Engine Turning - Who dunnit?
 

What's your technique?
I've adhered a round piece of leather to a 1/2" dowel and applied valve lapping compound to the rough side of the leather...in my drill press.
I tried using a piece of Scotchbrite but the leather is better...doesn't deteriorate.
I'm finding that the trick is to use a Sharpie to graph the piece of aluminum first.
Been practicing but hard to keep it from looking like a goober job.
Anyone?
.
Nice job here:
.
~~~~~~~~~~
http://forums.pelicanparts.com/uploa...1473097955.jpg

I've done it with a brass wire wheel. The cone shaped ones. It's easy in a milling machine. You can set X and Y and keep them all the same, and you can set a depth stop.

Only drill press here.
I need to practice more, for sure.
Thanks.
.
I have a coned Dremel steel brush...I'll experiment.

:)
.
PS Any photos of your work?

If I was gonna practice doing engine turning on a drill press, I might take the opportunity to set up a fence

...with "t" track on top and multiple flip stops so as you go down each row, they end up in the same place.

I downloaded some grids...printed out and am using them.
Just had to figure out 1/3 of a half inch. Somewhere around 1/6".
What I've seen online is that 1/3 of the diameter of the turning tool looks best.
.
http://forums.pelicanparts.com/uploa...1473128936.jpg
.
Here's my practice aluminum piece...my final piece will be on the flip side...it's mirror polished.
Two different diameter turning tools. The 1/2" one is leather glued to a dowel and a hybrid of valve lapping compound and rubbing compound.

.

http://forums.pelicanparts.com/uploa...1473128971.jpg

What you're looking for is a Cratex cylinder. Mount on a mandrel and go to town.

I have an old 1/2" Cratex "stick" from working in the avionics world 40 yrs. ago...but it's dry. Tried it and it crumbled too much and I didn't want to spend $22 on a new one...nor having to wait for its delivery.
Took me an hour last night to turn a 2" x 4" aluminum flat. Learned a lesson or two. Next time I'll make a jig so I don't have to be so careful of it not moving on the graph.
Also, the turning is not as pronounced (deep) as I had hoped.
.
Finished, so far...need to make some cuts and holes now for the switches and mini meters.
I love being retired...lots of silly but fun projects. :)
.
Thanks all. SmileWavy

The few items I've turned were with circular Scotch-Brite pads in my drill press. I was doing this on chromed steel, so going "too deep" was a concern.

After talking to a few bike builders I learned all about Cratex, but I've never had to turn anything since.

Do you remember the diameter of the discs, grit (color), and from where you got them?
The largest diameter I'd want is 1/2"...I could cut down a rectangular pad, I guess.
I have many fresh green pads...but they're a bit too mild.
Thanks.

What all the fuss was about re: engine turning on aluminum/brass.
Lascar DC gauge, switch, & Trail Tech Cly. Head Temp gauge on a '14 Royal Enfield Continental GT 535.
Check out that cute little grommet in the upper right corner. ;)
Thanks for the input, gents.
.
EMV 1200 | Panel Instruments
.
~~~~~~~~
.
http://forums.pelicanparts.com/uploa...1475203681.jpg

Great job Don. That looks so nice in place. I'm thinking you are going to get many complements on that piece.

Cheers Richard

I talked to a buddy of mine that works at a shop that restores early American cars. (Think Auburn, Cord, Duesenberg)

He uses a mill with a mandrel, 3/8" hard felt, and lapping compound.
1/3 overlap is typical.

He said Cratex and WD-40 would work good too.

It takes him 2 days to do a Duesey dash... The shop works a 4-10...so that's 20 hours!

Duesey dashes are pretty cool, they are engine turned brass but are coated with a black tinted lacquer. When looking into the car they appear almost black...but if the sun hits them you see the brass turning reflected through.

Cooper

Thanks, boys!
I found a 35 yr. old 3/8" Craytex (1 1/2" long) in my instrument tool box & used that with my drill press...after trying a few other ideas. Used a hybrid of rubbing compound & honing oil.
Took me over an hr. to do that little aluminum & almost that to do the brass plate.
I was careful to not touch while I rinsed them with naptha then hot sudsy water to clean them...not to mar/scratch.
I went online and marveled at the engine turning artisans...unreal beauty.
.
Need to put down the fun stuff now and get a room painted. :mad:
.
;)