Playboy Senior

[Andy Hat]

This is my just-finished Ben Buckle Playboy Senior.

I was careful to try and build it light BUT I've really messed up - there's no way I can get it to balance on the plan CG.

Perhaps I should have used a larger motor/battery combination (currently 3542/2200mah) but I calculated this would be adequate power. I moved the motor further forward but it made little difference.

Even with 420g/15oz of lead hanging off the prop adapter, it's still no where near the correct mark.

I've read that 50% might be adequate from this model but any experience or suggestions you have would be gratefully received.

[paul d]

Double post!

 

Edited By paul d on 05/08/2019 17:46:11

[paul d]

That's the trouble when converting vintage models to modern electrics, it was originally designed for a heavy old sparky.

First thing I would do is replace those rather small wheels with some big fat airwheels.

I presume the battery etc are as far forward as possible?

Try giving it a test glide, you'll be surprised how tolerant those old timers are to the cg position

[Bob Cotsford]

The other problem with these vintage designs is that the nose is so short that the slightest increase in weight at the tail needs a shedload of lead in the nose to correct it. You have something like a 5 or 6:1 moment at the tail judging by the photo.

[Dad_flyer]

I have acquired a Double Diamond. The previous owner had similar issues to you, as in this thread.

The end was 620g of lead in the nose. Flying it is lovely, even at 9lbs total weight and just 400W at full throttle with a fully charged battery.

[Chris Freeman 3]

A playboy is a great flying aircraft, I built one for a mate about 10 years ago and it is still flying. The undercamber wing and pylon arrangement were designed for maximum climb rates so the Playboy will climb under power so it may be best for initial flights to use limited power after a launch or take off. We tend to hand launch the playboy as it must be directly into wind. The cg can be further back than normal aircraft. Best to set up your rates on the radio as well. I am sure you will have lots of fun with it.

[SIMON CRAGG]

I regularly fly mine, which I have recently refurbished. The only way round the problem is to extend the nose. I have flown mine with a variety of engines and currently have an ASP .52 installed. Nose needs to be extended at least a couple of inches.

[Broken Prop]

Hi Andy

I had the same problem with my Playboy Senior and finally settled for a CG position at 40% of the wing chord. Even so lt needed about 12oz of lead attached to the bulkhead and quite a lot of down elevator trim.

It still exhibits 'homesick angel' tendencies. Make sure that you get the engine tickover as low as possible otherwise it will float on and on when attempting to land.

It is a lovely plane to fly.

[brokenenglish]

Posted by paul d on 05/08/2019 17:45:37:

That's the trouble when converting vintage models to modern electrics, it was originally designed for a heavy old sparky.

First thing I would do is replace those rather small wheels with some big fat airwheels.

I presume the battery etc are as far forward as possible?

Try giving it a test glide, you'll be surprised how tolerant those old timers are to the cg position

This is very misleading. The old sparkers normally used are very light, far lighter than modern engines. Browns and Ohlssons weigh less than a modern engine of half their capacity. OK, the light weight of the old ignition engines is partially offset by the weight of the ignition system, but the engine + ignition system will still be lighter than a modern four-stroke.

The problem is more due to "modern" builders not realising that this type of model has to be built very light aft of the wing, and particularly at the tail end, obviously. Modern coverings don't help either... Then the problem is aggravated by the use of electric power, where the main motive power weight (the battery) isn't in the nose, but further back, at least behind the fire wall, and this is very significant in the case of a short-nose model.

My advice would be to get everything as far forward as possible. Then add whatever ballast is needed to get a CG at around 50%, and fly it like that. It should be fine.

[brokenenglish]

Duplicate post. Sorry!

Edited By brokenenglish on 06/08/2019 08:32:10

[Andy Hat]

After fitting larger/heavier wheels (+100g), bending the u/c further forward and adding 240g of lead in the nose, it now balances on the middle lower spar which is about 50% of the wing.

The total, ready to fly, weight is 1760g - which includes the 198g 2200mah 3S battery (which is against the firewall).

I'll try it out when the weather improves and report here.

Thank you all!

[ken anderson.]

i have a junior 60 with 1/2lb of lead in the nose...it fly's and floats like a goodin….any space/gaps at the front,put in some lead...

ken anderson...ne..1..... flying lead dept.

[Bob Cotsford]

Replace some of the lead with either a bigger battery or a second 2200?

[Capt Kremen]

As others have mentioned, the tail end, (especially), needs to be kept light.

I built a vintage 'Air Trails', Ray Heit design the 'Scrappy', (similar to the 'Scram'. All traditional fabric and doped covering, couldn't get it anywhere near a safe balance point. In desperation, I ended up recovering the tail plane and fin/rudder assembly in tissue. I was amazed at just doing that simple little thing, made a huge difference to achieving a safe flyable C of G.

Also, with the advent of LiPo replacing the 'lead weight' NiCad cells of earlier electro-flight days, that has made the C of G balancing act more of a challenge!

[Djay]

I downloaded a plan a couple of years ago and made one of these .

Do not worry at all about the weight, the wingspan is so big and fuse so small you could double the weight and it will fly without any issues.

Mine is powered by an OS 26 4 stroke and is way overpowered.

It takes off in a few feet and will climb at 80 degrees like a homesick angel, then it flies at nothing more than tick over for ages, I usually just let it free fly and use the trim on the TX to change course or height as it hardly needs any input. flies at anything from backwards in a wind to very slow walking pace to a couple of miles an hour, not designed to fly fast. In a wind it will hover or go backwards for ages, fully under control.

Do not try and fly it like a modern plane as it was designed for free flight, so let it do its own thing and enjoy it. it is virtually crash proof even if you put full control inputs in

My C of G is about 75% back from the L/E as per the original plan, but it really does not matter as long as it is some where within the wing forward of the rear spar and aft of the L/E.

Do not put the C of G forward like a modern plane, again these designs are different to them. If you can view the original plans on the internet and see the notes and C of G on them.

I have an album with some construction images in if you are interested.

Darryl

[paul d]

What a lovely looking model Darryl!

[Andy Hat]

I flew it yesterday and it was great. No trim or extra weight needed. My problem now is learning how to get this plane down. It just didn't want to come out of the sky. Very pleased!

[Dad_flyer]

[robert chamberlain]

Hello, I am in the course of building a FlyingQuaker with a 4 foot wing span from plans. I finished the wing and the fuse is still in the jig, so no weight figures as yet. The plans call for a .15/.20 two stroke. Does this sound about right? I do have an OS .15 at hand. The bigger sizes seem a bit too large. Has anyone built one and ,if so, what size did you use? ____ I would like to use Trexler wheels ( if they are still available) as this might be helpful in WT/Bal.--------Bob in Kansas.

[cymaz]

When I had my Junior 60 ( before the wings clapped), I used to enjoy the challenge of trying to land it. Powered with a SC 30fs. It was a little gem.

[David Davis]

Posted by robert chamberlain on 27/11/2019 05:09:36:

Hello, I am in the course of building a FlyingQuaker with a 4 foot wing span from plans. I finished the wing and the fuse is still in the jig, so no weight figures as yet. The plans call for a .15/.20 two stroke. Does this sound about right? I do have an OS .15 at hand. The bigger sizes seem a bit too large. Has anyone built one and ,if so, what size did you use? ____ I would like to use Trexler wheels ( if they are still available) as this might be helpful in WT/Bal.--------Bob in Kansas.

Bob,my Junior 60 with its 63" wingspan, flew very well on an Irvine 20 when I first built it, in fact I learned to fly r/c on the model. Admittedly it was an engine originally intended for model car racing so it may have been more powerful than a standard Irvine 20. I had previously installed it in a 50" trainer, a St Leonard's Models "Gemini." This was not a vintage model and it proved to be too fast for me as a novice pilot. For a four foot wingspan vintage model, I would be looking at a 12-15 two-stroke or a fourstroke in the 20-26 range.

Andy Hat, congratulations on a successful maiden.

[SIMON CRAGG]

What a great video. Sums up the pleasures of rc model flying perfectly. Had my Playboy for many years and it is still my "go to" model for really stress free old school; flying. Long may it last!.