Best Al cutting solution..

I have a new Tormach CNC mill I'm using for some hobby stuff. A lot of what I'm doing is making parts of Aluminum billet.

What is the best cutter solution for removing lots of aluminum.

My Max RPM is 4500, the tooling is R-8 The spindle is 1.5Hp.

So I'm looking for suggestions as to the best bit for roughing out aluminum.

I'd also like feed and speed reccomendations to go with it .

Thanks in advance

Paul.

Reply to
Paul
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Why,

I'm sure we're all *very happy* for you....

No such thing exists what is properly called an 'aluminum billet'.

Not gonna remove any material at much of a competitive rate what with having only 1-1/2 hp. available...

Suggest cut dry, and with a 'roughing endmill' whenever possible....usually will be 3 fl and med helix in Al....look for nice deep gullets, highly pronounced rake generally speaking, of course.

Cut at a removal rate just slightly below where the spindle would otherwise stall.

Reply to
PrecisionMachinisT

possible....usually

Oh, I almost forgot.

Also, suggest learn how to quickly DUCK.

Reply to
PrecisionMachinisT

Paul, You could try one of these.

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've used the 3/4 dia. at about 3000 rpm x 1/4 to 3/8 deep @ 20 ipm. and had good luck on a machine with similar hp and rpms (bridgeport) as yours. I used microdrop mist coolant. There's a speed and feed chart on the page but you don't have enough power to push it that hard so you'll have to experiment. I could remove more at 3000 rpm then wide open I think because of the torque. I used the cheap one on the top of the page but the cobalt isn't much more. Steve

Reply to
Steve P

Steve, thanks for a response to the origional question.

For the other posters... If you ask an electronics question I'll make sure to ridcule you first and then not answer your question. (Electronics is my profession)

I realize that the machine is not a 50 hp CAT50 VMC, but that would be a bit of overkill for my Garage ;-)

I've had the Tormach for about 3 weeks and I'm quite happy with it. For $6800 it comes ready to use.

Most of the stuff I build is small

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and Parts
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I had been using a Taig and the tormach is a nice upgrade for me. Heres a simple tutorial I did for some other rc modelers...
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Paul

Reply to
Paul

Proper term would be barstock...

alas if you google billet parts you will find that it's the popular term for parts machined from a signle peice of barstock. See:

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really to my taste but they clearly have a differnt view of the term billet thn you do.

;-)

See my follow up post at the end of the thread for other comments wrt this post.

Paul

Reply to
Paul

Paul: Some people in here just like to play to the role of the crusty curmudgeon, I wouldn't take it personal.

Two flute end mills are good for removing a lot of material in aluminum. Four flute end mills don't have as much gullet clearance. I wouldn't cut alum. dry since it's a gummy material and often likes to adhere to the end mill (with sometimes disastrous results). A spray mister, of even a hand squirt bottle of mixed coolant can work wonders.

Nice work on the plane.

Is that servo operated ball valve your invention? If so (and it has zero leakage under 3,000 psi), you might try to sell it to an automotive performance oriented supply house as a Nitrous Bottle remote operated valve.

Reply to
BottleBob

I've been posting on newsgroups for a long time. I know not to take it personal, alas its sometimes nice to poke fun at the curmudgeons....

If your fairly new to a group you can pose as the innocent newbe and mabe make the curmudgeons feel bad for a few uSeconds. Its all part of the sport.

As for the Ball valves they are probably a lot bigger than they need to be for nitrous. The key component is the very high torque servo.

I'm using the ball valves for my air rocket and also for a biprop rocket similar to

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Paul

Reply to
Paul

snipped-for-privacy@Rasdoc.com wrote in news: snipped-for-privacy@4ax.com:

Paul, If you want really nice finishes, PCD or diamond coated tooling is the answer in aluminum. Not cheap, but they will last forever.

Reply to
Anthony

Does "crusty curmudgeon" equal "Grouchy old bastard"? If so, I resemble that remark.

Reply to
alphonso

Hanita has some FAQ type info here that you might find useful:

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A friend has been using roughing end mills with his manual mill on aluminum recently and has been pleased with how quickly they work compared to standard end mills.

BTW, I'm planning on ordering a Tormach mill soon myself. Did you get the Tormach stand with flood coolant pump? That might help if you need to remove a lot of material.

Mike

Reply to
Mike Henry

I used to have an aluminum part I would in batches on a cnc knee mill with a

2 hp motor. It had a 2" wide x 1" deep slot 11" long down the middle. What got me the most metal removal for the money, using a clamp on amp meter to max out the motor current, was a standard 3/4" ferrous rougher. I ran it at about 2700 rpm with a variable speed belt drive. That gave me a good torque match for the motor and with flood coolant blasting the chips out of the way it did amazingly well. Without flood coolant or air blast to remove the chips you really slow down from recutting the chips. I also tried a Hanita aluminum rougher in the same size. It didn't work as well. It was easy to tell that if I had the horsepower and rpms it would have been a great choice. However the standard fine pitch rougher did a better job with the low horsepower.

Gary H. Lucas

Reply to
Gary H. Lucas

Yes I got the stand and coolant pump so I have flood coolant. I had to increse the height of the splash guards so every one and every thing in the shop did not get a shower ;-)

I would reccomend that you buy the stand as it would be hard to reproduce for what they are charging.

I'm very happy with my mill. I would make the purchase again in a flash. it was not perfect, but I believe that I got more than my moneys worth.

The only negatives at all are:

1)The mill had a broken door latch on the electrical cabinet. (Broken when I received it , replaced quickly with no hassles under warenty.)

2)The VFD would sometimes trip off if you decresed the RPM too fast with a large tool in the spindle.

A simple adjuatment pot fixed that issue.

The stand itself had several minor issues....

3)They relocated the Y axis cableing on the mill and The version of the cabinet did not match so I had to cut a small hole.

4)Some of the splash guard bolts were difficult to get in place, one either needs to have a set of metric hex drivers that you can put on a socket extension, or you need to replace the SHCS with philips screws. since my junk box is a bit light on metric hardware I needed to buy some a metric hex drive socket to get the bolts in.

Reply to
Paul

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Reply to
Mike Henry

snipped-for-privacy@Rasdoc.com wrote in news: snipped-for-privacy@4ax.com:

Paul,

Have you considered Z-axis roughing with a drill bit?

It might make best use of your R8 spindle's limited side load capacity and HP.

G'luck, Paul

Reply to
Paul

Hey Anthony, along those lines, we have started using quite a bit of PCD tooling - largely from your recommendation. It has worked out very well for us, even though our particular application is not necessarily ideal for any cutting tool. We have a very high volume production part that is made out of 2024 AL, that needs a reflective surface on one of the faces.

Our speeds, feeds, and depth of cut is not really optimal cutting conditions, but it is what we found works. We run 8000 rpm on a face starting at .375" diameter and going to .650" diameter, feed .0005"/rev. with a .03125" nose radius, and take about a .002"-.003" depth of cut. This ends up with nice results for us, although with PCD inserts, after about 10,000 or 20,000 parts, we start to get poor results. So we tried a TFD insert (chemical vapor deposition sheet of some type) from SP3 Diamond Cutting Tools, and we have had much better edge life so far, as well as better surface finishes.

Thanks for steering us that way, we are now using both types for turning as well as boring applications, with outstanding results.

Another particular job that it has worked out well on has a bore that is finished after a 4-48 cross hole is roll tapped through the side, and standard carbide boring bars were leaving a burr in the threaded hole. PCD bars leave virtually zero noticeable burr of any kind. That's super nice.

Reply to
Bryce

Bryce wrote in news: snipped-for-privacy@4ax.com:

Bryce, The grade of PCD will have an effect on the finish. For roughing or normal machining, a coarse grade is better, as the larger diamond particles last longer. But, with larger diamond particles, the binding agent breaks down at the cutting edge between the diamond crystals, leaving a rougher surface finish. A smaller (finer) crystal size will help this considerably. Check with GE and Debeers for a fine-crystal PCD blank. This may be the reason TFD is outperforming the PCD in this application. Edge prep on the diamond also makes a difference. Relief angle plays a major role also. That's an itsy-bitsy radius for trying to get a mirror finish. If you can get to the part with something along the lines of a 0.120" radius you could speed up your feeds considerably and maintain the finish. It will impart a bit more load into the cut as your surface contact area is larger.

Your welcome. I just try to help.

That is one NICE thing about diamond tooling, it cuts CLEAN - Meaning it actually cuts instead of just mashing it out of the way. I'll also bet you don't make many (if any) adjustments during a run either. Consistency is it's other enduring trait.

Reply to
Anthony

Unfortunately, our part geometry barely lends itself to 1/32" radius. These are screw machine parts, dontchaknow (.650" part OD). Our failure indication is actually a chatter problem, which even with a new insert, is evident at our current feedrates if we take a lighter or a heavier depth of cut. Just had to play around for awhile, but everything is working great now.

Only for temperature, which depends on which axes of our swiss machines we are using to position the tool (or part). The longer the axis travel, the more temperature changes become a factor. We're in a new building with a much bigger shop recently, and the ambient temperature doesn't change as much. :-)

Reply to
Bryce

Thanks for that - it could come in useful. My only mill at present is a Clausing 8520 (1/2 BP size) with 3/4 HP so 1-1/2 HP is a significant step up for me.

Mike

Reply to
Mike Henry

Bryce wrote in news: snipped-for-privacy@4ax.com:

Bryce,

You might want to see if the insert can be prepped with a wiper. We did a turnkey a while back on an aluminum casting that had a taper that was a sealing surface.

It was a very high volume part so by having the insert prepped with a wiper we were able touble the feed rate. It was also a fairly light DOC and we were restricted to a small radius due to the part geometry.

I want to say it was Kennametal that provided the inserts but I don't remember for sure.

Note to Cliff: Yes a wiper will work on a tapered surface. It just needs to be lapped on the proper angle.

Not that the note will prevent a hundred posts, but one can dream, eh?

Reply to
D Murphy

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