[CNCAuburn]

So can this thing hold at least 7 tenths on .5" ID or even a .375" ID bore. I'm machining aluminum at the moment and would like machine stainless as well-I'm guessing no on the stainless with this machine. What kind of surface finish are you guys achieving?

I'm prototyping right now on a manual lathe. These are small parts, and I have bearing seats to deal with, and I'm currently using a roller burnishing tool on the seats to get within 0 to .0003". I may investigate honing as well, but there are benefits to roller burnishing such as finish and cold hardening the seats. It takes me a little while to make these parts by hand. I eventually want to produce parts. I have been looking at used 20 year old big CNC iron. Only problem is finding one local at a good price and fitting it in at my house until I can get an industrial space--about 1.5 years away. Just moving 10K lb lathes cost about $1500.

My hope would be to use this lathe to speed up my prototyping at home and do some small productions runs eventually in 6061 and 7075. I have been looking for a good used gt27, but they are fetching pretty high premiums at the moment. I live in No. California.

[adamvs]

My experience is it should easily hold 7 tenths. The trick is to approach critical diameters cuts from the same direction as you zero the tool on the radial ( X ) axis. Otherwise you encounter backlash, which is inherent in an open loop tool. Same is true on the Tormach mill. If you have say a hole pattern and setup your strategy such that all holes are approached from the same direction on the lead screws, the thing gets freakishly accurate. But on diameters that small, why not use a chucking reamer. The machine has 3 HP to spindle so I don't see why stainless should be a problem. BTW, I also live in NorCal up in Marin.

[CNCAuburn]

Thanks for the prompt response. I have tried reaming bearing seats with mixed results. I have found roller burnishing to be the best/cheapest solution so far with the added benefits of work hardening the bearing seats and leaving a very fine finish. As far as reaming and then roller burnishing,it is not not recommended as it leaves tears that are hard to remove with the roller burnisher. It is recommend to use a boring bar to get the proper surface finish.

[adamvs]

Agreed, I've used roller burnishers before for the same application. As I remember we were holding 2 tenths in cast aluminum, no problem over runs of several thousand, with all the benefits you mentioned. I didn't know you could get them that small, but cool! The Tormach, for the money, is a great prototyping / short run tool. For long runs you might be bugged by the rapid speeds ( they are steppers ). They have come out with a tail stock also. My main complaint, as I've mentioned is with SprutCAM, which is still pretty buggy, but is usable and generates good code. I've been using my own post-processor so I can have both gang tool and QCTP working on the same part. Here's a cheesy video I made for a coolant fitting:

[CNCAuburn]

Agreed, I've used roller burnishers before for the same application. As I remember we were holding 2 tenths in cast aluminum, no problem over runs of several thousand, with all the benefits you mentioned. I didn't know you could get them that small, but cool! The Tormach, for the money, is a great prototyping / short run tool. For long runs you might be bugged by the rapid speeds ( they are steppers ). They have come out with a tail stock also. My main complaint, as I've mentioned is with SprutCAM, which is still pretty buggy, but is usable and generates good code. I've been using my own post-processor so I can have both ave ave gang tool and QCTP working on the same part. Here's a cheesy video I made for a coolant fitting:

Thanks, great video! You are starting to win me over more.....Can it handle stainless 303 or even 304 and 316?

The benefits of running a small machine at my house without annoying my good neighbors is a big plus as well.

Yeah, my smallest is a 0.375" roller burnisher (off ebay, almost new) and I believe they go even smaller. It is adjustable by 0.0001" increments. Just getting the correct suface finish and proper dimention to start with for the burnisher can be trying on my manual lathe-lots of scaped parts.

Also, is that coolant spash contained ok?

[adamvs]

Can it handle stainless 303 or even 304 and 316?

The benefits of running a small machine at my house without annoying my good neighbors is a big plus as well.

Also, is that coolant spash contained ok?

I haven't run stainless, but at 3HP there's plenty of power. It's more a matter of getting the right inserts and having an aggressive metal removal strategy so you can get the toll under any work hardening.

I run this at home also, and my neighbors are a concern. So far so good. As long as I'm not wolfing past 10pm and don't have Metalica going on the stereo, it's a fairly quiet machine. In fact they've joked about the weird noises coming out of my garage.

Tormach has done a good job about coolant splash. I did go down to TAP plastics and get a sheet of 1/8 clean vinyl and cover the open area by the headstock. I don't get any on the floor. It's a little drippy when you open up the shield over the cutting area, but they have a drip catcher that bolts to the front of the machine that gets it. I usually don't even open it, I pop tools on the QCTP back at the G30 point and leave the guard down.

There is one caveat and that has to do with zeroing tools. When you start the machine you need to 'ref' the X and Z axis. It does this by micro switches, which I've found to be off by up to .010 from one shutdown to the next startup. Ideally you should be able to adjust this out by re-zeroing on tool 1 by setting the work offsets. I've found the first part has been off on the X axis by as much as 3 to 4 thou, but the following parts come in, after that they are fine. ??? Not quite sure what that's about.

[CNCAuburn]

Thanks Adamvs, good stuff. Yeah, I live in the countryside where sound carries. Not sure if running a 20 year old 10,000lb Okuma would go over well....Although it might keep the deer away from my yard-that would be good.

[CNCAuburn]

So I'm looking at their website--they don't make it easy to figure out ( I don't really like that kind of selling, just be upfront), but it looks like the lathe does not come with any accessories, i.e., no chuck, no tool post (looks like you need to purchase a separate tool post plate), not even a gang plate. So after buying all that the price goes way up making the $12,200 lathe, after shipping, much more expensive. More like a $14000 to $15000 lathe just to get it running properly. Please correct me if I am wrong anyone.

[menzzer37]

It will do stainless. I've machined a bit of stainless and a LOT of titanium. Works great!

[300sniper]

I live in No. California.

Auburn, Ca? If so, I'm just across the canyon from you in Greenwood. I'm running a 20hp turning center off a 40hp phase converter in my garage. I can hear the buzz of the florescent lights outside but can't hear the machine or phase converter. Go figure.

[CNCAuburn]

That's great, I'm about 6 miles outside of Auburn. I might still look at a bigger lathe. Given the price on the Tormach seems to be going up and up the more I look at it, a used gt27 would probably be a good compromise given I can find one for the right price.

[BAMCNC.COM]

Good video Adam - Subscribed

Note: If you plan on running anything with "real chips/strings" then you need to run your tooling upside down- EASY don't think you have to reverse X in code or CAM or anything, can be done in the control for ZERO fuss (have a vid)

However the REF off by .010" doesn't sound right. I ASSUME they use the same tormach PCNC 1100 switches.. which are off by less than .001" UNLESS gunked up. At which case I have a video for the fix

[tmarks11]

Good video Adam - Subscribed

+++1. Thanks for posting it.

[mountaindew]

Looking good!
Nice setup and clean video, Adam.
md

[adamvs]

However the REF off by .010" doesn't sound right. I ASSUME they use the same tormach PCNC 1100 switches.. which are off by less than .001" UNLESS gunked up. At which case I have a video for the fix

Yes, .010" sounds way wrong. Could be a flaky switch. I doubt it's gunked up - it's a few moneths old. I've had to clean the Y axis switch on the PCNC 1100 a couple of times. I was watching your videos this morning. Nice! Keep'em coming. I'm going to write a 'warm up' program ( per your video - for both machines - ) which I'm thinking might help.

[kirk_wallace]

In my opinion, the proper way to set up homing switches is to have a index flag on the axis screw in series (or parallel depending on the switch configuration) with the slide switch. The slide switch gets you close, the screw switch gets you to the resolution of the stepper or servo encoder.

I suspect one should watch for backlash too. On a new machine, it might be wise to check the screw preload after the machine has been broken-in. Checking the gibs might be wise too.

[adamvs]

In my opinion, the proper way to set up homing switches is to have a index flag on the axis screw in series (or parallel depending on the switch configuration) with the slide switch. The slide switch gets you close, the screw switch gets you to the resolution of the stepper or servo encoder.

Kirk, this sounds good. What's available to do this - do you have a link? Can it be adapted to the Tormach?

[kirk_wallace]

Giving this more thought, I may have been a bit hasty with my original comment. I am more of a machine integrator than a machinist and the integrator says, if the machine has an accurate home then upon powering up the machine, and homing it, one can continue cutting a workpiece without setting the workpiece origin. The inner machinist says he wants to set the workpiece origin every time to make sure it is right. I am fairly new to Tormach machines and it seems that setting the workpiece origin is pretty easy. The other use for homing is to set the workspace soft limits. Since there is some space between the soft limits and the firm limits, the slide switches are plenty accurate.

Besides modifying your machine may interfere with getting support. At this point, I would need to study how the lathe is set up to find out how it could be made better, then try to decide if there is a clear advantage to making a change.

I looked for some links, but didn't really find anything. My HNC is based on this:
Homing Configuration
LinuxCNC Documentation Wiki: Homing And Limit Switch

[MichaelHenry]

I don't have definitive data, but the few times I've tripped an E-stop mid-job so that the axes had to be re-referenced the new part origin came out very close to the old one - just a few tenths off. Based on that limited data the limit switches seem to work a lot better for me than one might expect.

Mike