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-   -   Guillow 16" span electric conversion (http://www.Wattflyer.com/forums/showthread.php?t=73456)

Griff Murphey 03-29-2014 07:21 PM

Guillow 16" span electric conversion
 
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Here is my rc micro conversion Bf-109, just about to start covering, as soon as my radio arrives. I went kind of crazy with lightening holes... Building skeleton structures would have been much better weight wise, but I was too lazy. Will be "gear up" or as the Germans say, "ein." I built up a new nose which is about 3/8" longer than the vac form kit one. This will help out with the moments. Balsa will also absorbe impacts better. My plan is to split it, horizontally, top half will come off (held with magnets and .010" steel strips), will give access to motor and battery, wing will be held on with magnets. Planning on doing a Battle of Britain scheme with green and pale blue tissue. Weight is an all encompassing issue, I am trying to make it fly with the Powerplant from a micro foamy Flyzone biplane. Will soup it up with a bigger prop. Just getting back into the hobby, if nothing else it's an experiment. FLIGHT TEST?!

Don Sims 03-30-2014 06:32 PM

Welcome back to the hobby Griff! Best of luck on your project and keep us updated.

JetPlaneFlyer 03-30-2014 08:23 PM

Good luck with the project, keep it light.

As for lightening holes, i prefer to call them 'weakening holes'. IMHO this is a more accurate description because they greatly weaken the structure (a 3mm dia hole in a 6mm strip halves the strength), but they have no significant lightening effect.

Calculation shows that for every 100 3mm (1/8") holes that you cut in 1/16" balsa you save around 0.1g (0.03 oz), or 0.001g per hole.

Griff Murphey 03-30-2014 11:01 PM

Thanks for that, I have at least 100 holes I bet. Of course, Guillows are way overbuilt to begin with! Wings are strengthened with one spar replaced by basswood and same deal here and there in the empennage.

We'll know in about a week or two if it flies. In any case it's fun learning to build again. This is my second e-conversion stick and tissue plane after the Aerowerks pup which flies pretty well, same span, but lighter construction and of course, lots more wing area.

Griff Murphey 04-10-2014 03:19 PM

109 is slightly HEAVY I fear..!
 
Weighed the 109's component assemblies - she weighs 2.0 oz. this will be pushing the Flyzone micro foamy biplane powerplant. Those planes are 1.2 oz. I had fair success with the DCPM pup which is 1.6 oz. so we shall see. I have a tiny bit more covering to go and then can test fly it and figure out number one: if it flies at all; and number two: if I can get away with adding decals and gee gaw details.

I am wondering about a direct drive 3.7 v motor that would provide more thrust and be compatable with the Flyzone brick. Any ideas?

I looked at some out runner engines, why do
They have three leads? I understand positive and negative but what is the third one?

There is enough room in the engine compartment for a bigger 3.7 v battery.

Griff Murphey 04-26-2014 04:06 AM

Here is how it finished up
 
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Here is how it turned out. I have gotten a few brief flights but it is a handful.

JetPlaneFlyer 04-26-2014 10:06 AM

She looks real nice. I built one as a kid and looking at yours brings back memories. The one I built was rubber power freeflight but never really flown worth a damn (too heavy) but it looked ok.

As you know, keeping the weight down on these small conversions is the big challenge, especially Guillows which are overweight to start with. What was the final all up flying weight on yours after all the covering and decals and with battery?

Griff Murphey 04-26-2014 02:02 PM

I weighed it when I was nearing finish and hoping it would not go over 2 Oz. ( much) but I confess I have not weighed it. I will get back to you on that!

Griff Murphey 04-26-2014 03:56 PM

I have been trying to post a video. I think it needs more dihedral yet. Climbed out into 5-8 mph wings, then starts mushing sideways and I landed it. Wing s a breakaway with magnets.

I keep getting invalid file messages when I try to post a video from my iPad.

fhhuber 04-26-2014 04:08 PM

The brushless motors are not really DC motors... they are 3 phase AC with permanent magnets, operated by the ESC's providing variable frequency half wave AC to the motor (full wave would work but make the ESCs very complex and expensive)

There is no + wire on the motor.. each wire in turn gets + or - depending on what part of the AC is going to it.

One phase is powered, one is unpowered and one is sending a feedback to the ESC at all times. It changes which is doing what based on what is needed to meet the demand made by the radio's signal to the ESC.

**************

For the invalid file messages... probably the file is too large. Try posting to imgur.com then linking.

Griff Murphey 04-28-2014 02:20 PM

Increasing dihedral
 
I have increased dihedral twice by sawing the wing in half and installing a new stub center spar. If you go back and look at my frame up pics you will see I decked the center section in 1/32 basswood. That has proven really useful (by accident) in helping out stability. If you look at the plane in profile, the wing tips are now just above the forward fuselage upper decking.

Every increase has resulted in better stability and controllability. There is a picture of a rubber powered Easy Bilt 109g in their catalog that has gigantic dihedral maybe the wingtip are 1/2" or MORE above the canopy.

Anyone building one of these, either the mini or the bigger one, ought to probably build a whole new wing with about 20 percent more span and more chord out toward the wingtips.

I had some semi controllable flights this morning - as I said before, it IS a handful. Power is "enough" and the plane flies best about 85 pct. power, NOT full throttle even with the anemic Flyzone biplane Powerplant. The wing, which is held on with Moses magnets, was getting knocked off so badly I had some dinked tissue so I glued it with silicon sealer. This works pretty well, adds shock absorbency, but needs to set up overnight.

JetPlaneFlyer 04-28-2014 07:46 PM

Yes, i missed that you were flying without ailerons. You are going to need masses of dihedral to give any rudder authority.. about 10 degrees each side i'd guess as a minimum.

I hope you get it dialled in.

fhhuber 04-28-2014 08:03 PM

Generally you go with the FF dihedral (by the plans for flying instead of display) if you don't have ailerons.


Most of the Guillows flyable scale models used to show scale dihedral and what is needed for rubber band powered flight so the builder could decide on having a display model or flying model. They also usually showed scale tailplane outlines vs the size the kit's parts build since the tailplanes were almost always enlarged.

JetPlaneFlyer 04-28-2014 09:07 PM

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It's MANY years since I built my Guillows Me109 but I think I recall that the dihedral shown on the plan wasn't enough.

I did a dime scale rubber power model of the 109 a few years ago, same size as the Guillows one but much lighter built it was about 16g all up. This one actually flew ok... see attached.

Griff Murphey 04-28-2014 10:13 PM

Nice build! What kit?

JetPlaneFlyer 04-28-2014 10:30 PM

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Quote:

Originally Posted by Griff Murphey (Post 946772)
Nice build! What kit?

It was a prototype build from a plan by Mike Nassise. I took Mike's original hand drawn plan and developed it for a laser cut kit that was briefly sold by a company now no sadly longer in business.

You are welcome to a copy.. Attached is plan, parts template, instruction sheet (complete with pic of my model!) and templates for the canopy and card stock radiator and decals.

It's a quick build and flies nice, also attached 'bare bones' photo.

Griff Murphey 04-28-2014 10:48 PM

It's so clean and the outline is so good it looks like a plastic 1/24 scale injection molded model.

JetPlaneFlyer 04-28-2014 11:04 PM

Thanks! The photo hides a 1000 sins. I picked the winter camo scheme as it does a good job of breaking up the stringer lines and only needs a dusting of paint to get the effect. It doesn't have many stringers so the fuselage really doesn't have a very scale shape but it catches the dime scale spirit quite well. Mine would be illegal in dime scale contests because I don't think paint is allowed, but it was never built to compete.

Griff Murphey 05-03-2014 02:00 AM

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I am still not happy with the way the plane is flying. If you launch it into gusty wind it will climb, on a calm day not so much.

So I am building a sport wing that I think will have quite a bit more lift. Should be no heavier, maybe even lighter than the kit one.

thepiper92 05-03-2014 06:03 AM

Better performance could be had from the brushless power found in the eflite UMX beast or SBach. Brushless and 2s will give the plane a better flight.

JetPlaneFlyer 05-03-2014 09:16 AM

Yes, much better performance could be had out of a brushless set up, but the complication is that the brushed speed controller that's built into the 'brick' would need replacing. Then you need to get an output from the brick to control the new external brushed ESC.

This is possible on the Parkzone ultra micro bricks but I'm not sure about the Flyzone ones.

Griff Murphey 05-03-2014 09:33 PM

I'm using the Flyzone stuff because a Flyzone brick and Powerplant cost $60 max so it seemed a good entry level package. Free if they come out of a wrecked SE-5. However I am tiring of it and I don't think I will be content with it much longer. A decent programmable 4 ch transmitter, bigger engine, and aelierons are possibly in my future. But humor me. Been flying foamy Flyzone WW-1 bipes 1 year, the 109 is my 2nd stick and tissue 3ch rc. I am almost ready to cover the new wing. The kit 109 wing area is really miniscule! This should help. I shall let you know!

I look in these caralogs at radios and engines and I cannot tell what goes with what anyway.

Like Lloyd Bridges as the admiral in HOT SHOTS, "I don't think I've ever landed a plane in my life!"

Griff Murphey 05-11-2014 02:30 PM

Bigger wing, new battery
 
The bigger wing has made the 109 much more stable. With a new battery, it will climb into the wind. I flew it this morning in 15 mph gusts, too high really, but I had fun holding it into the wind at zero ground speed.

I can confirm that the plane is still underpowered but but the new battery definitely helps.

There is a lesson here and after watching 109 videos on youtube I would highly encourage you to increase wing area if you build one.

I think the Flyzone power plant from their micro biplanes can be pushed to run 16" stick and tissue biplanes but it isn't adequate for a WW-2 monoplane fighter particularly one like the 109, and this may apply to small wing kits such as the Deils Frank or the Jack(!).

Griff Murphey 05-15-2014 02:28 AM

Finally... It flies, climbs, and cruises
 
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After adding the bigger wing, I still was not getting any climbing. So I went back to the same prop I used on the AEROWERKES Pup, the Ares Umicro 5.5x2.75 prop from the local Hobby USA. I bought a new 3.7v battery and fully charged it. The plane is now fun to fly. Btw the P-51 spinner still fits OK.

Below are photos of the wings and my Adolf Galland pilot figure....

Griff Murphey 05-15-2014 02:30 AM

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Here is Galland


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