Quote:
Originally Posted by DaveGee
That looks better Steve. A good wrap around the worm to ensure good meshing at all times. Well done! Now there's just another to make.  |
I'm not moving on to the RA gear Dave until I'm happy with every
aspect of the DEC attempts , including how consistently I can
repeat this all.
I reckon I'm nearly there though.
The inspiration and reason for my success so far would all
be down to your work, and the work of others
Quote:
Originally Posted by hikerbob
I decided to try out an approach which first occurred to me when I heard about hobbing.
Using a conventional tap held in the lathe chuck. I used a 3/4 16TPI UNF tap which I had on hand an offcut of 63mm OD alluminium round. 10 minutes or so to tidy up the round and another 10 minutes or so of hobbing and the thread is cut deeply and as a first pass looks quite passable. I'm wondering how that would work if I later bed a worm into that for the final tidy up. Possibly not up to astrophotography standards but maybe suitable for a lot of other uses.
I wanted to test how well a conventional tap would turn the gear blank and also how well it would go without having a grove already cut. Excellent on both counts. The cut as it is at the moment has a slightly raised edge on the lower side (where the cutting teeth exited the blank) but that should clean up neatly.
Bob
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Nice looking result Bob.
On a bigger diameter wheel you would have to extend the tap from
the chuck.
I've seen this done on a few webpage examples and it seems to work
well.
I also get that same exit roughness on the teeth even with the multi
scoring on the hobber.
But as you say, it does clean up after a skim on the faceplate and/or
a bit of fine wet and dry.
Oh, and the things I could make with that 63 OD alu round!!!!
Steve