How should I clamp down thin aluminum sheet for milling? (63 thou)

[metalchipmaker]

Hello, I just wanted to verify clamping method on thin aluminum sheet.

Most of the times, I deal with aluminum or brass bar that are usually clamped with vise.
There is one component that I need to machine out of aluminum sheet that is too thin (0.063" x 5.5" x 14") to clamp with vise.
Looks like most of times, these parts are machined with laser cutter or CNC router.
I've been outsourcing these to be cut on laser cutter, but I wanted to see if I can just make them in-house with a CNC mill to save some outsourcing cost.

I've saw YouTube videos with a vacuum chuck, but other components that are already set-up for vise system do not justify getting a vacuum chuck.
I also saw the superglue method, but I don't know if I trust the rigidity of the set-up when 45% of the material is removed from the aluminum sheet.
I was going to just make an aluminum subplate (1" x 6" x 15") that will clamp the sheet with 6x toe clamp.
Is this the most painless way to get this part machined or am I overlooking something obvious?

 

[BugRobotics]

Face a subplate, apply tape to the subplate, apply tape to your sheet metal, use super glue between the two, clamp and let set up for 20 minutes. Tons of tapes and super glue but I've had great success using this tape and this super glue for years.

 

[metalchipmaker]

Face a subplate, apply tape to the subplate, apply tape to your sheet metal, use super glue between the two, clamp and let set up for 20 minutes. Tons of tapes and super glue but I've had great success using this tape and this super glue for years.

Got it. I will try this first.

 

[Scruffy887]

I was going to just make an aluminum subplate (1" x 6" x 15")

Making your sub plate into a vacuum chuck is super easy. Easier then adding toe clamps.

 

[EmGo]

If I have to work on thin sheet like that I usually just sandwich it. What's the stuff that's pegboard without the holes ? Brand name escapes me but works okay for that.

Masonite ! that brain cell was there, just sleeping.

 

[alphonso]

Masonite?

 

[EmGo]

Masonite?

Yup. It came to me, just had the feedrate set too low

 

[crossthread82]

The tape and glue trick works surprisingly well. More convenient especially if you're cutting lots of through windows. If that 45% material removal you're referring to are blind pockets you may be better served making a vacuum plate.

 

[706jim]

Or clamp it to a wooden board leaving tabs to cut off after its done. We made fixtures out of arborite with top clamping plates to stop the thin sheet from lifting (0.020?).
You might also try reverse helix end mills which tend to push thin sheet downwards instead of lifting it.

 

[Nmbmxer]

How do you release .063” aluminum from the tape? I’ve used that for thicker parts but have been nervous to try it when the material is thin.

 

[Freedommachine]

I used to do A LOT of work like this at Lockheed, airframe skins and whatnot. We used vacuum plate fixtures for all of the thinner stuff.

It is a lot easier to do than it sounds. A vac pump, motor, old 5 gal air compressor tank, an oil separator catch can and some fittings. The gasket material is sold in rolls and you just draw up a channel for it that seals around all of the features in the part.

 

[crossthread82]

How do you release .063” aluminum from the tape? I’ve used that for thicker parts but have been nervous to try it when the material is thin.

I usually pour some isopropyl alcohol or MEK around the edge of the part and let it wick through the tape, that'll soften the glue enough to let it come up relatively easily.

 

[rons]

Use a block of wood. Seal it with Tung oil.

 

[Luke.kerbey]

It’s got wire EDM written all over it. I can cut 6mm aluminium at 30mm per minute, 1.5mm is double or triple that speed depending on flushing.

I know you specify milling but that does sound a pain.

 

[EmGo]

It’s got wire EDM written all over it. I can cut 6mm aluminium at 30mm per minute, 1.5mm is double or triple that speed depending on flushing.

$3500 laser will blast though that in a heartbeat too, but I don't think he has one

 

[Houndogforever]

Make sure and use reverse helix endmills so the cutting force is DOWN, not up.

 

[SteveEx30]

I wouldn't suggest superglue for thin pc like that. Be difficult to remove it after without ruining it.

Fwiw, I use superglue a few times a week holding work in EDM applications-just not thin stuff.

 

[couch]

Are there holes or features that go thru the center at all? Clamp the outside, finish the inside, clamp down into tapped holes in the fixture, remove the clamps and hit the outside. Or make a small vacuum plate that you can put in a vise and get a vacuum generator. The Vacuum Power Unit from Pierson Workholding is very simple to setup and use, and requires very little air.

SmartVac 3 Vacuum System – Pierson Workholding

piersonworkholding.com

 

[BT Fabrication]

ive got so many shops with a laser around here, it costs more for me to do it then it is for them to just cut it all.

 

[Gecko779]

Wax?

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