3" SH Turbohead possible mod to R/C battery

The N2 bulb is nice and bright driven by 6 rechargeables at 7.2 V -- prabably just about what the voltage drop on 3 @ CR 123s deliver.

It would be nice to be able to use this turbohead driven by a single R/C battery. The reason I've delayed is that I haven't been able to figure out how to keep the LA snug in the TH without sacrificing a body with a bonded dummy to wire to the battery source.

I've noticed that there is a depression in the back shank of the TH that gets covered with the TH collar that connects the TH to the body. I'm thinking that I could drill a hole the rest of the way through and use it for a self-tapping set screw that will firmly hold the N2 LA in place. Then, if I wire the R/C battery (with a switch) to the springs of a N2 I can clamp the TH to the R/C battery and enjoy a 2 1/2 hour run time on the compact rechargeable package.

When I put the TH back on my 9P body the hole in the shank will be unimportant because it is inside the various O-ring seals of the standard configurations.

The major complication may be connecting the wires to the springs. The springs appear to be steel so they probably can't be soldered. I'd may have to use tiny clamps if I can't persuade someone with a TIG welder or other small spot welding device to weld the leads.

Any reactions or suggestions?

Lemlux,

I'm not certain I understand your issues but I have been successful in taking lead wires and wrapping them once over a section of the spring and then soldering the lead wire. The lead is not soldered to the spring but is now captive. If you position the lead correctly, once the spring compresses, it bares on the lead and squeezes it. I have had good results with this approach.

- Don

Don:

Thanks. The most likely problem with your suggestion is that it requires spring compression to assure good contact. In the configuration I described (not clearly enough, apparently) the spring would be uncompressed, and the only thing holding the N2 LA in place in the TH would be the newly installed set screw.

Originally posted by lemlux:
The major complication may be connecting the wires to the springs. The springs appear to be steel so they probably can't be soldered.

Any reactions or suggestions?

Click to expand...

<font size="2" face="Verdana, Arial">Steel solders just fine. When I build custom cycle fenders for HD's, I solder all seams and lips to prevent cracks from vibrations. You WILL have to have a perfectly clean surface and use flux.

Any problems doing this would have to do with any plating that might (be incompatible) on the spring.

I tried solder with additional flux on the SF springs and got no where but perhaps I didn't have enough heat. Since the springs are not being compressed, it sounds like you have some room? I suspect that with some small nuts, washers and screws, you could place the screws through the spring center and come up with some type of lug connection? The screw can be inverted with the contact made within the cone section.

- Don

Slick:

Thanks for the input -- It sounds like plating on the springs might be a problem (not to mention my relatively primitive soldering skills.)

Don:

I really like the screw and nut idea. I'd used screws and nuts on the bottom of the polycarbonate DB head fingers that go into aluminum chambers to wire terminal connections, but I didn't have enough imagination to do the same at the bottom of a conical spring.

What an elegant, simple, and reversable suggestion!