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Cast Tools

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Posted by Ian McKernan on April 21, 2002 15:18:31 UTC

Hiyah All! Ive finally given up on the cast, steel covered tool i made. It seemed to be giving me a funny shape when i tried to correct for hacking the hole out way too deep. I'm not ready to try and do a mirror at less than f5 yet! Anyhow, ive made up a tile tool to continue with, and spent 2 and a half hours wearing that in this weekend.
I'd like to revisit the concept though and i have a second blank that ive already hacked out to some kind of curve. I think the problem was that i just didnt get the cast tool a good enough shape, and then covering it in steel meant that it wasn't going to be able to wear into shape very well. Getting the curve on the tool wrong meant the sagitta was getting down to 3.1-3.2mm when i was after 2.6mm. Ive got 2.7mm on it now at the end of #80 grit ( i hope), and i figure on using the tool on top for the next couple of stages so if anything it should go shallower.
What i plan on is to cast two tools when i get to the stage of making something to carry the pitch lap. I'll cover one of these with washer dumps and use this to finish that second mirror.
Anyhow, any comments appreciated, and thanks for the replies to my previous posts.


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