Thanks for all the comments, I will try to answer them all at once. The hobs on eBay are cheap, however unless you have a dividing head that rotates in sync with the hob, they are no good. They have a pitch like a thread on them and are made for gear cutting machines.
I realise that .5module is very close, I will have to lay it out on my CAD to see if I can change to it, the biggest problem is the centre distances to each gear change, I'm not very optimistic that I can alter things.
The pressure angle stated in the drawings is 14 1/2 deg, the only reason is that the cutters are much cheaper than the 20deg ones, the angle is not important on model engines. The 14 1/2deg cutters are about $45 each.
I have a set of Mod 1 cutters that I purchased from CTC, they are great, however they don't have DP cutters. I also purchased then for about $100 the set.
Making my own hob is looking more likely at the moment.
Paul.
