What is it called when aluminum has the "circles" machined into it like this dash? I saw an old pic of a pre-unit triumph with cases finished this way & it really looked killer. I'd like to do it on my unit 650 but i dont even know what its called, let alone how its done. any ideas?
thanks for the fast response guys. is it possible to engine turn a surface that has curves (like my 650 triumph primary, kicker & timing cover)?
I've done it poor boy style using sanding rolls, scotchbrite disks, and also a wire brush in a drill motor at low speed. To use the wire brush, wrap the cir***ference tightly with black tape several laps. Practice first.
Eamonn Keogh's page on engine turning still looks like it did when I first saw it about five years ago. I have some parts I'd like to send him to do. He's one of the best in the country. Dave http://www.roadsters.com/
I've heard of/seen folks do it using old engine valves and grinding compound,but I don't know of a reference at the moment. try Google. Oh,try this:http://www.cs.ucr.edu/~eamonn/et/et.htm
I have done this two different ways. The old school method is to glue a small circle of suede to the end of a wooden dowel. Dab some valve grinding compound on the suede, chuck-up the dowel into your drill press (slow speed)and go. Later, I found a rubberized abrasive called "Cratex" it comes in cylindrical shapes and can be used like the dowel, when the tip wears, you just "dress" it by slicing off a bit off the tip to make it square again.
I tried the wooden dowel thing - it ****ed because of two reasons - first you had to have your dowel perfectly square (to itself) and then you had to have it perfectly square to the part. Instead I had better luck just glueing felt or leather or even a SOS pad to a bolt head chucked into the drill press. One thing I found useful was a straightedge to slide the part across as you did each mark - the spacing is NOT critical to the eye so long as they are on a straight line - IMHO. The "trick" when using the non-abrasive mediums is to wipe a coating of valve grindign compound (rubbing compound - whatever abrasive you prefer) across your part - this time each new mark gets a fresh "charge" of abrasive - if you apply the compound to the end of your "pad" you may notice (immediately or even years later) that the marks tend to fade away in their depth. I have also had good results using cratex - my only issue there was that I at times wanted to make a larger swirl diameter than the size of teh cratex stick - so I made a "fixture" - works pretty good all considering.
My Grandpa would set me in front of the drill press with a old box of pencils ( used the erasers ) and a s**** of aluminum sheet .... keep me busy for hours ... looked pretty good for being 7 or 8 ......
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