Any Suggestions on How to Turn this Piece?

X

XXXXX

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This piece is a bezel that a piece of glass will fit into.

The outside diameter is 5".

The opening diameter is 4" (thus leaving 0.5" on either size), and there's a rabbet/step with a diameter of about about 4.5" (leaving about 0.25" wall thickness) where the glass will sit in.

Material is 6061 alum which will be polished afterwards.

The height of the finished workpiece is 0.6"

I have a mini lathe, which I think means I'll have to be creative about how I turn this down.

Any suggestions or ideas?

Adam

bezel_mc.png
 
Being Al, you could finish the "plain" side and glue it to a faceplate and finish the other side. A little heat will turn it loose. You will need to use a sacrificial piece to glue to, with a step to locate the bore, which should be finished with the plain face and OD. Light cuts will be key to success.
 
You have not given enough info. Is your chuck too small? Are you just unsure about which way to work on it.
I would say work the side that is up right now in your pic, do your roughing from a larger /longer piece and then cut the final shapes, then part it off.
Try to get as good a parting as you can, you don't want to work this too much if you can avoid it.

If you need to work the side that is down in your pic.. make a mandrel and center drill and tap it, then make a cap and use the cap and screw to hold the pressure while you finish cut that side. Or use your tailstock for pressure on the cap, but I think the tail stock would be too in the way, so the mandrel cap and screw might be a better idea.
Without much info, I can't be sure of what you are looking for.
 
Yes the chuck isn't big enough to fit the 5" piece inside of it, otherwise I think you're right with parting off.

The "down side" is actually the finished side that will be polished and visible in the end product. The "step" (side up in image) will be down and hidden.

And with the glue... good idea as well, and I didn't realize that was a possibility but it makes sense. Standard epoxy?

With the glue I'd have to make sure the stock was faced to begin with, wouldn't I?

Good idea with the mandrel. I have access to a milling machine with DRO, so centering a mandrel could be done with acceptable accuracy. Is a threaded rod or carriage bolt used for this?

Either would work. Accuracy isn't critical, it's simply a bezel/cover for a dial. I will be wet sanding the finished side on a slab of granite and then polishing.

This is the first time I wish I had a bigger machine :( And, in fact it's not the machine... it's the chuck I s'pose
 
Superglue! Very cool!

Thanks guys I will try those ideas.
 
Do you have a face plate with your lathe. You can screw/bolt your material/ sheet stock/plate onto the face plate and do most of the machining with that set-up theme. Leaving about 0.010” of material between the bolted stuff and your almost finished ring. Cut the two apart with a jig saw or similar and remove the final little bit of material with a file (it could be made into a chamfer and never noticed)…Dave.
 
XXXXX said:
The "step" (side up in image) will be down and hidden.
Click to expand...

Perhaps more complicated, but another idea; you could put an internal thread on the step (hidden) side.
Then use a stub arbor with external threads. Spin the ring onto the arbor to turn the finished side.

-brino
 
I think I would drill a 1/2 hole thru part center. Then take a piece of 1/2 inch threaded rod thru spindle and part and clamp part to spindle with 1/2 inch nuts.
Then turn OD and face and trepan and bore the finish bore to depth. Then turn part around and trepan to cut part from stock. You could leave a little stock and finish Id
After part is free from center piece. If you trepan stop about .01 before you break thru
And break free by hand. The total cost of threaded rod and nuts is about 5 dollars. And you could clamp stock right to front of your chuck jaws.
Jimsehr
 
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