Gear Cutter Centreing

[Bluechip]

Hi Troops

Centreing a Gear Cutter ?? Can neither spell it nor do it ... 

The cutter has a large radius, so it's not very accurate to do the 'trapped feeler guage' stunt.

The 'Workshop Practice' book on Gear Cutting is very glib about it, just says put a centre in the dividing head ( knew that bit anyway  )

and set the cutter to the centre. Helpful b****rs.

There has to be a better way ... in any case, if I were to want a slot using a slitting saw, it wouldn't work anyway ... would it ??

Dave

 

[BillTodd]

You could try the same trick used for setting a lathe tool height. i.e. lightly nip a steel rule between the centre and the cutter edge and check that the rule is square to the cutter.

Alternatively, use a electric edge finder (or eye-ball it ) to locate the cutter edge and move the table half the width of the cutter.

Bill

[Bogstandard]

Hi Dave,

Look at the C-o-C and I hope that explains it for you.


John

[Bluechip]

Hi Troops

Thanks John, will try that  knew there had to be a way ...

Bill, Tried that first way. Owing to the radius of the cutter, ( 10DP ), it's possible to move the quill fine feed up down by about +/- .020" before the trapped feeler guage looks anything other than vertical. I assume that's what you were describing.

Regret I have no idea what the other method is ...  C - O - C ??

I only have a HND in Electrical Engineering, anything vaguely resembling two bits of metal banging together ... I'm utterly stuffed ... 

It had occured to me to use the Myford 2MT drilling pad I have. This has a Vee-groove across it. I presume it is truly across the centre ??

Genuine Myford. I suppose I could try it, then verify with John's method ... like this ... att.

Dave BC

[Jasonb]

Measure the thickness of the cutter and then touch the edge onto the top of the gear. Then just lower the tool by 1/2 the gear dia plus half the cutter thickness. You can use any known shaft in the dividing head it does not have to be the gear. This does assume the cutter is symetrically ground.

J

[Bluechip]

Thanks Jason, something else I will try ...

Overtaken by events at the moment, z-axis digital readout is loose on the WM16 ... about .030" backlash in it ... 

Moves up and down by about that much with the strip wotsit, so I've got it out cleaning all the gunge off it.

How does it get infested with crap up there?? Must get sprayed on from the cutters etc.

Dave BC

[No1_sonuk]

Regret I have no idea what the other method is ...  C - O - C ??

IIRC, it means "Crap-O-CAD".  The rough sketches people make to explain points, or preliminary designs.

[Bluechip]

Regret I have no idea what the other method is ...  C - O - C ??

IIRC, it means "Crap-O-CAD".  The rough sketches people make to explain points, or preliminary designs.

Not very well put by me ..    as ever ..

Was requesting a C-O-C of the method ..

Dave ..