Gear Cutters

Hi all

could someone point me in the direction of a supplier of Gear cutters

I need to cut two gears

One with 30 teeth and one with 25 teeth

both are 20 DP and 20PA

so I think I am looking for a number 4 and a number 5 cutter

Thanks Bob

You could just buy a couple of Myford changewheels for around £24.

Phil

I think the Myford wheels are 14.5deg PA. Same with the reasonably priced cutters from RDG all 14.5deg.

Two gears from HPC would be cheaper than two cutters unless they are an odd material or very wide. I did that with the smaller gears on my 2" Fowler just bought stock gears and machined the bore and sides to suit.

Tap die list 20Dp, 20PA

J

Edited By JasonB on 19/07/2013 08:20:47

[quote] Tap die list 20Dp, 20PA [/quote]

At £140 each I think someone is taking the piss ?

Definitly cheaper to buy two gears off the shelf, HPC lists the 25 T at £12 AND THE 30 T at £12.58 all plus VAT and carriage.

These are plain, no boss and 3/8" wide. The bossed gears are dearer but still the same width.

**LINK**

They will also do custom sizes for not a lot more, I did that, bought a wider gear for 10 or 20% more then cut it in half

Or you could get one of us with a hobbing machine to make a couple for you, all beer vouchers gratefully accepted.

Phil

1.25 Module is 20.32 DP and a No.4 cutter (26-34) would probably do for both gears, depending on the application. Watch the number designation of module cutters, they seem to start with No. 8 as rack. CTC in Hong Kong do good value module cutters.

HTH

Rod

Thanks All

The gears I need are for graham meek's Super 7 clutch and are wider than normal .

Thanks for the link Rod I have sent of an order .

Thanks once again Bob

I am sure Gray will be along soon to explain, but I wouldn't be making those idler gears from steel.

I would thing twice about mixing DP and Module gears as well.

I have built the clutch you are talking about, and used Tufnol for those gears, if you use steel they will be extremely noisy, and if you have a crash they will not break a tooth off, so you will risk damage to your lathe.

Think about using an engineering plastic instead. If you turn the blanks, I can put the teeth on for you.

Phil

Edited By Phil P on 20/07/2013 09:21:54

If you can work with module gear cutters than I would also recomend CTC tools. Their cutting tools are very good quality and very good value. Regards, Dave

I'v only cut 3 or 4 gears, they were to match existing gears, and did not require to be perfect, and each time I ground up a tool (by eye) and used it in a flycutter, it takes time, but it worked for me. Ian S C

I have used OILON mateial for these gears and they are 20DP 20PA as they are driven from the Myford Spindle gear.

Edited By JasonB on 20/07/2013 14:11:51

Can something be done about the photos, when they are transfered from the albums, they grow to about double the width/depth, and this is having an adverse effect on each thread it happens on.

Ian S C

Ian can you PM me the other threads and I'll see what can be done. Kwil's one should be OK now.

Using an album used to resize to suit but it seems it may not be working now.

My photo was OK for width when I transferred it and viewed the result before ADDING POST.

Hi Phil

I will not be cutting steel gears but tufnol as Graham says

and I will be using module 1.25 instead of  DP 20 PA20 cutters from the site that Rod suggested.

Bob

Edited By Redpiperbob on 21/07/2013 07:54:34

I'd follow Ian's advice and make a single-point cutter, either by the Ivan Law method or filing to match an existing gear. This is a hand filed cutter that made the alloy gear below.

Neil

Bob

If you are going to use module gears on the clutch unit, you might as well make a new main spindle gear at the same time, that way all the meshing gears will be the same type. Mixing DP and module might be "got away with" on slow running gears, but we are talking relatively high speeds on this unit, so the mismatch might give premature wear on your Tufnol gears.

Also I dont know if you realise, but all the changewheel gears starting with the 24 tooth clutch output are 14½° pressure angle, it is only the primary gears on a Super 7 that were 20° pressure angle.

Phil

One of the gears I cut was Tufnol, for a water pump, its been in use for the last 15 years or so. I made it sandwiched between two steel washers, these were also gear cut. Ian S C

You have to be careful to get the right sort of Tufnol, the grain direction is no good for gears of you use rod, it needs to be in sheet form.

Phil