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View Full Version : Making a table for the mill - iron or steel?



mixdenny
02-06-2012, 10:30 AM
I've had a project in mind for some time, that of making a longer table for my Shoptask Eldorado. Here is a link to my Shoptask page, click on the "extended table" link"

http://home.wowway.com/~dthompson4389/Shoptask.html

My plan was to machine both the original table and the extension so they are square to each other with the various planes lined up, and use pins and shoulder bolts recessed through the 6" extension and tapped into the end of the table. The two pieces are made several years apart, and the planes do not all line up at once. i.e., if I make the tops match, the V ways are not aligned, etc. So everything would have to be reground after being assembled.

Upon reflection, it seems that if I have to send it out to be ground anyway, why not just make a longer table from scratch. I would make it a bit thicker than the original, so it would be a slab 7" x 2" x 24" with two T slots on top, and V ways underneath. Plus some hollowing out to fit the leadscrew.

I have access to a horizontal milling machine to rough out the cuts, and another friend has a CNC Bridgeport if needed.

A newly cast slab of iron would be great and would save a lot of rough machining. I could provide a pattern as required. But so far I cannot locate a foundry that would do it. I can find a piece of steel much easier. Carefull milling will be needed to minimize bowing, but the final grinding should take care of that anyway. Any other reasons to eliminate steel as a possible material?

Dennis

Duffy
02-06-2012, 11:10 AM
You dont say where you are, but Durabar Metal services will sell you either grey or ductile iron just about any size you want, delivered to your door. Just add money!:D

mixdenny
02-06-2012, 12:34 PM
That's a good suggestion, and I had already checked their sizes. They have a 2 1/4" x 6 1/4" that would work, but the 72" length would run the project into serious bucks! Perhaps a stocking dealer can supply cut to length, I need to call the Ohio dealers.

There was a metal dealer in Canton who had lots of billet aluminum, brass and cast iron drops. Shelves full of large stock, cored rounds, etc. Alas, after checking around it seems they are out of business.

Dennis

Mcgyver
02-06-2012, 01:22 PM
imo its a no brainer, cast iron. Very easy to machine, stable, better at absorbing vibration and an excellent bearing material if its a sliding bearing member