maximum weight

[Ted Alexander]

Does anyone know how much weight I can mount on my 3520B? I contacted powermatic and they said if it can be mounted , it's not too heavy. This doesn't sound right to me.I'm not an engineer but I thought the main shaft or the bearings could be scored if you hang too much weight. The piece I want to turn weighs 90 pounds ;32 inch diameter. Has anyone hung this much weight on their lathe?

Thanx

[Harvey M. Taylor]

I have never hung that much on mine, but I am sure others have. For safety, be sure to engage1 the tailstock a

[allen thunem]

it can handle more than you probably want to lift on to it.

[Ted Alexander]

I forgot to mention that I can't use the tailstock;I'm turning outboard.

[Jon Nuckles]

I would hope that 90 pounds would not be too much. I bought the extension with the intention of turning pieces over 20" in diameter using the extension in the lower position. I expect that the blanks will weigh that much in the rough. Since PM's extension doesn't offer any tailstock support option, it would be of limited use if the 3520 couldn't handle that weight. (I have been in a wood supply and turning drought for the last year, so I haven't had a chance to use it yet.)

[Steve Peterson]

I don't have a 3520B, but I suspect that the bearings are much stronger than you are assuming. The first bearing I looked at on the VXB web site (25x47x12) has a static load rating of 1315 pounds and a dynamic rating of 2270 pounds. It costs $4.37. The 3520B might even use larger bearings than my guess.

Steve

[Jack Mincey]

Nick Cook turned a huge log down for an table pedestal years ago. The chunk weighed some where around 800 pounds I believe. He had to turn it between two PM's held together with bar clamps. If someone has the link to the video it is neat to watch. To answer you question any quality full size lathe should handle 100 pounds or more with no problems. Just start off at slow speeds and work the speed up as it becomes more balanced.

Jack

[Dennis Ford]

It is not the weight alone that you need to worry about. Having the weight far away from the shaft (tall work without tail-stock support) multiplies the load on bearings. Out of balance work that shakes the lathe puts huge dynamic loads on the bearings.
With all that said; I would not worry about the bearings when mounting a 90 lb blank. I would worry about it staying mounted. A fairly large faceplate with plenty of screws should take care of that.

[Kyle Iwamoto]

299802
I've had more weight than that on my Jet 1642, it's little brother. You'll be fine. I had a 2 foot long 15" Norfolk Pine blank a couple times. I would trust what PM says. If it fits, you can turn it.

[Don Bunce]

Here's a pic of a 1600 lb log mounted on a PM 3520b... 90 lbs will be no problem.

Sorry, I don't remember the name of the turner.

299807

[Thomas Canfield]

You are asking about overhung weight and not between centers at the 32" D. I have had well over 100# between centers, but down to about 75# as overhung and that was also just under 20"D. I do want to hang a 32" piece at least once just to say I did an use the drop support and tool rest that I bought with lathe 7 years back. In addition to the weight, you need to be concerned about the out of balance that might cause much higher load on the bearings. I expect at 32" you want something fairly balanced to start.

[Mike Peace]

Just as a point of reference: the Jet 1642 spindle has two bearings and the PM 3520 has 3.

[robert baccus]

I have turned a 34"x 150# bowl blank on a 3520(with extension) with no problems. Also 6 vase blanks in the 110 to130# weight class. These were up to 22" in length and were roughed out with a tailstock and hollowed out just hung out. All these pieces were mounted on a 3.5" glueblock and nova chuck screw. The hollowing out on a long vase is a good test but I'm sure the 3520 will hold much more if required.

[Ted Alexander]

Thanx to everyone for your help. Now I have another question. I only have Talon chucks--Would a 5" chuck be strong enough, or should I buy an 8" faceplate ?

Thanx again.

[Faust M. Ruggiero]

I would not consider using a chuck without tail stock support for a large piece. I would use a face plate no less than 6" and up to 10" with lots of screws. Is your lathe bolted down to the floor?
faust

[Dennis Ford]

I agree with Faust; use a faceplate. Could it be done on a chuck- yes but why would you risk it.

[Lloyd Butler]

I would stick to a face plate for roughing, and then once the piece gets round and sheds some pounds you could think about a chuck if you wanted. You'll want to start really slow as the balance of the lathe will likely be off a bit and you do not want it walking around. It will not take long to lose a chunk of weight unless you were just trying to make a solid large pedalistal.

How much extra material in depth do you have? You could leave it right on the face plate to the end if there was enough material depth. I would fasten a piece of 3/4" ply about 3/4 the diameter of the blank with plenty of screws and then fasten that to the face plate.

[Ted Alexander]

No, it's not bolted down. I was thinking a Oneway 8" faceplate.

[Dale Gillaspy]

For something that heavy, face plate, no question!!!

[Bob Bergstrom]

I've turned 26" x 10" of hard maple weighing about 150 pounds. Always use a face plate to round it up. You may end up with a broken leg or foot if the tenon breaks on a chucked piece. The 3520 is a very stout machine as Don Bunce has pictured.