How Are You Mounting Your Pm1340gt Lathe?

[mksj]

Made a video of my PM1340GT lathe vibration stability vs. speed. I think mass loading the bases and some bracing may go a long ways to enhance stability, I have about 200Lbs on shelving between the lathe cabinets. You could do a larger steel perimeter base frame with rectangular steel (2x6 or something like that) and weld some studs or threaded inserts for mounting the cabinets to. I would then pour cement into the rectangular steel tube or you could make a bottom plate and pour cement into the center of that.

Probably a matter of fine tuning of the feet, but no machine in this weight class is going to be rock solid. Bolting to the foundation should make a significant improvement, but that is not always an option.

 

[davidpbest]

That's one heck of a chuck and brake time. !!!!

 

[qualitymachinetools]

I've also seen setups kind of as described, with a larger steel plate that is right about the depth and width of the cabinets, you could either tap or weld a stud in to that plate to bolt it down. You dont want to just set the plate on the floor though, you would want to epoxy it or something like that like Steve mentioned. You can get a piece of 1" Plate pretty reasonably.
That would be about second best to bolting it down directly to the floor. Must be one heck of a nice shop with the radiant floor heat!

Adding some weight to it I am sure would help too. But try out the machine first before getting too much in to any of this.

The idea of a cast base is a good one, but it would be a lot more than a $500 option on this machine. I've already looked at that, and it is just not practical, at least not from what I could come up with pricing. And at that point, you are up to the next model in pricing.
And we have hundreds of these machines out there (Soon to be thousands), and these are the only comments I've ever heard about this issue is these couple in the last week or 2. Same with machines like the Sharp 1340VS and many others. That machine also does not have a cast iron base, it has the same type as the PM-1340GT. Same with the Hardinge HLVH, most older Clausing lathes in this size range just to compare. This is not a 4,000 pound lathe, but it cuts just fine how it is, and will handle exactly what you want to do just fine. Of course it is best to bolt it down as it is designed, but most people do not want to do that, so they use other methods and it works great for them.

I've ran lathes that were huge and had their own foundation poured for them, and even they were bolted down.

Marks video is great though, he has an amazing setup on his machine, no question about that.

 

[zmotorsports]

I would agree with Matt and run it before over thinking it. I have had mine for coming up on two years now and it is still just as smooth at when I first set it up. I have had an odd shape peice throw it off a bit but that is only on rare occassions.

Mike.

 

[sanddan]

I am using the same feet as shown above, it looks like only one person that has posted here used something else (mason feet). No one seems to have bolted to the floor yet so it is hard to know if it makes a big difference or not. Who is going to be the first? LOL

 

[sanddan]

I would agree with Matt and run it before over thinking it. I have had mine for coming up on two years now and it is still just as smooth at when I first set it up. I have had an odd shape peice throw it off a bit but that is only on rare occassions.

Mike.

Mike,

If my lathe ran smooth I'd be as happy as you are. My bad luck I guess.

 

[mksj]

Did you run your lathe with the PM 3J chuck that came with the machine? The machine is pretty lightweight, any imbalance in the chuck will cause the vibrations you noted, if not worse. I had Chicom 4J and anything past 230RPM caused intolerable shaking, the new Taiwanese 4J independent I have no problems. I swing my Bison 8" up to 1600 RPM with no significant vibration, you always get some vibration nodes. The machine just doesn't have enough overall weight to damp out poor chucks that are either out of balance or not running true. Bolting it down in my garage is not an option, but I did mass load the stand which helped.

 

[RIO]

I am using the same feet as shown above, it looks like only one person that has posted here used something else (mason feet). No one seems to have bolted to the floor yet so it is hard to know if it makes a big difference or not. Who is going to be the first? LOL

ME. I just did it:

Guess what.....didn't fix the vibration.
The one improvement is that with opposing anchors, it makes it real easy to level out the bed, and take out any bed twist (which is almost none with this machine already).

I'm now focusing in on the top where the lathe bolts to the stand. Check out this picture and the yellow text and arrows:

What I'm noticing is that if you have a well-balanced machine to start with, the lack of stability in the stand setup doesn't matter. I think for some reason, Mark's (MKSJ) machine seems to be much better balanced than mine. I tried running it with nothing but the dead center installed in the headstock, then put the Taiwan (PM) 4J chuck on. Same results with either.
Could the Bison be what's making Mark's machine run so smooth??


RIO

 

[Muskt]

Hey RIO--I can't tell from the pic, but does that machine have 2 drive belts? My 12x36 does, & removing one made a huge difference in my vibrations.
Jerry in Delaware

 

[RIO]

One belt. I'm running this one:
http://www.amazon.com/Gates-Tri-Power-Section-Outside-Circumference/dp/B00CJJCZSA

I think Mark is running the BX25. Bigger could be better.

My stock pulley on the driven end is also out of true, or has a runout of .005. Could be causing some of the shake too. I'm thinking about replacing that.

Mark, where did you buy that Bison 4J? That might be my next step.

Uploading a youtube video for you guys tonight....