Gear pitch guage?!?

[dan.taylor.1]

Hi folks,

I know you can get these 3d printed from thingiverse or whatever, but I haven't a 3d printer. Does anyone know of a cheap but reasonable set of gear pitch guages, metric and imperial.

Or does anyone have the dxf for them and I'll try find someone locally who has a printer?

Cheers

Dan

 

[Agroshield]

See this page:

Gemtrek Machining Merchandise - Shop for Tools & Apparel

www.gemtrek.com.au

It looks like they are available through the people who sell the 'Engineer's Black Book'. $60 for the pair if I read it correctly (https://engineersblackbook.com/index.php?app=shop&action=fulllist).

See also https://www.model-engineer.co.uk/forums/postings.asp?th=118117.

There is a good program called GearDXF which would allow you to roll your own if required.

See also: https://www.thingiverse.com/thing:4240511 and https://www.thingiverse.com/thing:3318864 (they download as STL but I do not know how well that will convert into dxf)

 

[badabec]

I can try printing the thingiverse items if you want to see what they look like

 

[dan.taylor.1]

I can try printing the thingiverse items if you want to see what they look like

I've tried downloading them but didn't want to work on my phone. Might try on the laptop. For the amount I'll use them as long as the definition isn't rubbish they'll more than likely be fine.

 

[Agroshield]

I hope I am not trying to teach you to suck eggs, but why do you (rather, why does anybody) need a gauge? There is a simple relationship between OD of the gear, number of teeth and Module or DP. I am struggling a little to think of a situation where it would not be possible to take these measurements. Maybe if you have an unidentified rack, a gauge might be useful but a lot of racks are circular pitch so the gauge still does not help.

Thanks.

 

[dan.taylor.1]

I hope I am not trying to teach you to suck eggs, but why do you (rather, why does anybody) need a gauge? There is a simple relationship between OD of the gear, number of teeth and Module or DP. I am struggling a little to think of a situation where it would not be possible to take these measurements. Maybe if you have an unidentified rack, a gauge might be useful but a lot of racks are circular pitch so the gauge still does not help.

Thanks.

Honestly haven't a clue about gears, I'll Google how you work it out. Just thought.a little guage might help I'd stuff quickly rather than working out a formula.

 

[Brad93]

Get them lasered.

 

[awemawson]

The late lamented John Stevenson had a whole batch laser cut a few years back. Not sure if they were sold by ArcEurotrade like most of his stuff was. Somehow I missed that he had and never got some.

they are available in the States mounted in a fold out holder like thread pitch gauges but I’ve never seen them on sale this side of the water.

 

[Brad93]

The late lamented John Stevenson had a whole batch laser cut a few years back. Not sure if they were sold by ArcEurotrade like most of his stuff was. Somehow I missed that he had and never got some.

they are available in the States mounted in a fold out holder like thread pitch gauges but I’ve never seen them on sale this side of the water.

I'd get a batch laser cut. Forum group buy?

 

[Agroshield]

I'd get a batch laser cut. Forum group buy?

You need a good dxf for that and it is difficult to find one.

The thingiverse ones above are STL and I am not sure how well they will convert into dxf. The curves of the teeth are involutes. There is no G-code for an involute move - the best you can do is a large number of line segments or arc segments. How large the large should be is difficult to say.

The other slight complication is that for the things that people here mess around with, you would likely need three gauges: 14.5 PA, DP for old lathes; 20 PA, DP for today's imperial gears and 20 PA, MOD for metric gears.

I was looking on HPC's website last night and their standard metric stuff goes from 0.25 MOD through to 8 MOD. All those will not fit on one gauge. The Gemtrek one goes from 6 to 0.5, misses 1.75 and skips modules between 1 and 0.5. So some input on the most useful 'contents' of the gauge is needed.

For info, a good copy of Gemtek module one would be a 120mm dia. perfect circle. 120mm is the smallest diameter that gives an integer number of teeth for all the modules shown on it while still having space for min. three teeth of each module.

 

[Agroshield]

This one is made via GearDXF. Comments welcome, particularly on the quality of the involute curves, the definition at the smallest size and how the lettering comes out.