Has anyone made or modified a turret on a lathe

Sam L · Oct 15, 2013

We have a lathe with VDI turrets. I am at the point now after 12 years with this machine, that I have to change the turrets or loose my mind. I asked the OEM for bolt on turrets and of course they gave me a ridiculous price. Now I am contemplating taking one of them off. Making a blueprint of all the dimensions. Then modifying to accommodate standard bolt on tooling.
My question is, what material is the turret made of?
Any info would be appreciated.

Sam

Cyclotronguy · Oct 15, 2013

Dunno, but liquid carburized 8620 might be in good taste and hard working once done.

Ox · Oct 15, 2013

I take it that you really only want new "top plates" for your turrets?

Is your VDI just worn out, or ???

While I am not a huge fan of VDI, I have found it to be remarkably solid and chatter free on my machines.
Much moreso than I expected!

Yes - I have heavily modified a turret, but I don't think that's what you are after....
I would order a cpl chunks of 4140 PH (if you can get it in your size) and yank a plate off and start whittlin'.

Keep in mind that there may be some mirror image features possibly.
Most likely only on the turret body itself, but I would Shirley be lookin' into that before cutting on the second one!
Coolant porting would be one feature that could be slightly different... ???

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Think Snow Eh!
Ox

Sam L · Oct 16, 2013

The problem is not in the static tooling. They are rigid, even though they don't repeat very well.
The main problem is with the live tools. They way that they are clamped in leads to a lot of accuracy issues and vibration when milling.

Ox · Oct 16, 2013

Oh boy - that could be fun - designing new hookups for the live toys too...
...and then replacing all the tools themselves yet too... :ack2:

Shirley doo-able, but a LOT more work than just the top plate eh?

Which tools are giving you the accuracy issues?
The end working toys?
Doo you have edge plates on the toys that locate off the front edge of the top plate to help alignment?

On the endwerking toys I have to adjust my C by a degree or two to get the holes where I want them sometimes, so I understand that issue.

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Think Snow Eh!
Ox

Philabuster · Oct 16, 2013

Sam L said:
The problem is not in the static tooling. They are rigid, even though they don't repeat very well.
The main problem is with the live tools. They way that they are clamped in leads to a lot of accuracy issues and vibration when milling.

What make and how big is the machine in question? Smallish CNC lathe with an 8" chuck or huge expensive machine with 24" chuck?

Did this particular CNC lathe have either a bolt on style turret or VDI turret as an option when purchased new? If yes, look on ebay for turret parts.

If above answer is no, how much idle time do you have on this 12 year old turn/mill lathe that you can afford to spend redesigning it? Why not vs just find another used machine to your liking and sell off the VDI turret machine?

Sam L · Oct 16, 2013

Ox said:
Oh boy - that could be fun - designing new hookups for the live toys too...
...and then replacing all the tools themselves yet too...

Shirley doo-able, but a LOT more work than just the top plate eh?

Which tools are giving you the accuracy issues?
The end working toys?
Doo you have edge plates on the toys that locate off the front edge of the top plate to help alignment?

On the endwerking toys I have to adjust my C by a degree or two to get the holes where I want them sometimes, so I understand that issue.

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Think Snow Eh!
Ox

The biggest problem is the radial tools. When tightening the VDI it causes them not to be square with the face of the turret. therefore the tooling is not perpendicular to the surface. it can be adjusted by shimming one side, but it takes a lot of time to do. We change tools so often it isn't reasonable to keep them all in the same position. The axial tools don't have an issue with alignment. they adjust from the front edge and we can always center using the Y axis.
Vibration is also a problem due to the clamping mechanism and the face od the too not sitting square on the turret face.
There is a lot of live tooling for this machine, we have 14 radial holders and 6 double axial.
We were thinking about taking the guts out if these holders and putting them in new bodies that we can make.
I know it seems like a lot of work, but I don't have many options.

Sam L · Oct 16, 2013

Philabuster said:
What make and how big is the machine in question? Smallish CNC lathe with an 8" chuck or huge expensive machine with 24" chuck?

Did this particular CNC lathe have either a bolt on style turret or VDI turret as an option when purchased new? If yes, look on ebay for turret parts.

If above answer is no, how much idle time do you have on this 12 year old turn/mill lathe that you can afford to spend redesigning it? Why not vs just find another used machine to your liking and sell off the VDI turret machine?

Its a Mori ZT2500Y. It did have a bolt on option, but was sold on the VDI.
before I bought it I went to see a demo, it cut great with the static tools. if I had any issues with the VDI, they were put to rest. This thing was taking massive cuts without a problem.
We tried looking for a new machine with the capacity and versatility of this one, and there were none from mori except the same one with bolt on turrets. It was too expensive of an option. That's why we are thinking about modifying this one.

Jashley73 · Oct 16, 2013

Sam L said:
Its a Mori ZT2500Y. It did have a bolt on option, but was sold on the VDI.
before I bought it I went to see a demo, it cut great with the static tools. if I had any issues with the VDI, they were put to rest. This thing was taking massive cuts without a problem.
We tried looking for a new machine with the capacity and versatility of this one, and there were none from mori except the same one with bolt on turrets. It was too expensive of an option. That's why we are thinking about modifying this one.

Did the original quote for the bolt-on turret include installation as well? What you have to consider is that there may be electrical and or mechanical bits that might need altered or replaced as well. Seldom is the case when a massive component like a turret can be replaced with a non-identical part, without running into issues. Just curious, how much was the new turret?

Ox · Oct 16, 2013

You are constantly changing holders on a dual turret lathe?

I usually have about a dozen live holders in mine, and they seldom come out.
One here or there, but not much. With all those positions - it seems a guy could get by w/o changing holders too much. That's one of the main benefits eh?

It sounds like your heads are not bottoming on the turret face. ???
I kant imagine a radial tool being an issue...

Are all of your live tools the same flavour, or have you tried a few different ones and have the same issue with all?

..just kant imagine shimming a radial tool.... :bawling:

On a Mori none the less?

If I had to go out and buy one today - that is likely the machine that I would have at the top of my list.

Does yours have the open lower turret design like the new ones?
If so - how has that worked for you?

I have a Hardinge that is about the same as a Mazak Hyperquadrex, and chips getting betwen the sub and lower turret make a mess of the lower rails and screw and .... More mess than an actual problem as it really seems. I have recently changed the rails, but after a dozen years .... and I have had to replace other rails too, so it seems like it is more "mess" than actual "mechanical liability", but still ....

That is what makes the Mori attractive to me.

...and you have the inboard live tool motor too? Or is yours too old for that?

It sucks to have to edit machines, but sometimes yuh gotta doo .... :wrong:

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Think Snow Eh!
Ox

Sam L · Oct 16, 2013

They are not bottoming on the turret face properly. I checked them with some Plastigage, used for checking bearing clearances in car engines, and it shows a little bit of difference from the top to the bottom on the face of the turret.
We are a job shop and are always changing setups and holders. many times the tooling setup depends on if we need y axis. Only the top turret has a Y.
We have 3 mori's, they are absolutely awesome machines, but this VDI sucks the big one. This was back in 2001 when everyone was pushing them as they were supposed to be a great choice for quick change.
We have 2 different types of radial tool holders, same problem with both.
Our lower turret has a way cover, it is not the open type. Also it does not have the built in milling motor, that came a few years later.
The cost of the 2 turrets from Mori is 50k, not including installation.
I know the service guys well. there are no major changes to any parameters in changing the turret if I keep them the same relative size.

Sam L · Oct 16, 2013

Here is a picture of the machine.

Ox · Oct 16, 2013

Oh - you have 8 pos top plates?
Or just 8 pos lower?
Or ???

I have 12 & 12, so that changes things a bit.

Have you tried just making a .015 (or ?) shim that would bolster the whole thing up even and see if the problem is more in line of being a "running out of stroke" type issue?

How much is it "off"?
How doo you notice it? Milling steps?

You ever stuff a drill into that big way cover?
I replace mine about every two yrs.
Need more daylight!

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Think Snow Eh!
Ox

Sam L · Oct 16, 2013

They are 12 position upper and lower.
I like the idea of shim. I will try it and see what happens.

I almost punched a hole through the cover one time with a reamer during transfer, but it just bumped it.
Close call.

Ox · Oct 16, 2013

It sure sounds like your holders just aint getting pulled down tight to the turret face to me.

That would possibly create a location issue, but definitely a chatter issue for sure.

Another possibility would be to see if the wedges are bottoming out in the top plate.
Will they go deeper with the holder not in the pocket?
Maybe you could trim the end of the wedges down a little to allow them to move in a little more - thus pulling the VDI further in.

Just sounds like something somewhere is out of spec.
Is that a VDI40 machine I am guessing???

I have VDI30 and I think it does pretty good really...
If you are that unhappy with it - you must just not be getting those holders seated.
.. but then the static holders are seating eh... ???
I think I would check the distance from the flange shoulder to the first V groove on them and see if there is any noticeable difference to start with.

Hopefully a second set of eyes can help you.
I know we can all get tunnel vissioned after dealing with something for so long...

Besides - I would like to hear that Mori knows how to make a machine tool...

Please don't let this thread rot away.
If you come up with something - please update us eh?

So then - doo you have much trouble with chips getting in the back of the machine through the gap between the lower and the sub?

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Think Snow Eh!
Ox

Sam L · Oct 16, 2013

Ox said:
So then - doo you have much trouble with chips getting in the back of the machine through the gap between the lower and the sub?

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Think Snow Eh!
Ox

On this machine there is no tight gap, there is a lot of space and the conveyor still runs about 3-4 feet from the right spindle.
The right spindle sits on the upper ways, so there is a lot of room behind the lower turret.

Sam L · Oct 17, 2013

I had the turret checked with one of those guns that analyses chemistry last night.
It came back as 12L14 ?
Checked the hardness also and maxed out at 21 Rc.
The only reason I could figure to use this type of material is for vibration dampening properties.
I had turrets checked on an Okuma, same thing 12L14.
Go figure, I would have made these out of 4140 HT.

Problem now is I cant find 16" diameter 12L14 anywhere.

Ox · Oct 17, 2013

12L doesn't come in anything but bar stock.
Round or hex. Square in a few sizes.

No plate, and highly doubt any bar size that is bigger than will fit in a multispindle screw machine.
Likely not bigger than 3-1/2". (Although multi's doo go up to 6" - if you can feed it...)

You could get it poured into any config that you want if you really wanted it though.

I would have a hard time trusting your gun.
Any chance that you have been running a lot of 12L in there recently?
Could the gun be picking up on residuals on the surface?
Does the gun show right on known sources?

If you run boat loads of 12L, maybe you could check the conveyor or tub on your chip spinner and see if it reads 12L there too - when you know that they will be 1006 or similar. This could see if it picks up on the residuals or not?

What does it read on the sheetmetal in the lathe?

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Think Snow Eh!
Ox

alphonso · Oct 17, 2013

Like Ox said. Check on the travel of the wedge.

I recently had a problem with a VDI (face mount) boring bar holder: would rough cut okay, but chattered like a 13 year old girl on finish cuts. Happened to notice daylight between tool and disc(proper nomenclature for the tool holding thingy mounted on the end of the shaft of the tool changer

). Turns out the shank was bent. Straightened it out as best I could and skimmed back side of body to be square with shank. Tightened down nicely, but there was daylight all the way around. Made a shim, problem solved. 2 inch bar sticking out 9 inches from face of disc. Absolutely no hint of a chatter on finish cuts.

Sam L · Oct 17, 2013

Last time I ran 12L14 in this machine was about 8 years ago.
I assume the gun is accurate, the shop that uses it always checks their materials with it.
I also had them check their Okuma turrets with it and came up with the same answer.
Im guessing it isn't actually 12L14, but some JIS standard that's pretty close.

I also just checked one more time with the plastigage. Here are the results.

---------------------------------- .006

---------------------- .004 ----------------.006

---------------------------------- .004

----------------wedge location

The bore is in the middle, the wedge is on the bottom left.

It looks like its not pulling down all the way.
Wedge is OK and the travel is not bottoming out
Also cleaned up the bore with some light sandpaper to remove any crap.

Will still try ox's idea with the shim as soon as I can.
Hopefully it will be that simple.

Has anyone made or modified a turret on a lathe

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