MadModder

Gallery, Projects and General => How do I?? => Topic started by: Darren on March 30, 2010, 07:44:39 AM

Title: Gears, CP-DP calculations?
Post by: Darren on March 30, 2010, 07:44:39 AM

Hi I've picked up a gear cutter but it's not much use to me

It's
20PA
No3
3/16"CP
35-54T
D+F
128"

I've no idea what the last two mean?

I know CP does not directly calculate to DP but how do you calculate it? I just want to see if it's near enough for my needs?

Title: Re: Gears, CP-DP calculations?
Post by: John Stevenson on March 30, 2010, 07:55:19 AM

D +f equals Depth [ D ] and clearance [ f ] so you cut 0.128 thou deep

3/16" CP equals 0.1875" Circular Pitch [ CP ] which  is 16.75 DP
1.5 Mod is 16.93 so to all intents and purposes and if the wind is in the right direction you could use this cutter to cat any 1.5 Mod wheels between 35 and 54 teeth

Title: Re: Gears, CP-DP calculations?
Post by: Darren on March 30, 2010, 08:01:36 AM

Thanks John, that cleared it up for me :thumbup:

What I actually want to cut is a 60T 20DP gear, but this seems too far out for that, even to just have a go.  :(



Edit, after reading around the net I'm now not sure if I need 20PA or 14.5 as both are quoted !!

I essentially want a Myford 60T gear, yes I could just buy one, but I'd like to have a go at making one for the fun of it  :dremel:

Title: Re: Gears, CP-DP calculations?
Post by: John Stevenson on March 30, 2010, 12:09:47 PM

For Myford you need a 14.5 degree PA cutter and to cut 60 teeth you need the number 2 cutter.

John S.

Title: Re: Gears, CP-DP calculations?
Post by: Darren on March 30, 2010, 02:03:09 PM

Thanks John, watch this space..... just don't hold ya breath at the same time  :thumbup: