Thanks for the video. What I enjoy most on this videos is seeing the little tricks from fusion that helps on designing easier like: offset face, the pull thing, and that thing with the circle where you don't measure from the middle. Not particularly the function, but when to use is the most useful thing
Thanks for mentioning my previous comment 😉 Yet I have some new ones here: - time 5:50: If you perform the cut this way, you'll generate a *cylindrical* shape at the end of each roller. That means clearance for the rollers in the exact position they are now, but as soon as they'll start to rool, they will interfere again. The "ideal" "final" shape the rollers ends should look like a *spherical* version (rotated around the roller's axis) of the *cylindrical* cutout. On a mechanical standpoint, these "spherical rollers' ends" have no purpose but avoid interference. - time 7:24: by creating an offset on the *track*, you effectively add clearance to the rollers' ends, but unfortunately to their cylindrical, "functional", "rolling" faces. This allows the two track to get closer, thus re-creating an interference on the rollers' ends, and defeating the added clearance. That's why the rollers are not rolling as they're supposed to. - time 10:11: by offsetting the rolling faces, you even "worsen" the point just above. The "contact and friction" area between 2 consecutive rollers is only a single point, not a big deal IMHO. Nontheless it's always a good idea to have some clearance due to 3D printing lacking the accuracy of machining operations for instance. But, in that case (time 10:33), you shall *divide* the desired clearance (1mm in total looks reasonable) by 2 times the number of rollers (10 rollers * 2), so the play don't pile-up. That's an offset of (1/20) = 0.05mm per roller => IMHO, It should work way better if you just do the following: > don't touch / offset the tracks > don't touch / offset the rollers' diameter (or only reduce by 0.05mm per roller or so) > just reduce the rollers' length by at least 2 (one for each roller end) times the maximum interference height, as seen at 5:50. As I can eyeball it, the interference is about half the rollers' chamfer size, so around 1mm in total ... The idea is to have the rollers' cylindrical faces still touching (and rolling) on the tracks, whereas the roller's flat ends should have enough clearance to clear the tracks (a bit more is better) Feel free to engage for further discussion if this is confusing 👍
Yes, they would slide instead of rotate given that you made the point of contact the flats of the cylinders instead of the rounds... The other problem you have is that the flats are large surfaces that end up dragging against the face. You should try and make it as small as you can print or, better yet, you print it so that each side of a cylinder snaps (or threads) together and the outer flats are completely round instead. Your first point of contact should be the cylindrical face. The flat faces are there to hold the cylinders in place. If you don't mind a bit of rattling, you could probably get away with making the height of the cylinders much shorter. Then you make one of the races have index points for the cylinders to hold them in place and that should be significantly better.
Hmm...I see what you're saying about the flats being the point of contact and should rather be the rounds. I'm not understanding the part about threading them in. I may explore options to hold the cylinders in place and maybe rounding the rounds to make them bulge out a bit to be the point of contact.
@@DesktopMakes I mean printing half of a cylinder with threads and the other half with threads so that the two sides can be attached. That way you can have a pointy bit on the end caps. Could also glue them together and have a pin on them. Careful about rounding that face, it decreases the surface area such that it will more easily deform and when it does that, you will have both a non round cylinder and it won't contact at that point leading to the situation you are at now.
I think we need to put a motor on it and be able to vary the speed. And make it bigger, maybe like small table size. Maybe add some LEDs for color. This could be a very long series.
the other issue (besides printing the curved roller end) is that the rollers do just that... they roll. if it has a curve like you made, as soon as it rolls 90 degrees it'll be binding again. also... it'd save time if you did the offset face before you mirrored the top race. :)
I understand using the cylindrical bearings was due to the 3D printable application, but is there a way to print spherical bearings without the tedious post processing? It would be great to see a comparison of performance if it was possible. Nonetheless, I enjoy watching the process involved with the design and reasoning behind it. Thank you
Thanks @Neomaster67. Without a flat surface for the model to lay on the print bed would mean you would have to enable supports which would require some cleanup and sanding if you want a smooth finish.
Two thoughts, and I'm an absolute novice so dismiss outright if I'm suggesting rubbish. Could you sculpt out of the top and bottom caps the profile of each bearing, so they sat in their own "carriage", preventing interference with bearings on either side? You could perhaps decrease the offset then so there was less gap between bearings? This may also assist with the bearings rolling rather than the top and bottom sliding. Second, maintain the flat tops on the bearings to enable easy 3D printing, but make the other face more spherical. You could also perhaps combine both suggestions?
Why not model the first two rollers, then use the "Spun Profile" tool to produce the correct shape for the contact surfaces in the races? They should not be straight cones.
I like all of your content, but this series with the deep dive has been one of the most informative for me.
Thanks for the feedback @lroyson!
Thanks for the video.
What I enjoy most on this videos is seeing the little tricks from fusion that helps on designing easier like: offset face, the pull thing, and that thing with the circle where you don't measure from the middle.
Not particularly the function, but when to use is the most useful thing
Got it. Thanks 👍
This type of content helps those learning CAD to up their game! Thanks.
Thanks for mentioning my previous comment 😉
Yet I have some new ones here:
- time 5:50: If you perform the cut this way, you'll generate a *cylindrical* shape at the end of each roller. That means clearance for the rollers in the exact position they are now, but as soon as they'll start to rool, they will interfere again. The "ideal" "final" shape the rollers ends should look like a *spherical* version (rotated around the roller's axis) of the *cylindrical* cutout. On a mechanical standpoint, these "spherical rollers' ends" have no purpose but avoid interference.
- time 7:24: by creating an offset on the *track*, you effectively add clearance to the rollers' ends, but unfortunately to their cylindrical, "functional", "rolling" faces. This allows the two track to get closer, thus re-creating an interference on the rollers' ends, and defeating the added clearance. That's why the rollers are not rolling as they're supposed to.
- time 10:11: by offsetting the rolling faces, you even "worsen" the point just above. The "contact and friction" area between 2 consecutive rollers is only a single point, not a big deal IMHO. Nontheless it's always a good idea to have some clearance due to 3D printing lacking the accuracy of machining operations for instance. But, in that case (time 10:33), you shall *divide* the desired clearance (1mm in total looks reasonable) by 2 times the number of rollers (10 rollers * 2), so the play don't pile-up. That's an offset of (1/20) = 0.05mm per roller
=> IMHO, It should work way better if you just do the following:
> don't touch / offset the tracks
> don't touch / offset the rollers' diameter (or only reduce by 0.05mm per roller or so)
> just reduce the rollers' length by at least 2 (one for each roller end) times the maximum interference height, as seen at 5:50. As I can eyeball it, the interference is about half the rollers' chamfer size, so around 1mm in total
...
The idea is to have the rollers' cylindrical faces still touching (and rolling) on the tracks, whereas the roller's flat ends should have enough clearance to clear the tracks (a bit more is better)
Feel free to engage for further discussion if this is confusing 👍
Yes, they would slide instead of rotate given that you made the point of contact the flats of the cylinders instead of the rounds...
The other problem you have is that the flats are large surfaces that end up dragging against the face. You should try and make it as small as you can print or, better yet, you print it so that each side of a cylinder snaps (or threads) together and the outer flats are completely round instead.
Your first point of contact should be the cylindrical face. The flat faces are there to hold the cylinders in place. If you don't mind a bit of rattling, you could probably get away with making the height of the cylinders much shorter. Then you make one of the races have index points for the cylinders to hold them in place and that should be significantly better.
Hmm...I see what you're saying about the flats being the point of contact and should rather be the rounds. I'm not understanding the part about threading them in. I may explore options to hold the cylinders in place and maybe rounding the rounds to make them bulge out a bit to be the point of contact.
@@DesktopMakes I mean printing half of a cylinder with threads and the other half with threads so that the two sides can be attached. That way you can have a pointy bit on the end caps. Could also glue them together and have a pin on them.
Careful about rounding that face, it decreases the surface area such that it will more easily deform and when it does that, you will have both a non round cylinder and it won't contact at that point leading to the situation you are at now.
I think we need to put a motor on it and be able to vary the speed. And make it bigger, maybe like small table size. Maybe add some LEDs for color. This could be a very long series.
Ha! Don't think I am beyond pursuing every one of these features! 😂
the other issue (besides printing the curved roller end) is that the rollers do just that... they roll. if it has a curve like you made, as soon as it rolls 90 degrees it'll be binding again.
also... it'd save time if you did the offset face before you mirrored the top race. :)
I understand using the cylindrical bearings was due to the 3D printable application, but is there a way to print spherical bearings without the tedious post processing? It would be great to see a comparison of performance if it was possible. Nonetheless, I enjoy watching the process involved with the design and reasoning behind it. Thank you
Thanks @Neomaster67. Without a flat surface for the model to lay on the print bed would mean you would have to enable supports which would require some cleanup and sanding if you want a smooth finish.
Two thoughts, and I'm an absolute novice so dismiss outright if I'm suggesting rubbish. Could you sculpt out of the top and bottom caps the profile of each bearing, so they sat in their own "carriage", preventing interference with bearings on either side? You could perhaps decrease the offset then so there was less gap between bearings? This may also assist with the bearings rolling rather than the top and bottom sliding. Second, maintain the flat tops on the bearings to enable easy 3D printing, but make the other face more spherical. You could also perhaps combine both suggestions?
Yes, that is a another path I could take - giving each roller their own little carriage to roll in place without moving around.
Why not model the first two rollers, then use the "Spun Profile" tool to produce the correct shape for the contact surfaces in the races? They should not be straight cones.
Hmm... Forgot about the Spun Profile tool. I may try that and see what I get.