Pressure Angle.

[Alan .204Participant @alan-204]

[Alan .204Participant @alan-204]

Will be ready to start making some of the missing gears for my Bantam lathe soon they are 16DP but does any one know the correct pressure angel for these gears I think it's 14.5 but not sure if it could be 20 its the mark1 Bantam, the other thing is the centre of the gears has a spline to fit the lathe has any one tried to make these before, the 127 gear on the lathe is held by the 100 gear via a pin I thought about doing the same with the new gears I cut, unless some one has a better Idea, the gears I have to make are 30-35-49-36 and 60 I haven't bought the cutters yet because I don't know the pressure angle of the gears, wish me luck guys I my well need it.

Regards Al.

[John Stevenson 1Participant @johnstevenson1]

14.5 degrees.

Alan i may have some gears with a good spline in. how many teeth ?, biggest diameter ? and width of spline ?

[Brian WoodParticipant @brianwood45127]

Try RDG for cutters, they stock a range of 14.5 PA and it may cover 16DP

Brian

[Alan .204Participant @alan-204]

Hi John I will try to find all the gears I have and get back to you with the right information on what is missing, Brian had a look at RDG and your right they have all the gear cutters I would need, thanks guys.

Al.

[Alan .204Participant @alan-204]

Does any one know where i could get a number 3 gear cutter 16DP need to make two gears 36 and 49 tooth RDG don't list that particular one, sods law.

Alan.

[Brian WoodParticipant @brianwood45127]

Alan,

There were some 16 individual DP cutters offered on ebay yesterday, to save time search for Gear Cutters and select Auction only at the top of the list of entries, you won't have more than two pages to search then. I think the ones I spotted were from the USA and labelled as 16P [P= pitch?]

They arent easy to come by though. Try CTC tools, google for contact info and there is still Chronos who might be able to help. Tracy Tools also but they can get expensive. After that they are all expensive!

Good luck

Brian

[John Stevenson 1Participant @johnstevenson1]

CTC only do module cutters.

[Keith LongParticipant @keithlong89920]

Alan

If you can work out a set up for hobbing the gears rather than cutting them Arc Euro list suitable hobs and at a price that is competitive if you need more than a couple of cutters.

There was an article in MEW about doing just this exercise on a Myford I think. It will depend on what kit you've got and how you can adapt it though.

Keith

[Alan .204Participant @alan-204]

Hi chaps I managed to get a number 3 cutter I had to buy a no 2 also to get the no 3 as they were sold together they cost me £30 plus post, they are used so will have to see what they are like when they arrive, Thanks again.

Al.

[Brian WoodParticipant @brianwood45127]

Well done Alan, not an unreasonable price.

If they need it, do remember to sharpen them radially ONLY on the front cutting face to preserve the geometry.

Brian

[David Clark 13Participant @davidclark13]

Hi Alan

If you do need to sharpen the face, grind the backs of the teeth first so they are all the same and then grind the front using the backs just ground against the tool rest.

regards David

Edited By David Clark 1 on 01/03/2013 09:18:32

[Brian WoodParticipant @brianwood45127]

David,

I don't like to contradict you, but to grind the rear faces first as you suggest requires indexing accurately so that those faces are all equally distant from the front cutting face.

If that approach is not done correctly then the front faces will be ground to differing postions by reference from the back, even while still radial and the cutter tooth depth will vary so that only some of them are doing the work.

Why add that complication; just align, then index the front surfaces to start with?

Brian

[David Clark 13Participant @davidclark13]

Hi Brian

You grind the back using the front as a reference so the backs are all the same distance from the front. Easily done indexing from the front face.

Then grind the front using the back as a reference.

You need to grind the entire front so then you have ground away the location face.

That is how Clarkson handbook said do it.

Always worked for me.

regards David

[Brian WoodParticipant @brianwood45127]

Hello David,

Jones and Shipman use a different approach [ after setting up the wheel] using a multi row indexing drum, with a fine feed to the work directly from the drum and then grind only the front face of all form cutters. No use of a tooth rest at all; it is though uesed on side and face cutters. An interesting alternative.

Regards Brian

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