Gear Hobbing

[GoetzInd]

Hello all,

I have a job on my desk that requires gear hobbing in one of our mill turn centers. We have the gear cutting function in the control. I'm asuming it is the same thing as polygon turning. My question is how do I calculate the Main spindle speed and milling cutter speed to cut the right amount of teeth? The gear specs are 28th, .4mod 20PA. Any help would be appreciated.

 

Thanks,

Mike

[John Summers]

The hob is like a single-lead thread, or worm. That means that for a 28 tooth gear, the hob will have to turn 28 times as fast as the gear.

[GoetzInd]

Any idea if I can output this with mastercam?

[crazy^millman]

This should be a function handles by the machine with some type of M and G code combination. Get out your book or call your machine tool Applications department and see if they can point you in the right direction. May have to be a contour pass or something else along those lines to get the correct cutting pressure and angle for the tool in relation to the spindle the book should explain it all pretty well.

 

HTH

[Greg Williams]

Mike,

 

Below is Hobbing code for a Macturn

 

G13

G140

G50 S1000

MT=02001

M321

G00 X2000 Z2000

G00 X100 Z55 TL=020020 BA=87 G52 M41

G138

X-15 M08

Y=65.4/2+30+4

M556 O0001 RC=24 RJ=1 RTY = 70

M612

SB=500 M13

G01 G95 Y=65.4/2+30 F2

Z-66

Y=RTY

M12

M555

G0 Y=RTY

X100

G136

G00 X2000 Z2000

M02

O0001

G00 Y=RTY

M12

RTI

[GoetzInd]

Thanks guys. Got it running perfect. Greg, do actually get MC to post that code?

[Greg Williams]

Ah not really. The code comes from a text file