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 circumference 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 sucked 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 scrap of aluminum sheet .... keep me busy for hours ... looked pretty good for being 7 or 8 ......
The Jalopy Journal
