Machsupport Forum

Tangent Corner => Tangent Corner => Topic started by: kdoney on March 22, 2010, 10:25:35 AM

Title: Holding down thin workpieces
Post by: kdoney on March 22, 2010, 10:25:35 AM

I'm trying to pocket .1250 thick 4" X 6" piece of 6061 aluminum and I keep getting bad vibrations :-). I am using a new kurt vise which pulls the piece down and a goodly amount of pressure but the piece still vibrates badly while being machined. Any ideas?

Title: Re: Holding down thin workpieces
Post by: RICH on March 22, 2010, 12:26:30 PM

Carpet tape the piece to a backing material or add additional clamping.
RICH

Title: Re: Holding down thin workpieces
Post by: Sam on March 22, 2010, 08:27:12 PM

Or sandwich the piece between two sturdy sacrificial pieces.

Title: Re: Holding down thin workpieces
Post by: edvaness on April 10, 2010, 10:15:22 PM

Forget the vice for this job. Clamp it over the top of another pc. of alum, and set your z depth to -.010 approx into the lower pc.
If your cutting through.

Ed

Title: Re: Holding down thin workpieces
Post by: BobWarfield on April 11, 2010, 02:44:07 PM

What they said.  1/8" is just too thin.  You can glue it to the tooling plate underneath and it will be held over its entire surface.  I'm not too comfortable using only the glue, although many do, but it sure helps. 

You can use hot melt, super glue, or even Loctite with metal.  All work pretty well and will release with heat.

Not knowing what your part looks like, it's hard to suggest further steps.  For example, if you have some holes, it can be helpful to drill these first and then use them as hold downs as well.

Cheers,

BW

Title: Re: Holding down thin workpieces
Post by: N4NV on April 11, 2010, 10:52:27 PM

You can use jewelers wax to glue it to another piece of thicker metal.  It melts at 150 degrees F.  A very thin layer holds well. 

Vince

Title: Re: Holding down thin workpieces
Post by: spunk on April 12, 2010, 08:01:00 AM

if possible use a vacuum table...