Level 1 => Electric Flight Technical => Topic started by: half throttle on December 03, 2019, 11:16:03 am

Title: Leccy Junior 60
Post by: half throttle on December 03, 2019, 11:16:03 am
SWMBO is treating me to a Ben Buckle Junior 60 for Christmas, could any leccy wizard recommend a budget power train please.


Title: Re: Leccy Junior 60
Post by: itsme on December 03, 2019, 11:27:01 am
Pretty much anything...a rescued setup from a foamy Wot ever would work, I should think.
Title: Re: Leccy Junior 60
Post by: PDR on December 03, 2019, 13:00:25 pm
The Wot4 Foam-e power set would probably work, but iyt might be a smidge undersized. If you only want take-off-and-stooge-around flights then you could stick to the 3s-2200 lipos (because they are the cheapest lipo format) and a 400-450W power system - with sensible throttle management you'd get 6-8min flights. With a 300W power system (eg the one from the wottie) you'd get 8-10 min flights, but take off and climb performance may be a bit sluggish. In this regard a 300w power system would be a 1,000rpm/v motor pulling maybe 30A on an 11-6 or 11-8 prop, while a 450W power system would be (again) a 1,000rpm/v motor but pulling 40-43A on (say) a 12-8 prop, or a 1,200rpm/v motor pulling the same current on a 11-6 or 10-7 prop. Speed controllers would be from 40A (in a quality Jeti or similar) or 60A in a "budget" range.

I think my personal preference would be to fit a 1,200rpm/v motor prop'd for 40Amps, but use a bigger battery like a 3s3000 or 3s3300. This would allow both spirited throttle use and gentle stooging, with flight times in the 8-20 minute region depending on throttle use (or even 30 mins if you're gentle and just stooge around). The motor I'm thinking of would be soemthing equivilent to either an Axi 2820-10 or Axi 2820-12, but these are expensive these days. Just pick something from a reasonable range (turnigy etc) with a max current of over 40A and a Kv of 1,000rpm/v (larger props) or 1,200rpm/v (smaller props).

If you want to deal with a UK supplier then look at 4max who does own-branded versions of the same motors, but be a little wary of his "equivilents" suggestions because they tend to be a bit under-spec'd for current. For example he offers his PO-3541-1270 as an alternative to the Axi 2820-10, but it's only rated at 33A continuous where the Axi will take 40A all day (and 45A for quite a while) as long as there is some airflow. I assume that's why he recommends a 10-5 rather than the 10-7 I'd normally use on this size motor. So from the 4-max range I'd probably suggest the PO-3547-1190. It's a bit over the top, but proped with an 11-7APC-e it would give oodles of pull for take off and climb, and then run stone cold for cruising around!

My current prefered "budget" speed controllers are the Turnigy Plush range, but to be honest there are cheaper ones and a cheap 60A ESC like the HobbyKing or similar will do this job just as effectively.

More than you wanted to know, I'm sure!

Title: Re: Leccy Junior 60
Post by: half throttle on December 03, 2019, 15:29:02 pm
Thanks very much chaps, much appreciated.  :-*
Title: Re: Leccy Junior 60
Post by: Patmac on December 03, 2019, 23:35:21 pm
I have a Flair version Jnr 60 built around 1986 flown with a pre schnurle version OS25 normally using an 12x6 Graupner grey prop or an 11x6 when fitted with floats. This combo gave bags of power for tootling around with some loops, rolls & the odd bit of dodgy inverted thrown in when boredom set in.
After flying like that fairly regularly for about 18 years it was stored in the loft until it was refurbed & converted to electric in 2012.
Model now weighs 1275g, motor used was a Keda A36-12L 1000kv with 3s 2200 turning an 11x6 Topflite wood ic prop. Current 28 - 30A with power around 330W is more than adequate & noticeably more than the OS25 gave. Climb for 30 secs from take off took the model to 370ft.
I usually use my older near end of life lipos for the Jnr, flight duration of 10 -15 mins is normal.
Recently changed the motor to a Turnigy 600kv one in order to use bigger dia props but not yet had the chance to try it out.
BTW I incrementally removed all of the nose weight that was needed to achieve the plan's cg & found that the model is still a pussycat with the cg about 35mm further back.   
Title: Re: Leccy Junior 60
Post by: PDR on December 04, 2019, 00:03:10 am
I would lean more towards Pat's actual experience with the particular model than my generic estimates.

Title: Re: Leccy Junior 60
Post by: itsme on December 04, 2019, 08:29:01 am
It all depends what you want to do with it. IIRC, the original, designed for FF as well as the radio of the day, was for 1.5 diesel up to a .60 glow or petrol. Quite a wide choice.
Title: Re: Leccy Junior 60
Post by: half throttle on December 05, 2019, 14:53:09 pm
I used to fly mine in the UK with an OS LA .40, way overpowered but loads of fun.  :D
Title: Re: Leccy Junior 60
Post by: leckyBB on December 05, 2019, 17:23:13 pm
Many, many years ago a novice model flying friend built one and in those days we were using Speed 600 brushed motors. This one flew successfully, if a little slowly on a geared Speed 600 and, I think, a 10x6 prop with 7 cell NiCds. This model does not need a huge amount of power to fly successfully.