• January Turning Challenge: Thin-Stemmed Something! (click here for details)
  • Conversations are now Direct Messages (click here for details)
  • Congratulations to John Lucas for "Lost and Found" being selected as Turning of the Week for January 13, 2025 (click here for details)
  • Welcome new registering member. Your username must be your real First and Last name (for example: John Doe). "Screen names" and "handles" are not allowed and your registration will be deleted if you don't use your real name. Also, do not use all caps nor all lower case.

Platter Chucking Without Vacuum Chuck?

J

John Chianelli

Joined
Jan 27, 2009
Messages
20
Likes
0
Location
Tres Pinos, CA
Website
www.johnchianelli.com
Does anyone have any suggestions on how to effectively chuck large (11'>) thin (2-3") stock to turn platters? I do have the reverse chucking part figured out. The only thing, other than a vacuum chuck, that I can think of is gluing a waste block to the bottom side and using my Stronghold chuck or a faceplate with screws to grab it.

I came into some nice 2-3" thick cherry planks and I am considering purchasing a vacuum chuck but want to explore any other options. Although, I suspect owning a vacuum chuck is probably a worthwhile investment. The only ones I have seen are the Holdfast and the Oneway with the Oneway looking to be the superior option (but costliest too). Any other commercially available vacuum chuck recommendations? Thank much for any inputs.....John
 
Oops, didn't really answer the question, did I? You could put the blank between centers, and turn the outsde, leaving a shallow tenon in the foot area, put that in the chuck and turn the inside...remove platter...put a dome-ish piece of wood into the chuck and cover with carpet pad. the put the platter back between centers(foot toward tailstock side) finish the foot until you have the platter held by just the nubbin at then tail center.remove from lathe and take of nub with sharp chisel/knife/sander
 
You could turn the inside leaving a ring which is held in an expanding dovetail. It's pretty easy to take off a 2" diameter 1/4 wide 1/8 deep ring with a curved knife and sand for contour. I do it for things where I don't want a flat bottom outside. http://i35.photobucket.com/albums/d160/GoodOnesGone/Cherry-Dish-Bottom.jpg

No artifact inside. http://i35.photobucket.com/albums/d160/GoodOnesGone/Cherry-Dish-Top.jpg

Or you could finish the bottom before chucking and doing the interior if you're going to let the platter sit on its own.

Here's one shallow piece with a broad base. Second ring is where the chuck fit. http://i35.photobucket.com/albums/d160/GoodOnesGone/CIMG_2236.jpg
 
I mount my piece of wood with a worm screw, then completely finish the bottom. It does not take a deep recess to expand chuck the bottom. It seems to work well for me.

Martha
 
I use a forstner bit (2 5/8 inch for my big Vicmark chuck) to make a recess in the top of the bowl. Expand into that and finish turn the bottom. I make a dove tailed recess in it, slightly over 1/16 inch, reverse and finish turn the top/inside. You can leave the recess as part of the bottom, or use cole jaws and turn it off. Watched Mike Mahoney turn one in Portland at the 2006 AAW symposium. It was maybe 14 to 16 inch diameter, and he used the big jaws, about 4 inches, and his recess was more shallow than I would use, but looked nice. Can't remember how he turned the bottom though.

robo hippy
 
I use a screw chuck with a wooden spacer so it won't screw in very far. I screw this into the top side of the platter. Then I turn the bottom leaving a very shallow rebate for the chuck. If I think I might want to re-turn the bottom I bring the tailstock up to put a small divot in the bottom. Then I chuck it up and turn the front side. If I want to turn the bottom I put a rubber sink stopper over the chuck and put the platter on this. bring up the tailstock so it hits the divot I left earlier. Then I re-turn the bottom to whatever shape I want and carve away the area left by the tailstock. I use a cup center so I don't get much penetration of the point.
 
robo hippy said:
I use a forstner bit (2 5/8 inch for my big Vicmark chuck) to make a recess in the top of the bowl. Expand into that and finish turn the bottom.

robo hippy
Click to expand...

Robo,

I have first briefly mounted between centers and turned recess in top of bowl, then expand into recess with chuck. With a forstner bit, you loose the dovetail -- any problems holding with the chuck? How deep is your drilled recess?
 
justaccord said:
Robo,

I have first briefly mounted between centers and turned recess in top of bowl, then expand into recess with chuck. With a forstner bit, you loose the dovetail -- any problems holding with the chuck? How deep is your drilled recess?
Click to expand...

The dovetail is a wedge to hold the end of the jaws square against the bottom of the mortise. If you use pressure from the tailstock to accomplish that, you can make the mortise very shallow. I use 1/8 to 1/4 on 4/4 to 8/4 stuff, half an inch to three quarters up to six-ten pounds, and occasionally sneak a heavier one through when I feel I need to.

Just remember to snug the jaws while the tailstock is engaged, then withdraw the tail and turn. In short, the same as you always do with centers before removing one. Just makes good sense.
 
willsturnery

As a segmented turner for years,, I use the waste block approach almost exclusively. With the many times on and off the lathe in seg stuff, it's the best way I know of to keep the piece centered. If you do have the reversing set, fine. If not, the cole jaws are the way to go, particularly if you plan to be making a fair number of over-8" pieces.:cool2:
 
I have turned several thousand bowls and plates, with diameters up to 18 inches, this way with no problems. I don't use the tailstock. I do drill about 1/4 to 3/8 inch deep. Deep enough so that the jaws are in a ways, but not deep enough so that the blank will sit on the face of the chuck since the blank top isn't always perfectly flat. Since there is no dove tail, I will use a deeper recess than I will for the bottom of the bowl or plate. Just a comfort thing to me. The only real problem I have had is with drilling smaller (6 to 8 inch) bowl blanks. There isn't enough mass to hold the bowl on the drill press, and the drill bit can catch the blank and spin it on the table. I make sure to get a death grip with one hand, or use a strap wrench with a handle for added leverage. Having a sharp bit helps as well. I do snug the chuck jaws up tighter than I do in a tooled dove tailed bottom recess. Also, since I mostly turn green wood, the wood will give a bit and seat the jaws slightly better than in dry wood, but the difference is minimal. If you feel more comfortable using the tailstock, by all means do. As Pats Fan on Wood Net forums says, "when sphincter tightening exceeds chuck tightening, you have a problem."

robo hippy
 
There are times when one should wear gloves when holding wood under the drill press. Some pretty bad splinters can be avoided this way when the wood takes off and spins. Have we all been there?

Malcolm Smith.
 
Malcolm Smith said:
There are times when one should wear gloves when holding wood under the drill press. Some pretty bad splinters can be avoided this way when the wood takes off and spins. Have we all been there?

Malcolm Smith.
Click to expand...

I'd say find a better way to hold the wood and don't wear the glove. Last Christmas Eve I was wearing a mechanic's glove for grip while holding a 6" or so diameter piece of wood and drilling it with a Forstner bit. Something caught, then slipped, and the glove (and subsequently my left hand) got pulled into the bit. It climbed up the back of the glove and into my shirt sleeve, trying to wrap my arm around the spindle. I stopped the spindle rotation with brute force (squealing the belts on a 1 hp 17" drill press) before I could hit the Off switch.

Here's a picture of the glove...and one of my sleeve. My hand didn't look quite as bad, but I could see bone before it was patched up. It could have been a lot worse.

/Sorry for the threadjack, but I have a big button now about gloves and drill presses. Now I find a way to clamp the piece. 😉
 
Barbara Gill said:
You could also get a set of Cole jaws.
Click to expand...

Will Hunt said:
As a segmented turner for years,, I use the waste block approach almost exclusively. With the many times on and off the lathe in seg stuff, it's the best way I know of to keep the piece centered. If you do have the reversing set, fine. If not, the cole jaws are the way to go, particularly if you plan to be making a fair number of over-8" pieces.:cool2:
Click to expand...

These are a couple of very good suggestions.

For myself, I use the waste block plus the cole jaws......it's a good way to do it, and easily handles platters up to 14" diameter, max (external gripping). If internal gripping is possible, then max is 16" diameter platter. I wouldn't think of not having the Cole jaws....they are much simpler apparatus than vacuum chucking........a Godsend, IMHO! 😀

I seem to remember a donut chuck posted earlier, so I ran the search for donut chuck to see if I could find what I was thinking of......and what others are doing with this concept.......and I came up with this thread, which was initiated by Rick H.......a regular contributor to this forum. There are good photos in this thread. I thought his idea was good enough to bring it up again in this thread. Great thinking, Rick!

click:

http://www.aawforum.org/vbforum/showthread.php?t=5716&highlight=donut+chuck

ooc
 
Last edited:
Actually 2"-3" is pretty thick. I have turned platters 12" in diameter that are only 4/4 to start with. I put the blank against the open jaws of my Stronghold and hold with the live center, turn the bottom and a tenon just deep enough for the first set of teeth to grab. Then I turn the top. I used to re-chuck in Cole jaws to remove the tenon but now I use the vacuum.
 
You must log in or register to reply here.
Back
Top