aluminum honeycomb machining

[kihocam]

Has anyone had experience surface machining of 5052 aluminum honeycomb core, 3/16 cell size, .001 thick foil? If so, can you share which surface machining toolpath (with parameters), tool used, etc? We are using a Haas VR11B 5-axis head-head machine. Any help is very much appreciated.

[Guest CNC Apps Guy 1]

I have filled it with water anf frozen the blocks in the past, then machine it "dry". Worked like a charm.

 

HTH

[SKIR68]

I have filled it with water anf frozen the blocks in the past, then machine it "dry". Worked like a charm.

 

HTH

 

 

 

Thats thinkin' outside the box right there! I like your thinkin'!

[Guest CNC Apps Guy 1]

Ice was my 2nd attempt...

 

The first attempt was wax... worked awesome, we just could not get all the residue out and it was going to be sandwiched with composites then autoclaved... wax was no bueno for this application but we learned something.

[Psychomill]

Yep.... Ice Chucking as we've always called it from back in the day. Work very well for that type of app and with general "thin wall, thin floor" type of work. I used to do a lot "contactor" work that I programmed this way. There is a particular fluid that we found that worked with even better holding power and "solid time" (frozen time) than water... I can't remember the name of that stuff now. At room temp, it had the viscosity of "Slime" if any of you guys remeber that product from years ago (kid's toys). It didn't have the expansion problems of water when freezing it...

 

Now I wouldn't necessarily use this for cavity work unless you don't care about the product mixing into your coolant tank or just the fact of machining it away. But pouring it into a "pan" then freezing a thin wall/floor part to it works no problem with minimal issues.

[dforsythe]

Ice works great. we do it on prodution parts. the run time is alomost 35 min. we use ended up having to insulate the fixture to keep is solid during milling

[jeff]

If you're freezing your parts like that, what do you do about the tolerances? Let's say you have a +0.000/ -.0005 diameter for instance

[dforsythe]

If you're freezing your parts like that, what do you do about the tolerances? Let's say you have a +0.000/ -.0005 diameter for instance

 

This is on Honeycomb. usually you are just trimming to size and mabye face a few step into it. +/-.01 is common and easy to hold.

[Guest CNC Apps Guy 1]

Ice works great. we do it on prodution parts. the run time is alomost 35 min. we use ended up having to insulate the fixture to keep is solid during milling

Oh, that reminds me... forgot to add... we had Liquid nitrogen at our disposal so we dropped the jaws in... they stayed cold enough for the cycles we had (about 110 min IIRC), but you could always put STEEL jaws in a freezer, I'll bet they'll stay cold for a while.

[Guest CNC Apps Guy 1]

If you're freezing your parts like that, what do you do about the tolerances? Let's say you have a +0.000/ -.0005 diameter for instance

You're never gonna treat a part that has to hold those tolerances like that. Like was said above, this is for a honeycomb material application... I think the tightest tolerance I've ever seen on it was ±.015 IIRC

[Joe788]

Isn't there some sort of electrical discharge milling process for honeycomb material? Where the tool spins like a milling cutter but uses electricity to cut?

[Psychomill]

You're never gonna treat a part that has to hold those tolerances like that. Like was said above, this is for a honeycomb material application... I think the tightest tolerance I've ever seen on it was ±.015 IIRC

 

 

Yes and no. Granted, most apps of this type are "loose" parts. However, depending on circumstances and the set up, there is something called LCTE ....

You can calculate expected movement and get pretty close... closer than most would think. Takes a good bit of work up front and likely several test runs but it's 'doable'.

5 tenths? Probably pushing it there but with certain geometries, materials and configurations it's possible. Generally speaking though, this app isn't my first choice... but kudos for people still thinking of this stuff....

[Mgrenier]

What Joe788 is right on for machining precise dimensions. We have to turn some and we use an electro-erosion machine to achieve what we want with close tolerances. Takes time but works good.

 

HTH

[Scrump]

We just took in a job with some honeycomb. We tried a few runs with wax but im going to suggest ice. We also have some liquid nitrogen that we can use on our fixtures. Anyone know psycomills suggestion of using the kids toy "slime "?

[mkd]

Isn't there some sort of electrical discharge milling process for honeycomb material? Where the tool spins like a milling cutter but uses electricity to cut?

 

Ur thinking of electro chemical grinding. The electricity burns the material while the wheel clears the excess.

[andate caga]

There is actually a compound you can fill the cells up with then wash out with water and reuse. I can't remember the name, but that's how the big aerospace places get it done.

 

Use no silicone based compounds either.