Companion forum thread to:

Make Your Own Gear - A Thumbscrew for the Steripen Adventurer

Roger, thanks for the article, especially the screw sizes, it makes it much easier having the correct sizes before going to the store, without trying to size everything at the hardware store.

BTW, have you tried just epoxying a something to the supplied screw? I thought about this but my screw is still loose enough so I just push down on my thumb to turn the screw (I don't over tighten it- I don't have to tighten it too much to get it to work then I just remove the batteries when I'm finished).

Hi Tad

> have you tried just epoxying a something to the supplied screw?
One of the options I showed involved making a knob out of a toothbrush handle to mate with the groove in the supplied screw, then gluing that in place. However, I am not sure whether epoxy will hold toothbrush plastic very well. Some cyano-acrylates (forms of super-glue) will bond OK.

But yes, of course you could epoxy something else to the existing screw. I would recommend giving it a bit of a mechanical test before heading out though: some forms of epoxy does not always adhere very well to plated metal (and won't adhere to copper or brass at all). This is why I machined my 'real' version out of black nylon: better strength.

Cheers

Thanks again Roger, I thought that epoxy was tougher and would thus hold better then the superglue- you again saved me some time.

I have been using the Steripen for about 3 years and twice the screw has become irretrievably stuck or stripped. I had to send it back for extraction/repair. This looks like a good fix.
Howard

Thanks Roger! Like Howard managed to strip the nut or screw. Need to drill out the screw and probably retap the nut. Thanks for providing options and guidelines for the repair and IMHO improvement.

Actually, I think the 'nut' which holds the screw is just that: a conventional nut. I haven't looked at replacing it, but it may be possible.

Cheers

by the way, I tested the battery issue by running a one liter cycle once a day until the batteries died. I started with two fully charged lithium rechargeable batteries. The entire test was indoors at 'room temp.' The batteries lasted about 30 days. Of course, in the field, you would be running more than one cycle a day.

>"In the middle of the second photo you will see a small circlip: this goes over the shaft of the silver screw in a special groove to stop it from getting lost. It is unlikely that you can re-use this idea unless you have access to a lathe. But there are alternatives."

I've used an electric drill and a triangular file or hacksaw blade as a quick and dirty lathe alternative for this sort of application: cutting a groove on a rod to hold a circlip. Just chuck the rod or screw in the drill, clamp the drill in a vice in such a way that the workpiece turns toward you, lock the drill on and then press the file or saw blade against the spinning screw, while pushing against the direction of spin. Unless the screw is hardened steel, you should be able to machine a nice groove with this method. It isn't precision work, but good enough to hold a circlip.

Edited by DavidDrake on 07/11/2009 10:30:55 MDT.

Hi David

Thanks for the idea. Yes, it will work, but please anyone who tries it: be very careful! Make sure everything is tight and secure, and don't use high force.

Cheers

Roger, for interest I weighed am actual 5c coin (a nickel is close in size for the US guys). The coin only weighs 2g, and works just fine to untighten and re-cinch the screw. Some countries use a very light alloy for their small coins, for which the small coins come in at less than 1g. Of course, the coin has to be put somewhere you can find it. Just a thought.

How not to lose it: Drill a hole in it and put it on a string around your neck. I can use the coin to pop open my bearikade too so it's multi-use....

The Nite Ize biners work great in the steripen.
The size 1 weighs .14 oz.

All good ideas, but having actually used coins and other things in the field, I think I will stick with my plastic thumbscrew. Yeah, lazy, I know :-)

Cheers

You could take a piece of aluminum with thickness to fit the slot or smaller. Size based on torque needed - surface area to grasp the screw. Epoxy it in place after material mating preparation. Finish filing edges and size modification to complete.

After reading through Roger's fine article, I realized I was essentially too cheap and lazy to seek out a metric thumbscrew for my new Stripen Traveler. So I drilled a 1/8" hole in a penny, and another hole in the hypotenuse of the Steripen cap; tied a stopper knot in a 6" length of light guyline, threaded it out of the cap and tied a loop through the perforated penny. three minutes, three cents' worth of materials, and the tool stays with the unit always.

Hi Robbie

Yeah, neat idea. I hadn't thought in that direction.

cheers

Any advice for removing a screw that won't unscrew. This fix looks great if I could just get the screw undone and take the battery cover off