spreadsheet. (Although other times, in smaller test cases I can). The Spreadsheet is at the top level, above any Body and created very first thing. All my Bodies where all create before trying to add a gear. Everything works great until I get to the Gear. I know you are not technical support but if you have a word of wisdom or can point me to the best place to go for help I would be most grateful. _ I now see that outside_diameter is dependent on thickness so I should be referencing computed.da but the same issues remain.
@SLCompulsion if it complains about units just put a space and mm Also, in the expression editor you can start to type the word spreadsheet and it will pop up in the list to click on. And then you can either put in the cell number also off the list, or over on the spreadsheet you can click on the cell with the data and give it an alias, in the upper right. And then reference that alias.
@@loughkb Entering: >.BearingID mm - outside_diameter gives the a "Failed to parse expression." params is the name of my spreadsheet. I can reference the params spreadsheet in the gear properties ok (for example, I am setting the base.height from a variable in my spreadsheet) but not the other way around. I can not reference the gear properties, for example da, in the params spreadsheet. -- It is amazing what one can learn if one reads the documentation 🙂. What I didn't understand is that in the Spreadsheet, best practice is to enter values with dimension. So for a length, enter 5.5mm not just 5.5 even though the later works just fine in Sketcher. I also can now reference the Gear by entering .da as example but I get a message " Document.cpp(2543): The graph must be a DAG."
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.
![Blox Fruits Dragon Rework Update [Full Stream]](http://i.ytimg.com/vi/EqDAp8udhm0/mqdefault.jpg)
Hey Kevin...I really like your gear video. Opened doors to my imagination in design..
It is nice to see you feeling well enough to engage in strenuous mental challenges!
Absolutely brilliant video, I learnt so much about gears and Prusaslicer I didn't know I could change from inside to outside brims that is so useful.
This has been real helpful. Thanks for keeping things simple. Been dreading having to go through learning about gears, but your video really made things much more clear. Thanks
thanks for these 3d printing videos, its getting myself back 'in gear' for more printing projects
Free cad is awesome. It does 99% of what I want in my 3-D print designs and I don’t have to sell my soul to autodesk.
It had one weakness compared to fusion 360, the topological naming problem, but the long awaited version 1.0 has made great strides toward fixing it.
That really simplifies gears!
Ooooooh, thanks Kevin! Now you've got me looking at getting one of those fancy 3D printers! 😁
Hi Kevin, good to see you again!
73…
This is a fantastic video 👍
Thanks for your help 😊
Hi Kevin,
Hope your health is still improving. Great explanation on how to make gears in FreeCad. Easily understood. Stay safe. 73 WJ3U
Hi, I love the design in this video. I'm interested in learning how to design gears for 3D printing. I was wondering if there are any specs I need to look for in a 3D printer model that provide an accurate result for these type of intricate parts? I might buy one but as a beginner I don't want to spend a lot of money yet.
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.
Thank you for sharing
Very nice. I am having a hard time getting freeCAD to work. Thanks.
I have a few more tutorials on my free CAD playlist, also a really good channel to look at is mango jelly. He does some of the best freecad tutorials and has an excellent beginner series.
A great tutorial, thank you! I have one question about the gears workbench. I noticed that in the properties panel for the newly created gear that you can set an axle hole (true/false) and that you can set the axle hole radius. However, when I try this it doesn't create a hole. Do you know if this is a flaw in the gears workbench module or is it not doing what I think it should be doing?
Either I never noticed that, or it didn't exist on that version of the gears workbench I was using making that video.
I just went back and looked at the video, there was no section for hole at that time.
I know there's been two updates since I made the video. I'm currently on Gears version 1.3.0 and I just tested, the axle hole function does indeed work for me. I set it to true and a hole appeared in the gear as expected.
@@loughkb I'm also on 1.3.0 and restarting everything, I do get a hole in the gear but it stops just at the last surface. That is, it is the same length as the gear thickness but the bottom surface still shows. Strange.
@@loughkb Ah, if I turn off Beta, set it to zero, then the axle hole does go all the way through. Could be a minor bug. The pocket way in your video is still the way to go for now.
That is definitely a bug. I want over to the forum to report it and somebody else already had. So I'm sure it'll be fixed in the next update.
@@loughkb LOL. That was me who reported it. Great minds think alike. Thank you again for introducing me to this extremely useful tool.
Thanks for the vid
Tnx from FarWest of France
This item could be printed in place pre-assembled. How would I go about arranging the gears properly in FreeCad? Thanks
First, you would have to scale each gear down so that there is about 0.2 mm clearance between each of them. You could probably do that in the Part workbench. You could duplicate the planet gears as separate parts in part workbench. Then you would have to use transform to position them all in place. Once they're all in place, you could create a compound of them all in Part workbench and export the compound as an STL file.
@@loughkb Thanks I'll try it out tonight
Do you know, that the double helix gear was an inspiration for the Citroën's logo?
That's an interesting factoid. Although I had no idea what Citroën was. So I looked it up. 1919 was when he discovered that gear design being used in Poland and bought the patent. That was an interesting read.
@loughkb that's correct.
Have a good day
...and 73
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.
I'm finding the Gears work bench very frustrating. It does not play well with paramedic references. For example, if on your first gear, if I make the hole's diameter dependent on the gear's df value by dimensioning the hole diameter as ".df - 2 mm" it at first works but if I then go change the number of teeth, the sketch fails to recompute. I get "Sketch: No planar face in AttachEngine3D::calculateAttachedPlacement()!".
That is the topological naming issue. Most CAD programs suffer from that. When the gear is regenerated the face names have changed, so your sketch references a face name that doesn't exist anymore.
A workaround would be to make sure the gear is centered on the origin point and then sketch your circle on the base plane, also centered on the origin point, and reverse the pocket direction to go up through the gear. Since the sketch is attached to the base plane it will no longer fail.
@@loughkb Wow. Thanks that works. Is there somewhere to learn best practices? I have a Spreadsheet which I renamed params after creation. It seems if I create the spreadsheet after the gear, I can't reference the spreadsheet. I need to create the spreadsheet first.
@@loughkb Another issue I'm having is that I want to use a spreadsheet variable to set the total outside diameter so in the gear's base.thickness field I am trying to enter into the equation: .BearingID - outside_diameter This gives me an error about "Unit mismatch" in the expression. The BearingID units are in mm as is outside_diameter.
I get the same if I enter: 2 - outside But this case I can change it to: 2mm - outside_diameter and then it works. I can also just enter: .BearingID and that works.
I can't reference the Gear in the Spreadsheet. (Although other times, in smaller test cases I can). The Spreadsheet is at the top level, above any Body and created very first thing. All my Bodies where all create before trying to add a gear. Everything works great until I get to the Gear.
I know you are not technical support but if you have a word of wisdom or can point me to the best place to go for help I would be most grateful.
_ I now see that outside_diameter is dependent on thickness so I should be referencing computed.da but the same issues remain.
@SLCompulsion if it complains about units just put a space and mm
Also, in the expression editor you can start to type the word spreadsheet and it will pop up in the list to click on. And then you can either put in the cell number also off the list, or over on the spreadsheet you can click on the cell with the data and give it an alias, in the upper right. And then reference that alias.
@@loughkb Entering: >.BearingID mm - outside_diameter gives the a "Failed to parse expression." params is the name of my spreadsheet. I can reference the params spreadsheet in the gear properties ok (for example, I am setting the base.height from a variable in my spreadsheet) but not the other way around. I can not reference the gear properties, for example da, in the params spreadsheet.
-- It is amazing what one can learn if one reads the documentation 🙂. What I didn't understand is that in the Spreadsheet, best practice is to enter values with dimension. So for a length, enter 5.5mm not just 5.5 even though the later works just fine in Sketcher.
I also can now reference the Gear by entering .da as example but I get a message " Document.cpp(2543): The graph must be a DAG."
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.
Howdy, see ya soon😅
🛵🛵🛵🛵🛵🛵🛵👋🏻