Sourcing Small Bevel Gears

The Centenary Suburbs Men’s Shed in Brisbane, Australia are building a ¼ scale model Atkinson Steam Truck based on drawings that were produced back in the 1980’s. The measurements on the drawings are all in imperial units. The drives for the engine camshafts are based around three sets of bevel gears that are probably no longer available and we are after a Company that may be able to supply them or a metric equivalent. Details of the original gear sets were as follows:

Main drive ratio 2:1, 16 D.P., 13 and 26 teeth (one of each)

Camshafts and countershaft drive ratio 2:1, 32 D.P., 12 and 24 teeth (four of the 12 and two of the 24 tooth gears).

If possible I think the PCD of the gears sets need to be as close as possible to the original so that the gears will fit into the cast housings. Shaft sizes are either ¼” or 3/16” diameter. Also the sets need to be able to run in both directions.

Can anyone recommend a Company that may be able to supply these items?

Hi Trevor have a look here.

https://www.hpcgears.com/stampede/index.php

David

Edited By David George 1 on 15/01/2023 07:47:48

I had a look at a few of the usual suspects such as HPC and Boston gear and none go down to such small tooth counts in 2:1 pairs in either DP or similar size MOD so looks like you may have to resort to cutting your own.

You may get closer if you use smaller tooth sizes on the same O/A size but as they are drive gears you would run the risk of stripping them

If you do a search on Aliexpress for Bevel Gears, a plethora of choices pops up, from slot car drives to real truck diff gears and everything in between. Stupid cheap but usually good quality, Chinese industrial quality, not hobby grade.

I recently retrieved a nice pair of spiral bevels from a burnt out angle grinder. Ratio approx 2:1, large gear roughly 1.5" diam.

Trevor,

Not the tooth count you specify, but numerically the same metric Module 0.8 available here which is within a gnat's crochet of the DP you ideally want and you did say metric would be OK/nice.

Not exactly local, either, but the page linked to gives the dimensions of the pairs and this page will take you to a choice of other MOD pairs with similar dimensioned drawings. Not stupid cheap, but then bevel gears seldom are.

Good luck with your search.

John

You could always make them yourselves?

The parallel depth method in Ivan Law's book gives very good workable gears.

I have a spreadsheet that works all this out. You can play about with the DP and tooth count until you get a blank size that fits into your housings. PM me with an email address if you would like it.

Les

DAVAL STOCK GEARS may be worth a look. Noel.

Thanks to all those who have replied.

Trevor

I also use the method of Ivan Law to make bevel gears and these gears are OK. 3D printed bevel gears also do a nice job and are easy to make.

Acorn Bearings seem to supply the 32DP pairs on p109 (9) of their catalogue
https://www.acornbearings.co.uk/downloads/catalogues/power-transmission/racks-and-gears/davall-bevel-gears.pdf

No immediate signs of 16DP 13/26, though there might be a metric equivalent

Bill

Trevor, personal mail sent to you

Hi Trevor sent you a person message! Best to avoid the bevel gears...chain drive superior....plus other mods for the atkinson.

regards Vic

Thanks Vic,

Do you have any drawings and a list of other changes made to the Atkinson?

Regards,

Trevor

Hi Trevor, TEA Transmissions in Tiaro, just south of Maryborough, make bevel gear sets in 2:1 ratio and Module 1.5 which is close to 16 DP according to my maths. I have purchased from them previously and they seem happy to supply small quantities and will post them to you. Another source might be Ronson Gears who list a range of metric bevel gears in stock which are close to your dimensions. Hope you have success in your search.

Thank you to everyone who replied to my request. The outcome was as follows:

The main drive gears were substituted for an available metric set. The numbers of teeth are different but there is only a small change needed in the bore size to make them fit.

The camshaft and counterdrive shaft gears were sourced to the original specification from Duvall Gears in the UK and are now in transit.

Regards,

Trevor Johnsson

Trevor,

Thanks for taking the time to give us feedback. Glad to hear you got what you wanted in the end.

Best of luck with the build. Maybe let us have a few photos of progress in a new thread - à la "McDonald Model Tractor" by Four Stroke Fred?

John

Hi Trevor, good luck with your build, strangely my personal message to you was marked unread! Which , could well be, but I do have a fair amount of info, and much of it came from a award winning builder of The wagon, which can save time , frustration, and cost.

One very successful builder used chain and sprockets instead of bevels which are prone to ingress or fail completely, It certainly goes very well.

Good luck with your build, Vic

Sorry Vic,

I don't know how to read your personal

Hi Trevor if you open the pm I have sent you and just send me your email address by reply, I have all the information ready to send you by email. Alternatively just put your email address in a posting , and delete it about 8 hours from now! I should have seen it by then!!!

Regards vic