Shop made screw press?

[Bob Hamilton]

I am sure I remember reading or seeing somewhere a design someone had put together for making a screw press for stack laminating bowl blanks, but I am drawing a blank as to where or when I saw it. I have purchased a shoulder vise screw and a lazy susan bearing which seem to me to be the main hardware components of the one I saw, but I would like to refresh my memory as to the construction of the frame components.

Does anyone have a link to such an animal?

Thanks
Bob

[Mike A. Smith]

I haven't used any of these but here's a link to a couple:

http://www.woodturningonline.com/Turning/segmented_turning/index.html#jigs

Hope this helps...

[Mike Hood]

I had a friend that would stack glued up blanks and then set a bottle jack like that on top and the use a section of 2x4 to press against the ceiling beams in his shop. He got TONS of pressure for the cost of a $20 hydraulic jack. Also... when compressed you couldn't budge the whole mess. It kept everything perfect in alignment.

[Richard Madison]

I used to use a couple pieces of 2x12 with holes through the center for 3/4" allthread rod. To attach the bottom I used 4 fixture (pipe) clamps on the 2x12 "clamp plates" instead of the rod through the center. During clamping the layers want to slide out of alignment until the excess glue is squeezed out and they "lock" together. Process of squeeze a little, realign, squeeze, realign, and after "lockup", apply a bit more pressure.

[Ron Fleice]

Hi Bob...Haven't heard from you in awhile...I have Bill Kandlers book "Segmented turning, a good start" and it has instructions and a picture of a press made with pipe if you would like it send me an email and I will scan and send it to you..
Ron

[Curt Fuller]

http://www.turnedwood.com/tools&jigs.html


This is a link to Kevin Neelley's segmented turning site. There are all kinds of good ideas here including plans for a press.

[Bob Hamilton]

Thanks, all:
I had been so focused on a timber frame I hadn't thought of allthread. That might make things easier. I am thinking of making the base a torsion box with a lazy susan turntable on top to allow ensuring everything is centered both under the clamp screw and in each layer.

Thanks again, all.
Bob

Ron, how's the General running? :)

[Ron Fleice]

Hi Bob...the General is still running as good as new and I have
put some large blanks on it with nary a problem...I have another Elm tree that is dying and when I get it dropped I will let you know if your still interested in some large blanks
Looking forward to retirement end of may 2008 :D
Take care
Ron

[Bob Hamilton]

Well, I put together something that looks like it will work okay. I still have to turn a dowel handle for the vise screw and a disk for a pressure plate as well as make a more permanent mount for the pointer, but for the most part it is done. I dry stacked these rings just to try it out.

71374

A close up of the temporary pointer. There is a lazy susan bearing (load rating 1000 lbs.) under the platen so rotating the disk lets you easily see if the rings are centered under the clamp screw.

71375

Take care
Bob

[Richard Madison]

Bob,
Can't tell the size of your "clamp screw", but if it is larger than about 5/16-18, you can apply a great deal more than 1,000 pounds of force. If I understand correctly (unlikely, according to a close family member), the lazy susan bearing is within the clamped section. It will probably support much more than the "rated" load at static conditions. Just a thought.

[Malcolm Tibbetts]

For those that desire a much simpler approach. The pipe clamp simply pushes against a ceiling joist. One key is to have something like a 1/8" rubber router pad under the ring covered with waxpaper. The pad helps distribute the pressure more evenly and the waxpaper allows the ring to be positioned and keeps the pad clean. Creating a nice tight glue joint should not require 1000's of pounds of pressure. All you need is enough pressure to drive the excess glue from the joint.

[joe greiner]

I'd suggest caution when jacking against a structure above. It's entirely possible to lift a house off its foundation with bottle jacks, particularly a very old house with inadequate tie-downs.

I had occasion to correct a sagging floor owing to substandard workmanship by the original builder, who omitted a pier under a beam. Not surprisingly, cracks developed in the walls above; easy enough to fix with spackling, though.

Like Malcolm says, you don't need a lot of pressure to create a satisfactory joint. A ton or two should be sufficient.

Joe

[Chris Friesen]

Creating a nice tight glue joint should not require 1000's of pounds of pressure. All you need is enough pressure to drive the excess glue from the joint.

While it may not be strictly necessary, if you look at the titebond website, they suggest 175-250psi for hardwoods, and 100-150psi for softwoods. Going by their suggestion, laminating two 9" diameter circles would need over 6000lbs of clamping force.

A local bass guitar maker uses a 20-ton steel press (similar to http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=32879) for his laminations.