rockrat

07-03-2006, 08:36 PM

Ok, I got a question on finding gear information. After making a few gears for others, I now have the need to make a gear for my lathe. I can gain a few strange instrument type pitches by making a gear or two for my large Southbend. The way I see it, I can spend $40 for a gear cutter and make a few different gears or I can spend $20 - $30 per gear and only have the gears. Greed!

So, I have been reading my little book on gear cutting and it tells me that finding the diametrial pitch can be done by adding 2 to the number of teeth on the gear and dividing by the outside diameter. This has worked so far.

But today, I check the outside diameter of the gear at 2.197 (ish) and 30 teeth. So (30+2)/2.197=14.5 DP. I can juggle the 2.197 around and assume that it is really 2.2 but that only changes things aout about the 2nd decimal place.

So, is this a special order cutter for this here gear? MSC and McMaster list some standard stuff but nothing in 1/2 dp's.

So what say you all.

Thanks rock-

So, I have been reading my little book on gear cutting and it tells me that finding the diametrial pitch can be done by adding 2 to the number of teeth on the gear and dividing by the outside diameter. This has worked so far.

But today, I check the outside diameter of the gear at 2.197 (ish) and 30 teeth. So (30+2)/2.197=14.5 DP. I can juggle the 2.197 around and assume that it is really 2.2 but that only changes things aout about the 2nd decimal place.

So, is this a special order cutter for this here gear? MSC and McMaster list some standard stuff but nothing in 1/2 dp's.

So what say you all.

Thanks rock-