I a piece of equipment that uses a set of large lenses. The lenses are approx 1"x7"x7" and weigh 2 or 3 lbs each. There are six lenses in the set. The lenses cost several hundred dollars each.
I'd like to build a wooden case to keep them in. I'm envisioning a case made out of a light colored wood that is felt lined and has individual 'pockets' for the lenses to slide into. When the lid is closed, I'd like it to hold the lenses securely in place with no slack.
The case needs to be strong enough so that it can withstand typical shipping stresses.
What's a good choice of wood for this? What kind of joinery would you recommend for the sides and bottom.
For the value of the lenses and the shipping policies of various carriers, I would think that purchasing a commercial made product, like an aluminum or steel clad equipment case would be a better choice. These typically come stuffed with a high-density foam with pre-made cutouts that you could adapt to handle the lenses. Perhaps building small individual wooden cases for each lens and having them fit the cutouts would be the best of both worlds. You have an approx value of $1,200 in lenses so spending 10% of that for a commercial case certainly seems reasonable to me.
Just a thought from having shipped lot's of 'spensive equipment around the country and seeing what's held up to the abuse of that 800lb gorilla that lives on those planes.
I'm curious as to what equipment these lenses are for. Gadgets like that fascinate me.
I'd recommend building the outer case out of relatively thick (5/8" or 3/4 ") high-quality, stable plywood (e.g. baltic birch ply), rabbetted into solid hardwood frame. The lenses should be wrapped in protective material (foam or whatever), and fitted into an interior rack that isolates them and holds then securely. The interior rack would also be built out of baltic birch ply. Use high-quality hardware (e.g. full-length piano hinges), and you're set.
Back in the good old days when high speed data was a 150 WPM 28 ksr teletype, some businesses were still using Morse, and test equipment was either cased in a wood box or the chassis was wood, the wood of choice was red oak with box joints. The finish, if I recollect correctly was usually a curing oil.
Got to agree with Bob. Zero Halliburton makes some great cases, and there are even some blow molded types around that should be sturdy enough. Several come with full fitted protective foam that can then be cut to fit the lenses. Add, maybe, a soft cloth bag to each lens, cut the inserts, install, close and ship.
Do NOT lock if shipping by air. All that does these days is increase your costs, as the locks will be cut off.
Charlie Self "Inanimate objects are classified scientifically into three major categories - those that don't work, those that break down and those that get lost." Russell Baker
I built a case for similar needs (expensive eyepieces for my telescope) using
1X maple and box joints. I take it on airplanes and it withstands the baggage handlers. I don't know how it would hold up to shippers though. I lined the inside with foamboard and velvet. The eyepieces fit into individual compartments achieved by 1/2" stock in bridle joints.
My instrument cases all follow much the same design. Two cases, nested inside the each other. The inner case has all the complex pockets etc., and is generally held together with half-laps or mortice & tenons. Wrapped around this is an outer box that's a "hard shell".
For the outer carcase I'd use a tropical, like African mahogany. It has the advantage of stability. My favoured wood source for this is old 1950s wardrobe doors, because they're big wide single panels that are already well dried and extremely stable. I can buy modern timber, but not in the same widths without paying a lot for it.
Inside I use lime (basswood), because of its moisture properties. I may use this for the outer carcase too, if I'm going for traditional Japanese work (I can't source Paulownia).
Finger joints are the best joinery. Dovetails are for those who either _want_ to cut them, or know they can cut this many and do them all accurately. Much of the strength actually comes from the two-layer internal construction and staggering the joint lines.
I wouldn't seal the case and make it waterproof. If I need that, then I buy in a ready-made plastic case. A small mating rebate around the lid edges is worth the trouble though.
Tops and bottoms can either be nailed on, or set slightly loose in an internal groove. They're not a structural part, they're an ablative buffer in case of serious impact. The strength is supplied by the internal lime framework. Have the panels spaced slightly away from the inner frame.
To get internal "spring" on a lid clamp, I like to make a tiny wooden replica of a "sprung" dancefloor. Lime works well for this - Fretsaw the closure frame inside the lid so that the pressure pad is supported by a 2" long cantilevered long-grain beam, fastened only at the ends. Unlike felt padding, this won't compress with age. For something complicated like a theodolite, make the lid part of the internal frame and hinge it to the lower inside part, so that it closes separately and before the main lid.
Label the internal nests so that it's clear where things go, how they go in, and which way you need to point their hinged brackets etc. to fit. Take a photograph or diagram of it correctly loaded and glue it inside the lid if you need to. Remember, it's not always you who will be loading it.
Don't use felt for padding. It has obvious problems with moisture, but it also gives off sulphur and that can be a problem for brass or disaster for silver. Use closed-cell polyethylene foam instead - tool box liners.
Design in space for dehumidifiers, ideally a removable sack the size of a sock. The little teabag sachets are too small to be of any use. Provide an obvious designated place for it, and a little brass strip or sprung wire clamp to hold it there.
Shellac is a good finish. Give it a week of warmth and there's no outgassing problems.
Study Victorian military campaign furniture for the best ideas about hinge, locks, handles and corner guards. Finding this sort of quality brassware isn't too hard these days, although some of it gets expensive.
A cheaper option is to go to a big mil-surplus dealer. Top quality fibreglass cases come in every size and for minimal money.
I wouldn't use a Haliburton product because they're evil bastards.
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