"PGG" wrote in message
newsan.2005.02.01.23.07.26.292000@NO_SP_A_Myahoo .com...
I have a 5x12" sheet of Cherry Wood, 1/8" thick, that is not quite flat.
How can I straighten it, and keep it straight?

Thanks
PGG

glue it to some 3/4" plywood

On Wed, 02 Feb 2005 01:09:17 GMT, PGG
wrote:


I have a 5x12" sheet of Cherry Wood, 1/8" thick, that is not quite flat.
How can I straighten it, and keep it straight?

Thanks
PGG

glue it to some 3/4" plywood

Can't do that. I'm making a lens board for my large-format camera.

Do I need to find a straight piece to start with?



yep.

Struts, like used in Guitar top bracing could be used OR

Wellllll- sticking my neck out here.
If you can enclose it in a frame of some kind during it's application,
that might help OR !!!

Try this: Weigh your board
Dampen the board-- both sides
Find a REALLY flat surface-- maybe your TS
Lay down newsprint ( NOT NEWSPAPER- newsprint is the paper they make
newspaper from - get some at the local crafts supply - paper towels
work, but use more-- an extra layer)- maybe 5 layers (plastic on the TS
or it will rust)
Lay down your board
lay down More newsprint
add a REALLY flat piece of Steel same size or larger than board--
Aluminum will work, MDF??? maybe if it is about 1 1/2 " thick (two
layers)
If you use MDF or plywood put plastic between the newsprint or wood on
top will warp also
Clamp like HELL-- Really full 5 gal paint cans come to mind.-- use two
or three

After 24 hrs change news print for dry stuff-
Keep this up for at LEAST three days ( make sure your 1/8" piece of
wood is dry) Keep weighing your board- when it weighs the same as when
you started, it is sstable -- USE & finish immediately (if it's flat
enough for your purpose

If this is TMT, buy a flat board

On Wed, 02 Feb 2005 03:16:54 GMT, PGG
wrote:


I have a 5x12" sheet of Cherry Wood, 1/8" thick, that is not quite flat.
How can I straighten it, and keep it straight?

Thanks
PGG

glue it to some 3/4" plywood

Can't do that. I'm making a lens board for my large-format camera.

Do I need to find a straight piece to start with?



yep.

What about getting it wet, and then sandwich it between 2 flat objects
with some weight on it? Paper towels in between to speed the drying.

go ahead if you want. for your particular board, this one time,
somehow, it might work. all you have to lose is a little wood and
time.

let us know what happens.

I have a 5x12" sheet of Cherry Wood, 1/8" thick, that is not quite flat.
How can I straighten it, and keep it straight?

You could rim it with a really sturdy frame, if not slots in a box then a
thick metal frame. (Sorry, I don't know what a lens board is so I can't
tell if that makes sense in your application.)

Do I need to find a straight piece to start with?

That's your best bet. It's a small enough board.

- Owen -

Can't do that. I'm making a lens board for my large-format camera.

Do I need to find a straight piece to start with?

Depends. Shoot everything at f64 and you might be ok.

It seems to me that 1/8" wood is pretty thin for for a lensboard. I'd just
as soon use a piece of aluminum. It won't be subject to seasonal
expansion/contraction issues, and will have no problem supporting a heavy
lens. Cover the front with leatherette and the back with flocking and it
won't look too bad. If you want to stick with solid wood maybe you could
laminate two thin pieces of wood together under pressure. It'll be thicker
than 1/8" but you could always rebate the the edges and the rear of the lens
hole if you need to.

On Tue, 1 Feb 2005 22:44:52 -0500, "Owen Lawrence"
wrote:

I have a 5x12" sheet of Cherry Wood, 1/8" thick, that is not quite flat.
How can I straighten it, and keep it straight?

You could rim it with a really sturdy frame, if not slots in a box then a
thick metal frame. (Sorry, I don't know what a lens board is so I can't
tell if that makes sense in your application.)

A lens board is part of a view camera. It fits into a frame on the
front of the bellows to hold the lens. To change lenses, you change
the board.

The advantage of this arrangement is that you can tilt the lens to
correct for parallel distortion and such as well as moving the lens up
and down to get 'impossible' shots.


Do I need to find a straight piece to start with?

That's your best bet. It's a small enough board.

- Owen -

I'd definitely get a better piece of wood. Flatness of the lens board
is critical on one of those camera.

--RC

"Sometimes history doesn't repeat itself. It just yells
'can't you remember anything I've told you?' and lets
fly with a club.
-- John W. Cambell Jr.

How about veneering the outside of a piece of 3/32" aluminum with a
really nice wood? Should remain flat if it's properly clamped when
drying...

In article , take out 'takeout' to reply wrote:

I'd definitely get a better piece of wood. Flatness of the lens board
is critical on one of those camera.

In that case -- he shouldn't be using wood at all, but something that won't
change shape in response to changing humidity (plastic or metal).

--
Regards,
Doug Miller (alphageek-at-milmac-dot-com)

Get a copy of my NEW AND IMPROVED TrollFilter for NewsProxy/Nfilter
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In article , PGG wrote:

I also have a piece of teak wood that is perfectly straight. I may just
use this rather than the cherry.

It may be perfectly straight now, but will it *still* be perfectly straight in
six months when the humidity is significantly different?


--
Regards,
Doug Miller (alphageek-at-milmac-dot-com)

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You need to make the lens board in three pieces (tongue and grooved together),
consisting of two side pieces (vertical grain), and one center piece
(horizontal grain). This worked well for my 810 lensboards. I used 3/8
mahogany, but cherry should be fine.

Curt Blood

PGG wrote in
newsan.2005.02.02.05.04.56.996000@NO_SP_A_Myahoo .com:

I also have a piece of teak wood that is perfectly straight. I may
just use this rather than the cherry.

Cherry is not really a good choice for what you're trying to do. It
doesn't tend to have that straight of a grain, and that introduces the
small stresses that, when cut very thin, take it out of flatness. If
you wet & weight it, as has been suggested, there's a good chance it
will just flex back into the same shape as it dries back out.

Teak might be a better choice. Pattern grade mahogany would probably
be even better (and cheaper than teak).

John