728VT really unhappy!

55fairlane

55fairlane

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2 weeks ago we set a 728VT in my garage, spent this weekend installing the power feed, traming in the vise, ect.....
Got around to firing the machine up and making chips....went thru the square up the blocks routine, will not square up (in Y ) I tried everything (including getting my text book out from when I served my apprenticeship) finally bolt a 2-4-6 to the table & in the vise....using Z run an indicator up & down the blocks......0055 in 3 inches, the head in nodding at me, crap, call PM.....got thru the details with them, new Kurt vise, new Lyndex collets, used interapid indicator, and started my apprenticeship in 1986....been running machines since then.....3 hours on the phone, try this, they that, thy this.....short answer I get to pull the column loose & shim it....$5722.16 for new machine & I get the privilege of fixing it.....feeling very cheated
 
Dhal22 said:
Return it?
Click to expand...
that's not a returnable problem. Shimming is a function of tuning the machine. Should it have been correct when delivered, YES, but is it scrap, no.
Had it been at the manufacturers, or distributors, they would be shimming it. I consider this a minor issue.

edit: but you do have a right to vent about it. It should have been correct from the Manufacturer.
 
When you pay that kind of money and the machine is not in advertised specifications I would return it. If you were paying Harbor Freight prices I understand it needs work. Unfortunately the next machine many be the in the same condition. Talk to them. You are lucky you bought it from who you did. They are usually more than helpful.
 
55fairlane said:
2 weeks ago we set a 728VT in my garage, spent this weekend installing the power feed, traming in the vise, ect.....
Got around to firing the machine up and making chips....went thru the square up the blocks routine, will not square up (in Y ) I tried everything (including getting my text book out from when I served my apprenticeship) finally bolt a 2-4-6 to the table & in the vise....using Z run an indicator up & down the blocks......0055 in 3 inches, the head in nodding at me, crap, call PM.....got thru the details with them, new Kurt vise, new Lyndex collets, used interapid indicator, and started my apprenticeship in 1986....been running machines since then.....3 hours on the phone, try this, they that, thy this.....short answer I get to pull the column loose & shim it....$5722.16 for new machine & I get the privilege of fixing it.....feeling very cheated
Click to expand...
Are you going to shim the column? I would look at the head, if it is like mine, you can shim the head to adjust the nod...
 
I just got mine yesterday and i am a newbie machinist. So thanks for the heads up that i may need to shim it.

I got everything running and bolted down. Tonight i am going to mount the vise and check things out.

I dont have 246 blocks. I have 123... not sure if that distance in Z is going to show head nod.
 
Archer60x said:
I just got mine yesterday and i am a newbie machinist. So thanks for the heads up that i may need to shim it.

I got everything running and bolted down. Tonight i am going to mount the vise and check things out.

I dont have 246 blocks. I have 123... not sure if that distance in Z is going to show head nod.
Click to expand...
It will, you just need a machinist square or a DTI and flat plate to see it well....
 
verbotenwhisky said:
Are you going to shim the column? I would look at the head, if it is like mine, you can shim the head to adjust the nod...
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Shimming the head may not be sufficient. He may need to shim the column so that the head maintains XY position when moved up/down, and he may also need to shim (more likely scrape) the head-to-column connection to get the quill to move straight up/down relative to the XY table surface. I have a write-up on this that might be helpful. It includes links to some videos. I've attached it for reference, but it's also available on my web site here.
 

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davidpbest said:
Shimming the head may not be sufficient. He may need to shim the column so that the head maintains XY position when moved up/down, and he may also need to shim (more likely scrape) the head-to-column connection to get the quill to move straight up/down relative to the XY table surface. I have a write-up on this that might be helpful. It includes links to some videos. I've attached it for reference, but it's also available on my web site here.
Click to expand...
David, I had to think about your comment, it took a few minutes to work out the geometry in my thick skull..... Your right, it depends on which is screwy if the column isn't 100% perpendicular to the base and I shim my head then it will not maintain the same position over the table; however, if the column is 100% true to the base then the nod would need to be shimmed :rolleyes: in the head. The mills I have worked on in the past were knee mills and did not have this dynamic... I had discovered that My 940 had developed a nod and I thought about it dreading dealing with the issue then discovered the gib had loosened up, simple enough....
 
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