How Are You Mounting Your Pm1340gt Lathe?

[sanddan]

I want to hear from the owners of the PM1340GT lathe, how are you setting your lathe on the floor? There are several possibilities using the standard stand supplied with the lathe. The factory designed the stand with 4 threaded holes and supplied bolts to be used to level the lathe and then use the larger holes to anchor the lathe to the floor using threaded studs in the concrete. Other options are leveling feet of different types or just sitting on the floor. Please let me know what you did and why you chose that particular method.

 

[zmotorsports]

I have mine sitting on TECO adjustable feet. That is how I leveled mine as well.

Mike.

 

[wrmiller]

I followed Mike's setup. Works great for me.

 

[mksj]

Have not had any vibration issues with the lathe, but initially put on Mason large metal cupped feet, I used heavy washers on either side and locking nuts. I do not use the threaded hole and keep the distance between the feet and base as close as possible. Have a set of TE-CO metal adjustable feet like Mike & Bill's, just haven't gotten around to switching them. But have had no issues with the Mason's even though they are a no, no. Also have the Mason feet on the mill and they have worked well.

 

[RIO]

I bought the same thing as Mike and Mark are using, just got mine from ENCO.
It's not working for me. Maybe my expectations are too high, but if I bump the headstock with my hand, it shakes. Matt said to take the adjustable feet off and use the bolts that came with it. I did, and it's no better. However, he said the main key is bolting it down, which I can't do. In-floor radiant water circulated heat lines. Can't drill the concrete floor.
I've got other ideas that will require a lot of time, work, and money to get this thing rock solid, the way it should [must] be to do precision work. The best fix for other guys would probably be to bolt it down, I just wish I could.
What it really needs is a ONE PIECE CAST IRON STAND. Matt says he has tried, but it's too costly. I say, please do it anyway, Matt, and add it to your options list:
Example: "Upgraded, one piece case iron stand: $500", or whatever it costs, I'd buy it. What a shame to have a 6-7k dollar high precision lathe, and not have a stand that allows it's potential.

Also still trying to figure out why my compound slide bound up. I'm sure Matt will make it good, but I've wasted hours working on something that I shouldn't have had to, and it still won't work. Hope I find out it was my fault.

Still no chips.

RIO

 

[wrmiller]

That is interesting because I've not noticed any shakes or vibrations on mine. But I am only one example, and have no idea what the difference might be.

 

[mksj]

The machine with base weighs ~1300 lbs, the base maybe 250lb, other lathes in this size come in at a similar weight category. I think there is the over expectation of rigidity that one should expect from the base. It just isn't going to be unless you add a massive base and a 1000lbs. There are other HD lathes, with cast iron bases they weigh in at at over a ton, they are more expensive then the PM1340GT, and you would end up paying twice as much for a machine made in Taiwan (like an ERl1340). Even if a cast iron base was available, the shipping costs and ability to deliver it at a reasonable price would be problematic. You can turn the cabinets upside down and pour concrete into the bottoms to mass load the bottom of the bases, and add some structural steel across the back of the cabinets to brace them. Agree the bases could be heavier and more rigid, but in using the machine I am not aware of any current individuals using this lathe that have issues with finish or tolerance.

 

[wrmiller]

The machine with base weighs ~1300 lbs, the base maybe 250lb, other lathes in this size come in at a similar weight category. I think there is the over expectation of rigidity that one should expect from the base. It just isn't going to be unless you add a massive base and a 1000lbs. There are other HD lathes, with cast iron bases they weigh in at at over a ton, they are more expensive then the PM1340GT, and you would end up paying twice as much for a machine made in Taiwan (like an ERl1340). Even if a cast iron base was available, the shipping costs and ability to deliver it at a reasonable price would be problematic. You can turn the cabinets upside down and pour concrete into the bottoms to mass load the bottom of the bases, and add some structural steel across the back of the cabinets to brace them. Agree the bases could be heavier and more rigid, but in using the machine I am not aware of any current individuals using this lathe that have issues with finish or tolerance.

I am having no issues with finish or tolerance and can easily hold tenths on mine.

 

[RIO]

Sorry for the negative attitude in that last post boys. Have been going on little sleep for too long, and I'm raising a kindergartner on my own, and I'm too old for both. HA. Matt doesn't deserve any trouble, he works extremely hard to keep happy customers. Other severe friction [woman] in my life is causing my impatience. Apologies.

As usual, Mark [MKSJ] explains things very well, and puts it into great light. Very good perspective. Bottom line, my expectations were a little lofty.

I guess I should level this thing up the best I can, then put it into service, and see how the work comes out before I b*^ch any more about it. Might turn out awesome work anyway.

As I sit and stare at this thing, one thing does jump out at me: THE MARATHON MOTOR HANGING OFF THE BACK, IS A LOT HEAVIER THAN STOCK. An unexpected consequence. And looking at the machine from the side, it is obvious that directly exacerbates the issue. The shake isn't in the length of the machine, it's in the depth. I would humbly submit five suggestions for Matt that I think will help greatly:
1.) The plates that are welded up under the top of the stand, that the lathe bolts directly to are are two pieces. If that was one thick, solid plate across the top, I believe that would help the lateral stability a noticeable amount. Then take those flimsy shelves out of the middle of the stand sections and make them 5/16 steel plates.
2.) Widen the lateral (depth) stance of the stands so the feet are a few inches further apart. In other words, make the stand sections bigger front-to-back. That will make it a lot less top heavy, making it more solid.
3.) Make the stand a one-piece welded together unit, by simply adding welded angle iron braces across the top and bottom. I understand this will make shipping and transit more cumbersome, but well worth it. Make it an added option if you need to.
4.) Thread those 3/4 inch holes in the bottom and put large, adjustable 3/4 inch feet on there, and make the 1/2 inch hole for anchoring it down.
5.) Pour the stands full of molten lead. [Joking]

The main concern here is I am worried that any shake/vibration in the machine will cause reamer chatter when chambering these match barrels. Guess I should have just saved up another 10 grand and bought a bigger lathe if that was the concern. However, the main draw for a gunsmith with this machine is the short headstock combined with a large spindle bore, therefore being able to chamber a 20" barrel through the headstock. Nearly impossible to find that combination in a bigger, non-China lathe.

I guess the other option is take the lathe off the stand, bolt it to the floor, and do my work lying on my belly?

Maybe I should just stop obsessing about perfection and just play along in the sandbox of life.
Thanks for the help.
RIO

 

[mksj]

Rio,

I hear you and agree. You may want to beef up the stands, I am pretty sure it will work out well. There was a thread with a G4003G owner beefed up his bases with square tubing and others where they weighted the bases. I have also heard of putting some sandbags in the base. Gave him some additional machine height widened the stance, looked really rigid. I would tie the bases together top and bottom. I am serious about pouring cement into the bases to increase the mass and the dampening. I have made speaker stands, poured cement in the metal frame/base and it was dead quiet with the knuckle test.
http://www.hobby-machinist.com/threads/new-g4003g-lathe.15636/#post-123851

The Marathon motor is a TENV, they require a lot more iron and fins to dissipate the heat, they are supposedly quieter and have less vibration then the TEFC version. I believe having wider mounting feet bracing would go a long way, this is similar to what Dan did for his smaller Enco (nicely done). This is the customization part that each machine owner does for their machines to get them to where they want.