Need fixture ideas for holding thin, suspended floor thickness

[MetalFlake]

One of our programmers is trying to figure out how to hold thickness on a .060" aluminum floor (actually a web) of multiple pocket's that are about 6" square without doing the vacuum fixture thing. He's come up with 1)light compression springs under the web. 2)squashed aluminum foil (sounds crazy but it might just work). 3)A rubber like epoxy or bondo. I was going to suggest bubble gum but I haven't got this guy quite figured out in the sense of humor dept yet.

 

Any fixture fanatics have a favorite way to deal with this kind of thing?

 

Many thanks for any input.

 

MF

[crazy^millman]

Well you could use ice only problem is thermal expansion. I would say bondo but I would not tape the back of the part bonod sticks better to aluminum bare but a real pain to get off. If looking for machine back side Might look at leaving .005 to take of the back if it is flat. If it is a doublesided pocket part then you might make plastice inserts that press fit into each pocket with a tapped hole to use a dent puller to get them out. I have done parts like this by making a male to put the parts over then doing a cam to lock the parts down takes tiem but if doing production soem time the best way to be productive.

 

Like I always say what may seem crazy may be the best idea. The last thing I can say speed kills so I might try rouginh it with .01 at high sprocess then finish at like 200 rpm at .004 per toot feed may look a little rough but my good friend the chatter monster doesn't coem out to play much here at this speed and feed.

 

Good luck try different things and don't let anyone breathe down his neck and he will get it.

[Guest CNC Apps Guy 1]

Here's how I'd do it.

 

1) Double back tape. Can't use coolant, but light oil mist should suffice.

2) When Pocketing, create extra pocket geometry so that you can cut your first section all the way to ght finished floor, then expand out one pass at a time. This will keep you from sucking up to floor. Done it many times - works liek a charm if done properly.

 

HTH

[Fig sign]

I don`t know how you part looks but you can also try false (technology ) islands outside and inside your part with holes for screws and reamed holes for pins .

You mill your part and take them off conventionally .

I did this many times with thin parts of the craziest forms .

[Quickmike]

Can it be put on the FTP site?

[F. JAVIER]

Mitee-bite has some heat activated wax that you use to heat between a simple any size plate and the the material. When it cools down you can machine it and after machining you heat it again to remove the part from the baseplate and voila! you are done. They may have some info on their website.

(Just another idea)

F. Javier

[Heavycut]

When in doubt try Pixie Dust always does the trick,but very pricey $$$$$

[Nominal]

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When in doubt try Pixie Dust always does the trick,but very pricey $$$$$

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Since Pixie Corp relocated their mfg facilities to China the quality just hasn't been the same.

[MACHINEMASTERG]

quote:

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Pixie Dust

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yea but the guys in assembely always seem to abuse it

[heeler]

We have done some stuff with using a ball endmill and a small step over (.010)-(.015). If you have a fast spindle such as a router ect. you can do feedrates of 200-500 ipm. Doesn't take long and the ball mill will not pull up the surface. We've done this with thickness as thin as .010". On our mills we run 10,000 rpm and 100 ipm with a 1/4" ball mill.

 

HTH

 

Glenn

 

P.S. We've done this while holding the part with vises, Mighty bites, fixtures and doublesided tape. You don't have to have something on the backside to be able to hold the thickness.

[Tim Aydt Prototek Engineering]

I agree with James. Double back tape sometimes known as carpet tape works wonders on situations such as these.

[Tim Johnson]

Use jig plate underneath the part and rough leaving about .030 on the floor. Finish with a left hand spiral right hand cut end mill. It will push the material into the plate. Run at about half the rpm you would normally run and feed for your finsh.

[CAM-mando]

As James eluded to eliminate finish cuts on the floor if possible, taking a rough cut only on the floor and spiraling out so you are always cutting into supported material. You would be amazed how well that works.

 

If not, I have used the Mitee Grip paper that was mentioned, the double sided tape and Iskanders' temporary fastener approach.

 

quote:

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try Pixie Dust

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I have a friend who "tried" that stuff ... he's never been the same since.

[Harryman]

Time to introduce Tim Aydt to the forum.

 

Tim is doing tech support for Prototek Engineering, my reseller. Dude just took on a proactive look / tweek of my post. Something that needed to be done but I was to busy to document and request in a formal way.

 

Support doesn't get any better than that.

 

WOO HOO

[CAM-mando]

Welcome Tim

[Tim Aydt Prototek Engineering]

Thanks Harry You are way too kind

 

Tim

 

[TheePres]

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Finish with a left hand spiral right hand cut end mill.

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Great Idea, has worked for me. Also, have used Tooling stone, similar to bondo, but no expansion, and some other goop called "BEAR **** ".

 

Oops!! admin will not allow full name of this product on this board.

[Chris Rizzo]

That mitee bite wax works pretty well, and easy to remove from your part. The double sided tape works pretty well too, just make sure it's not to thick or squishy. I've also used 3M Super 99 or 77 spray adhesive, which works WAY to well, and makes part removal a real pain...sometimes it turns into a part maiming situation.

[MACHINEMASTERG]

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I've also used 3M Super 99 or 77 spray adhesive,

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i just tried this stuff last week works great if you get it on do you work and get it off in 1/2 hr but then had to skim that side to get the goo off but held great

[Guest CNC Apps Guy 1]

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..and some other goop called "BEAR **** ".

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The technical term for that is Casting Retainer Putty or Babbit Putty if you ever actually want to find it anywhere. This too works very well and does not suffer the same problems with coolant that double back tape does. It's available at McMaster-Carr Part number: 8902K1 Casting Retainer Putty 5-lb Container $ 20.42 Each. We use this where I work for out large open area thinwall/floor parts.

 

HTH