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Timber stacker
31st July 2009, 06:00 PM
I've decided to make a clock for my unit 4 Visual Communication folio at school. And I've got this idea to turn a profile for the hands then somehow remove the two sides to make the clock hands. My question is; does anybody know how I can remove these two sides? Or is there some other better way to turn clock hands? Any help at all would be appreciated, thanks.
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echnidna
31st July 2009, 06:06 PM
Glue 3 pieces of wood together with a brown paper sandwich between the layers.
When it's time to separate them the paper should split away.

skot
31st July 2009, 06:29 PM
Use a lamination method...
Glue a piece of timber the thickness of which is equal to the required thickness of the hands between 2 pieces of timber of equal size...use a diluted glue mixture.

See image below

Turn the laminated block as per your shape (Centre it on the middle piece).

Separate the 3 pieces and the middle one (clock hand) will be as you required

As echnidna says

Skew ChiDAMN!!
31st July 2009, 06:50 PM
I've used the lamination method quite a bit in the past and found that it's not the best for when the piece you want is really thin; chunks can be pulled out when you seperate.

I'd imagine that for clock hands you're only talking about 1 or 2mm thickness?

With 2mm you might get away with laminating, but for 1mm... well... you'd want to turn up a few because odds are good you'll have a high failure rate.

An alternative is a large dia. disk linisher or wide belt-sander.

Sand one side of the turning flat. This is best done with the piece held so that the grit sands along the length of the tuning, if you sand across the grain (assuming it's spindle turned) the piece wants to roll, giving you a curved surface. Which may sound good, but makes the next step near impossible.

Then use a length of double-sided tape, longer & wider than the turning to stick it to a flat piece of wood. For a 1/2"(W) x 4"(L) hand, I'd stick it to a 3" x 5" offcut. It doesn't hurt to flatten the wood on the sander first, either.

This'll allow you to flatten the 2nd side with more control. So long as you keep an eye on the gap between the sides of the wood and the grit, keeping them as square and equal as possible, then the hand will be sanded to equal thickness.

You'll need to check progress often, as the dust tends to stick to the exposed bits D/S tape. I suppose you could use an exacto knife to trim them away if this annoys you, but I'm inherently lazy.

Either way, lamination or sanding, it's a very fiddly job to get right and has a high failure risk.. So I'll wish you the best of luck! :U

KenW
31st July 2009, 07:14 PM
Glue 3 pieces of wood together with a brown paper sandwich between the layers.
When it's time to separate them the paper should split away.
When thin pieces are needed, I use double sided tape instead of paper, just a few pieces of tape.
When the wife isn't looking, I use her thin carving knife to separate.

Jim Carroll
31st July 2009, 08:30 PM
You would need to use balsa wood as the hands, any other timber may be too heavy for the movement to push around.

Ed Reiss
31st July 2009, 11:57 PM
Hi Timber Stacker...welcome to the asylum :2tsup:

It's nice to see you younger guys taking an interest in turning...good for you !

Essentially the clock face you've designed is flat work, so why not just scroll saw the shape from a thin piece of wood, or am I missing something :?

tea lady
1st August 2009, 11:44 AM
:think: Sounds interesting but tricky. Maybe the top hand would look good not flattened. Still looking like half a spindle.:cool: The bottom one has to be flat cos the other handles have to go over it.

Sound good though.:2tsup:

Timber stacker
1st August 2009, 06:44 PM
Essentially the clock face you've designed is flat work, so why not just scroll saw the shape from a thin piece of wood, or am I missing something :?

A scroll saw would be good, but I just don't have access to one. And I think I could make it more symmetrical if it was done on a lathe. So far I think I might have to go with the laminated method.

Skew ChiDAMN!!
1st August 2009, 06:52 PM
Hmmm... ya gotta keep in mind what Jim said about the mechanism.

I've had battery clock mechanisms that lost time every 2nd half-hour, as the hands didn't want to go "uphill." And they were the commercial pressed tin hands, just a bit on the large side. Wood would be much worse.

I wonder... perhaps if you made the hands counterbalanced, like the old 'uns that had the big circle on the opposite end? (If you know what I mean?)

Jim Carroll
1st August 2009, 08:36 PM
Hmmm... ya gotta keep in mind what Jim said about the mechanism.

I've had battery clock mechanisms that lost time every 2nd half-hour, as the hands didn't want to go "uphill." And they were the commercial pressed tin hands, just a bit on the large side. Wood would be much worse.

I wonder... perhaps if you made the hands counterbalanced, like the old 'uns that had the big circle on the opposite end? (If you know what I mean?)


Good idea skew.

May help a bit to get that uphill push, would still stick with balsa etc.