Junior 60 build

[Gary Murphy 1]

Just been given a old boxed BB Junior 60 kit.

I intend to electrify it but is there anywhere that needs to be updated or improved in the build structure wise?

[Former Member]

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[Dave from the future]

I put the battery immediately behind the motor in mine (a 3s2200 sitting vertically), and the top of the nose lifts off for access. The further forward everything is the better, to reduce nose weight required for the CG.

[cymaz]

Do what Percy says and strengthen the dihedral brace.....I used to have a Junior 60.

You will also need to pack up the wing seat at the trailing edge. I ended up with an extra 6-7mm as it went up like a homesick angel.

[Engine Doctor]

As Cymaz says the wing angle ,incidence , will need changing for powered flight as the BB were the same angle as the original free flight version and will balloon under power. You could alter the angle of the wing seating during the build rather than retro fit the packing. A 1° to 1.5°pos incidence should do it with the tail plane at 0°. You will still need some down and side thrust on motor. Have fun .

Edited By Engine Doctor on 26/08/2017 06:59:39

[Former Member]

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[David Davis]

I have built two Junior 60s and three Junior 60 fuselages. On the second and third fuselages, I continued the top longeron to the tailpost.This lifted the leading edge of the tailplane and reduced the tendency of the model to climb all the time under power.

I agree with Percy that a Super Sixty is a better model for radio controlled flight but I like the slow-flying characteristics of the Junior 60.

[Paul Jefferies]

Certainly beef up the dihedral braces but all this talk of it ballooning under power probably means that the model had too much power or possibly not enough down thrust....... Ballooning is not a function of power but of too much speed caused by too much power. Back in the day these models didn't have much power and the problem didn't arise until it got into a dive when the speed would build up and it would pull itself out....... That's what they call stability and the J60 had loads if it! If flown as it was designed to be flown it should stooge around not far above the stall, hopefully achieving a modest climb and when the motor stops you should hardly notice the difference except that it starts a gentle descent. Most people seem to want more exciting flying these days and yes, if that's what you want you want, build a Super 60 but please don't modify such an iconic design..... just fly it as it was designed to be flown.

Paul

[Former Member]

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[Gary Murphy 1]

Thanks for all the tips guys. I am ok reading plans BUT structural stuff is not my bag. I will defo look into the wing eating and finding a good way for battery location.

A quick look at the box contents and I can not see any undercarriage wire! and if its banded or fixed.either way does this area need any beefing up?

[Former Member]

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[David Davis]

I don't think you're right Percy. In the case of the Super 60 it may have been banded on from the start, but the Flair Junior 60, which I built, and which was a later version of the Junior 60 with a wider fuselage and bigger rudder, had the wire undercarriage sewn onto the two plywood formers.

[brokenenglish]

Percy, have another look. The u/c was never banded on a J60. The front legs are bound and glued to the firewall and the rear legs are "loose bound" (hinged) on the second former. Excellent design.

The plane will be great if built exactly to the plan and flown like the original.

The problems you've seen (and that I've never had in quite a few J60s) must be due to clowns wanting to fly aerobatics and stuff.

It has to be said that the J60 is only a good trainer if your objective is to fly vintage models in a vintage manner.

If your aim is to learn normal club RC flying. You'd be better off with a Super 60 or a more recent trainer.

I'm always amazed at the number of beginners who pick a model that's been flying perfectly well for 60-odd years, and who think things need to be modified...

The bottom line is that any model should be flown "as intended". If you want another type of flying, then pick an appropriate model.

Edited By brokenenglish on 26/08/2017 10:34:02

Edited By brokenenglish on 26/08/2017 10:54:04

[Don Fry]

I used to have one of these for years. I started out with packing under the trailing edge, to improve penitration. But ended up wth it trimmed as plan, and dialled in down elevator to do the penitration bit. They don't balloon as such, but with the undercambered wing they are a single speed aircraft, more power, more lift, and they go up. They are after all a rudder only aircraft. I flew mine on the left stick only, rudder and throttle. The elevator was used to trim for penitration.

I bow it others wisdom regarding dihedral braces, and wing clapping, but I bet loops were involved.

Take note about nose weight. Mine had a glow moter, a 4 oz tank slotted upright in the engine bay, servos right at the front of the cockpit, battery under the servos, and by dint of a light build at the back flew without added lead.

A delight to fly at what it did, gently fly round. Interest was doing a circuit very low. By low I mean not exceeding 2 feet off the ground. And relax, put the transmitter down, roll a fag, get it lit and going well, pick up transmitter.

Sold mine after 20 years of ownership. Bit bored with it.

[Peter Miller]

Yes, the Junior 60 is a FREE FLIGHT DESIGN.and as such flies beautifully. They will fly happily on an ED Competition Special which was a side port 2 cc diesel. An ED racer over powered it.

My second one was powered by a Super Tigre 2.5 diesel and had RCS Guidance System single channel. IT flew perfectly until I set the engine at full power and the wings folded.

NOTE. NO mods, built as per plan.

Last one that I saw was a standard Junior 60 powered by an old OS 30. The poor man's four stroke as I called it. The owner (A modeller from the vintage era like me) used to just cruise it round gently.

The Super 60 was another beast altogether but better for radio

Edited By Peter Miller on 26/08/2017 12:28:58

[Don Fry]

But again , Peter, I bet those wings folded when you got too high due to all that power, yer buttocks clenched because you feared loosing it, and all the rudder twiddling trying to loose height, caused it to do some acrobatic manoeuvre.

But then again reinforce if wished. One thing I used to do in anything other than sub 5 mph winds, was to strap half a pound of lead onto the cabin floor, under the centre of gravity.

[ken anderson.]

The jNR 60 was designed all them years ago(before even I was born) 1946, for a petrol engine and all the gear to go with it battery,coil etc...I think that the design is robust enough for our modern gear.anyone who builds one to do aerobatics with it is wasting there time and money...its not designed for that..... ..... let common sense prevail...I hear you say..

ken Anderson..... ne....1 .common sense dept.

[Peter Miller]

Yes, you are right Don. It was fine stooging round but that insane power

[Dave from the future]

Mine weighs 3.5lbs and flys with an electric motor at 210 watts (full throttle), so about 60 watts/lb. It takes off happily at 1/2 throttle so even less power would be fine. It has spruce spars and 3mm ply dihedral braces as I'd already watched a club member fold the wings on his .30 4-stroke powered one doing fast loops!

[Broken Prop]

Incidentally, 4Max do an motor/esc kit for the Junior 60. I fitted one to mine (Flair kit) and it is just right with a 2200mAh battery. Because this is a slow flyer, the current draw is fairly modest and so low 'C' rated batteries can be used.

I recently bought 20C rated batteries from HK for £8.50. They give around 5 to 7 minutes flying (Or longer if you set up a glide flight phase)

[PatMc]

Posted by David Davis on 26/08/2017 08:19:35:

I have built two Junior 60s and three Junior 60 fuselages. On the second and third fuselages, I continued the top longeron to the tailpost.This lifted the leading edge of the tailplane and reduced the tendency of the model to climb all the time under power.

I agree with Percy that a Super Sixty is a better model for radio controlled flight but I like the slow-flying characteristics of the Junior 60.

Increasing the tailplane incidence is a better idea than reducing the wing incidence as suggested earlier, since the latter will also effectively reduce the motor's downthrust.
But you can always build & rig as designed using the throttle & elevator trim to achieve the same outcome.

[brokenenglish]

Posted by PatMc on 27/08/2017 21:59:53:

But you can always build & rig as designed using the throttle & elevator trim to achieve the same outcome.

Exactly Pat, I've never seen any reason to do otherwise!

I much prefer accepting a trim change between climb and glide, rather than hacking a model about to satisfy a pointless "no trim change" dogma.

In any case, full size aircraft are flown like that, they're trimmed for the climb, then retrimmed for the cruise phase, and again retrimmed for the descent.

[Stewart Mason 1]

Electrify it by all means, but still doesn't mean you have to fit radio. They weren't designed for radio. Fitting a radio D/T is as much control as it needs, or enjoy the pure experience and leave it to the thermal gods.