Gear Lab - Cylindrical, Bevel, Face Gears

antlu65

(Writing this partly to organize my own thoughts, and possibly to spur further discussion or comments.)

I think many of these issues result from my (admittedly poor) decision to include all types of gears in the feature. The bevel angle input was meant to allow users to create different types of gears, including cylindrical and face gears (bevel angle = 0 and 90, respectively). As someone who was completely new to gears, I thought this was a neat feature for exploration and learning. As has been mentioned in previous posts, this is far from the ideal workflow for generating a bevel gear pair. As currently implemented, a gear pair must be created sequentially, instead of simultaneously. The first gear's bevel angle and tooth count (δa, Za) are fixed after creation. When creating the second bevel gear, the user specifies a desired shaft angle (Σ, Zb) and the feature attempts to satisfy these constraints by calculating the second gear's bevel angle δb. The range of bevel angle δb is continuous, whilst the range of tooth count Zb is discrete - the latter is restricted to integer values. It is not always possible to satisfy the user-requested shaft angle Σ, given the user's other inputs. I readily concede that these details were not communicated properly, and even if they had been, would be a poor design choice for most users who want to create bevel gear pairs. Much frustration ensued, and I extend my apologies to the injured parties.

Instead, from what I have gathered from comments and other linked bevel gear features / calculators, a better workflow would be if the user could specify both tooth counts Za, Zb (and consequently the gear ratio) and shaft angle Σ. The feature would then calculate the bevel angles δa, δb to exactly satisfy the inputs.

antlu65

https://forum.onshape.com/discussion/comment/108664#Comment_108664

@james_aguilar160

"Importing the number of teeth I want and my desired shaft angle, and then picking any face width. Adjusting the face width didn't seem to affect things. Then, I took the bevel angle output from that calculator and input it into OnShape. Onshape is still reporting shaft angles about five thousandths of a degree off from perfectly level, but I think that the manufacturing processes I'm using are not up to producing this level of precision anyway, so this is good enough for me.

The ideal would be if the featurescript could be updated to automatically calculate the bevel angle."

Roger that. Unfortunately, my code was not structured for the workflow described. I think the best solution would be to create a new bevel gear feature - I will look into that.

Drew

First, I'd like to say that this is the easiest gear tool. I really like that you added the feature for internal gears, it saves having to use workarounds.

Now, I would just like to see if there's some clarity you can provide on how some of the fields get calculated. Tooth width and Internal gear ring depth seem to be a ratio of something. I can't seem to just input a number that gives me the width of the tooth and the outer ring diameter exactly. IE, I want a gear with a Module of 2.5, with 200 teeth, outer diameter of 555mm, and width of 25mm. To get these numbers tooth width is 10 and Ring Depth is 9.75. It seems width is just the Module x Tooth width. But I can't seem to make a good correlation with the Ring Depth.

Thanks.

alessio_zoboli

Hello, your function was very helpful to develop bevel gears for my parkinson's auto stabilizing spoon. I'm going to use them in my universitary project so I would like to ask your permission to use them for it. I would really like to thank you for you great work.

joshtargo

can you make the icon public again so we can see it in the FS dropdown?

bob_bobson946

Hi there! Loving this tool so far.

I think I may have found a bug - it looks like when generating a Bevel gear that inherits from a parent, the Teeth field doesn't actually do anything.

After playing around some, I found that the Bevel Angle in the parent gear is what determines the teeth count in the child gear. That may be intentional (or at least a math limitation), but I figure it should at least throw an error tooltip on the child's Teeth field.

For reproduction, I was dealing with a simple 90 degree shaft angle change. I originally started with a standard 45 degree Bevel, but was stuck with 50 teeth on both gears. I eventually settled at 40 in the parent, so that the child gear ended up with 60 teeth.

Thanks!

elliott_g615

@antlu65 When I go to click herringbone, it just clicks and then doesn't actually do anything, immediately going back to unchecked. This may be an issue on my end, but if not I thought I might bring it to your attention. Let me know if you figure anything out, sorry to bother you.

ricky_piacentini

https://forum.onshape.com/discussion/comment/114848#Comment_114848

@elliott_g615

to create a herringbone gear the helix angle can not be 0

ivan_zubov364

Hello there! For better of for worth, this is the best gears script for onshape I have found so far, but it is really frustrating that it generates nice and beautiful bevel gears which are completely unusable because they never allign at correct angle, the only way I managed do get bevel gears at 90deg angle was creating two identical with 45deg bevel angle

dan_lezak

Thanks for the amazing script. I'm not sure if i am missing something or if this is an actual issue, but i am unable to rename the features created by this script, which means that any parts that have dependencies are lost when a gear is edited. is there a work around to this or is it not possible in the current version?

Thanks

Dan