[c131fr]

I am a newbie in its truest sense. I have been using CAD software for years, but all I do is design the part, save it to disk, and give it to the machinist.

I want my own CNC machine to mill parts out of stainless steel. The parts will require a 4 axis machine, but are fairly simple. I am not rich, and this will be for my hobby, but I must make my parts out of stainless steel, unfortunatly. I have access to some pretty spiffy CAM software, and I'm told that it will generate my tool path for me, and all I need to know is my tool size and material to be milled (for rate, etc.)

Taig claims their machine will mill stainless with no problem. They say I need to buy a 4 axis from somebody else, but when I do, I can put a part in before I go to sleep, and by morning it will be completed with an accuracy of .0005 all the way around.

I posted a pic of the part. It's a fan disk for a very small turbine engine. An expert machinist who works with me stated unequivically that this part only requires a vertical mill with a forth, rotary axis.

I see folks here machining plastic, wood, and aluminum, but not much talk about steel. I am not interested in mass producing parts. I don't care how long it takes. But before I slap down two or three grand on a 4 axis Taig setup, I want to know from a non biased expert (you guys) if their machine is up to that task. If it isn't which one is?

Thanks in advance. I really appreciate you reading this long post.

[c131fr]

Okay, maybe I didn't post a pic. How do I do that???

[Cold Fusion]

Cnczone doesn't allow big pictures. Just email it to me and I will host it for you.

[Cold Fusion]

[c131fr]

You're a gentleman and a scholar Cold Fusion. Thank you very much.

As you can see from the close up, this part was CNC milled. The piece is 6" in diameter. This particular piece is made of titanium, however I'm poor and will prabably use stainless. The parts I want to make have slightly different angles and sizes of the blades, but the basic configuration is as shown.

Well, anybody know if the Taig machine is up to this task? If not, is there a hobby cnc mill that is? Thanks!

[Cold Fusion]

No problem C131fr. I'm happy to help anything from this board (all of whom have been extremely helpful when I was first starting).

[JOE65]

From the look of the machine specs your a little short on y travel

I.m not sure how this could be over come?

MACHINE SPECIFICATIONS:
Maximum Travel Speed: 30 in/min.
Maximum Travel: X = 9.5", Y = 5.5", Z = 6.0"

[JOE65]

Maybe your 4th axis overcomes this??

[Jcadwell]

I've got a taig. I don't think .0005 is quite accurate. Mine works well to about .001. Twice as much. I could tighten the nut down more, but you get to the point where the included steppers either can't run the machine or you tear things up because the motors are working harder. Because all of the Taig's adjustments increase friction of sorts (the ways have a tapered piece that tightens or loosens and the leadscrew nut has a brass screw that opens and closes) you run into issues as you try to go faster and with higher accuracy. I find that I can get 15 IPM on all axis with repeatability of about .001. If you were to go with a ballscrew you could be significantly faster with the right motor.

I would buy Taig's CNC ready machine and add your own motors and drivers. You will be ahead in the long run. Taig's motors are unipolar, and the included drivers are phase drive, not step/direction, which limits your driver software options.

I would buy Geckodrives and bigger unipolar steppers.

The only other beef with the Taig is proprietary collets. They limit you to a 5/16 tool diameter, which means you can't use 3/8 tooling which is VERY standard. You can work around this, but you need a lathe. Buy a bunch of taig's spindle blanks and you can bore tool holders to whatever size you want. I have a fly cutter with a 1/2" shaft in one and it works great.

The spindle motor as supplied is on the weak side. (1/10 HP) The speed drive is adjustable by pulleys and my motor won't start the spindle every time at the fastest setting. Once it is moving it isn't a problem. For the slow spindle speed you would want it isn't a problem.

The taig will cut steel without any problems. Just go slow. You will probably also need a reflow coolant system to do that.

I wouldn't hesitate to buy another one if I had a need. It is a sturdy machine, and I haven't had any problems with the actual operation. I would build my own control system around their CNC ready mill if I could do it again.

[teilhardo]

I'm trying to make turbine blades to on my taig. see my website for details. i was optimistic when I first got the mill too but it has proved to be a pretty daunting task. maybe both of us together can figure out how to get a taig mill to make SS parts!
-Tei

[kong]

i have just got rid of my Taig lathe, since it was too wimpy. Depth of cut was tiny, I only turned mild steel a couple of times, butthe finnish was poor. Obviously lathe and mill and different machines, but a lot of parts are the same. If I had my time again, I would not have bougth the Taig, and would have gone for a bigger machine instead. I reckon you should takle a look at www.homecnc.info and check out his cnc-converted mill.

[c131fr]

Originally posted by teilhardo
I'm trying to make turbine blades to on my taig. see my website for details. i was optimistic when I first got the mill too but it has proved to be a pretty daunting task. maybe both of us together can figure out how to get a taig mill to make SS parts!
-Tei

I see you cut out your diffuser. Very nice work. It looks like the clearance between the compressor and the diffuser is a bit too generous though. Is that just an optical illusion?

I actually have build several turbines before. Did you see Junk Yard Wars when they made jet trikes? The one with the afterburner was my design. The guy who built the engine, Chris Krug, is a good buddy of mine.

Do you plan to spin your casing? I found a place that sells a 6"X6"X1" plate of Inconel for $115.00. They say it machines like any other stainless. I planned to cut my turbine into it. Inconel ratains 75% of its strength at 1500 deg F, and thus doesn't require supplimental cooling. Pretty neat stuff.

After looking at the homecnc.info site, I gotta tell you, making your own really looks like the way to go. I don't know. I kinda like the fact that the Taig is pretty much ready to go.

Well, thanks for all the input, and I welcome more if care to give it. When I do make my decision, I'll fire up a web site so you guys can see what I'm up to and maybe lend me a hand. Thanks again.

[ESjaavik]

Check that the kind of stainless you want to machine is not work hardening. Then you cannot just downscale your cut. It will just harden the steel and then that's how far you got. I understand you have machinists in your company, ask them for the full story on tiny cuts in work hardening materials.

[c131fr]

Originally posted by ESjaavik
Check that the kind of stainless you want to machine is not work hardening. Then you cannot just downscale your cut. It will just harden the steel and then that's how far you got. I understand you have machinists in your company, ask them for the full story on tiny cuts in work hardening materials.

Okay, thanks. I'll ask, but have you got any suggestions? The only thing this part will be doing is compressing air, so it doesn't have to be terribly rigid. Most production pieces of this size are made of titanium, but that is mostly for weight. Is there a metalurgical table somewhere that lists hardening properties?

Thanks again.

[JFettig]

I really have a lot of doubts in that machine, first of all, the spindle motor. not nearly enough for anything more than aluminum(unless you take tiny tiny cuts) but stainless, thats even worse than regular steel.

I would suggest you looking into a much bigger machine, you will be glad you did. If you check out the machine at homecnc, thats what I would be looking at if I were you. I wish I had the space and all for one rather than my homier mini mill retrofit.

$2000-$3000 is a lot for one of those little mills, I did my complete conversion and everything for under $2000 and got a much better machine than one of those aluminum taig mills. I have run a sherline at school once apon a time, and that was horrid.

If your really set on one of those mineature things, check maxnc. I dont know if they are better, but its just another option.

Jon

[TyRex]

True, but the minis and the one on Homecnc are only 3 axis......while he needs a 4 axis

[c131fr]

Originally posted by TyRex
True, but the minis and the one on Homecnc are only 3 axis......while he needs a 4 axis

I talked (emailed) Jeff Davis and he thinks that a 6" rotary table I found could be used as my 4th axis. I'd have to convert it, or course, but I think I can do it. I'm thinking of really doing something radical. Look for future posts. :idea:

[JFettig]

yes, you have it right, you need to add a rotary table, either a cnc one or retrofit it. I think that will be one of the next addons to my cnc.

Jon

[marjamar]

We just bought a Taig mill CNC ready. I put USDigital MS23 steppers on it and got a DenverCNC 4 axis driver. The driver was to low on current, so I have to put together a gecko system. I'm looking at using a 300 watt 48v power supply as I will also be using a rotary table.

We also bought a shurline CNC ready mini lathe to do whatever else was necessary that the mill couldn't do or do as well as a lathe would.

Still setting up and testing, but using the mill the little I have so far, it seems to be very accurate, better then 1000ths of an inch I would say.

-Rodger

[bean7795]

inconel is a lot like 340 s.s. but kinda sticky on a lathe but when you machine it watch for heat it will melt carbide emills down in a hurry if you let one get a little to dull and keep running it