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Skew ChiDAMN!!
12th June 2006, 07:39 PM
So, I started sizing stock to make a display box today... and totally screwed up. (Been one o' them days I'll be glad when it's over) Throwing hands in the air, I decided to take a break and headed for the lathe to recover my 'couth.' That's when it hit me... a totally different box than originally envisioned, but turned. I'm not sure on the fine details, but the idea's firmly embedded itself in the ol' grey matter and will probably brew to perfection over a few more sleeps.

Basically, it'll be a 150mm x 320mm cylinder standing upright and opening like a book. Think of it as two pirates' treasure chest lids hinged together and standing on end. Sized to hold a goblet, although that's not what it's for. (That's my secret until/if finished. ;) ) It will also be tapered by about 2cm towards one end, but that's just a minor detail.

So... the construction. I was thinking along the lines of cutting simple staves for gluing into a pipe shape and turning the inside and out to final dimension. Cut a couple of disks to plug the top'n'bottom (and for a couple of internal shelves to be added later) then splitting in two on the BS.

It all seems perfectly feasible except... what's the best method for mounting the blank onto a lathe? The outside'll be straight forward spindle turning, but mounting it for hollowing? I'm thinking hotmelt glue onto a faceplate but I'm not sure I'll manage consistent thickness once I get more than halfway down, given the depth & width of the form. Perhaps turn the inside end closest to the tailstock, then glue another faceplate onto the tailstock end, seperate from the orig. faceplate and flip it over?

Accuracy in thickness (and, of course, rechucking) is gonna be fairly important here...

Anybody got a more reliable or alternative method? And no, I don't have any powergrip jaws to handle these sizes. ;)

hughie
12th June 2006, 08:19 PM
[Accuracy in thickness (and, of course, rechucking) is gonna be fairly important here...

Anybody got a more reliable or alternative method? And no, I don't have any powergrip jaws to handle these sizes. ;)


Maybe its time to purchase some power grip jaws. I have a 50mm set your welcome to if you want.They will hold but the bigger ones would do better. The jaws are vicious in the way they grip so I use some spare Venetian blind slats. The modern ones a are a soft plastic wood look a like. They grip fine by embedding into the power grips and the wood finish helps the grip on the turned object.
I would also use a lathe steady, this gets you away from the tailstock support need.
hughie

Wood Butcher
12th June 2006, 08:23 PM
Skew, for mounting have a look at the home-made jaws linked to in this post.

Maybe you could knocj up something like these to hold the cylinder, turn one end, reverse it, then turn the other end?

Slow6
12th June 2006, 09:15 PM
300mm Forstner bit and a bloody big drill press? or something to that effect.

sounds like a great box skew.. my only fear would be movement in the wood once you split it on the bandsaw.
What timber did you have in mind for it?

Skew ChiDAMN!!
12th June 2006, 11:46 PM
Being a prototype with some not so simple parts and crapiata being in abundance.... :rolleyes:

Later, maybe a nice bull-oak.

Slow6
13th June 2006, 12:11 AM
ah.. I must have been rushed when I read the first post.. I had a box in my head 320mm wide and a meter'n'half high.

bull oak sounds good tho :)

Skew ChiDAMN!!
13th June 2006, 12:13 AM
If this 'un comes out OK, there's every possibilty that I'll be upscaling it to similar dimensions.

I reckon it'd make an unusual liquor cabinet. :)

Captain Chaos
13th June 2006, 01:07 AM
G'day Skew,
I reckon that you're on the right track by mounting on a spigot / wooden faceplate with a recess using hotmelt glue to secure it in place. You could support the outboard end in a three legged rest - you know, the ones with roller blade wheels & adjustable legs. Turn the inside to size as deep as you dare, then turn around & glue to the spigot / faceplate, reset the rest & turn the remaining section & finish A/R.
Sorry I don't have any pictures or drawings to illustrate the procedure Skew. I hope that you can decipher my hieroglyphics!:confused::)
Regards,
Barry.

Hickory
13th June 2006, 01:13 AM
Hope I can explain verbally as I don't have time for a drawing. Cut tree disks, One to fit as a spikot in the chuck (favorite chuck diameter) and two as top and bottom. Sand or slice off flats (on the top and bottom) to accomadate glueing on staves. Center and glue with paper between (break-a-way joint) the spikot to the base. Then attach (glue) as you suggested, staves to the bottom, locate the center and hot glue the top in place as well, Chuck mount (Between centers) and turn the outside. Heat the top end and remove the top plug. (may need a steady rest if the piece is tall enough for a bottle of Port) Turn the inside. Sand etc. Reglue the top plug and finish turning the top. You will probably need a jig for the Bandsaw to hold the Tube steady, but then slice the length Top to bottom. Had finish the inside sanding and such hing and clasp and insert that favorite house warming gift. Of course with this set up you will need to figure the angle of the sides of the staves, etc.


Another approach is to go with a barrell design and Using the same 3 disks, Cut a dado in the top and bottom of the staves and glue to the T&B discs. Mount and turn the outside, slice in two and leave the jointed inside with flat faces (rustic look)

Rustic = another wood for lazy

These were ideas that popped in as I read your post, may or maynot be of any use..... but perhaps you can draw from them.

Lance Stunning
13th June 2006, 07:09 AM
Can you turn the cylinder between a regular drive center and live center at the biginning? Make your end disks extra thick and turn a groove with a parting tool to fit your spigot sizes. Turn the outside, remount using the spigots, cut the insides, chisel off the ends, sand and finish.

Skew ChiDAMN!!
13th June 2006, 09:13 PM
Thanks guys, you've given me a few options to think about. :)

Here's a pic of the piece in question: the "staves" were 70x35mm pine studs. Being a radiata prototype to work out whether it's feasible in the first place, I'm not being particularly fussy over joints, etc. at this stage.

In a worst case scenario, I guess I can convert it to antistatic ductwork. :rolleyes: