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Old Feb 24, 2010, 12:01 PM
that guy
United States, WA, Parkland
Joined Feb 2010
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Guillow's #403 Spitfire...yeah...

i am currently building a Guillow's kit spitfire with electric flight in mind. based off posts of read here and on other sites i pretty much have full intentions on crashing and burning once its completed and attempted to be flown

that said, its still my goal to actually get a successful flight a time or two, even if it is entirely on accident. it will be a simple build with stock wing and simple R/E/T only. im considering not even using the landing gear to avoid the both weight and tearing it up on landing (if it comes belly side down in a controlled fashion ever). so far the plan is to have the front of the fuselage removable for battery access and the nose planked for added support. im considering planking the LE/TE of the wings somewhat for stability on impact but not sure if that is worth the added weight.

my list of parts is looking like it will be as follows:

EDIT:

using an e-flite park 250 brushless, e-flite esc, and 2 blade 9x5 prop


i have a 4 channel controller, just have to check if the current receiver will fit the small spitfire and how much it weighs.

any suggestions/ideas on how to go about this build or the above parts?
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Old Feb 24, 2010, 02:06 PM
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USA, FL, Tampa
Joined Jul 2002
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Welcome to rcgroups and the Guillows conversion addiction.

You sure didn't pick and easy one but have a good attitude about it thinking failure is a possibility.

Having done a few conversions this size here are my comments about your equipment selection.
Your battery selection looks good.
Not sure that motor will fit in the nose? It is also a bit heavy for a model this size but will have plenty of power.
I would use 5 gram servos and save the extra weight.

Insert planking the nose back to the leading edge would be a good idea.

Modify the wing to include a proper spar. Shear webs would be the minimum.

I like to skip the hatch in the fuse and make the wing removeable and retained with a pair of magnets. This becomes the hatch and everything is installed from there.
Glenn
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Old Feb 24, 2010, 02:30 PM
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West Central PA
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Quote:
Originally Posted by crazysccrmd View Post
i am currently building a Guillow's kit spitfire with electric flight in mind. based off posts of read here and on other sites i pretty much have full intentions on crashing and burning once its completed and attempted to be flown
Mine did, although overgrown grass saved it. It started as a rud/elev attempt, which actually flew ok on the Guillows 190, but is much better with ailerons now. The first hand launch with the Spitfire resulted in 4 or so rapid rolls. Adding significant right thrust and washout solved the problem. I added ailerons, but did not need to use them whatsoever on the next launch. This plane actually flew very uneventful. This plane ha 1 sq-ft of wing area and flies well at 14oz. Mine has an old GWS 350C brushed setup.

Like Glenn, I'm not into sectioning hatches on these planes. The wing is quickly removable with a nylon bolt that can be turned by hand, for batt access.
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Old Feb 24, 2010, 04:42 PM
that guy
United States, WA, Parkland
Joined Feb 2010
36 Posts
Quote:
Originally Posted by glewis View Post
Not sure that motor will fit in the nose? It is also a bit heavy for a model this size but will have plenty of power.
I would use 5 gram servos and save the extra weight.
what motor would you suggest as a substitution? or if not a specific one, what weight, size and thrust capacity should be adequete?

also, what torque rating should i be looking at for these lighter weight servos? i dont want to end up with something that cant get the job done
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Old Feb 24, 2010, 05:21 PM
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USA, FL, Tampa
Joined Jul 2002
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I would go with the lightest possible solution.
Something like this one http://www.hobbycity.com/hobbycity/s...trunner_1700kv
This motor is very similar to the CDROM conversions I use in my models this size.

The Spitfire has a longish nose and with the light motor the battery will need to be near the wing leading edge.

OTOH, WTFLYR used a GWS 350 geared power system in his and that weighs as much or maybe more than the motor you proposed. Some guys like a higher wing loading on their models and can fly them in much more wind than my 8oz light weights.

I ues the 5 gram servos in models this size without problems. Not sure what the torque output is but it's adequate for my stuff.
Glenn
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Old Feb 24, 2010, 06:40 PM
that guy
United States, WA, Parkland
Joined Feb 2010
36 Posts
well, my plane will probably be heavy, i doubt i have the skill to craft it as light and agile as yours. wish i had a scale to weigh it on
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Old Feb 24, 2010, 07:15 PM
that guy
United States, WA, Parkland
Joined Feb 2010
36 Posts
figured id upload a picture. fuselage is just resting on the wings...and yes, im working on my kitchen bar/counter

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Old Feb 25, 2010, 09:08 AM
MPP
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Looks great!

Your beverage choice, most excellent.

Good luck,

Mark
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Old Feb 25, 2010, 11:12 AM
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United States, CA, Garden Grove
Joined Oct 2000
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Ailerons on any low winger warbird are almost necessary. Some omit rudder control and use ailerons and elevator plus throttle for belly landers. I like to taxi models and like having rudder for ROG takeoffs. Some couple aileron servo to rudder to get a certain amount of rudder with aileron commands, without weight of a rudder servo. You need to plan battery and R/C system placement to avoid need for nose ballast, avoid any tail heaviness to get through the maiden/trim flight.
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Old Feb 25, 2010, 12:24 PM
that guy
United States, WA, Parkland
Joined Feb 2010
36 Posts
what would you recommend for covering the surfaces? in spirit of the budget-probably-going-to-crash spirit i was thinking of just using the tissue in the kit, but would using some microlite give it enough strength to maybe survive a bit longer?
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Old Feb 25, 2010, 02:10 PM
MPP
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Microlite would be a good choice. Just stay away from the heavy films. Nelson lite film aka solite works well but loosens or should I say has poor memory. Solarfilm is a good alternative little stronger and on the lower end of film weight. Doculam is also a candidate however you need to buy a lifetime supply or I think Charlie at Manzano has "short" rolls. While tissue and dope would be your lightest choice it is very prone to puncture and might not meet your survivability criteria.

I agree with E, put ailerons on, correct the airfoil from the plans flat profile, correct either the wing or horizontal stabilizer incidence unless you are ready for lot's of down trim, 1/8" Washout in the tips (as this is an elliptical wing) right and down thrust will also help in a successful first flight, CG forward of the FF line. I believe this one has a CL CG marked on the plans? might be a good start.

The challenge is going to be the front end of the Spitfire. It has a short nose and not a lot of room in there. As WT did you can go up to 14 OZ.'s or so and probably be fine. Just remember the lower the weigh the lower the stall speed.

Hope this helps,

M
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Old Feb 25, 2010, 02:33 PM
that guy
United States, WA, Parkland
Joined Feb 2010
36 Posts
im headed off to the local shop to see what they have. also going to see if i can pick up a cheapo/light brushed motor. ive got an ESC for one but no motor. hopefully they've got something that might work out. if not i'll just see if they have a brushless esc/motor.

im not going to ailerons on this go around, but i might end up picking up another kit while im there...


edit: cg for both ff and cl is shown as at the b3/4 former, roughly directly above the thickest part of the wing
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Old Feb 25, 2010, 03:43 PM
that guy
United States, WA, Parkland
Joined Feb 2010
36 Posts
i ended up getting an eflite park 250 brushless outrunner (14g), eflite 10amp brushless ecs (10g) and a small 7.4v 300mAh lipo. total weight combined is only about 1.5oz, so not too bad. went ahead and spent a little more money figuring that these will be used many times in small scale models
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Old Feb 25, 2010, 04:01 PM
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West Central PA
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My tail could have been lighter and the fuse was sheeted, but I still needed considerable ballast, along with the relatively heavy motor setup, in addition to the batt and servos mounted very far forward. The longer nose than some is a bit misleading on this plane, as the elliptical wing moves the MAC considerably forward than that of straighter wings. I would use something comparable to a Park 370 outrunner. You'll likely need the weight, unless you can keep the rear fuse and tail very light. Nothing wrong with the setup you have, as long as the rear is kept very light. These planes are what gave me the respect for shaving all the tail weight you can. On the CG, I have found the Guillows CGs in general to be a good bit aft of what I needed for stable rc flight.
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Old Feb 25, 2010, 04:23 PM
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USA, FL, Tampa
Joined Jul 2002
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That looks like a good choice for your power system.
You will need to place the servos, rx and esc near the leading edge. You may need a larger battery mounted up in the nose to get the CG like WTFLYR has suggested. And keep the tail as light as possible!

Now that you have the airframe nearly done is a good time to experiment with the equipment position to achieve the proper balance. Set it up a bit nose heavy now. The tail will get heavier after covering.
Glenn
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