Basic repairs - j-3 ultra micro cub

[RONALDO_UK]

Hi - I'm brand new to RC planes and have left it late in life. I haven't spotted any info yet on VERY basic repairs. I bought a J-3 Cub ultra micro and in just a couple of weeks, it's needing some work. The long wire linkage from control surface has come out of the sleeve (not sure how) and the short length is still attached to servo. Are these wires simply a push-fit thru sleeve and just pushed/pulled to adjust overall length?? I've also got to replace tail-section. Will this be marked for the horn position or do I make a cut? myself? Is its retainer just pushed on or glued and/ or taped? Do I bend the plastic horn to hook in the wire or hook it in and then get wire into the sleeve? Sorry these questions are incredibly basic but I can only get spares by mail order - it takes time and they're fairly expensive so I don't want to abuse/break anything. If anyone can answer or direct me to appropriate thread(s), I'd be grateful. Or even suggest a good beginner's book that covers these topics and more.

[ronhawker]

Originally Posted by RONALDO_UK

Hi - I'm brand new to RC planes and have left it late in life. I haven't spotted any info yet on VERY basic repairs. I bought a J-3 Cub ultra micro and in just a couple of weeks, it's needing some work. The long wire linkage from control surface has come out of the sleeve (not sure how) and the short length is still attached to servo. Are these wires simply a push-fit thru sleeve and just pushed/pulled to adjust overall length?? I've also got to replace tail-section. Will this be marked for the horn position or do I make a cut? myself? Is its retainer just pushed on or glued and/ or taped? Do I bend the plastic horn to hook in the wire or hook it in and then get wire into the sleeve? Sorry these questions are incredibly basic but I can only get spares by mail order - it takes time and they're fairly expensive so I don't want to abuse/break anything. If anyone can answer or direct me to appropriate thread(s), I'd be grateful. Or even suggest a good beginner's book that covers these topics and more.

The control linkage does just slip into the sleeve. Once you get the length right you can drop a drop glue like CA to hold it in place.

When you get the new tail surfaces you will have to cut a small slit in the surface and insert the control horn with glue. You should be able to get the position right from the old one.

The plane comes apart very easily for repair. The fuselage is help together with tape. The wing and the top half of the fuselage are together and the the fuselage splits horizontally. Once you take the top off you can see and repair just about anything. Probably won't be the last.

I found after carefully cutting the tape with a razor blade or hobby knife that putting it back together was easy. Most of us use simple Scotch tape to hold it together after repairs. However, if you need to take it apart again the tape can pull the color off the foam. The first time I put it back together I used packing tape which is stronger. Then next time I cut the packing tape and put it back together with Scotch tape and then the Scotch tape could be pulled off for repairs or changes without damaging the color on the foam. Took several rebuild to figure this out. But now it works great.

[RONALDO_UK]

Thanks ronhawker for your very quick and helpful reply . The Cub is already in pieces! - it was coming loose so I helped it! As you say, some of the paint has come away (what type is used? - altho doubt I'll get a good match?). I'm waiting for spares - I had a spare wing, props and shafts but those bits are fine! If I flex the horns to hook in the wire linkage, do they flex back into shape ok, they don't seem brittle? Could (old) tail be stiffened with flat carbon fibre? Would be nice to have a bigger plane so it's less like brain surgery and you're in the realms of adjustable clevises etc. I'm hoping I can adjust everything back to original set-up.
Regards.

[RONALDO_UK]

Luckily the parts I bought were pre-cut for the horn positions! But can someone advise me if the plastic sleeve over linkage wires is heat shrink? I haven't got any so I'm reluctant to cut/pull off. Is there a subtle technique for re-connecting the linkage wires? - are they hooked on servos 1st/last? Are the horns bent to hook on the wires? I appreciate there are weight/size restrictions but it's a shame there's not a simpler adjustable clevis arrangment.
I would be grateful for any advice and general tips.

[ronhawker]

Originally Posted by RONALDO_UK

Luckily the parts I bought were pre-cut for the horn positions! But can someone advise me if the plastic sleeve over linkage wires is heat shrink? I haven't got any so I'm reluctant to cut/pull off. Is there a subtle technique for re-connecting the linkage wires? - are they hooked on servos 1st/last? Are the horns bent to hook on the wires? I appreciate there are weight/size restrictions but it's a shame there's not a simpler adjustable clevis arrangment.
I would be grateful for any advice and general tips.

I don't remember on the rods as I reused the ones I had as they were not damaged. They can be adjusted by length by pulling on them and then you can set them with a drop of glue.
The holes in the control arms are for response adjustment. The farthest out is the slowest response for beginners. The more you move in the quicker the response to control input for that surface. Truthfully mine are on the 2nd hole in from the outside and I fly on high rates in my DX7 and that works even with the P51 motor. It will turn on a dime just about. It is still just a 3 channel rudder plane so scale type flying is about all it can do, especially with the dihedral the wing has built in.

[RONALDO_UK]

Thanks again! Are you in the UK too? I re-used existing rods too but had to detach them as I was renewing the complete tail section. One (long) rod had somehow come out of sleeve so was obviously not glued or heat shrunk. Believe it or not, I've actually got it all back together again - I had to wait for good daylight for my dim eyes! I turned the plastic horns to get the hooks in and put both in 1st hole as they were before. I used gorilla-glue to hopefully hold, not best choice as it expands but was quickest setting glue I had. It's not quite as perfect as before but hopefully I can compensate in flight? - used a lot of scotch-tape too! When I dare to fly it, l'll wait for a very calm day and be well away from trees!

[ronhawker]

I live in Arizona, so we are quite a ways apart. Today there will be lots of sun and a high of 107F or 42C. It was 110F yesterday. Summer has arrived here! Where are you in the UK? I ride a Triumph and have had many English bikes over the 50+ years I have been riding.

[RONALDO_UK]

I just wrote you a lengthy reply which disappeared when I submitted it??! Drat! And on 2nd occasion too, but this time I took a copy.
I was guessing your location by the time of your reply which was early (in Arizona) but not here because I think we're 8 hours ahead.
I'm in London, about 10 miles south of the centre and on the road to the south coast, about 40 miles away. But nobody in the UK is more than 70 miles from the coast.
Can't match your weather but for several weeks we've had a heatwave (by our standards) with temperatures in the high 70s and very little rain in these parts. But that's all changed recently as "summer" approaches and it's now wet and windy.
Until recently the last bike I rode was a BSA Bantam, over 30 years ago. It's still in my garage and a legacy for my son! But my uncle's pride and joy was a Triumph Speedtwin, about 40 years ago. However, last year I bought a small 125 cc Yamaha (quite new but old-style), probably equivalent to a 250cc from yesteryear. I found the Japanese had swopped sides with the gearshift and brake! I picked it up 100 miles away and rode it home - didn't take long to adapt.
Feels like I've written a bucket list but it's just that I'm at an age where I can indulge myself a little more - I even bought my wife a kite!