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Tal Siegmann
09-30-2020, 2:35 PM
I recently purchased a PM 3520. I am looking to turn large bowls and would like to beef up the lathe. Planning on adding sand for weight.
What have you guys done to widen the base? Seems to me that the lags are not wide enough to counter all the forces.
My cement floor is not so even- am wondering how you guys level the lathe? What kind of levelers might I install that can withstand the forces and the weight?
Thank you
Tal

Richard Coers
09-30-2020, 5:51 PM
Are you talking about a 3520C? They added more weight to that machine and it now weighs 726 pounds. That's more than my Oneway 2436 and I've never had trouble with it walking with 20" blanks on it. If it does walk, you're spinning it too fast. The 3520C comes with adjustment feet.

Jim Barkelew
09-30-2020, 7:18 PM
I don't have a 3520 but I have my lathes and band saw bolted to the concrete slab with anchor bolts. It's very solid setup. It requires a hammer drill but that's a handy tool to have anyway. It takes less than 30 seconds to drill a 4 inch deep hole. The machine can be leveled with shims. The down side is moving the machine to a new location. The anchors have to be cut off.

Jim

Thomas Canfield
09-30-2020, 7:43 PM
I have a 3520B with bed extension always mounted increasing weight. I built a storage rack at base of frame based on the information in the manual, and have wood stored adding possibly 100#. There are adjusting screws at each leg for leveling and I made a wooden cup for the screw head to set in (add a flat washer to inside of cup to spread weight on wood) and give a bigger footprint on the concrete floor to help resist any movement with vibration. You could add some rubber to give a better bite. As said, if the lathe is moving, you are turning the out of balance work too fast. I have turned some extremely out of balanced work starting at about 200 rpm and never getting over 350 rpm on 18" swing. I normally have my headstock and motor away from the extreme end of the ways to keep more weight on all legs. Unloading weight off the tailstock legs makes the lathe easier to shift with vibrations. Get the best level you can to level ways in both directions and check the torque on each leg screw to make sure they are equal for the 2 screws each leg since the load is different for each leg. I marked the floor to help check for movement and to be able to replace lathe is needed to be moved.

Sam Force
09-30-2020, 7:53 PM
I put my 3520 on 7 1/2 inch 2x6 risers with rubber pads under them. Then added about 280 lbs of weight in a box between the legs, it is very solid and stable

Tal Siegmann
09-30-2020, 9:27 PM
442323I am not sure which model this is. I don't have an A after the 3520. Any idea which model this is?
Thanks for the ideas!
I am happy to say that my lathe has not walked as of today ! Because it is on uneven cement it rattles quite easily, therefor forcing me to turn the speed down immediately.
Sam- I like your idea of risers- is the lathe too high?
Thomas- I like the idea of adding rubber under to dampen any vibrations.
Thx

Sam Force
09-30-2020, 10:16 PM
I don't find it too high for me, but I am 6`4" and it was killing my back before I raised it up. I should add that my risers go front to back on each end with "trim" boards on the outside to make sure that the lathe stays put. I also have braces running lengthwise to help with stability and if a shorter person joins in they can stand on them or I built a platform that will slide out for them as well

Reed Gray
10-01-2020, 11:15 AM
Very seldom do you find a dead flat concrete floor, and that includes the ones I poured.... So, you want your lathe dead level. If you are in a garage, they are generally poured with some slope to them so when you drive in from the rain, the water flows to the door. This means the foot levelers are extended out more on one side or end of the lathe than the other. Next step, after leveling, is to back off on one foot so it is floating. Then, mount an uneven bowl blank, in the 14 to 16 inch range, and turn on your lathe at a slow speed. Turn the speed up till the lathe starts to wobble. Adjust the floating foot down until the wobbling stops. I generally go maybe 1/8 to 1/4 turn past the 'balance' point because when I tighten down, that seems to move it just a hair. Now, the lathe is sitting evenly on all 4 feet. Add weight as needed. I do mark on the floor where the feet are supposed to be because a lathe with an uneven piece on it will want to walk around. Some times I have adjusted the feet a couple of times till I get it right.

With my 3520A, I needed it raised. I put it up on 2 pieces of 2 by 4, with tiny recesses for the feet. I extended the feet back to the wall and nailed a cleat into the wall to hold it down. That extra splaying of the feet by being on the 2 by 4s helped a lot with stability. You can't really stick any board feet on the turning side of the lathe because you will trip on them...

Mounting any lathe on a wood floor that is floating, rather than on concrete, will always have some vibration issues because wood will want to flex, which is the nature of wood. Direct post support down to concrete pads is probably the best solution.

robo hippy

Jeff Jackson
10-02-2020, 8:18 AM
Since I'm 6'6" tall, I mounted mine on 4×4 blocks, bolting them using the holes for the adjustable feet. I remounted the adjustable feet using threaded inserts in the wood. Then on top of the 4×4's I built a platform to hold about 400# of sand bags.