Boddingtons Mannock

[G-YRUS]

This will be my first biplane and also my first real venture into electric flight but I am almost converted as the goo is just so gooey. I want to convert the Mannock which I will build from the plan to electric power. Is this a good idea? Any suggestions on motor size? And do I still need to set an electric motor with the thrust angles as indicated for IC? All help gratefully received.

[PatMc]

I built a Mannock many years ago from a DB kit. I modded it for ailerons & powered it with a Merco 61. The plan had no cg shown so I estimated it & reduced the silly downthrust angle (in fact I may have made it 0 degrees).

The model was very relaxing to fly - easier than some trainers. It was later fitted with Flair vintage style floats, which suited it well & I flew it at a number of floatplane meetings.

I later found that I'd moved the cg back quite a way from the design position which probably explains why the original needed so much downthrust.

The Merco 61 could manage about 0.8HP max using IIRC a 12x6 prop. I'd be looking at a motor capable of 600 - 800W using a 12" - 14" prop with 6s 4000mAH lipos.

[Allan Bennett]

I'm not familiar with the model, apart from what I've seen on the internet. But I would encourage you to go ahead and build it as an electric.

The closest model I have is a 58" DB Sport & Scale Tiger Moth, which I electrified with an AXI 4120/14 motor powered by 6S A123 battery to give 750 watts with a 14x7 prop. It weighs 6lb 2oz with battery.

In my experience thrust angles should be exactly as for IC -- the plane doesn't know what's powering it!

The biggest problem with a glow-to-electric conversion is finding a suitable place for the battery, and making an access hatch for it which doesn't require removal of wings. All of my electric conversions have required the battery to be placed where the fuel tank would go, and sometimes even further forward into the engine bay, to get the c of g right.

I use an A123 pack because it's about half the weight of the 14-cell NiMh pack I originally used, and it gave more power. If starting again, I would probably use a 4S or 6S LiPo because LiPo prices have come down, they're more reliable than they used to be, and there's a wider selection of capacities (A123 only come in 2300mAh or 1100mAh size).

An E-flite Power 60 motor would probably be good for your model, with 6S LiPo, a 70A ESC (to give a safety margin above the 55A maximum rating of the motor), and a prop somewhere around 14x8.

If you're going to be serious about electric power, get yourself a wattmeter so that you can check the actual amps your system draws, before you burn something out.

[G-YRUS]

Many thanks this is all useful information. I am serious about electric power although where I fly we have no noise or size restrictions and think as my skills develop I may use petrol for larger models but I am convinced this is the way to go for sport size models. However I love to build and sport size models are just fine at the moment. I have my watt meter and have converted a glider on my own calculations which works OK but this is a more serious build. My drawing is not from the kit and shows 2 wings. I am going for the shorter span aerobatic wing with ailerons, although I am guessing aerobatic means more capable of rolls and more traditional manoeuvres given the age of the drawing. I thought this was a goodway to go before something really scale.

[kc]

The Mannock ( an SE5 lookalike ) was republished in Radio Modeller OCT 84 and is plan no RM280 which should still be available from MYHobbyStores. The plan is also available as a plan pack from DB Sport & Scale and they supply plan and rib sets etc . DB Sport & Scale also do the Richtofen which is the same design but 'German ' style with a radial cowl. If you look at their Richtofen section of the website it gives a link to a suitable electric setup.

I believe the Mannock was really very aerobatic in clipped wing form.

Note that there is a Boddington day at Old Warden soon ( I think it's the 12 & 13 th May weekend)

[Tim Hooper]

The Mannock sounds good!

If it helps at all I have a couple of bipes in the 7-8lb range that use the following;

Turnigy 4250 500Kv motor

Turnigy Plush 80 ESC

14*8 prop

5S 4000Mah cell pack.

Yields over 1100 watts at full whack, but the models fly on half power quite happily.

Hope this helps!

tim

[Tom Wright 2]

I converted my Mannock to leccy about three years ago ,a very straight forward job.I cut away the top nose decking and made it into a hatch as there is enough room to accommodate a 4A four cell .

The model is easy to fly and quite happy with a 600W motor .

Tom.

[G-YRUS]

Thanks Tom. Nice to have a reply from someone who has done it . I just need to get busy now.

KC. I think this May might be just to soon. I dont build that quickly flying and work get in the way but I will have to try and get it done and visit next year. I am at the stage in my flying where getting out and about is probably a good idea. My plan is from My Hobbystore. Perhaps I will have to put the pressure on myself and put up some photos as I go, maybe. I have a copy of the Richthoffen plan as well but thought I should be patriotic in my build. Perhaps I need a dogfight buddy although reading the mid air thread maybe not.

Has anyone done away with the elastic band wing fixings? Although practical just a tad unsightly. Is ther a good alternative?

[PatMc]

Mine was modified to take peg & screw fixing. The lower wings were easy but the top needed a bit of thought.

I had the piano wire for the cabane project forward, & a couple of gussets at the rear corners with nuts soldered to them. I made a couple of metal lugs from brass, fixed these to ply reinforcement in the inside of upper the wing LE projecting down so that they could be hooked on to the cabane wire. A pair screws through hard points secured to the wing finished the job.

I described this from memory as best as I can but may have a drawing somewhere, if I come across it I'll scan & post it.