# Checking Mill not under power?



## Hozzie (Apr 24, 2021)

I have been looking for a knee mill for a bit and as most, the ones you see are either sky high or beat to crap, rusty, whatever.  I got a lead on this Jet JTM-4VS 3HP 3 Phase which looks to be in great shape.  I can buy it for 3k and plan to unless something obvious shows up when looking at it.  The guys seems on the up and up and didn't seem to be hiding anything.  He runs a machine shop and said they are simply replacing a few machines with newer machines.  Without me asking if anything was wrong with it he did tell me the X power feed isn't working, but said he hadn't looked at it and thought it could be a fuse or something.   I will assume it doesn't work at all.

From the pictures, it looks like it's about as good of shape as you see things around here.  I looked at a Bridgeport from the 70's with a lot of wear and surface rust and the guy wouldn't budge off of $2500.  I know this is a clone and I believe made in Taiwan.   The only real concern is they unhooked it from power and I can't run it.  I realize it is some risk, but I think I am willing to take that risk if the rest of it is in good shape. 

Any recommendations on something to really look out for since it isn't under power?  It seems like a steal to me so I suppose even if I had to do a little work the price still seems worth it to me.  It does have a Newall DRO that works.  Opinions?  I am headed over tomorrow to look at it and pick it up if all goes well.

Here are a couple of pics.


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## jbobb1 (Apr 24, 2021)

Take the belt covers off and make sure things turn as they should. 
Take some indicators to check spindle run-out. 
Make sure the quill moves freely. 
Check that the back gear and quill feed engage properly. 
Take a collet and end mill (if you have them) and make sure things seat.

Myself, I'd have a hard time buying any machine not under power, but I also totally understand your position


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## Aukai (Apr 24, 2021)

Good luck, looks nice.


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## tjb (Apr 24, 2021)

I hear you, Hozzie.  I live in the same equipment desert as you.  That mill is almost exactly like the one I found in Montgomery, AL.  It was a ten year-old Vectrax when I bought it, but only used one year and then stored in a residential environmentally controlled garage for the next nine.  One step removed from brand new.

The most important consideration I would offer is that you make certain the machine is made in Taiwan - not China.  If it is a Taiwan machine, it was probably built in the same factory as my Vectrax.  The decal on the side of your second picture should tell you where it was manufactured and the year it was built.  You might want to check with the seller to find that out before you go there.  Also, find out how old it is and how heavily used.  Mine came out of an electrical engineer's home hobby environment.  It has been a great machine.  I have no regrets, but again, mine was essentially a one-year old machine.

Let us know if you get it.


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## Hozzie (Apr 24, 2021)

Thanks.  I will take some indicators with me and check runout and the other items.  I am not building things for NASA, just my home shop where precision is within reason relative.  It's only 90 minutes from me so not the end of the world if I get there and it isn't what it appears to be.  I know the motor plate shows the motor was made in Taiwan in 1999, so I am guessing it all was, but I will verify as you state.  I am trying to figure out if it has been repainted.  If they did, it was a decent job.  Hard to tell in pictures.


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## rabler (Apr 24, 2021)

I would wonder why it couldn't be powered up.  It looks like it is sitting in a shop environment.  I realize it is 3 phase and there may be an RPC or some plugs involved, but it shouldn't be difficult to run power to it.


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## Ken from ontario (Apr 24, 2021)

That's a nice mill, great price too, I hope it checks out.


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## mikey (Apr 24, 2021)

Jet mills are made in Taiwan. Meehanite castings, which is very good. Looks to be a recent model. If they kept up with the lubrication schedule, I bet it's in decent shape.


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## Hozzie (Apr 24, 2021)

rabler said:


> I would wonder why it couldn't be powered up.  It looks like it is sitting in a shop environment.  I realize it is 3 phase and there may be an RPC or some plugs involved, but it shouldn't be difficult to run power to it.


He said they moved it from where it was to put the new machine in it's place.  He thought it was hooked up the first time I called him.  I think it's just sitting out away from where there was power for it and they probably don't feel like messing with it.  Not that he couldn't be BS'ing me, but you get a pretty good feel for the people when talking to them and I have a pretty good BS meter.  I don't get the feeling he is trying to pull a fast one or he wouldn't have told me about the x power feed.  And I think he is pretty confident it will sell easily.  Around here a Bridgeport in this shape would bring 5k minimum, and more like 6 or 7 most likely.

I am basically looking at it vs a new PM 949TV.  That would be $9600 to me.  If this one is made in Taiwan, I think it is basically a very similar machine.  I would get a warranty on the PM, but Jet does at least usually have parts available if needed.


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## Hozzie (Apr 24, 2021)

Maybe one of you can also tell me if the head can be turned upside down on this model?  I am thinking not.  It shows +/- 90 degrees in the manual, but I don't know if that means it can't (or shouldn't) go past that point or if that is only more when using it.  I see the Bridgeports are typically turned upside down with a block between the head and table, but not sure I can do that with this.  I have plenty of straps, etc, but definitely want to get the COG as low as possible.


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## hman (Apr 24, 2021)

Hozzie said:


> I am trying to figure out if it has been repainted.  If they did, it was a decent job.  Hard to tell in pictures.


If it was ever repainted, for sure it wasn't recently, and definitely not a "lipstick on a pig" job for the sake of a quick sale.  Both photos show areas where the paint job has worn away or been chipped off.  I'll go +1 on others' comments and suggestions.  Jet has a good reputation for machinery, though IMHO they do list for inordinately high prices.  

An examination of the table surface will let you know if it's been abused, or used by indifferent jerks.  Then do as careful an examination of the gib surfaces as you can.  Also give the table a "shake" test, to check for worn or misadjusted gibs.  You can check for spindle smoothness by manually moving the belts.  And -worst case scenario- if the motor is shot, it shouldn't be too expensive to replace it.  Maybe bring along  a multimeter, to check the motor windings.

Best of luck!  If that mill is what it appears to be, you'll have a great deal.  Also ask about how much tooling might be included!


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## T Bredehoft (Apr 24, 2021)

Witihout personal knowlege I'd say yes, with the probable removal of the motor, or swivel the  ram 90º and then  swing the head and motor down. but then it's no longer centrally balanced.

Update.
Silly me, hadn't thought about dropping the knee, of course that's the way to go.


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## Hozzie (Apr 24, 2021)

T Bredehoft said:


> Witihout personal knowlege I'd say yes, with the probable removal of the motor, or swivel the  ram 90º and then  swing the head and motor down. but then it's no longer centrally balanced.


Yeah, if it does, the motor doesn't have to be removed from the others I have seen.  You just lower the knee as low as it will go and then the head rotates 180 degrees and you move the knee back up and support the head with a block of wood.  I am just not sure if this particular model head is meant to go around 180 degrees in the vertical position.


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## markba633csi (Apr 25, 2021)

I'm sure the articulation of the head is just like a Bridgeport
As far a clones go you could do far worse than Jet
-Mark


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## Hozzie (Apr 25, 2021)

Well, I drove over this morning.  It was well taken care of, but had been used a lot.  I didn’t see any flaking left on the ways, both axis had about 35 thousandths backlash although the DRO worked well.  He did move it to power and I was able to run it.  Was in general good but had a little noise above 2000 rpm. 

In the end I decided to pass on it.  Just little things overall that I felt like could become bigger issues later.

Thanks for everyone’s input.


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