From memory, the standard gear pair that meshed on 1" centres are
The best fit for those gears is 38 dimetral pitch (DP)
OD of the blank = (no of teeth +2)/38 inches
No idea of the pressure angle. Could be normal 14 or 20 but knowing
meccano could be a special.
You might find locating 38dp cutters difficult and have to make your own.
Ivan Law's book on gear cutting could help you with this.
There's a website out there that goes into great detail on this. I seem
to remember that it arguess that Meccano used a commonly available
Looking at the replies, the sense of it is that it's all a bit of a
compromise. The project uses four meccano gears the small brass spurs that
will look the part, and two larger steel gear wheels (127 and 56 tooth from
memory) and look cheap and nasty, which are the ones I intended to replace
with home made versions in either brass or cast iron, machined to look the
part. Sounds like I'd be better off making all four from scratch to a
Looks like a 0.7module or 40dp cutter would be the place to be and make all
four gears instead of trying to make to the Meccano standard.
I'd forgotten I had the Ivan Law book :-)
If I look at pages 114 and 115, there are instructions to guide making
custom gear cutters, but the dimensions in the two tables (for 20deg PA and
30 deg PA) don't seem to work.
The form tool uses two steel buttons of 51.30 inches, (normalised at 1DP)
but the distance between centres is given at 49.6 inches, surely the
minimum distance between the centres is 2 x the radius of the two buttons?
Meccano Magazine published a gear cutting machine (made of Meccano) that
used a 1/2" BSW tap as the gear cutting hob. I don't remeber which issue
and it would take me some time to find it as I don't have an index. The
gear cutting machine worked OK for plastic - not sure about anything harder.
I have a Mikron Hobbing machine and if you sent me some suitable blanks
I could fairly quickly put some teeth around them for you, the 127 tooth
would not be an option as I dont currently have that changewheel setup,
but most other numbers are OK if you can make some adjustments to the
design to suit. 38 or 40DP hobs are both in stock.
The actual gears are:
2 off 19 teeth
1 off 57 teeth
1 off 95 teeth
My eMail address is good - if you let me know the diameter of the blanks you
would need and what the beer token tally is that would be great. The
material for all four gears will be brass.
If all four are cut from scratch, then just use the best hob that suits the
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