[kentavv]

Is it possible to step the Duality Lathe like the 4-th axis table? In videos I've only seen the Duality Lathe spinning or locked down. I'm just wondering if it is possible to "get by" with the Duality Lathe if the 4-axis table is also are needed.

Thank you

[howecnc]

I believe they already have that as an option. Now they need to make the new speeder into a right angle head and they could have a full mill turn.

[Freddy Bastard]

Yes, you can add that option to add 4th axis capabilitys. But... I'm really disapointed with the performance of the duality. That was my worst investment.

[kentavv]

Freddy would you please elaborate a bit on your experiences? I'm mainly only interested in the Duality Lathe as an alternative to a full CNC lathe. Do you have the 4th axis rotary table? Was that a better investment for you? Thank you.

[bobeson]

I have a duality lathe, and I've stopped using it for CNC operations. Now it's a regular mini-lathe, which is somewhat handy to have at times, since I have no other lathes. However, like Freddy, I consider my duality to have been a poor investment overall. While I did learn CNC lathe programming, and was able to produce a number of parts using the lathe, the overall experience was one of great frustration. Given that I paid about $800 more for the Duality than a similarly equipped mini lathe would sell for, I consider this purchase to have been a fairly useful hands-on training class, but I wish I had a decent CNC lathe capability at the end of it all.

I think the biggest problem stems from the utter lack of torque available from the motor, particularly at the slow speeds that anything over 1" swing requires. When using these lathes in manual mode, your are using force feedback from the handles to ride the fine line between rubbing and cutting the miniature-scale chips that the lathe is capable of cutting. When you are programming CNC toolpaths and thus chip loading in advance, if you don't know exactly where that exceedingly fine line is, you stall the motor. When the Duality lathe stalls, the spindle motor stops but the rest of the machine does not stop, so your tool then gouges your workpiece, every time. And you might break your tool, too, depending on how quickly you can hit the e-stop. Small parts made from soft materials like brass or aluminum can be cut, no doubt about it, but I'd much rather use a real lathe.

[Greg Riach]

Thanks Freddy and bobeson I was seriously considering one but wanted to get some hands-on experiences before I committed to buy one.

Greg

[LENS_CAD]

I agree that the lack of power of the duality lathe limits it. Perhaps a better motor could be installed.

I did some production runs of several hundred 1/4" dia 304 stainless steel parts which were quite sucessful. I have also cut mild steel of 1-1/2" dia. I found the key is to make many light cuts, .005 to .010 deep.

[davidperry3]

I found it just was not rigid enough (on top of not enough power) I never could get a good finish on 1018 steel and ended up finding a way to do those parts on the mill itself. It did teach me but what it taught me was to find a way to do it on the mill. I have never bothered with it in manual mode. I do like the basic concept and think Tormach could make an inhouse design that would be very useful.

[flick]

Right! Doing coarse threads up to a shoulder is always slow, nerve-wracking or both. radii need a different tool for each size, and large ones chatter, so a radius fixture becomes necessary. If there is more than one or two angles on a piece it means messing about with the taper attachment and/or wrenching on the compound rest. And there's no power feeds on the compound rest, so getting a good finish is an art... etc, etc, etc.

Point being that although a CNC lathe doesn't make impossible things possible the way a CNC mill does (think surfacing with a ballnose) it makes really difficult or impractical things quick and easy, which is virtually the same difference in the real world.

[flick]

Anywho, that's enough hijacking for me... back to the OP's question: I've got an 8 inch 4th and it works well. If it's still shipping with the round bottom clamps, throw them out. They'll peen your table surface. Use normal strap clamps and step blocks or, better yet, machine slots directly in the base like I did. On the back side you can tap some holes and mount an angle plate for extra stability.

Without ever having used the duality, I'd say it's only good for tickling aluminum micro parts.

[Don Clement]

To me threading would be the first thing that comes to mind that a CNC lathe would be good at solving issues for. A good example is in the last week I needed to machine some male ISO 98mm-1mm threads 0.2” depth up to a shoulder. For some reason my thread milling (TM) software would not let me TM a male ISO 98mm-1mm thread on the Tormach mill. On my manual 12x36 lathe I can thread imperial male threads up to a shoulder using the thread dial and split nut. But because my lathe has an Imperial leadscrew cutting metric threads prohibits the use of the split-nut and thread dial. In addition to not being able to use the split-nut and thread dial when threading metric I have to change some gears by hand on the gear banjo, a PITA. On my manual lathe threading male threads of imperial pitch up to a shoulder is a difficult process anyhow as either the undercut before the shoulder needs to be long enough to allow time to release the split-nut or spindle speed has to be slow enough to allow the split-nut to be released before running into the shoulder. ( BTW my Sherline lathe has a hand crank for threading but that is another story altogether.) I always find that the speed is too slow for a decent surface finish using my Vardex full profile carbide threading inserts using the standard method of threading towards the headstock on RH threads. The exception to adequate surface speeds in threading on a manual lathe is threading internal RH threads using the reverse helix method where the feed is towards the tailstock. I can thread imperial internal RH threads from a blind shoulder at maximum spindle rpm using the reverse helix method on my manual lathe. But that doesn’t help with external RH ISO threading up to a shoulder on my manual lathe. My solution was to make the part containing the 98mm-1mm threads in two pieces with a smaller diameter part that used UN3.5”-24 threads up to a shoulder that I could cut on my manual lathe and the ISO 98mm-1mm threads not being up to a shoulder so they could be threaded without needing the half-nut. I held this piece containing the two threads types on a 5C internally expanding collet that would hold pieces internally with a 3” diameter hole in it. When the piece was completed it screwed into another piece with female UN3.5”-24 threads so that the 98mm-1mm threads 0.2” long were up to a shoulder. The moral of this long story is to either find the right software to TM on the Tormach PCNC or to get a CNC lathe rather than design the part to fit the machining process using a manual lathe. Oh BTW this part would have streached the limits of the small duality lathe. I made this part on a 12x36 manual lathe with 5C capablity.

Also there were also some complex shapes turned into this part on my manual lathe that were made using two different tools; An Iscar Do-Grip grooving/cut-off tool http://i72.photobucket.com/albums/i1...GripChip-1.jpg and a specially ground HSS form tool bit. This part would have been better made using a single profiling tool such as Iscar Cut-grip tool http://www.iscar.com/ProductLines/Pr...LineDetailID/1 ( the lathe equivalent of a ball end mill) on a CNC lathe. Not everthing can be done on a CNC mill. Some parts are best made on a large CNC lathe with 5C collet capability.

Don

[Scott_M]

For some reason my thread milling (TM) software would not let me TM a male ISO 98mm-1mm thread on the Tormach mill.

Don
I have been using Advents software for threadmilling. LINK It is very nice. Rather complex at first but spend a little time with it and it is great. I had to choose "ISO Special" and then put in 98x1 for threadsize and it properly populated the major and minor fields. You can also specify abs. or inc. Toolpath center or edge ( it uses cutter comp on all outputs ) so you can easily take a second cut by adjusting the comp.
It has many tools to choose from but I did not see any single point cutters. If you are using a single point there may be a little copy and paste to do.


Scott

[flick]

Don
I have been using Advents software for threadmilling. LINK It is very nice. Rather complex at first but spend a little time with it and it is great. I had to choose "ISO Special" and then put in 98x1 for threadsize and it properly populated the major and minor fields. You can also specify abs. or inc. Toolpath center or edge ( it uses cutter comp on all outputs ) so you can easily take a second cut by adjusting the comp.
It has many tools to choose from but I did not see any single point cutters. If you are using a single point there may be a little copy and paste to do.


Scott

Perhaps you could just throw an L word on one line? Or does the software output the main cutting helix as several lines?

[Scott_M]

I just looked at the program again.
You can specify Cutting length of the tool and dia. so for a 20 pitch thread I put in .050 as cutting length and it output the correct toolpath.
So there is a workaround. Specify tool params.
There are a lot of options and it takes a while to figure them all out. But it is nice. You can even specify how many degrees of leadin /leadout you want. start angle , overlap, tool # offset#, material , number of passes.

check it out

Scott

[Don Clement]

Thanks Scott. I was using Vardex TM software version 12.0.2 with a TTS modified Vardex TM075 holder and 3E1.0ISO insert. http://i72.photobucket.com/albums/i1...dification.jpg For some reason the software didn’t produce code that would run a complete thread milled circle on my Tormach PCNC with Mach III. The same software did produce code that runs good code for a ISO 60mm-0.75mm external threads see: http://i72.photobucket.com/albums/i1...ng60mm_1mm.jpg (Note the use of yet another 5C chuck with internal expanding collet) and good code that runs internal threads for ISO 98mm-1mm threads. I didn’t have time last week to troubleshoot the code or figure out how to get SprutCAM 7 to generate the code. Perhaps later this week I but I have too many things to do first. In any case the manual lathe workaround did work well after I redesigned the part to be threaded on a manual lathe with Imperial leadscrew.

Don

[twocik]

Don awesome job !


I owned a 7 x 10 mini lathe and took it right back. The motor was extremely weak and stalled quite a bit on normal cutting passes. Smaller work it's great, but anything over 2" it started to show its weakness. I bought a 9 x 20 and love it. The cross slide is a little sloppy and needs to be replaced but for the money it was worth it. I was curious if I could get my 9 x 20 on the table, but I think I'd need to make an adapter plate. I wonder if you they could make a lathe that would do both 4th axis work and turning....

[g29cc]

Thank you for the input on the duality lathe. I was looking at those because it seemed like a really nice idea/concept.

[Don Clement]

The ignore button,...

After sifting through so many extraneous posts it’s getting harder to find.