Pushrod for 3M Scooter

[erich]

Need to replace a pushrod in a 3M Scooter. Since I don't want to perform major surgery, I need to get a 1/16" dia. (can be slightly less, but no more) x 36" (40" would be better) long metal rod with threads at least at one end. Have looked at local hobby shops all I could find in the right dia was 30" or less. All the 36" long stuff is to big in dia. Can't use the usual nyrods, cause the outer rod is to small dia. The flex cable stuff needs to be soldered at both ends. Found it's almost impossible to solder in that close without burning up the plane. So I believe the threaded rod is the best solution. At least as far as I can figure, which isn't to far. So here's (finally) the question, where can I get that size metal pushrod? Any help will definitely be appreciated, if not actually used.

Thanks

erich

[Kristjan]

Erich,

I have had good result using epoxy and flex cable. I have used it on various plane for 5 years or so now with never a failure. Began to try this after a painful soldering accident (soldering iron dropped into lap).

Or:

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXEMG1&P=7


might work although 1.8mm and you looking for 1.6mm.

-Kristjan

[erich]

Kiristjan

Is flex cable that gold colored metal rod, stuff. You epoxied metal to metal, that works??

Yea, have the .72 stuff, to thick won't go through the tube (will actually go through, but really to tight a fit).

erich

[Kristjan]

Erich,

Yes it is "bronzed cable" and I have had no problem with gluing with epoxy.

If the threading is not an issue I have also used carbon rod with a clevis glued with epoxy to the end. I have purchased rod from:

http://www.goodwindskites.com/goodwindskites/merch/list.shtml?cat=framework.solidroundcarbon

Very stong and quite light in weight as compared to steel or cable.

Best wishes,
-Kristjan

[erich]

I have carbon rods that will fit perfectly. In fact that is what was in there. Had connnected a threaded coupler on one end and a metal clevis on other. Used thin CA for both. The clevis held, but the coupler came loose. Re-glued it several times with CA, but it kept coming loose. I do need to glue a threaded brass coupler on one end. Will give epoxy a try if you think it'll hold.

Thanks

erich

[cynjon]

erich, two things I would try: First, maybe use JB Weld instead of regular epoxy? Super strong stuff. Second, maybe you can drill a hole through the coupler before securing the coupler to the CF rod (not drilling through the CF, however, since this will probably splinter/shatter it). This will allow more of a mechanical bond to the metal, which is harder to bond to than the CF.

Just an idea...

[erich]

Jon

Yea, I like it. The extra epoxy in the holes (will make a hole allway through brass coupler) should do the trick.

thanks

erich

[becsta]

One of the things Paul Naton does in one of his DVD's (I think it's F3 Building Clinic?) when gluing rigging couplers to CF rod is to carefully nick the CF rod where the glue will be, so that the glue has more surface and bumps to hook onto.

[regis]

First, the carbon rod should fit snugly into the coupler. Once the glue has dried on the carbon it will not absorb more. I have actually crushed the end of the carbon rod and that helps if rod is a little loose and provides a lot of surface for the glue to bind to. Drilling a hole through the side of the coupler is good too. BTW, I like your Scooter. I use to have one and loved it too.

[LVsoaring]

Perhaps soldering two pieces of 1/16 together using a piece of brass tube as a joiner? It would, obviously, be bigger in diameter where the joint is, but if it would fit, it may work.

[sno]

I would use rubber ca. Its the black stuff at your LHS (the car guys use it to glue tires to their rims). Then wrap it with kevlar and thin ca it.

[Mark Miller]

I commonly CA carbon pushrods to brass threaded couplers and have no problems. First I use a pair of pliers and squeeze the end of the carbon pushrod until the strands of carbon crack lengthwise a bit. This will give the CA bood bonding to the pushrod. I then fill the coupler with CA and push the rod into it. I then take a pair of diagonal cutters and slightly crimp the coupler onto the rod. Wait for it to cure. I then take a piece of shrink wrap tubing and put it over the joint. Put a dab of CA inside and shrink it. it will be bullet proof.

Mark Miller
Isthmus Models

[erich]

Mark

Sounds pretty thorough!!! Do you use thin CA or thick? Alsos do you still carry the 3M Scooter?

Almost forgot, your MIRAGE has become my favorite glider, along with the Camano. Have flown it a lot lately, about 50 flights, with no damage. She's a beauty!!

erich

[Mark Miller]

Erich,

I use thick CA. Make sure you clean the coupler well on the inside so the CA can stick too. The crimping will act as a mechanical fit too.

I took the 3M scooter off my site while the manufacturer redesigned a few parts of the kit. They took it off the market for awhile. I need to check back with them to see if it is available yet.

The Mirage is a great plane and not as popular as it should be. I will take it over the Oly II and the Paragon. Back in the day it seems to not have had the marketing force of the other two kits.

Mark

[cynjon]

The Mirage is a great plane and not as popular as it should be.

Maybe someone should offer a full kit... ;) :p

[Mark Miller]

Whoops...YeeHaw!!!!

[Mark Miller]

heheh....Thanks for the push. It's getting closer. I'm working on the manual as we speak. Adding pictures and such. Then it's just a matter of cutting the dimensional lumber and putting it in a box. Since we are in the middle of selling our house and the shop is packed away I'm looking for someplace else to do it.

BTW...does anyone have a NIB old Mirage kit around? I'd like to know the box dimensions so I can have boxes made.

Mark