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What do you gents think of an OmniTurn?

DocsMachine

Titanium
Joined
Jan 8, 2005
Location
Southcentral, AK
I'm looking at an OmniTurn GT-75 to add to a currently almost-all-manual small shop, to be used for short-run production. (50 to 200 parts per run.)

It's a Series II but has a Gen4 control, about 500 hours. (On the machine or the new control, I don't know.) Machine looks clean, but is on the opposite coast so a personal inspection is impossible. Coming from a machinery dealer.

I've been looking at it as almost all of my parts are small enough for 5C or small pot chuck, the weight and footprint fit my small, cramped shop, and as I don't have proper 3-phase, I like that it can natively take single phase.

I put a WTB in the wanted section here, with no offers. (Well, except for a scammer. :)) Is it that nobody has OmniTurns, or that no one with an Omni wants to sell it?

From what I've read they seem well-regarded, and should be able to do everything I need it to do (1" and under aluminum, max of 4-5 tools, etc.) Is there anything I should know beforehand, or to look out for on a used example?

Doc.
 
I have 2 converted machines with Omniturn slides and controls. The slides are ideal for 5C class work. I have done a few parts with larger collets with a Hardinge closer. I would not like the idea of taking larger cuts with an unsupported collet at high RPMs. Centrifical forces would tend to open the collet and let the part fly. Assuming the the GT-75 has a long lived precision spindle it should be a low running cost machine. Can not take huge cuts but part to part precision you can hold plus 2 tenths and minus 1 tenth all day long with free machining materials and a good set up.
Between the 2 running machines in 25 years I have spent about $2000.00 on repairs. Gotta a third conversion machine that I have not had time to finish the spindle motor mount. That is on me though.
Support has been very good.

I have seen a few posts on you tube of jobs running. Mostly i see a lot of room between tools with wasted time going from tool to tool. Pack the tools close and minimize the wasted time, wear, and tear.

1/2 dog screws being run https://youtu.be/FuieVnLx7WY
 
Nice video. I liked how you had oil piped through the die head. Good way to both lube and flush chips out.

This would be their complete machine, not a refit, though I understand they more or less use the same software. Any quirks I should be aware of?

I don't think the pot chucks would be an issue- the GT-75 has a Hardinge taper nose, and if I were to use a 2" or (unlikely) a 3", I'd use the outer taper closer unit. But even 2" would be rare- as I said, the bulk of my products are 1" and under.

On the tool spacing, I've seen kind of the same thing in some of the videos, but I attributed that- right or wrong- to the operator keeping the spacing open in case they did switch to a chuck or larger collet.

In any case, I would not be overly concerned with trying to shave too many seconds off a cycle time- when you're only making 50-60 parts, it's almost irrelevant. And really, anything would be an improvement over cutting 'em manually. :)

Doc.
 
I have 2 converted machines with Omniturn slides and controls. The slides are ideal for 5C class work. I have done a few parts with larger collets with a Hardinge closer. I would not like the idea of taking larger cuts with an unsupported collet at high RPMs. Centrifical forces would tend to open the collet and let the part fly. Assuming the the GT-75 has a long lived precision spindle it should be a low running cost machine. Can not take huge cuts but part to part precision you can hold plus 2 tenths and minus 1 tenth all day long with free machining materials and a good set up.
Between the 2 running machines in 25 years I have spent about $2000.00 on repairs. Gotta a third conversion machine that I have not had time to finish the spindle motor mount. That is on me though.
Support has been very good.

I have seen a few posts on you tube of jobs running. Mostly i see a lot of room between tools with wasted time going from tool to tool. Pack the tools close and minimize the wasted time, wear, and tear.

1/2 dog screws being run https://youtu.be/FuieVnLx7WY

Nice work Fred. Is the air collet being operated by a switch and a dog on the table or something?
 
Doc, this machine is a Hardinge AHC with a kit. Machine was put together and painted for a show. Fresh zinc plating on the chip pans and drawer. But I bought it first so it never made it to the show. The control you get will be the generation 4. I have that on the new kit but have not plugged it in so I do not not know of the changes yet. Most programming is backwards compatible from them so I expect no real issues.
Spacing is different when deep drilling second operation parts compared to bar work. Setting all the tools the same length helps prevent crashes. Both my die heads are much longer than the rest of the tools. Be aware to prevent crashes, especially with the diehead closing arm. It will be in a different place when the diehead snaps open. Learning good tool placement even though not necessary for real short runs will pay off when you are doing a couple thousand pcs.

Volitan, the AHC had automatic closer from Hardinge. Opening and closing is done in the program. One thing you do not notice while watching is I drop the spindle speed to 200 RPMs when feeding. The 5C does not release as cleanly as B&S style. Low RPMs feed better than a dead stop even if you have perfect bar feed alignment.
 
You probably should name the dealer to see if anyone has done business with them and their experience.
 
Citizens' point is well taken, there are a few bad actors out there, but then if you tell us who the dealer is, someone might beat you to it if the dealer is reputable.

Doc, you asked about points of concern. There are lots of slant beds out there. Never figured out how those guys running them level out their boring bars. On the "flat" style I just lay a small insert or 1/8 pin across the flat and turn it till it is level then tighten the screw. With any slant bed you will have to have a different plan.
 
The dealer is Mullin Machinery in New Jersey. Checking the ad, it's actually a Series I, but is definitely a Gen4 controller.

Apart from a ratty one on eBay, that's the only one I've found for sale.

Never figured out how those guys running them level out their boring bars

-I'm assuming you mean the tips? If one has individual gang-bars set up, as noted, for different jobs, why not set it up on the bench? (Or rather, on a surface plate.)

Doc.
 
The dealer is Mullin Machinery in New Jersey. Checking the ad, it's actually a Series I, but is definitely a Gen4 controller.

Apart from a ratty one on eBay, that's the only one I've found for sale.



-I'm assuming you mean the tips? If one has individual gang-bars set up, as noted, for different jobs, why not set it up on the bench? (Or rather, on a surface plate.)

Doc.

Yes, almost a five month old post.....
Marcus is a nice guy and honest too. I've done business with him before he moved to his current larger warehouse. His descriptions are accurate.
 
Since this has been brought back up, here's an update:

Ordered the machine first week of August, had it in the shop and wired by the second week of September. Mullein was indeed a good guy to deal with- he shipped when he said he would, included everything he said came with it, and crated it very solidly. Arrived at the Other End Of The Planet intact and with no issues.

omniturn003.jpg


It did, however, need some cleaning and comparatively minor maintenance. The worst issue was the corrugated, flexible "conduit" that protected the wires from the controller to the X servo, had come loose and was hanging. I replaced that with fresh stuff from McMaster.

I scrubbed a lot of the crusted old coolant residue out, and repaired a couple of the pneumatic hoses (mainly replacing ones that had simply been patched with butt-connectors earlier on)...

omniturn018.jpg


Rewired it from 3Ph to 220v single (no native 3-phase) added some detail bits like better feet, grommets for a lot of the cables where they came through the sheetmetal, and new machined rings to hold the regulators since the old plastic ones had apparently broken, and the regs held on by zip-ties.

omniturn042.jpg


I replaced the old, nonfunctional fluorescent work light with a new LED...

omniturn046.jpg


Reworked the coolant nozzles...

omniturn064.jpg


Cleaned and regreased the slides and screws...

omniturn078.jpg


And, most importantly, as somebody in the mists of prehistory for some reason peeled off the "II" in SERIES II, I upgraded the machine to a SERIES X. :D

omniturn090.jpg


I then dumped ten gallons of Mobilmet 426 cutting oil in, taught myself how to sorta-kinda program the bloody thing, and started running parts:


So far it's been nearly 100% reliable, with the only issues being in that part run, in around 200 parts, it stopped twice. Both times in the same spot- just feeding in the last grooving tool. Spindle stayed on, coolant stayed on, no error messages on the screen, just motion stopped.

I used the 'motion stop' and "ESC" to end the cycle, jogged the tool out, re-homed the axes, and re-ran the part both times. Other than those two times it's been perfect. Dimensions and thread fit on the last part were as good as the first. OD on the turned portion on the first one was 1.0000" according to Mitutoyo calipers, and 1.0000" on the last.

Doc.
 








 
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