23" Hard Maple Bowl on PM3520 Lathe (Safety)

[Joe Vincent 63]

I have a couple of 23" hard maple bowl blanks that I need to rough out. The diameter of the blanks is larger than what the 3520b can hold unless I move the headstock to the end of the bed. I have the short bed extension mounted in the bottom set of holes for the toolrest, but I am concerned that I will not be able to use the tailstock to support it. The blanks have been pretty well carved up with a chainsaw, but they are still quite out of round. I plan to use a Vicmarc 5" Chuck with the standard jaws to hold the piece.

Any thoughts, opinions, or suggestions would be greatly appreciated on the best (and safest) way to turn these.


Joe

[Pete Jordan]

Joe.

I have the same setup. I recently did a piece about the same size and used a 7" faceplate. I felt it was safer.

[Bernie Weishapl]

I would use a 6" or 7" faceplate like Pete to get the outside rounded and your tenon turned then use you 5" chuck.

[Curt Fuller]

For the roughing part, I agree with the others that it is definitely a situation where a large faceplate would be safest.

[Roger Chandler]

+1 for what Pete and Bernie said..........faceplate is the way to go!

[Dennis Ford]

+1 on using a faceplate. I am sure that a chuck could be used but believe that a faceplate will be stronger and possibly easier in this case. A 6" faceplate with 12 #10 x 1" screws would be my choice (this is the size faceplate I have). The 1" long screws would penetrate the maple just over 1/2" using my faceplate. I would carve the bottom away leaving 3 feet since the lathe is not big enough to reverse the bowl to dress up the bottom.

[Jake Helmboldt]

Another vote for faceplate. Big long screws in each hole. That is too big a blank for the chuck until it is better balanced.

Start with a slow speed and turn it round.

[George Guadiane]

I would use a 6" or 7" faceplate like Pete to get the outside rounded and your tenon turned then use you 5" chuck.

This is about as safe as you can get. Be safe and PATIENT and turn at a slower speed.

[Bob Bergstrom]

With a good flat surface it is all about the number of screw you put into the maple. Here is a 24" hard maple on a 3" powermatic face plate with 6 1 1/2" screws. I used a Oneway #4 chuck when I rough it out. Take it easy and get it as round as possible with the chainsaw. Once it is round it much easier and less intimidating. One thing you should know is that the when you shut the lathe off, the blank will override the electronic braking system on the 3520. This will kick out the system and it won't run till it is reset. It can be a pain in the pants. You can provide braking assist by pushing something against the turning blank when you shut the lathe off. The real problem will come when it is dry and it has to be mounted without being able to jam chuck it between the tailstock and the headstock.

[Joe Vincent 63]

Thanks everyone!!

Bob, that bowl looks very familiar, its huge! You were OK with a 3" face plate versus a 6"? I have the 3" that came with the PM, but was looking for a 6" based on the earlier suggestions. The only decent one I saw was the Oneway 6" face plate, but it is cast iron. Any other face plates that folks really like in that size (stainless steel would be ideal)? What size screws did you use?

Joe

[Bob Bergstrom]

There are a lot of variables involve. I've pulled out the screws on a 6" bowl if the wood is too punky, soft, or a bad catch or the matting surface is on good and flat. The Powermatic face plate is quite stout. If I had had a 6" I would probably use it. I do have a " delta, but it is a 1x8 thread and has to be mounted on an adaptor (vibration). When you pull a big blank off the face plate it will never fly, but it will make you dance to avoid having it land on you foot or bang into your shin. The 24" above weigh 120 lbs. I'm not sure of you reason for a stainless steel face plate. The Oneway is a very strong faceplate. You are going to turn away all of it. You'll will notice that under the lower way I have a hydraulic table under the ways for support. Cutting down any unnecessary vibration will help. If you are in doubt, I would suggest going with the best solution you can. One mistake with wood that size could cause severe damage. Be safe first. The next problem is what to do with a 23" bowl. That more that a bushel basket full of whatever:eek::eek:.

Thanks everyone!!

Bob, that bowl looks very familiar, its huge! You were OK with a 3" face plate versus a 6"? I have the 3" that came with the PM, but was looking for a 6" based on the earlier suggestions. The only decent one I saw was the Oneway 6" face plate, but it is cast iron. Any other face plates that folks really like in that size (stainless steel would be ideal)? What size screws did you use?

Joe

[Joe Vincent 63]

Thanks again, great info. The wife is looking at those big blanks and shaking her head about the couple of little ones I've done now :). At least she is not asking why I spend so much time in the shop, she wants me out turning big bowls!

The stainless steal was to prevent rust from wet wood. I've read many folks that believe cast iron is too brittle and can break with a piece that large. No idea if true or not, just trying to pick the right one as they are fairly expensive.

Do you use the hydraulic table to move the piece? My father-in-law had recommended an engine lift to help.

Joe

[Harry Robinette]

Joe
I use a steel face plate I had made on the Vega 2600. If you need to borrow a face plate I'll let you have one till you can get one.I use 1 1/2" #10 SS sheet metal screws from McFeely. I also put a Harbor Freight electric hoist over my Vega to pick up blanks. If you need anything send me a PM.

[Bob Bergstrom]

Most good face plates are steel. The Powermatic and Oneway are about as heavy duty as it gets other than Serious and V36s. Roughing out a 23" is not terribly hard as compare to making the finish cuts in a fairly deep large bowl. I also recommend a curved tool rest for reaching into deep large bowl. When the tool starts to hang over the tool rest with that large a bowl you will find it harder to keep the cutting edge in a proper angle. I have a 1" Crown PM Pro because of its stoutness. The curve rest I have is a Oneway, but the new Robust might be even better.

[Pete Jordan]

I use a chain fall to lift the wood but I wish I had something electric.

[Joe Vincent 63]

One thing noted by Bob was the pith. The log was just cut in half, so the pith is still there. Would the 6" face plate be sufficient if I just use very long screws for the holes lining up with the pith, or should I look for an 8" face plate? Oneways versa mounting system looks interesting, but not sure it buys you much.

Joe