There are head lock devices made for this application, but I wanted something a little smaller and use items I had in my shop. The glo plug in my O.S. .90 four stroke is in a bad location (glad O.S. changed that ). Having an onboard glo driver in this plane I needed a permanent connection to the glo plug. What I used was a small wheel collar, a Sta Kon ring lug, (a number 10 or 14 is about the right size and matches the diameter of the wheel collar), soldered to the wheel collar, and a small piece of .030 lexan plastic with a hole drilled in it for the insulator.

It may have been easier to just buy something like this


http://www2.towerhobbies.com/cgi-bin...&I=LXBC35&P=ML

DelRay, I often do just what you do as it gives a much shorter profile than the commercial units does. You do have to make sure you get a brass wheel collar though as most are now aluminum and you can not solder to them. I just use a small piece of silicon fuel line as an insulator although lexon is probably a more permanent solution.

DuBro has an excellent clip that is very small.

It comes in two versions. One goes straight on in case the glow plug is recessed and the other comes in from the side for a low profile.

Here is the side-mount type:

Thanks for the comments. Myself, Technito20, I don't care for the push and twist glo plug unit like the one you gave the link to, although it probably is a good set-up. Thanks for that link. I might add that it wasn't that difficult to put it together versus the 11 or 12 dollars the Du Bro unit sells for.

Good point made Rodney about the collar selected should be made of brass. The silicone fuel line piece used for the insulator sounds like it would work fine.

MinnFlyer, thanks for the pic.

I just knew this had been done before but I just had to type something.

I make mine out of hair pins and solder a wire to it with teflon washer for insulator. Never comes off in air and hair pin has plenty of tension for clamping pressure. You will have to cut and rebend the pin to keep it short and strong.

None of the cheap fixes are as good as a plain old control rod connector. The kind that has a pin that goes through the servo horn and a clip holds it on. Great Planes makes them in 12 packs or larger. Just drill out the hole big enough so it will fit over the glow plug pin. The handy allen head set screw will tighten up on the glow plug pin so tight i've never had one to slip. This aint my origional idea, i saw it yrs ago in RCM, it works great. Lastly, solder a wire to the pin thats origionally meant to go through the servo horn with some shrink tubing to help relieve the strain and you got a connection that cost about a Quarter. Run these wires to a switch and then to a Radio Shack C or D size battery holder. Run the end of the other wire coming out of the battery holder to a mounting screw on the engine block comleting the circuit. According to the club that designed this ingenious little device, they can fly all evening with one battery with the power on the entire flight time turning it off only when the plane lands. I've never tried this , but i do leave my battery on until im out on the runway and ready to fly, then turn it off, i hate flameouts just when im ready to take off.

kamakazi You have aroused my interest. How about a link to the connector you are referring to? Did a quick search at tower but did not see what I was visiualizing.

I am not 100% sure what Kamikaze is referring to myself Mike. This is what I use on my heli's though, http://www2.towerhobbies.com/cgi-bin...?&I=LXK099&P=0 They are brass and make for great soldering. First thing to do is tin the little protrusion with solder and this is where I solder my wire to. The end opposite of the protrusion is where the screw goes in and the hole on the side is where you drill out to fit your glow plug pin. Once you get that big enough, you simply screw in the screw and it locks it down to the glow plug. I use silicone wire from the gas grill shop too, that way I don't have to worry about the wire melting on the head or such. I hope this makes sense and helps you out.
Eric

Very interesting. It sounds to me he's referring to a clevis that is fastened to a control rod and held on the rod with a set screw. The pin is held into the control horn with the small clip on the pin. Myself, I would never use that type of clevis for a control surface, but it sounds like it would work fine for this application. I might be wrong on my theory, but it had me wondering also.
My favorite plug connector is the one made by MPI, it costs about $5.00 and is very well made. It has a nice rubber boot that seals it down around the plug.

The part I'm referring to is the Great planes pushrod connectors, part #GMPQ3870. And i never use them for pushrod connectors either. I either solder on a solder clevis or the dependable "Z" bend

Ahhh, sooo, it wasn't exactly what I was envisioning, but close. A good application for that piece, thanks for the pic.