I'd like to design a pair of bevel gears meeting at 90 degrees.
I know of, and have used, the excellent spur gear script I guess that there isn't a script for bevel gears as Search finds nothing.

I'm wondering if there is a way to start with a spur gear and 'deform' it to produce a straight bevel gear?

I'd appreciate any pointers or suggestions.

Thanks,

Mike.

http://en.wikipedia.org/wiki/Bevel_gear

You could draw the gear wheel profile and use the Extrude 'To Point' or 'Tapered' option to get what you need.

Martin.

Thanks. That looks easy enough even for me!

Mike.

maybe

http://kyticka.webzdarma.cz/3d/moi/#SpurGear

Thanks...

I'll use that as my starting point.

Mike.

Easy enough to extrude.
Not sure of the pitch circles and how two bevel gears mesh

http://www.sdp-si.com/D805/D805_PDFS/Technical/8050T060.pdf

Thanks very much for the info - very useful.

Extruding to a point worked well. I couldn't get extrude tapered to give the same result.

Now printing one 12 tooth Module 2 pinion and a 30 tooth Module 2 gear so soon will be able to assess them. If they look good I'll print shaft and a box to mount them in to assess more thoroughly.

Mike.

Hi Mike,

Great that you worked this out, is it possible you could upload a MoI screen shot of your result?

Cheers

I tried (very quickly) using the new 3d Rail Revolve option on the gear profile which I projected onto a cone surface. It seemed to work OK!

File attached.


Martin.

EDIT: I stretched the projected profile slightly to give more height to the teeth, but there will be a more accurate way to maintain the correct proportions.

Danny,

Turns out not so good.

The 12 tooth pinion looks quite good but the 30 tooth is way off.

Had another go at the 30 tooth gear this time extruding one tooth vertically to a point, then rotating it to lay it down onto a pre-made cone and then arraying the tooth around the cone. Looks much better

In the attached file the 30 tooth gear has been drawn as described above, and the 12 tooth pinion by simply extruding the entire 12 tooth spur gear profile to a point.

Using the latter approach with the 30 tooth gear causes the loss of most of the tooth profile height.

Revised design printing now.

Mike.

Great! I'll try and get my mind around this tomorrow.

Mike.

Cool!
Moi (very low Poly) -->Sketchup+Lightup a very funny Render "real time" of all the 3D scene
after a little calculate you can Move, Rotate, Resize, Walkthrough... the scene, "render is always yet done" !!!

You may try to consider lofting 2 gear profiles. I think using extrude method is morphing the gear splines...

What a fantastic imagination you have, Frenchy!

Mike.

Thank you all for your suggestions and help.

I've achieved results good enough for my purpose which is 3D printing.

I choose a 12 tooth pinion and a 30 tooth gear using Module 2 meeting at 90 degrees.

I used the formulae from the info that Brian supplied to calculate angles - see below


Basically I trimmed one gear profile from the spur gear script output, extruded it to a point, laid it down on a cone and arrayed the extruded profile around the cone.

I think that it's a bit of a bodge because I couldn't find a way to extrude to the point that I wanted to extrude to which was vertically above the pitch circle I could only extrude to a point vertically above the centre of the bounding box - auto chosen (as far as I could tell) by the extrude-to-a-point function. This introduced a very slight error that I had to fudge my way around.

Images below and file attached.

Mike.

Hi Mike, re:

> I think that it's a bit of a bodge because I couldn't find a way to extrude to the point that
> I wanted to extrude to which was vertically above the pitch circle I could only extrude to a
> point vertically above the centre of the bounding box - auto chosen (as far as I could tell)
> by the extrude-to-a-point function.

If the auto chosen tracking line is not what you need, you can make extrude to point freely pick the point by pushing the "Unlock direction" button in the command options:



- Michael

Aha!
Thank you, Michael, I hadn't noticed that.
Great.

Mike.