A tutorial showing how to create a matching rack gear for a pinion gear created using the SpurGear add-in. I also show how a motion link can simulate the gears meshing.
For anyone watching this in 2017, the SpurGear addin has changed, so rather than "diametral pitch," the plugin now relies on "module"--which is the inverse of diametral pitch. This makes a lot of sense, since the proper units for diametral pitch are 1/(length unit), which Fusion360 doesn't allow, whereas the units for module are just length units, which are fine. However, the plugin demands that module be unitless, for reasons that are unclear. It's best to keep the units on module, and just divide them out when you run the plugin. I actually prefer to start with the pitch circle diameter as a primary length, since this is how you calculate things like the mechanical advantage of the gear, and have Module as a derived measure. Then your derived measures are: module = pitchcirclediam / spurteeth addendum = module dedendum = 1.25*module racktoothpitch = PI*module outercirclediam = 0.5*PI*cos(pressureangle)*module The only weird thing then is that, when you enter the module in the SpurGear addin, you need to divide by your length unit to make it unitless, because the addin demands that even though it the units are actually pretty important. So I was using mm, so my expression was module/1mm. Otherwise the plugin turns the number red and greys out the "okay" button. The rest of the tutorial works as normal.
Another update to make things easier - when generating the gear using the SpurGear add-in, the third sketch of the gear is the diametral pitch, so you don't have to generate the first circle shown. Simply unhide the third sketch and then project it into the rack sketch.
Well i thought that fusion 360 will be more automatic in this matter. I was looking for a way to create rack gear. So I made one in blender. Exactly in the same way as here.
This tutorial is good, however, it could have been better if it did not involve some magical numbers and equations. Also this needs to be updated, because the Plugin is completely different now.
I know this should be obvious, but why if I am working in mm and not centimeters does this all go to heck. pitch circle diameter being number of teeth / diametral pitch makes no sense if the diametral pitch is 80 mm, you end up with a tiny cirlcle....
Looked this up, diametral pitch is not in units of cm, it is in units of teeth per cm, so you probably should have used no units here and that would have solved the other unit problems you were having
Great tutorial. :) But how would I go about making the pinion roll along the path of the rack? as in the the rack is stationary? I can make the pinion revolute on its own axis, make it slide along the rack as long as I don't have contacts enabled, but can I make it do both? with contacts enabled?
I don't doubt the functionality, but the simplicity of the rack geometry seems almost too good to be true. 4 straight lines. - Might be a rabbit hole around here... I don't intend to jump in it, but I'd at least like to know whether or not it exists.
i need the pinion to roll around a curved rack, is the proccess the same? how do i stablish a distance between teeh if i want to do it with the circle pattern tool?
Your voice, is not suitable for a tutorial where people would like to be able to hear you clearly without having to crank the volume knob to the ceiling.
Dude, it was a problem with the volume when I saved the video. The problem has since been remedied. Crank the volume knob to the ceiling and it'll be fine.
Learnt some handy tips here. I was watching the video mostly to learn about making joints/motion links for the gears I have already modelled, but useful nonetheless. Cheers!
I just tried it and they work as shown in the video. Double check that you're using the parenthesis in the same place. Also, the plugin has changed since this video was made so you might want to look at the pinned comment by Nicholas Halderman. Someday I will make a replacement for this video that takes his comments into account. Good luck.
Nope, it's just that the levels are low - if TH-cam would let me replace the video with a fixed one I'd do it. It's the same with a couple of my other videos. Keep turning it up.
You might have to be the one to create the tutorial! I haven't tried it, but I'd be interested to know if it's just a matter of doing a circular pattern instead of a rectangular one at 13:31
I wish someone would work with real world gears with the correct dp pa etc.... while gears like these are ok and would technically work they would make an engineering professor facepalm
Sorry, Professor Clown Whisper 😂 I hope the information in this video will help inform someone who wants to change the dp pa etc to be correct. Should be the exact same thing, but with different values I would expect.
But ... this gear is not *actually* a propper matching rack gear for that generated spur gear, is it? I mean, it doesn't have the curve. I bet those curves are there for a reason. Or am I missing something? I know its proably good enough for most use cases. But it would be nice to actually have the propper gear.
Gefrickelt BLN the rack will have a different tooth profile, so you shouldn't expect the teeth to look the same as they do on the circular gear. Check out this website - it seems as though the fillet on top is optional, but you could easily include it (as well as the fillet at the bottom) in the sketch. Just base the dimensions on a diagram like the one shown on this site - I used a similar reference for all of the dimensions/formulae that I use in the video. khkgears.net/new/gear_knowledge/gear_technical_reference/involute_gear_profile.html
I'm not sure if we mean the same thing, are you talking about topping/semitopping? I don't, I mean the contacting side faces of the gear are straight lines in your sketch, but the contact faces of the spur are curved. Like here khkgears.net/new/images/involute_gear_profile/Fig.-3.12-Magnitude-of-Semitopping.jpg vs here khkgears.net/new/images/involute_gear_profile/Fig.-3.9-Tooth-Profile-Modification.jpg
Yes, this is how the reference that I went from described it. (That the faces on the circular gear's teeth are curved, while the faces of the rack teeth are straight). A quick Google search seems to verify that this is how it normally works. But maybe there's more to it, as you say.
Good question. I would say that you could do everything exactly the same but pattern the teeth along a curved path instead of in a straight line. I suspect, though, that the spacing would not be the same "rackteeth" parameter. I just tried it really quick and it looked close - worth more investigation. If it's not "rackteeth", it just means you'd have to figure out what formula comes up with the correct value for the pattern spacing.
Interesting. I will give it a shot later. On second thought, my design really just needs a gear that is a half circle, so maybe I could create a larger spur gear and then modify it? I'm making a miter gauge for a table saw and my idea is to have a pinion gear with a knob that adjusts the angle of the miter gauge as you rotate the knob.
sir can you send me the cad file for a gear of following specification ..pitch 4 mm, 1" diameter pitch circle, 20 teeth,20 degree pressure angle, one with 40 teeth
I don't think you're right. The spur gear plugin is still there, it just has a slightly different interface now. Look at the pinned comment from Nicholas Halderman. Also, now that Fusion 360 has several tabs at the top to organize commands more logically, you'll need to click the Tools tab to find the "Scripts and Add-ins..." command.
For anyone watching this in 2017, the SpurGear addin has changed, so rather than "diametral pitch," the plugin now relies on "module"--which is the inverse of diametral pitch. This makes a lot of sense, since the proper units for diametral pitch are 1/(length unit), which Fusion360 doesn't allow, whereas the units for module are just length units, which are fine. However, the plugin demands that module be unitless, for reasons that are unclear. It's best to keep the units on module, and just divide them out when you run the plugin.
I actually prefer to start with the pitch circle diameter as a primary length, since this is how you calculate things like the mechanical advantage of the gear, and have Module as a derived measure.
Then your derived measures are:
module = pitchcirclediam / spurteeth
addendum = module
dedendum = 1.25*module
racktoothpitch = PI*module
outercirclediam = 0.5*PI*cos(pressureangle)*module
The only weird thing then is that, when you enter the module in the SpurGear addin, you need to divide by your length unit to make it unitless, because the addin demands that even though it the units are actually pretty important. So I was using mm, so my expression was module/1mm. Otherwise the plugin turns the number red and greys out the "okay" button.
The rest of the tutorial works as normal.
Thanks for the update!
OK, and what does all of that means? what do I have to do? In English
Just what I needed, thanks for putting this together!!
Thank you!
exactly what I needed, thank you :)
Another update to make things easier - when generating the gear using the SpurGear add-in, the third sketch of the gear is the diametral pitch, so you don't have to generate the first circle shown. Simply unhide the third sketch and then project it into the rack sketch.
Such a detailed tutorial! Thanks!
The construction lines are moving @_@
Well i thought that fusion 360 will be more automatic in this matter. I was looking for a way to create rack gear. So I made one in blender. Exactly in the same way as here.
I don't know jack shit about engineering, but that was interesting nonetheless.
This tutorial is good, however, it could have been better if it did not involve some magical numbers and equations. Also this needs to be updated, because the Plugin is completely different now.
thanks for doing your tutorials ... they have helped a lot.
I know this should be obvious, but why if I am working in mm and not centimeters does this all go to heck. pitch circle diameter being number of teeth / diametral pitch makes no sense if the diametral pitch is 80 mm, you end up with a tiny cirlcle....
Looked this up, diametral pitch is not in units of cm, it is in units of teeth per cm, so you probably should have used no units here and that would have solved the other unit problems you were having
Great tutorial. :)
But how would I go about making the pinion roll along the path of the rack? as in the the rack is stationary?
I can make the pinion revolute on its own axis, make it slide along the rack as long as I don't have contacts enabled, but can I make it do both? with contacts enabled?
Peter dønvang right click on the component that you *don't* want to move and choose Ground
I don't doubt the functionality, but the simplicity of the rack geometry seems almost too good to be true. 4 straight lines.
- Might be a rabbit hole around here... I don't intend to jump in it, but I'd at least like to know whether or not it exists.
Great Video Rob, thanks for sharing!
#youareawesome
i need the pinion to roll around a curved rack, is the proccess the same? how do i stablish a distance between teeh if i want to do it with the circle pattern tool?
Thanks for the tutorial i learned a lot. gonna be pain in the ass to create de gear / rack for my servo with those 3d printing fdm tolerance ^^
Thank you. Thank you very much.
This video saved my life.
yo dude can we make a telescopic stick using rack and gear?
Is it possible to copy one tooth of the pinion, flip it and do an array?
This was very helpful. Thank you very much.
Your voice, is not suitable for a tutorial where people would like to be able to hear you clearly without having to crank the volume knob to the ceiling.
Dude, it was a problem with the volume when I saved the video. The problem has since been remedied. Crank the volume knob to the ceiling and it'll be fine.
Future 4 years and contact sets now work pretty well!
Learnt some handy tips here. I was watching the video mostly to learn about making joints/motion links for the gears I have already modelled, but useful nonetheless. Cheers!
Excellent Video , Thank you very much.
Thanks a lot!!!! It really helped
just fyi the last 2 formulas do not work at all in fusion anymore not sure what to do
I just tried it and they work as shown in the video. Double check that you're using the parenthesis in the same place. Also, the plugin has changed since this video was made so you might want to look at the pinned comment by Nicholas Halderman. Someday I will make a replacement for this video that takes his comments into account. Good luck.
anyone knows how to add revolute joint between pinion and rack?
Awesome tutorial - thanks!
With my volume all the way up I could barely hear you. You need to speak louder.
Nope, it's just that the levels are low - if TH-cam would let me replace the video with a fixed one I'd do it. It's the same with a couple of my other videos. Keep turning it up.
very useful thank you
So, can you make a pinion plugin instead of tutorial?
Nope 😂
@@RobDuarte Waaaaaa :D please!
Thank you very much, Rob, a great tutorial
is there a way to create internal gears in fusion 360. No tutorials show up
You might have to be the one to create the tutorial! I haven't tried it, but I'd be interested to know if it's just a matter of doing a circular pattern instead of a rectangular one at 13:31
I wish someone would work with real world gears with the correct dp pa etc.... while gears like these are ok and would technically work they would make an engineering professor facepalm
Sorry, Professor Clown Whisper 😂 I hope the information in this video will help inform someone who wants to change the dp pa etc to be correct. Should be the exact same thing, but with different values I would expect.
you can get real gears and racks from the mcmaster thing
@@artski09 Yes, I show this in the previous video. th-cam.com/video/KbhSQZ236EE/w-d-xo.html
But ... this gear is not *actually* a propper matching rack gear for that generated spur gear, is it? I mean, it doesn't have the curve. I bet those curves are there for a reason. Or am I missing something? I know its proably good enough for most use cases. But it would be nice to actually have the propper gear.
Gefrickelt BLN the rack will have a different tooth profile, so you shouldn't expect the teeth to look the same as they do on the circular gear. Check out this website - it seems as though the fillet on top is optional, but you could easily include it (as well as the fillet at the bottom) in the sketch. Just base the dimensions on a diagram like the one shown on this site - I used a similar reference for all of the dimensions/formulae that I use in the video. khkgears.net/new/gear_knowledge/gear_technical_reference/involute_gear_profile.html
I'm not sure if we mean the same thing, are you talking about topping/semitopping? I don't, I mean the contacting side faces of the gear are straight lines in your sketch, but the contact faces of the spur are curved. Like here khkgears.net/new/images/involute_gear_profile/Fig.-3.12-Magnitude-of-Semitopping.jpg vs here khkgears.net/new/images/involute_gear_profile/Fig.-3.9-Tooth-Profile-Modification.jpg
Yes, this is how the reference that I went from described it. (That the faces on the circular gear's teeth are curved, while the faces of the rack teeth are straight). A quick Google search seems to verify that this is how it normally works. But maybe there's more to it, as you say.
Great job! Learned a lot!
great tutorial. Thanks
what is rack tooth pitch?
the distance between the teeth
Is it possible to use the same method to create a curved rack gear?
Good question. I would say that you could do everything exactly the same but pattern the teeth along a curved path instead of in a straight line. I suspect, though, that the spacing would not be the same "rackteeth" parameter. I just tried it really quick and it looked close - worth more investigation. If it's not "rackteeth", it just means you'd have to figure out what formula comes up with the correct value for the pattern spacing.
Interesting. I will give it a shot later. On second thought, my design really just needs a gear that is a half circle, so maybe I could create a larger spur gear and then modify it? I'm making a miter gauge for a table saw and my idea is to have a pinion gear with a knob that adjusts the angle of the miter gauge as you rotate the knob.
Thanks!
5 thumbs up!
nice
Awesome Tutorials! why are my add in options different? more detailed. is there a setting i need to change?
Johan Pais it's been updated since I made this video
I thought so. thanks Rob
sir can you send me the cad file for a gear of following specification ..pitch 4 mm, 1" diameter pitch circle, 20 teeth,20 degree pressure angle, one with 40 teeth
I don't mean to be rude, but can't you make it yourself, considering that the VERY helpful tutorial is right here?
Broken tutorial with updated plugin that does not match, beginners will need to find another rack and pinion tutorial else where.
I don't think you're right. The spur gear plugin is still there, it just has a slightly different interface now. Look at the pinned comment from Nicholas Halderman. Also, now that Fusion 360 has several tabs at the top to organize commands more logically, you'll need to click the Tools tab to find the "Scripts and Add-ins..." command.