Workholding Tape

[Dave.L]

Good Morning all,

 

We have a requirement to make some prototype parts, only 10 pieces, aluminum.

 

Outside dimensions are 2.4 x 2.4 x .063 thick, flat wihin .005 Just some holes and a shallow pocket.

 

I am thinking of trying workholding tape, anyone with experience doing this, can you post any suggetions?

 

Thanks!

[Kevangel]

There use to be a company called TCI ?? in Calif. that specialized in aluminum blanks to your size and they had double disc grinders that grind both sides at the same time.

[Kevangel]

http://tciprecision.com/

[Dave.L]

Kevin,

 

In many cases we use double disk grinding, and it works well. In this case, I wish to machine all 5 sides of the part at once, then flip it to face and chamfer.

 

To small and too few of parts, and needed to quick to double disk grind.

 

But, I do appreciate your reply, Thanks!

 

BTW Dix Metals is another in Hunnigton Beach that I have used from blanks.

[Dave Ball]

I do this all the time with alum. & plastics, its an excellent method. 1)Be absolutely certain your mounting surface is clean & dry, we use MEK. 2) make sure you "mount" the part over some type of slot or hole that will allow you a way to pry the part off, also soaking with the MEK after cutting, helps to loosen the adhesive when your worried about bending thin parts. I will try to get the name of the tape/supplier but I'm not in the shop currently.

[Goldorak]

we use krazy glue

 

when the part is finish , just tap it gently with a rubber mallet and voila

.

 

but we make 3/32 part not 1/16... 1/32 is a huge difference at thees thickness

[Chris Rizzo]

3M 3M 3M!!

 

When I get in to the shop I'll give you some part#'s.

[Odell]

If your holes are big enough, could you put your holes in fist and bolt it down to another piece?

[Cad-Camr]

Yes, 3m makes different grades of double back tape which are also different thicknesses. cleanliness is crucial to sucess. It helps if you can capture any or all of the profile in a pocket. Good Luck

[Dave.L]

quote:

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If your holes are big enough, could you put your holes in fist and bolt it down to another piece?

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Not if I want to face the part, the bolts might not like that

[Odell]

They'll quit complaining once you take there heads off

[Dave.L]

quote:

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They'll quit complaining once you take there heads off

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LMAO

[Rob @ Target Machine]

Dave - We do alot of "4047 Laser Weld" covers for our hermetic housings. .187 thk down to .020 thk stock. I usually use 3M double sided tape.

 

Our trick to getting the parts off the block is to heat the block with a soldering plate set at 157 Celcius for a couple minutes, slip a razor blade under the part, spray a little alcohol in between and the parts come off easy without any residue.

 

Kevlar gloves help with handling the blocks hot.

 

As stated above, cleaning with a little MEK, MIBK, or just acetone will help keep the parts on the tape.

[Jim at Gentex]

Yes, I've also used double-sided tape to hold small, thin parts.

 

As others have said, it is vital to keep the work surface clean and smooth. We also use MEK as a cleaner, and to loosen the bond after machining.

 

Other than some kind of vacuum fixture, double-sided tape is a very good choice.

[Steve Hattori]

Mitee-bite makes tape that releases clean with heat- they have it on their website-

www.miteebite.com

[crazy^millman]

Dave can you get away with a vacuum? The tape used in automotive applications for holding molding is really strong. Acetone works real good for dissolving the glue and allowing you to remove after machining.

 

Does the part have holes in it? If it does could you machine around them using smaller bolts than the holes. Clamp the part down then drill or mill them to size? Now flip it and hold using tape to just qualify the thickness? Have you looked at super glue like suggested I have done it before with good results. Also have used bondo to hold parts, but you need to either prime the material or tape it since the bondo will stick to alum and other metals.

 

HTH

 

[ 02-02-2010, 06:09 PM: Message edited by: Crazy^Millman ]

[Dave.L]

Ron,

 

Vacuum would certainly work but I think the best application for these parts would be tape.

 

Thanks for your suggestions though.

[Jeff Kemper]

3M 665, releases with alcohol.

[left coast lefty]

I use double-back tape all the time for thin aluminum parts.

We use acetone, just clean both the mill surface and the part until you see no residue. . Try not to leave it overnight as it will be hard to get the tape off in the morning.

[kunfuzed]

Mag chuck.

 

[kunfuzed]

Flat within .005

 

That sounds kinda tough for something so thin. Especially if you have to pry it up. What size stock are you starting out with? I've never had to face something this thin, so I don't know. Our thin parts are usually cut out of sheet. Stock size good enough.

[Dave.L]

Last time I checked, aluminum is not magnetic

[Dave.L]

We will probably start with .25 plate. Sheet will be to hard to get flat. We have lots of experience holding parts flat. There are many tricks and the type of material will dictate what tricks are needed. The bigest factor is you need to cut one side without distorting the part at all. Once you have one flat side, then the rest goes much better. Clamp pressure, or lack of, is the key

[kunfuzed]

quote:

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Last time I checked, aluminum is not magnetic

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Well, not with that attitude!

 

 

Wow, that's quite a ratio of start to finish removal! I guess it depends on the condition of the metal, but do you foresee it curling up as you release some of the stress in it? I know we've had that problem before. How many times you going to flip it? Start with a vise, or clamps? I guess at a 1/4 the double stick tape might work, if it's flat enough to hold it.

 

Thanks for sharing the experiance!

[moeh]

+1 to 3M

 

We run parts dialy out of .063 thk aluminum, and I don't think we ever get outside of +/-.005, but we normally do this on a router with an MDF board puling a vacuum thru it. If the vac doesn't hold for whatever reason, we glue it down.