Quote:
Originally Posted by AdamHeard
We don't do it in steel, there is no reason for the pulleys to be steel imo. I do know feeding too slow can be a problem, there are formulas out there for all this that others can cover.
We rough cut the OD of the pulley with a larger cutter (1/4" and above) to .020" or so larger than the actual OD. Then we rough the teeth partially with a 3/16" or 1/8" cutter (I forget), and then finish with a light pass with the 2.5mm cutter. I don't know exact feeds, speeds, depths, etc... but on our router (which is not a very fast accelerating machine currently due to steppers) it was ~ 6 minutes for the entire pulley (including pocketing) for a 24T 5mm pitch.
I would heavily recommend broaches, at least a 1/2" one at this point. Followed by 3/8". It really opens up your COTS options as quickly adding hex bores becomes easy. I'd recommend getting the matching size reamers to make machining that much faster.
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A side note on hex broaches: if you do buy one, make sure you have a press big enough to fit the broach. My team bought a $200 1/2" hex broach, only to discover we would need to go to Lynbrook to use their hydraulic press to broach anything.