How Do I Turn A Fairly Thin Aluminum Sheet

[prasad]

Guys

I want to turn a 16 gauge (~1.6mm) aluminum sheet to get a 5 inch diameter round disk. Tools I have are my 9x19 Grizzly lathe and a Grizzly mini-mill. How should I do it?

Thanks for your advice,
Happy Valentine's Day
Prasad
Eastern PA

 

[planeflyer21]

Here's how I would do it.

Cut a square a bit over 5" across the flats (say 5.01"). Then layout the circle you need to cut. Using a hacksaw or jigsaw, cut off the corners leaving a bit of meat to machine away.

Face off a piece of good sized round stock (2" at least). Clean your circle and the part just faced, then advance the tailstock to apply pressure against the aluminum sheet and hold it in place. You can use a piece of wood or center drilled brass/aluminum as the contact point for the tailstock center/live center.

Using a pointer on your toolpost as a guide while turning the spindle by hand, adjust the sheet until your layout line for the circle is running true. Now you can really snug up the tailstock.

Turn on the power, and take light cuts, slowly feeding in until you are up to your 5" layout line.

 

[genec]

You could super glue it To a face plate and then turn it, then heated up to remove it

 

[prasad]

Here's how I would do it.

Cut a square a bit over 5" across the flats (say 5.01"). Then layout the circle you need to cut. Using a hacksaw or jigsaw, cut off the corners leaving a bit of meat to machine away.

Face off a piece of good sized round stock (2" at least). Clean your circle and the part just faced, then advance the tailstock to apply pressure against the aluminum sheet and hold it in place. You can use a piece of wood or center drilled brass/aluminum as the contact point for the tailstock center/live center.

Using a pointer on your toolpost as a guide while turning the spindle by hand, adjust the sheet until your layout line for the circle is running true. Now you can really snug up the tailstock.

Turn on the power, and take light cuts, slowly feeding in until you are up to your 5" layout line.

Great!! And thanks. I will go ahead per this.

Regards
Prasad

 

[seasicksteve]

Sandwich it between two pcs of sacrificial matl and turn it size I would preturn the sacrificial matl slightly larger than your finish dia. I would be willing to try two sided tape as well. Use the tape to attach the sheet to a smooth backer plate. Solvent will loosen the part from the backer after you have finished

 

[Steve M]

I recently saw a video on this that came as part a collection on lathe operation. It showed using double sided carpet tape on a faceplate.

 

[TOOLMASTER]

SOMETHING LIKE THAT I CUT WITH A TRIM ROUTER ON A MASTER CIRCLE

 

[David S]

Sigh with this so thin I just use my aviation snips on the layout lines. Ya I know I will be banned from the machining section.

Davdi

 

[RJSakowski]

Another way would be to fasten a piece of plywood backing to the lathe face plate and screw a 5"+ square to the four corners of the plywood. Use a trepanning operation to cut the 5" circle. As you approach the completion of the cut, slow the feed rate down to avoid grabbing the part. If you are careful, you can fairly well get a complete separation. Otherwise, you may have a little hand work with a file to clean up the part. Some double stick carpet tape would add suspenders to the belt.