Need Help Identifing Q500 Plane

[orenda635]

I bought this plane at a swap meet last year. The guy told me it was a Q500 class plane, that's it.
http://img230.imageshack.us/img230/5797/dscn0036yr2.th.jpg (http://img230.imageshack.us/my.php?image=dscn0036yr2.jpg)

I'm positive it isn't an ARF. Any ideas what this plane might be called so I can get more info on it?

Second, I'm dealing with an engine mounting problem. As you can see in the picture, it has a ring mount. I'll try to get a close up of it later. The problem with this mount is it doesn't fit the engine I want to use. It has three holes in it for mounting some sort of engine and three more for bolting it to the firewall. There are three threaded grommets into the firewall for the bolts. I tried using the DB mounts but I couldn't get them on strait due to the way these grommets are positioned. Any ideas what sort of engine this could be for? Is there anything I could substitute? I'm trying to use an OS LA40 with it.

[Konrad]

It's a Viper and not the Hobbico unit.
You got me on the engine mount
Konrad

[daven]

Too me, it kinda looks like a modified Doddger kit. Most were built with standard tails, so the V tail looks a bit different.

I'd remove the threaded inserts, drill out to a commonly available size of hardwood dowel, and epoxy those in the holes. Redrill the firewall to whatever mount you want to use.

[orenda635]

Too me, it kinda looks like a modified Doddger kit. Most were built with standard tails, so the V tail looks a bit different.

I'd remove the threaded inserts, drill out to a commonly available size of hardwood dowel, and epoxy those in the holes. Redrill the firewall to whatever mount you want to use.

Ok thanks. Sounds like a plan. The threaded inserts are epoxied in there pretty good. The model is not covered either, that's a fiberglass monoque fuselage. That puts using a heat gun out of the question. What's the best way to get those out?

[dwbebens]

Orenda635;

Are those threaded "grommets" you speak of actually what are called "T" nuts or "blind" nuts? Are they like little flanged top-hats placed in from the tank side of the firewall? If they are, I may have a removal method. Get a matching steel socket head cap screw 3/4" to 1" or so long. Clean the oxide layers off the head as well as you can. Thread this screw into one of the "T" nuts from the front side of the firewall. Do not run the head up against the front face of the firewall, leave about 1/4" space. Then position the fuselage vertically with the firewall facing up. Heat up a soldering iron (50 W or so) and using solder and flux make a nice bead of solder on the top end of the head of the socket head cap screw. Now just keep the soldering iron against the head using the molten solder as a heat transfer medium. This will transfer a lot of heat just to the screw and thus to the "T" nut, minimizing any unnecessary heat to the fuselage. After a while, enough heat will be transferred to the epoxy around the "T" nut to make the epoxy soft enough to push the "T" nut back into the tank compartment using the cap screw. If there already is a screw in place that you can't remove, use the same method as well as you can, to first remove the screw. Then proceed as described above.

I've done this a number of times for a number of similar "epoxy locked" situations and it always has worked for me.

Doug Bebensee

[rdyturn]

Since I designed the original Viper Q-500 I can verify that it is not my airplane. Looks like one of several copies of my aircraft from the mid 90's. I designed the Viper in 1985, sold it to Hobbico in 1993.

Doug Whiteaker
AMA 5488

[wylieruneyjr]

If you can get the mount off redrill it four holes to match back plate of the 40 LA and use it. Get longer back plate screws and bolt the mount to rear of engine, don,t remove back plate. You will then need to mount the remote needle valve on the fuselage somewhere. Just something to consider! ;)

[orenda635]

I think I may have solved the engine mount mystery. I was looking at Jett's website and the Cast 500 seems to use a similar mount. The bad news, it's $325 for one of them. :(

http://www.jettengineering.com/engines/all-race.html

[daven]

Remove the engine mount and either unscrew the threaded inserts or pop the blind nuts out.

Buy some 1/4" hardwood dowels and drill out the holes for the dowels and epoxy 1/4" pieces into the holes. Sand the firewall flush and redrill the firewall for whatever mount you want to use.