Precident Fly boy

[Christopher Mayers]

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My dad has given me a complete Flyboy kit thats unopend.

How cool is that!!

So I'm going build the Precedent (why not!!), but I was wondering what your thoughts are on converting these to electric? They are all designed to run on a .25-.30 engine. What would be a suitable electric conversion?

Any other build tips would be welcome.

Chris.

[Richard Wood]

Hi Chris,

The Flyboy should convert to electric very well with a little thought.
Some will always disagree but don't listen to those crusty old codgers! .

If you're new to electric look through the helpful tutorials on this forum
for a start.
400W should be enough for your model & there are lots of motor & ESC
options to consider.
One is the 400W/40A combo from BRCHobbies.co.uk for around £40
with their 3000mAh 3s Lipo for around £15 or perhaps the 4000mAh
for longer duration.

You'll need to sort out a battery access hatch unless you're happy to
remove the wing to get to the battery.
If the kit has a plan this is handy for helping with this sort of thing.
You'll also probably need to remove the hardwood motor mounts
to enable you to back mount the motor to the firewall with stand-offs
of some kind & add triangular reinforcements to the firewall joints.

Hope this gets you started - do ask if any questions.

[Robin Kearney]

Hi Chris, you lucky thing! I learnt to fly on a FlyBoy which was also my first RC build. When you start the build I'd love to follow a build log if you feel like posting some pics as you go along!

r

.

[Christopher Mayers]

Thats great news. Sounds so much cheaper than an IC engine too.

Living on the Isle of Lewis means i have no access to fuel as it would have to be posted.

Hmmm Build Blog. I will do my best. I hope to start building in the next few days.

[Christopher Mayers]

Just been having a think about the job in hand.

I am now wondering if i should shorten the wing ribs, reduce the dihedral and add ailerons.

After all, i hope that my son enjoys building it with me and with ailerons i could become a better trainer plane.

Any thoughts on this?

[Richard Wood]

Possibly the best way to add ailerons would be to build in 'outboard'
types near the tips of about 25% of wing chord & 30 - 40% of span -
ie where the existing rib bay spacing makes it most convenient.
Extra structure will be required of course to accommodate the ailerons -
TEs, LEs etc & extra rear spars may also be needed in the wing.
Reduce dihedral by about a half.
The model won't be quite as self righting in flight but should be more
responsive.

I should just ask you Chris - are you new to flying?
If you are you really need help initially to learn to fly.
Is there a local club you could join?
Apologies if you're already a flyer!

 

 

Edited By Richard Wood on 06/12/2012 14:28:26

[Christopher Mayers]

Thanks Richard thats just what i was thinking. I have just the right wood in the scrap box to modify the wing.

Flying experiance - Like most of us blokes kids got in the way and stopped our fun for some years. My break has been 10yrs and i have moved from Wigan to the Isle of Lewis in the outer hebridies. No flying clubs on the island but miles of open space and beeches to enjoy flying.

I currently fly gliders but want to see if i can interest my son hense the flyboy build.

Getting materials can be difficult at times as everything has to be shipped so far.

Chris.

[Richard Wood]

Yes, suppliers seem to charge a small fortune to ship stuff to the Highlands
& islands - sounds like a great place to fly though!
Just another thing about the outboard ailerons - I've found micro servos
mounted in the wing driving each aileron is better than pushrods &
bellcranks driven by a single servo.
Good luck with the FlyBoy - I hope your son takes an interest!

Cheers
Richard

[Christopher Mayers]

Can someone have a look at this mount and let me know if this is designed to fit to existing i/c engine bearers to make the electric motor sit in the correct position.

**LINK**

 

Any ideas on prop size for this motor too.

Edited By Christopher Mayers on 06/12/2012 15:21:34

[Christopher Mayers]

Well we're off. The lad didn't want to go to bed. Beltin.

[kc]

I am not sure but that looks like a mount for an old 400 size brushed motor which is very different to a modern 400 watt brushless. I suppose it would raise the engine shaft higher than it should be if used on top of wooden bearers.

[Richard Wood]

Chris,
That mount probably isn't really suitable - as kc says it was designed
for an ancient 400 size brushed can motor.
Better to remove or narrow the motor mount beams to enable you
to mount the motor to the bulkhead via it's backplate on standoffs
such as M3 threaded rod or a ply box or similar.
Use an 11x7 APC E-prop.

[Christopher Mayers]

Thanks Richard. I am just about to order the motoe and batteries. Glad you gave me a prop size too.

Chris

[Richard Wood]

Chris,
An alternative way of mounting the motor would be to 'back mount' it onto
a ply plate right at the front of the nose.
A little bit of re-working of the front area is obviously required to do this but
it could be done relatively easily & even all enclosed if wished.
The motor shaft will have to be reversed to do this however.

[kc]

I would say you are goint to need to redesign the front end a bit for electric.

First leave out the engine bearers and replace with an 1/8 ply plate lower down to support battery Support this on 3/8 balsa side pieces. Ply plate can have slots cut in so a Velcro strap secures Lipo.

Next replace the front former with one with a hole large enough so the Lipo can be slid back if necessary to adjust CG. Probably with 3S 2200 mah Lipo you will not need this hole but will need the lipo right at the front. You will need a hole anyway for the ESC lead to reach the Rx.

Make an engine bulkhead from 6mm ply and mount between the sides,so the motor can project out front which will be needed to get CG and wont look to bad . Fit the engine mount ( cross type )to this bulkhead, also drilling a big hole for the leads with connectors to pass through.

Make a battery hatch so you can replace lipo from the top ( for safety ) You could also construct a hatch underneath the ply battery plate to fit a seperate Rx nicad. You might need more weight at front so it might as well be usefulweight.

Store the original former and engine bearers intact in case you ever want to convert back to IC. In any case draw around all the components before you start building so you have patterns in case of crashes!

[Martin Harris - Moderator]

Posted by Richard Wood on 06/12/2012 14:26:57:

Possibly the best way to add ailerons would be to build in 'outboard'
types near the tips of about 25% of wing chord & 30 - 40% of span -
ie where the existing rib bay spacing makes it most convenient.
Extra structure will be required of course to accommodate the ailerons -
TEs, LEs etc & extra rear spars may also be needed in the wing.
Reduce dihedral by about a half.
The model won't be quite as self righting in flight but should be more
responsive.

Eeek!

I spent yesterday afternoon test flying a variety of warbirds, doing my best impression of a steely eyed test pilot, laughing in the face of dangling undercarriage legs and generally enjoying myself with other people's models...until I was asked to maiden a newly re-commissioned (and new to the owner) Fly-Boy. It's only a trainer and I'm invincible....

Until I opened the throttle....and it almost instantaneously flicked one way, picked it up on the rudder and it flicked the other - repeated a few times, a crunch and then silence. Post mortem - one prop destroyed and the wings had slid sideways under the bands.

Somewhat chastened, replaced the prop, added some more bands (although the leading edge had resisted lifting) and reduced the rudder/elevator movements dramatically. C of G seemed well forward (confirmed since on a plan that I have found on line) so left that alone.

Tried again, the monster was still almost unflyable while my clubmates were doubled up in hysterics and the owner resigned himself to taking it home in a bag - until I disciplined myself to only apply the slightest of stick pressures and gained some semblence of control. As the rain was coming down a bit harder by this time, the owner thought it a good opportunity to beat a hasty retreat with the model still in one piece and I didn't try to dissuade him too hard!

So - I don't think lack of responsiveness is likely to be an issue for this model. While I'm at it - and out of interest to see where we end up - can anyone give me some figures for recommended control throws and C of G? The few references to the Fly-Boy (as opposed to the Hi-Boy) I've found on the 'net seem to suggest that it wasn't a very wonderful trainer (and that's editing the comments somewhat!) so if the project is still on the go, I'd advise Christopher to get it set up and test flown by someone with a reasonable amount of experience.

Edited By Martin Harris on 28/06/2013 15:34:21

[Skankster]

Hi, I have a part built flyboy in my attic that I am thinking of converting to electric, I had built the wing with full span strip ailerons and have recently cut the engine bearers to give enough space for a motor to slot between them and have cut out a ply firewall to fix the motor to. I have a 240watt brushless motor that I was thinking of using just because I have it and if it's not powerful enough I can always change it. Was thinking of a servo in each wing so the ailerons can also be used as flaps (flaperons) .

Did you ever get yours flying Christopher?? P.S love the Hebrides, been up there surfing a few times , loads of good slope soaring spots as well

[kenneth payne]

Hi All I have the flyboy and I was just want to know what flue is used and what percentage is used to start the engine

and and also what size it the flue tank

if you cold help me that would be great

thanks