I think Dan has done all the replies necessary, I see no reason why an end mill can't be used, in fact because the DP changes as the tooth approaches the centre it's probably the only way to generate a tooth that requires no finishing.
Just to make it clear take a sample gear and say this gear is 10 DP measured on the outer diameter, pitch circle etc.
This gear has a face width of say 5/8" and because it's a genuine bevel it tapers on pitch and root to the cone point which is zero.
So at the inner face diameter this gear has a DP of probably 12 DP.
This is the problem milling, do you use a 10 DP cutter or a 12 DP ?
Your method will allow the profile to change. Using an involute cutter on the side it won't, it's back to milling.
Using a slitting saw probably won't work either as the the saw will interfere as it passes thu.
In the case of spur and helicals its on the cards ? to allow Gearotic to generate it's own involute cutter shaped like an end mill / D bit to allow very small profiles to be done that can't be done with convention end mills because of risk of tool breakage.
This feature won't be possible with bevels because of the differing DP / MOD.
One way round this may be to allow the user to define a tapered cutter similar to an engraving tool where the user specifies an included angle and tip width. The advantages of this are a stronger tool for a given size.
These are quite easy to make in HSS or even carbide given a couple of simple jigs.
Now back to mounting and cutting the gear.
If we have 45 degree bevels then cutting from the flat or horizontal is exactly the same as regards axis travels.
The Z axis is probably the most important as it will have to raise from the inner DP to the outer DP.
The problem I can see is the differing angles.
![Image](http://www.stevenson-engineers.co.uk/files/45_10helical.jpg)
Take this 45 tooth wheel and the 10 tooth pinion, using a 4th axis the 10 tooth pinion will be easy as the cone angle is quite low. However the 45 tooth wheel is a different matter in that the cone angle is nearly vertical and an end mill will not be cutting perpendicular to the pitch line, in fact it will be hard put to form the tooth depth.
I know not everyone will have access to a tilting dividing head but there are simple ways of doing the same, this is one
![Image](http://www.stevenson-engineers.co.uk/files/tilttable.jpg)
My take on this is that anyone wanting to do bevels will either be geared up or be prepared to gear up so if the president is set that the blank HAS to be on the pitch angle it will make the maths a lot easier.
John S.