[Gerry Kmack]

A few weeks ago I received a new Tormach Duality mini lathe. After spending several hours cleaning the shipping goop off, I finally plugged it in & slowly turned up the RPMs. To my dismay, the lathe had serious vibrations - at all RPMs, but worse at some than others. I called Tormach customer service & after spending an hour or so checking out what I could over the phone, they decided to send me a new replacement. They also said that they would check the new lathe out before sending it. (Don't they do that for every lathe?)

Two weeks later, the new lathe arrived. I moved it to my shelf & this time immediately plugged it in & slowly turned up the revs..... While this new lathe is definitely better that the original (it doesn't vibrate at all rpms), it does vibrate - at approximately 1100 RPMs & again at near max speed (2600 RPMs). Even then the vibration is not as extreme as the original, but I am surprised to feel any vibration at all. I removed the chuck & experienced the same thing.

I called Tormach support once again, and they told me that the vibration is normal for this lathe. When I pointed out that I currently owned 2 (woodworking) lathes & had owned numerous others, which had never shown this kind of vibration, the tech said "well, that lathe is not really very accurate", and that what I was experiencing was indeed normal.

So - Is it normal for the Duality lathe to vibrate - with no load or chuck? Am I just expecting too much? I know the lathe is made in China - likely the same factory that makes the Grizzly, Harbor Freight etc lathes, so it certainly won't perform as well as say Tormach's new CNC lathe - but I do expect to use the lathe to fabricate parts (wood & aluminum) to within .002" tolerance. That's why I bought it.

Also - it it possible that the lathe just needs some tuning & adjustment? If so I'm game to try - anybody have any ideas?

Gerry Kmack
Cave Creek Woodworks
Pagosa Springs, CO

[mountaindew]

No experience with the lathe or ways to improve its performance. sorry
I do like the area where you live! No mountains like the San Juans.
Hope you get your new lathe working correctly for you!
Fellow tormach owner in SoCo
md

[MichaelHenry]

I replied over on the Yahoo Tormach forum, and will repeat here. Have you checked runout on the lathe spindle? Maybe the spindle bearing pre-load needs some adjustment.

Mike

[pickled]

I second MichaelHenry on this recommendation. I upgraded to an aftermarket 4 bolt 4" chuck (from the little machine shop folks) and adjusted the spindle bearing load a little hotter and my lathe has been smooth. Next month I plan on working on the anemic drive motor, but I can't complain about the runout.

[bobeson]

Sorry to tell you this, but as an owner of a Duality lathe, I have given up on using it for anything except simple manual-mini-lathe duties. If you have small set of part designs in soft material that you need to make regularly, you could probably tune this setup to produce what you need, after a bit of debugging pain for each part and different tools, etc. Overall, while I was able to eventually produce a fair number of acceptable parts on my Duality, I found the system implementation to be sorely lacking, as did a number of other Duality owners. If you search the archives here a few years back you'll find a few conversations that spell this out pretty clearly, but not in great volume. I think with some kind of new closed-loop control system and optimally-refurbished hardware, the PCNC & Duality could be much more useful, albeit still quite limited in function because it is simply underpowered and not stiff enough in cnc lathe mode. As it stands, the open-loop CNC implementation just isn't worth using, for my needs. I am planning to purchase a Tormach lathe, for whatever that's worth to you.
If you are finding the Duality not to your satisfaction, I would seriously consider returning it, if possible. I'm not a hater here; I'm still a satisfied PCNC owner, and I have plenty of confidence in Tormach as a company, but the Duality just didn't hit the mark, IMHO.

[Gerry Kmack]

Mike,
Thanks for the feedback. I just put an indicator on my spindle & measured ~. 0005" runout. Coming from a woodworking background, this seems pretty good to me, though I'm not sure if that is good enough from to a metal worker. In any case I am game to try adjusting the spindle bearing preload to see if that will reduce the vibration.
Can you point me to a reference on doing this? The manual seems more oriented towards using the CNC mode & does not address it. Thanks again! Gerry

[Gerry Kmack]

Thanks for the feedback - I was half expecting to receive your response (or one like it) as I am seriously rethinking my purchase of the Duality Lathe. On the one hand, my needs (& budget) do not really indicate a stand-alone CNC lathe, on the other hand, I bought this lathe specifically because I need to manufacture a variety of small, precision parts. Right now I plan to use it in manual mode, as I have not yet purchased a PCNC - but I do plan to use the Duality in CNC mode when my mill is installed.
I'm glad to hear that you are still happy with your PCNC, as my first contact with Tormach customer support has me rethinking that as well...

[Gerry Kmack]

Thanks Pickled - I have already found TLMS & will go back & check out their 4 bolt chucks. I'm also interested in your plans to upgrade your motor - please post about your progress with that when you get to it. Gerry

[SCzEngrgGroup]

I bought this lathe specifically because I need to manufacture a variety of small, precision parts.

Keep in mind, a lot of things you would normally do on a lathe, you can do just as well on a mill, putting the workpiece in the spindle, and holding the tools in a vise, or a fixture bolted to the table. I very rarely use my larhe, even for parts that would typically be done on a lathe. I much prefer doing them on the mill This works especially well for small parts.

Regards,
Ray L.

[pickled]

No problem Gerry. I have enjoyed my Tormach products and have had excellent support over the years from their group. I have yet to find how I could have received a better bang for my buck on any of their products- except for the Duality Lathe. I too bought it before I bought my milling machine as a "test the waters with Tormach" and was kind of like, "hmmm I hope I did the right thing". My spindle speed sensor was DOA and I didn't find out until my 1100 arrived 5 months later. The folks at Tormach took care of me and have been quite responsive since. After learning the nuances of the duality (light cuts and tail stock being essential for most designs) I was able to make some semi-complex parts that were decent enough for my prototyping needs (wood, aluminum, brass, UHMW and delrin).

Ray is spot on with using your tormach with an R8 chuck for runs of products with tough materials or simpler geometry that are also short in length. You can crank out spacers, contours and shoulders real quick on the pcnc in vertical lathe mode and they will be well within most tolerances. As I work on upgrading the Lathe's power plant I'll post how things are going. I recently used a friends mini-lathe that he had bought from the good old Harbor Freight and was really surprised how strong it was in comparison. I ripped through some Titanium and Stainless Steel on the thing and actually produced a good finish! If it is rigid enough to do this out of the box with an unmodified compound and tool post there is surely hope for our little late to improve. Constant surface speed and more torque would make the Duality a much higher value tool in my shed. Good Luck! Doug

[MichaelHenry]

Keep in mind, a lot of things you would normally do on a lathe, you can do just as well on a mill, putting the workpiece in the spindle, and holding the tools in a vise, or a fixture bolted to the table. I very rarely use my larhe, even for parts that would typically be done on a lathe. I much prefer doing them on the mill This works especially well for small parts.

Regards,
Ray L.

How well would that work for 3-in or a little larger diameter aluminum or brass? The parts are turned down to 3-in OD and faced on both ends to make an approximately 1-in long rod in each material. I generally turn these on the lathe at around 1700 rpm. Would that present a problem with balance of the material and/or spindle-mounted chuck?

Mike

[SCzEngrgGroup]

Mike,

I once turned a 12" diameter, 1/2" thick aluminum disc on my mill. Worked fine. I think a 3" piece would be no problem at all. My only advice would be to get a chuck with an integral R8 shank. I've seen 3-4" 3-jaw chucks with TTS shanks, and that scares me.

Regards,
Ray L.

[pickled]

How well would that work for 3-in or a little larger diameter aluminum or brass? The parts are turned down to 3-in OD and faced on both ends to make an approximately 1-in long rod in each material. I generally turn these on the lathe at around 1700 rpm. Would that present a problem with balance of the material and/or spindle-mounted chuck?

Mike

You should get yourself an R8 3 jaw and just set that type of job up in the PCNC if you there isn't a capacity constraint at your mill. I have turned and faced 4" aluminum round bar, 3" stainless and 2" titanium via the R8 mounted 3 jaw. It was s m o o t h and having flood coolant for the titanium was a big bonus because I hate the fireworks show that you get when your lathe's mister gets knocked out of position and you are the one at the helm dialing in the cut. Seriously though it is pretty slick.

[pickled]

Mike,

I once turned a 12" diameter, 1/2" thick aluminum disc on my mill. Worked fine. I think a 3" piece would be no problem at all. My only advice would be to get a chuck with an integral R8 shank. I've seen 3-4" 3-jaw chucks with TTS shanks, and that scares me.

Regards,
Ray L.

WOW you saw a 3 jaw mounted on TTS?!?! Man if that cut loose it would probably leave a mark LOL! Can you imagine someone just turning that thing up to 4000 RPM with the stock stand guarding configuration and putting their face up there as they are jogging with the keyboard to kiss the material....uggh!!! Talk about an uneasy feeling!

[sansbury]

The Duality lathe is nothing but a 7x lathe, variants of which start around $450 on sale at Horror Fright. The $450 version is better than it should be, but whatever Tormach adds that raises the price by $1000 doesn't change the guts. A careful user can turn out very precise work but not without patience or effort. I've turned 3" cast iron and 1.5" O-6 tool steel on my 7x with success, but neither was fun or fast. Last year I bought one of the ubiquitous Grizzly 10x22 lathes, and it's almost comical how much more effortlessly that moves metal. My real regret though was chickening out and getting the 10x when I had the room and money for one of the 12x36 lathes, which add a speed-change gearbox, QCGB for threading, power cross-feed, and bore to handle a collet closer. Add a DRO and you have a machine that can efficiently do any kind of work that fits on it. Or if you feel like shopping, $2-3k will get you into a lot of decent used older US-made lathes, though I understand there's fewer of those out West than we get up here in New England.

[popspipes]

The Duality lathe is nothing but a 7x lathe, variants of which start around $450 on sale at Horror Fright. The $450 version is better than it should be, but whatever Tormach adds that raises the price by $1000 doesn't change the guts. A careful user can turn out very precise work but not without patience or effort. I've turned 3" cast iron and 1.5" O-6 tool steel on my 7x with success, but neither was fun or fast. Last year I bought one of the ubiquitous Grizzly 10x22 lathes, and it's almost comical how much more effortlessly that moves metal. My real regret though was chickening out and getting the 10x when I had the room and money for one of the 12x36 lathes, which add a speed-change gearbox, QCGB for threading, power cross-feed, and bore to handle a collet closer. Add a DRO and you have a machine that can efficiently do any kind of work that fits on it. Or if you feel like shopping, $2-3k will get you into a lot of decent used older US-made lathes, though I understand there's fewer of those out West than we get up here in New England.

I had an Atlas 6" lathe for years and then bought a chinese 12 x 37, it moves metal as you say much better than the little Atlas did, it was just fine for small projects though except for parting off, that was always a problem on the little lathe.

The Chinese manual was about 3000 dolars in 1987, they are about the same price today.