Junior 60 Equipment Advice

[Andy Goddard 2]

Hi,

I’m new to this forum and to remote control flight. I’m building a Junior 60 model (advised that it would be a good starter model to get up in air!). Ben buckle design.

Im now at the stage where I need to buy equipment to fit in and wonder if anybody could advise on specs / models for the main kit (prop, motor, battery, esc, etc.)?

thanks in advance,

andy

p.s, I intend to join a club before attempting flight so should get more hands on advice before I take to the air!

Edited By Andy Goddard 2 on 16/09/2019 22:45:36

[Foxfan]

Good luck Andy. Build it as light as you can, especially for electric. Saw one flying yesterday on electric by a chap who was sitting back in a comfy chair while he idled around!

Martin

[Denis Watkins]

From 4max site http://www.4-max.co.uk/recommended-setups.htm

Junior 60

60" 1524mm

4.1lbs 1.97Kg

Very last listing at the bottom of the page

Edited By Denis Watkins on 17/09/2019 08:13:34

[Peter Miller]

Go and look at 4-Max Reccomended set ups.

**LINK**

Down towards the bottom of the list and you will find everything that you need for the power train.

Phone George there and he can also provide lots of information and otherc items like servos etc.

[Peter Miller]

Dennis beat me to it by a couple of minutes

[Andy Goddard 2]

Thanks so much. That’s really helpful. Andy

[Andy Goddard 2]

Ideally I’d love to understand why this spec is ideal for this particular model. I assume one starts with the weight and prop size to work out the thrust required. From that gives the spec for motor and then the spec for esc and batteries. Is anybody able to help me understanding the calculations one does to work these things out?

[Robin Etherton]

It’s a black art Andy.

it will give you a headache trying to understand it.

Just take the advice, get an easy chair, fair weather and just enjoy one of the most pleasurable models to fly ever.

a real classic. Had mine for 30+ years. Just superb.

Robin

[ken anderson.]

hello and welcome from me andy...the JNR 60 is a great model and fly's nice and slow-but if you learn to fly with a one you wont know what has hit you when you decide to move on to some thing else...(think milk float to F1 car)..if you only intend to fly slow/vintage types...OK.

Consider powering your JNR with a ic 2/st motor...ie20/30 size also...simple to install and use....

ken anderson...ne...1...JNR 60 dept.

[David Davis]

Mine was originally powered by an Irvine 20 but later I converted it to electric power. Sometimes I wish I'd fitted a little fourstroke engine. Fuel up fly and repeat etc! I use mine to teach nervous, elderly, ham-fisted beginners how to fly!

I learned to fly on this model and Ken's right. It's a whole new learning curve once you move on to ailerons.

[Romeo Whisky]

You might find this link helpful Andy

Basic Guide to Electric Flight

[Andy Goddard 2]

Thanks Romeo - fantastic link

[Martin_K]

Posted by Andy Goddard 2 on 17/09/2019 08:59:29:

Ideally I’d love to understand why this spec is ideal for this particular model. I assume one starts with the weight and prop size to work out the thrust required. From that gives the spec for motor and then the spec for esc and batteries. Is anybody able to help me understanding the calculations one does to work these things out?

The Basic Guide linked to above appeared while I was typing. Hopefully my shorter version is consistent.

I hit this problem recently when moving from building gliders to a powered plane. There is no one source I can recommend but the rough process to predict the charactersitics of your plane and it's required power train is;

Work out the wing area and the expected total weight of the plane. Divide weight by area to give the wing loading. If you are British or American this will be measured in ounces per square foot, the continentals use metric units.

From wing loading there are formulas to approximate stall speed, i.e. the slowest speed at which you are still flying.

There are then 'rules of thumb' for the multiple of weight to use for various styles of flying. Watts per pound for 'sport' rather than 'aerobatic', for example.

Having established how much power you need from the motor in watts you then need to know how much current the motor will draw when delivering that power, using a specific size of propeller. At this point I decided if a motor manufacturer did not supply test data for power (W), Current (I), Voltage (V), rpm, prop size, I simply was not going to use their product.

After all that the only way to know what is actually going on (i.e. whether your ESC is suitable) is to use test gear, something to measure current, voltage, and hence power, e.g. a power meter. This is easy static on the ground, I haven't tried it in the air.

While researching I noticed that over time how much power is recommended has gone up and up. Apparently modellers now have much higher expectations of performance than in the past.

There are various on-line calculators that can give you a feel for how all this relates. Sadly, the one I like, WebOcalc, is no longer maintained but is available on the Internet Archive.

 

Edited By Martin_K on 17/09/2019 11:09:34

[Robin Etherton]

See what I mean!

I use ecalc, it’s not free but it seems to work.

[Andy Goddard 2]

Thanks for all the advice. I’m now ready to purchase with at least a little understanding.

Regarding Ken’s comment (milk float to F1) I’ll remember that when I take to first flight. 😀 My intention is to upgrade to a more complicated model but my initial objective is simply to get a plane in the air and back down to earth in one piece. Hence my choice of Junior 60. I have memories of my first foray into RC 30 years ago and the plan didn’t make it past the first outing. So my aim is to take it easy to start with and learn the basics ......

thanks again.

[Peter Miller]

I have found over the years that giving people a couple of flights with a very simple vintage model gets them learning how to steer it, especially when coming towards themselves.

I have taken a similar model to a school and allowed kindergarten kids to take turns flying it.

Many, many years ago our current club secretary came to me. He had been trying to learn with another club and due to various factors just could not get on. I took him out and gave him two 20 minute flights on a Super Scorpion. He is now the best pilot in our club.

Another member could fly a trainer but could never master the landing approach so I gave him a simple three channel model and he flew that for a few weeks. After that he could land anything happily.

Low stress flying like that builds the basic skills so DO NOT knock that sort of learning

[gangster]

We I would suggest that you start by taking the advice given earlier and take the advice from 4max. That will get you started. You will get the feel for things electric as you go along and get a feel for what works. Next get a power meter that measures current. The most important parameter to concern you is current (amps) eg let’s assume you need 300 watts. A given motor may claim to give that power however trying to run that on a 3s battery will not deliver that power without exceeding the max current rating of the motor so you need to go 4s. The next concern is the esc if you calculate max current is say 30 amps go for the next size up. They are not generously rated. Putting a bigger one in won’t do any harm. Finally as well as adjusting power by prop selection there is the good old throttle stick. Now there will be some pedantic purists who will argue with this but there is nothing wrong with calibrating your esc at 100 % throw and then adjusting your throw to say 50%. Gives you a hell of a lot of flexibility. My own Junior 60 has an emax 2820 07 which with 3s and the prop I have will give over 400 watts totally or for that model but the throttle end stop is at 40%. So electric can be suck it and see as in glow but with a whole lot more flexibility. By the way great choice of model

[Andy Goddard 2]

Kit ordered. I went with the 4 max recommendations in the main but did read the useful guides so can at least convince myself I understand the physics! 😀

Ok let’s think positively.

I get the junior 60 finished. Successful first flight. Whilst I master the basics and practice on the junior 60 I can start a build for my second plane. With ailerons, rudder, elevator.

what would you recommend for a second model..........

[paul d]

A super 60 would be my logical choice Andy, you could happily use the electronics from your junior 60 ( fantastic choice by the way) all you would need is a couple of extra servos for the ailerones and your set!

regards Paul

[David Davis]

Just a brief word to the wise about your Junior 60 build. Please keep the tailplane light.

When I built my first Junior 60 from a Flair kit in 1988, I inadvertantly used the hardest wood in the kit to build the tailplane. As a result it needed 1.5 pounds, that's right one and a half pounds (680 grammes) of lead in the nose to get the CG right! It still flew well especially in a blow!

Later on I built a lighter tailplane for it and I was able to remove all of the lead.

[Nigel R]

"Low stress flying like that builds the basic skills"

Bears repeating.

RC airplanes don't get a lot easier to fly. As Pete says it is easy to build basic skills if you are relaxed.

Moving to a quicker model then ups the game a bit, but the jump is not too much if you pick the right 'next' model.

Ass for the second, something like:

**LINK**

[David Davis]

Posted by Nigel R on 19/09/2019 16:06:49:

"Low stress flying like that builds the basic skills"

Bears repeating.

RC airplanes don't get a lot easier to fly. As Pete says it is easy to build basic skills if you are relaxed.

Moving to a quicker model then ups the game a bit, but the jump is not too much if you pick the right 'next' model.

Ass for the second, something like:

**LINK**

Or one of these, **LINK**

...or even one of these if youy want to go a bit radical,**LINK**

[Andy Goddard 2]

[Andy Goddard 2]

Picture posted - build so far. Just waiting for equipment to arrive so I can size battery box etc.

[gangster]

You are not forced to go to a quicker model. It’s not compulsory. If you want to stick to vintage then why not. What are your plans for the battery box? On mine I built it into the nose and poke the battery in from the front. Velcro keeps it in and a prop blade parts the Velcro to get it out. It’s a pain in the rudder if you need to take the wings off to change the battery