# Pattern making to repair a broken cast iron machine base



## Bob Korves (Feb 18, 2019)

Here is a Keith Rucker video showing him making a pattern for casting to repair a broken cast iron machine base.  It all looks good to me, but I am mostly clueless on this interesting subject.  Still, I am looking forward to the follow up videos...


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## middle.road (Feb 18, 2019)

Did you see Emma's with the 3D Printed 'patterns' and then cast for the loco wheels?
Pretty cool.

We shutdown the pattern shop where I worked in '79. I ended up having to trash (3) truckloads of patterns.
They were works of art IMO. All types of exotic wood.
I wish I had some of them this day.


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## astjp2 (Mar 20, 2019)

Draft and draw, these are 2 concepts that are crucial to pattern making.  You need to have just enough angle on parts to allow the pattern to be withdrawn from the mold and this angle is based on the thickness of the part.  If there is no angle, it will not release from the sand in the mold without causing the sand to breakout.


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