Lathes UK may provide more details, or what other lathes used the same, or a similar, gear, (possibly other Colchester lathes? )

With details of the gear, either, you mat find someone like Davall, Reliance or HPC gears could provid one (At a PRICE, no doubt )

Failing bthat, armed with the details, (DP, Pressure Amgle ) you may find someone who woulf make mone for you.

You will beble to provide the other details, tooth width, bore etc from the gear that you have.

Howard

You could try the following if you have not already, you might be lucky.

https://www.colchesterspares.com

Neil

Once had a missing tooth on a steel gear repaired by an ACE welder. And then machined the weld back mto size, having located off the other vteeth.

Sadly, he moved away overseas!

If your gear is cast iron, as I suspevct, you could braze a replacement into place and machine , with na suitable gear cutter, or file the repair back to the correct shape.

Howard

Most likely cast iron but it still can be repaired may be by brazing and filing Worth a go ! Noel..

Please can you confirm that it is a change gear you require.

Are you absolutely 100% sure on the tooth count?

If you look through the Chipmaster manual, a 46t gear was not offered by the factory either for the imperial or the metric version of the machine.

The only use for a 46t gear, being 2 x 23 or 4 x 11.5 is to cut US NPT pipe threads. In the manual, both the imperial machine and the metric machine use a 69t gear for this purpose.

Hence, if you do have a 46t gear, it will be of third party manufacture.

If you need buy a gear from a stockist like HPC etc, they are normally sold with pilot bores for you to machine to correct bore.

Be careful the pressure-angle of the replacement matches that of the existing set, though it may not be so critical if only used once in a blue moon.

There is a Colchester and Harrison lathe owner’s group on Facebook, may be worth asking them?

Tony

As it is a 48t gear, that implies that you have a metric (Continental) Chipmaster.

The Continental is less often seen than the imperial version so that might make finding a replacement difficult. The other issue is that with 48t, it would come from a set of gears 'by fours'.

Other lathes that use the same 14DP 14.5 degree PA gears are Harrison L5 and 140, Drummond and some early larger Colchesters. Someone might know if 48t was part of the Drummond or Harrison set.

The gear is quite important for most metric threads. It is used as either 28/48 or 56/48, which reduce to 7/12 or 7/6.

You would have to check if the gears would fit the space available, but it is possible to reproduce those two ratios with 35/60 and 35/30. Coming from a gear set 'by fives', they might be easier to find.

The other difficulty is the six-spline centre detail of the gear (it is the same as Boxford X10 models) – you could re-use the broken gear if you find a single 48t replacement, but if solving the problem involves more than one gear, how do you make more than one new centre?

if you didnt get sorted send me a pic and sizes i have a box of colchester change wheels