|kevin large||13/04/2019 20:25:25|
|136 forum posts|
While drilling a large hole in back gear the small gear broke into pieces it looks like it's been broken before and locktited n the shaft
My question is how many teeth should there be and what is the pitch is what cutter would I need to make another
|Yngvar F||13/04/2019 21:03:58|
|63 forum posts|
Is it the small gear on the spindle?
I think he does a part exchange on the back gear spindle too.
Edited By Yngvar F on 13/04/2019 21:04:33
|David George 1||13/04/2019 22:37:28|
1185 forum posts
Why were you drilling a large hole in your back gear!
|Michael Gilligan||13/04/2019 23:43:49|
15427 forum posts
... the wonders of English ambiguity
|not done it yet||14/04/2019 00:22:11|
|4472 forum posts|
You can work out the DP from the diameter and tooth count of the gear which was in mesh with it ( at least, and likely other gears). Now knowing the DP, you could measure the centre to centre distance and work out the other gear tooth count from that. All straight forward once you look up the formulae for sorting out gears.
|Dave Halford||14/04/2019 11:01:02|
|684 forum posts|
From the tumble reverse info on that link it looks like the mk2 is 20pa and the mk1 is 14.5pa.
European 20pa cutters are rare secondhand and a lot of new Asian sets are module and not DP, but HPC is another source of machined steel generic 20pa gears.
|kevin large||14/04/2019 13:44:18|
|136 forum posts|
It looks like a dp16 14.5 pa still not sure how many teeth yet as I can't all the bits
So if someone can confirm that would be great
|163 forum posts|
Just measured the small back gear on my Boxford and it is 24 tooth 1.625 inches OD which makes it 16DP
5125 forum posts
If you make the replacement out of aluminium it will be weaker and act as a sacrificial one for future problems. Then also make it narrower so it cannot be in mesh when the bull wheel is retracted for direct drive. This saves the danger of the back gear left hand lever being engaged when the bull wheel is still engaged with the pulley.
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