Quote:
Originally Posted by Karls48
Steve,I think that hard disk platers are too soft to be good for telescope drive. Easy to work with yes, but I think it will wear out too quick.
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This one is purely just a test Karl.
I don't intend to ever use it. The alu is quite soft, you're right, but
it could always be anodised?
Quote:
Originally Posted by Karls48
But my biggest problem is how to calculate blanks diameter.
So how do you calculate diameter? I’m casting my blanks from scrap aluminium.
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All guesswork this end Karl!
Some machinists try to aim for a 359 or 360 tooth worm.
I think that's because the motor at the start of the reduction does
1rpm or something....I vaguely recall that was why.
With microstepped steppers (my Bartel drive) this isn't an issue.
I only need a total reduction somewhere in the order of 1:10,000
for the stepper to 'sing' at a nice high pitched , smooth rate.
This test worm ended up having 230 teeth.
The diameter was purely a guess.
Some articles have the same problem calculating the theoretical
starting diameter. As I'm from the same type of background as you
it's all a bit over my head too!
I think indexing on a rotary table is a way better start though.
There is no way to know how accurate my cutter drove it's way
around the circumference to start with.
Some teeth might be stretched and some might be squashed etc.
Testing will show how accurate it ends up.
Steve