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| Building a milling machine |
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| Lykle:
Nice build! Whatever you use as a filling, do not use polyester resin. It shrinks about 5% so there will be gaps and voids. Especially along the edges, just where you want it to be. Epoxy does not shrink so much, so use that if you want to use a resin. Lykle |
| NormanV:
Thank you for that information Lykle. I think that I will most likely use concrete as epoxy is rather expensive if it needs it. I intend finishing it and testing it before I decide whether to fill it or not. |
| awemawson:
Filling with dry sand without a binder will deaden it and stop vibrations and is reversible. |
| NormanV:
I like the idea of filling it with sand, I can get all I need for free off the beach! Today I fitted the motor, I needed a mounting plate so I cast a flat plate 250x150x10mm. I'm getting hooked on casting. The mechanism for raising and lowering the knee took some thought. I have a worm gearbox that I thought would be good for turning the nut on an Acme thread leadscrew that I can buy. Unfortunately the gearbox ratio is 50:1 which would have entailed many thousands of turns of the handle to go from top to bottom. I decided to motorise it and as I already have a 1/2HP motor that was straight forward, even with the motor it will take three minutes to go from top to bottom. this shouldn't be a problem as I will normally be making relatively small adjustments in height. I have made it so that I can also use a handle for fine manual adjustment. One turn of the handle raises it 0.1mm which will give me very precise setting. Does anyone have a leadscrew of 25mm or 1" dia with a thread length of at least 500mm that they want to dispose of? |
| awemawson:
After all the Chinese usually leave sand inside their castings so it MUST be good :ddb: Seriously though beware of the salt content of beach sand or your aluminium will go all furry. |
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