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sbmathias
08-13-2010, 08:19 PM
I have a fairly old point-and-shoot Kodak camera. The little latch tabs that keep the battery door shut have broken off. I wanted to try to save the camera by gluing on the one piece that I have, but didn't know what kind of plastic it was. I took the back off, and right there in plain sight I saw "ABS". So, I carefully glued the broken piece back on, and it seems to be OK.

However, notice that I said the (plural) tabs were broken. There is still one tab broken off and the part is missing, and that tab is part of the inner "chassis". It is black in colour instead of the beige of the outer case.

My question is: Any guesses on what type of plastic the chassis might be made of? Although I don't have the missing piece, I'd be happy to try to glue on a billet and then (here comes the machining component) machine it away to leave a functional tab.

Any guesses that have any reasoning behind them?

Duffy
08-13-2010, 11:55 PM
If they made the battery cover from ABS, it is not UNREASONABLE to assume that they would mold the case from ABS also. It has the properties of reasonable strength and stability, and the WONDERFUL property of CHEAP and readily moldable, (think of all that black drainage plumbing!)
If you are going to try and machine a small part, use some material from a plumbing fitting.

sbmathias
08-14-2010, 12:08 AM
I kind of guessed ABS, but it wasn't obvious how to expose more of the chassis to look for a designation.

Using plumbing fittings as raw materials is a great idea!

aostling
08-14-2010, 12:09 AM
My question is: Any guesses on what type of plastic the chassis might be made of?

Polycarbonate is often used on the chassis of DSLR cameras. That might be a good guess for you P&S camera too.

Paul Alciatore
08-14-2010, 01:24 AM
Why bother with IDing the plastic? Get some J-B Weld or other high quality epoxy and put a couple of small music wire pins in the break. Have them in an inverted "V" if you can for added mechanical strength. Then build a form around them and pour in the epoxy. Machine it to the latch shape when it hardens. It will probably last longer than the original plastic. I have repaired broken plastic gears this way.

sbmathias
08-14-2010, 09:08 PM
I hadn't thought of JB Weld. One problem with this, regardless of what I use, is the size and shape. I do have a (almost!) second camera to measure, and the latch tab I need to recreate is an L-shape that the battery door slides under to hold. The thickness of the L leg is only about .050", and measures about .1" x .1". I like the idea of small wires to connect existing to new - will have to see if I could pre-bend some wires then epoxy them into some holes, then build up.

Liger Zero
08-14-2010, 10:50 PM
Put a TINY dab of nail-polish remover on it. If it softens it's styrene-based. If it doesn't... well...


If you could clip off a small sample you could burn-test it. Each material has a unique smell when burned. Styrene smells totally different than Delrin which smells different than polycarb. Won't tell you the specific brand but it will get you close.