PDA

View Full Version : Making Lensboards



jdaivpmed
21-Aug-2009, 15:40
I have a couple of questions on the subject of making your own lensboards...

1. Does anyone know of a list or database of lensboard dimensions by camera make and model, (ie. overall thickness, plateau height, size, bevels, etc)?

2. From an engineering standpoint is it better to make the lens board out of plywood or a solid piece of stock hardwood? For example, my Zone VI is made of Black Walnut... am I better off cutting and milling my lensboard out of a piece of walnut plywood or an actual solid piece of walnut? I can get either locally, and while the solid wood is a bit more expensive it's really only adds about two bucks to the cost of a piece big enough to make five lensboards.

Thanks,

John

jb7
21-Aug-2009, 16:18
Plywood would be better structurally-
less inclined to move- warp or twist.

Unless you can pick a very well seasoned piece of Black Walnut,
you're not entirely certain how it will react to being machined.

That said, I don't know your camera, or the design of its boards...

And it's only my opinion-

Walter Calahan
21-Aug-2009, 16:59
I make my lens boards using modeling plywood. They function perfectly, but aren't as pretty as black walnut.

Mark Sawyer
21-Aug-2009, 17:09
For my 6" square and smaller lensboards, I like Pergo or a similar material. For dimensions, I'd recommend using an existing board as a template, or measuring directly off the camera.

Jim Michael
21-Aug-2009, 17:25
I found thin mahogany that was 1/8" thick, cut one piece for the inner and one for outer section and glued them together for my 2D. If the wood is too narrow you can use 2 pieces for each section and layer them orthogonally.

Vaughn
21-Aug-2009, 17:31
Original solid hardwood lensboards always seem to be made out of several pieces of wood to prevent warping -- so they are more complex to make.

That said, I have made several for my Zone VI 8x10 out of a piece of solid black 4 ply mountboard drymounted to a piece of 8 ply matboard. After several years, still 100% functional.

Vaughn

Archphoto
22-Aug-2009, 15:44
It depends a bit on your local availability.
If you can get a beautifull aged non-warped piece of solid wood: by all means get it and make a lensboard from it.
But be prepaired to replace it when it warps.

As it has been said before, plywood is stronger, looks less beautifull at times, and warps less.
And you have the option of making a lensboard from a sandwich of aluminium with a thin covering of wood vernier. In that way you would have strengh, non-warp and beauty together.
It all depends on your skils......

Peter

eli
22-Aug-2009, 16:58
Woodcraft stores usually carry a good selection of hardwoods and quality thin plywood's. If you buy some 1/16th thick solid mahogany, for example, and glue it up at cross sections... TA-DA... Plywood!

African Blackwood, Bubinga, some of the Maples and Ebony are also good choices. I suggest you use Titebond III for the glue-up.

Eli

tom north
22-Aug-2009, 18:26
John,
Lens boards can be made out of anything, almost. I've made them out of mahogany and fir plywood, solid oak, aluminum and cardboard. They all work and I have solid oak and mahogany lensboards that are over 70 years old that have not warped. All had to be made from scratch. Solid wood however may warp as you plane it down to your required thickness, that is why some of the older lens boards are made from 3 pieces glued togather. Your only limitation on lens boards is your imagination and woodworking/metalworking skills.

Best

Tom

mandoman7
22-Aug-2009, 19:58
http://www.horizonhobby.com/Products/Default.aspx?ProdID=MID5326

erie patsellis
22-Aug-2009, 22:24
for a database of sorts, try http://www.skgrimes.com/lensboards/index.htm The the more popular ones are there.

Roger Thoms
23-Aug-2009, 09:09
for a database of sorts, try http://www.skgrimes.com/lensboards/index.htm The the more popular ones are there.

I had missed this on the Grimes website, nice resource for lensboard sizes. I also have drawings for 5x7 and 8x10 Seneca boards if anyone is interested. These are the ones that have several chamfers and a small screw at the top.

Roger

Alan Davenport
23-Aug-2009, 09:28
I make Calumet/Cambo lensboards from 1/8" modeling plywood. Those boards are over 6 inches square; I'd worry about solid wood eventually splitting, not to mention getting broken if cut that thin. I paint the boards flat black inside and out, so it doesn't matter what kind of wood they are.

Roger Thoms
23-Aug-2009, 09:58
I make Calumet/Cambo lensboards from 1/8" modeling plywood. Those boards are over 6 inches square; I'd worry about solid wood eventually splitting, not to mention getting broken if cut that thin. I paint the boards flat black inside and out, so it doesn't matter what kind of wood they are.

I would not worry to much about solid wood boards splitting. I think the key is to make them three piece with tongue and grove joints. That said plywood is much less work and it is strong and stable.

Roger

eli
23-Aug-2009, 11:19
If you decide on butt joints for building each layer from narrow widths, which in this application are good enough, I suggest you use a thick, quality 'super glue' to quickly join the edges of separate pieces. Afterwards, use an aliphatic resin yellow glue, like the Titebond (http://www.titebond.com/WNTitebondIIITB.asp) III I mentioned earlier to join the plys.

Eli

eli
23-Aug-2009, 13:51
Here (http://sketchup.google.com/3dwarehouse/details?mid=7c62cec202035b17ad2b2411a6a77633) is a quick sketch of a sanding-paper shooting board for making edges square for butt joints. Add 'L' brackets, or wood supports to the ends, if needed, to ensure it is rigid as it must be square at 90 to work properly.

Use a quality sand-paper, about 120-180 grit should be fine enough, glued on with double stick tape or aerosol glue and don't worry about any edges other than those that are to be joined. After you lens board is glued up and trimmed close to final size should you work on the outside edges.

Finally, Bees wax is a good protective finish for unpainted wood surfaces. You can make a excellent compound by taking equal parts of Bees wax, boiled linseed oil and turpentine and melt the wax into gently warmed linseed oil and turpentine, outside with no open flame, into a small glass jar, reserving the lid for storage. It doesn't take a lot of material to make this, two ounces each is plenty for a lot of compound.

A cardboard box with a black plastic bag wrapped around it and inside as well, with a pane of glass or acrylic on top will do the job as a solar oven when the sun is high.

Cheers

BradS
23-Aug-2009, 17:19
Here (http://sketchup.google.com/3dwarehouse/details?mid=7c62cec202035b17ad2b2411a6a77633) is a quick sketch of a sanding-paper shooting board for making edges square for butt joints. Add 'L' brackets, or wood supports to the ends, if needed, to ensure it is rigid as it must be square at 90 to work properly.

Use a quality sand-paper, about 120-180 grit should be fine enough, glued on with double stick tape or aerosol glue and don't worry about any edges other than those that are to be joined. After you lens board is glued up and trimmed close to final size should you work on the outside edges.

Finally, Bees wax is a good protective finish for unpainted wood surfaces. You can make a excellent compound by taking equal parts of Bees wax, boiled linseed oil and turpentine and melt the wax into gently warmed linseed oil and turpentine, outside with no open flame, into a small glass jar, reserving the lid for storage. It doesn't take a lot of material to make this, two ounces each is plenty for a lot of compound.

A cardboard box with a black plastic bag wrapped around it and inside as well, with a pane of glass or acrylic on top will do the job as a solar oven when the sun is high.

Cheers

good stuff! Thanks eli.

Are you suggesting melting the bees' wax in a solar oven?


For the OP....I just finished making a lens board out of a scrap of 3/8 inch plywood....next time I will pay for a real one!

eli
23-Aug-2009, 17:49
Yes, I suggest warming the bees wax and turps together, with some Saran Wrap over it, so it does not evaporate off too quickly, with the linseed oil in a separate container .

When everything is ready, stir in the oil so everything is well blended and allow it to cool, lid on.

Use it like a regular waxing product; apply with a piece of denim or cotton muslin, with a wad of cotton balls inside to make a small ball. Wipe off any visible excess and allow the waxed piece to cool. After it is cooled, it should have a slight haze. Buff it up with a clean rag and repeat; two coats should be enough. To kill a gloss effect, mix a bit of alcohol with some water and wipe the finish down lightly.

I should note that if you use wood with large, open grain, like an Oak, the wax will fill the grain and may show as a light colour. Some folks find it distracting so if you have any doubts, try it out first on a scrap piece.

Of course, if you're going to paint the backside of the board, you'll want do that before waxing the front or edges.

goamules
23-Aug-2009, 18:33
I haven't seen my method mentioned, so here it is. I use two pieces of masonite glue them together to make the light trap step. I use Gorilla Glue. Then I use contact cement to glue a thin piece of mahogany verneer over the top of the outside piece. The inside is painted flat black. You end up with a strong, flat, cheap lensboard that looks like solid wood on the outside. Mark's pergo method also looks very nice.

Ernest Purdum
24-Aug-2009, 14:02
Model shop plywood is great. It may not come in the exact thickness you need, but there is an easy answer. Nice hardwoods come in so many thicknesses that you can laminate up to whatever dimension is needed. The source I have used has a website, WWW.MicroMark.com. They are useful for other items too.

Archphoto
24-Aug-2009, 14:41
Thanks for posting, Ernest, now somebody that knows such an adress in Europe...
They shure have everthing for modelbuilding...

Peter

Jim Michael
24-Aug-2009, 15:04
Looks like they ship internationally.

eli
24-Aug-2009, 17:39
Peter, look for a local model railroad hobby shop. Chances are they will have what you need.

Eli

Archphoto
24-Aug-2009, 18:52
I will, I will, but looking at what these guy's sell...
Haven't seen this much together in a long time.

Thanks,

Peter