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So this is not exactly vintage Motorcycle related, but since the technique is sometimes used, I wanted to share some pictures of the dash I just finished for my Ghost Roadster. Over the years, the original aluminum dash had been replaced with a burl-veneered monstrosity, completely out of place for a 1920's car... nothing like the original aluminum dash which is what I replicated in aluminum right down to the three lines in the middle. This was my first serious attempt at engine turning. Nothing like diving in with both feet.
After much searching about the Web for worthwhile information on Engine Turning (there isn't much!) I finally found a web site by an engine turner named Eamonn Keogh. His work is just superb! http://www.cs.ucr.edu/~eamonn/et/et.htm He doesn't give a primer on the techniques, but he does show the patterns, which is really key to doing a nice job. There is a lot of really bad information on engine turning and some of the YouTube videos are just appallingly bad (which is unusual, as you can usually find good instructional videos on YouTube.)
To figure out the technique, I played a bit with some test panels, using 240 grit Clover lapping compound, motor oil and a felt pad from Restoration Supply Co. Before starting, I polished the panel to 3000 grit and then buffed. It was very well-polished before the first circle was cut. My biggest challenge wasn't making the circles... but figuring out the patterns and overlaps... and finally recognizing that the 'pad' grew under pressure and was slightly asymetrical. I solved that by setting the depth on the Bridgeport quill to stop with just a few thousandths of pressure and then by measuring an actual circle made under pressure. Turns out that a 1" pad makes a 1.2" circle! So all my patterns had to be based on multiples of 0.6"... not 1/2".
Once I had that figured out, the whole thing fell into place. Ultimately, using a digital readout on my Bridgeport I was able to set up a really good pattern. The engine turning on the dash took about 6 hours of steady work but I didn't want to stop part way through the process. I watched/listened to the entire series of Daniel Yergin's "The Prize" while doing this. And I can do my multiplication tables for the number 6... way up into the triple digits. One of the major challenges was fixturing and I had to move the clamps several times, requiring careful cleaning of the area to be clamped. And almost any 'wiping' created scratches from the compound. Solved that using lacquer-thinner as a flush and dabbing the compound away.
Attached is a picture of the finished dash. The picture is from a phone, so not great. But the finish is really lovely and came out better than I could have hoped. It's dazzling in sunlight and I can't wait to see it with instruments installed!
If anyone is interested in doing this themselves, drop me a note and I'll post some more details.
Cheers,
Sirhr
After much searching about the Web for worthwhile information on Engine Turning (there isn't much!) I finally found a web site by an engine turner named Eamonn Keogh. His work is just superb! http://www.cs.ucr.edu/~eamonn/et/et.htm He doesn't give a primer on the techniques, but he does show the patterns, which is really key to doing a nice job. There is a lot of really bad information on engine turning and some of the YouTube videos are just appallingly bad (which is unusual, as you can usually find good instructional videos on YouTube.)
To figure out the technique, I played a bit with some test panels, using 240 grit Clover lapping compound, motor oil and a felt pad from Restoration Supply Co. Before starting, I polished the panel to 3000 grit and then buffed. It was very well-polished before the first circle was cut. My biggest challenge wasn't making the circles... but figuring out the patterns and overlaps... and finally recognizing that the 'pad' grew under pressure and was slightly asymetrical. I solved that by setting the depth on the Bridgeport quill to stop with just a few thousandths of pressure and then by measuring an actual circle made under pressure. Turns out that a 1" pad makes a 1.2" circle! So all my patterns had to be based on multiples of 0.6"... not 1/2".
Once I had that figured out, the whole thing fell into place. Ultimately, using a digital readout on my Bridgeport I was able to set up a really good pattern. The engine turning on the dash took about 6 hours of steady work but I didn't want to stop part way through the process. I watched/listened to the entire series of Daniel Yergin's "The Prize" while doing this. And I can do my multiplication tables for the number 6... way up into the triple digits. One of the major challenges was fixturing and I had to move the clamps several times, requiring careful cleaning of the area to be clamped. And almost any 'wiping' created scratches from the compound. Solved that using lacquer-thinner as a flush and dabbing the compound away.
Attached is a picture of the finished dash. The picture is from a phone, so not great. But the finish is really lovely and came out better than I could have hoped. It's dazzling in sunlight and I can't wait to see it with instruments installed!
If anyone is interested in doing this themselves, drop me a note and I'll post some more details.
Cheers,
Sirhr
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