Best Way to Cut Parts

Depends on the size of the parts, When I work at the shipyard we had Naval contracts we used a router and cut laminated aluminum as well as pheonolics.

Laser may get burns on the vaneer, and too much heat was a crappy edge on the pheonolics.

Water jet may leave watermarks on the vaneer but works great with pheonolics.

Router is the more versitle. Draw back is vacuuming you piece, What we did was leave 0.002 aluminium flashing and not cut through, and then this foil flashing was easily removed.

How thick is your vaneer

Vaneer down. We used spiral upcut, Use a file to remove your flashing, careful do not remove too much.

And cutting pheonolics was like a hot knife through butter., Spiral Upcut, If I remember climb cutting

p911

Need to append my last post.....with apologises

Memory serves me......eventaully, I have to append that last statement. Not spiral up-cut but spiral down cut...spiral up cut would tear the piece away from the vacuum. We had sometimes even screwed (2-3) screws down the piece (piece blank being 120x144 inches) to give us piece of mind because we had cut rather aggressively (high IPM) to ensure the piece did not move and lose vacuum. and efficiencies reasons

I like to add my experience with waterjets. Since there are stratification with extremely different properties such as veneer and aluminum, if you cut these pieces on a waterjet, you lay the blank on the table with veneer side up, the jet will blow through the veneer and as its penetrating through the aluminium there will be a slight dwell until penetration, that water has to go somewhere and it may/will delaminate your veneer until you punch through.

If you lay veneer side down, the jet may blow out your veneer on the bottom side, plus it may have water damage to your veneer even if you use cardboard bricks to help drain it away.

p911

I agree that a cnc router is the way to go, but mainly because I have been using CNC routers everyday for the last 23 years.

You are correct with the down shear cutter but a conventional cut works better on composites or aluminum and the climb cut is preferable on the wood veneers mainly to eliminate tearout. If the veneer is well bonded to the substrate, a conventional cut would be my preference. The feedrate would depend on the diameter of the cutter, the rpm of the spindle, the chipload and desired edge finish. Larger diameter cutters give a better edge finish but cannot exceed the minimum radius of an inside cut or hole radius.

If the finished part is greater than 50 sq inches or so, a gasketed vacuum fixture would be a sufficient hold-down method without onion-skinning or tabbing. (14.7 lbs/sq in X 50 = ... a lot) For larger parts we draw vacuum through a sheet of surfaced MDF without gasketing.

Coolant is best on aluminum but messes up the wood veneer and air blast should be used on composites during the cut to clear the chips and reduce heat.

Thanks for the info, OpMan:.......

We had operated (2) Shoda NC163 (2) Head, (2) drill pack and a NC263 (5) Head (4) Drill pack dual table. I am sure tooling improved since my day last was in '94.

Familiar with wood and Nonferrous, The contract was Avenger Class Minesweepers. Wood, Oak, Cedar, Pine and wood laminates/composites and nonferrous-metals and plastics. check out the complements.

Some composites we had trouble with such as FRP or other glass base material. we had a rasp type of bit. Our problem we had we could not operate the router under 7000 RPM, because thats when our inverter kicks in.

We never or rarely used coolant because we had a MDF bed and it threw the accuracy off. Wh had cut a variety of metals even stainless, (stainless unsuccessful what the heck where they thinking ) otherwise copper/nickels, brass aluminium the hard stuff 6066 T6 cut great left a mirrored finish, the softer AL was a little gummy and silicon bronze.

And as stated earlier we used the chip load to carry the heat away. The chips would leave a burn mark on your bare skin. After a shift we would have about (1) 55 gallon barrels of chips that did not make it up the vacuum.

Thickness of aluminum were light gage to 6" thick.

But I have to say spiral up cut isn't bad if it doesn't tear away you part from the table, especially on the thin aluminium. Our MDF table we cut on was also our holding table for the part with vacuum.

p911

Ah yes, the Shoda's. A good heavy old machine. They're probably still operating some where! Those machines were built to outlast their technology.

Machines now have to have automatic tool changers with HSK spindles, C-Axis, 40hp vacuum pumps, huge drill banks, million pulse encoders and are capable of cutting speeds of 2500 ipm. Many machines have rack & pinion drive or rotating ballnuts because ballscrew whip becomes a problem at high feedrates. Tooling manufacturers can't keep up with the machine tools. We usually machine wood products at around 1500 ipm with three or four flute solid carbide or diamond compression bits which have an abbreviated up shear at the bottom and the rest is a down shear. At that speed there is a rooster tail of dust that can't be collected and you would swear the cut would look like it had been done with a chainsaw, but it comes out clean and precise.

BTW, those minesweepers are incredible!

When I interviewed there, they had one laid up on Dockside unpainted, that impressed my. It looked like an Ark.

Yes, we had those shoda's customized. 60 HP Vacuum Pumps 15 HP Drill Packs and 30 HP on each head. BT 40's and 40HP with a BT50?????? I think

We should have gotten a tool changer but could not afford lead time. They used us as a showplace on the versatility of the router. We made alot of sales for them.

But a $7.50 fuse could shut the whole thing down and did, Japanese translations on the operators/maintenance manuals where complete but wrong translations, but were consistant......it had a lot to desire. Thats when I pick up my Robotics and Industrial Electronics degree.....just to keep those going 3 shifts.

1500 ipm it did come a long ways. We left the operators chose the R's and ipm some of the heads had a attitude problem. with RPM stability at a certain RPM Range and one with fretting. .

Wood/MDF we usually ran about 18,000-22,000 Rpm.

Tables were so big we have 3-4 project on them at once........wish we had pallet changers. and some of time for the intricate cuts we had to get on the bed. to actually examine the work.

In the early 90's they just came out with the Super Shoda routers I guess 30,000 RPM.

p911

PS for doing hogging we had a very aggressive bit, the maker was called Fantucci I believe. When through a 3" x 2" deep pass on Red OAK like a hot knife through butter......but not at 1500ipm....more like 150-300ipm...can't remember

As I recall, the best saw tooth size (and speed) differs among these materials. I suspect the same may be true for routers. Your idea of a laser seems the most promising, and another possibility might be high-pressure water jet cutting. You could contact some suppliers of these technologies and get their advice and limitations.

Agree with phoenix911, router is the way to go.

Phoenix 911 has given you all the options I would, personally I'd have some sample pieces cut using router & waterjet & see which gave the best results, I don't think laser will work, by the time it's cut through the ally the temperature will burn the veneer.

There is an alternative though, check out www.decoralamerica.com this company have a process of coating aluminium with a durable, printable powdercoat. I have seen samples & it's a very high quality product, which sounds perfect as an alternative to laminating an exotic veneer!

Another thing about cutting aluminium with a laser, it has to be masked, otherwise aluminium has some reflective quality's,

CNC router