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Old Dec 30, 2005, 08:59 PM
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Guillows 20" Fokker DR1

This thread is also in Scale Models, although it finally hit me that is is somewhat of a micro, so I thought I'd put some less detailed information here, just to show the plane if anyone is interested. The more detailed thread is there.
All the components are built at this point, and it needs covering and final assembly. Some important features are extensive use of CF, such as CF rods behind the wing LE's and CF spars recessed in the wing and gear struts. CG is one the major challenges on this plane. I have the batt and servos directly behind the cowl, with the Cirrus 4.4 servos against the fuse sides. I wanted to put them in the cocpit floor, but it would not balance there.
A guy on RCU got one of these flying with a geared IPS, which I'm using also, mounted on a stick 2" in front of the plane. With my concern for scale looks, I didn't care for this solution. With everything up front, it seems to balance so far, with little if any nose weight if needed. The geared motor is actually mounted and hidden in the simulated engine. The motor can even be removed from the gearbox, while leaving the gearbox mounted to the simulated radial. So far, I have everything on the scale, including covering estimated weight, to give an AUW of about 6.5oz. Not to bad, considering this thing has 144 squares of wing area (1 sq-ft). In the photo, everything is loosely stacked like a "card house" just to give the effect.
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Old Dec 30, 2005, 09:33 PM
Honey,just one more thing
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Rensselaer,IN
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There's nothing like a Guillows kit, balsa and glue. Wish you the best Bud
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Old Dec 30, 2005, 10:32 PM
Team30 Micro EDF
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Add positive incidence to the tailplane - the rubber version doesn't have it nor is it shown on the plan. This is reaaalllyy important.
I learnt that the hard way as this was my first Guillow's conversion to r/c.
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Old Dec 30, 2005, 11:16 PM
Old Tyme Electric
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Quote:
Originally Posted by NitroCharged
Add positive incidence to the tailplane - the rubber version doesn't have it nor is it shown on the plan. This is reaaalllyy important.
How come and How??


TIA,

Steve
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Old Dec 30, 2005, 11:41 PM
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Quote:
Originally Posted by NitroCharged
Add positive incidence to the tailplane - the rubber version doesn't have it nor is it shown on the plan. This is reaaalllyy important.
I learnt that the hard way as this was my first Guillow's conversion to r/c.
So you have one of these that flys. Like to hear more. Pics? How much positive incidence? For example: should the front of the tailplane be shimmed up say 1/16" (about 1 to 1.5 degrees), or some other measurement? Also like to hear how you balanced the plane (comp location), and was the CG where it is on the plan?

Back to the build, I managed to mount the 2 servos, receiver, 2s-340 lipo, and esc all between the firewall and the first bulkhead. Fairly tight, but fits, as I've determied its necessary for cg setting on this short nose bipe, without adding no-no nose weight. I finally bought the new Dubro adjustable control horn clevises for .032 wire. They are nice little buggers, although I ususally just use the adjustable e-z connectors on the servo horns. In this case, they will be tough to get to, once covered, so I wanted the adjustment. I used .015 music wire, however, to save weight, as .032" is not needed. I pull tested the small wire, CA glued in the little brass threaded adapter to at least a good 10 lb pull. Much more than these control surfaces will ever put on them. Too late now to get motivated to cover parts, so maybe tomorrow.
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Old Dec 31, 2005, 06:51 AM
Trainer Pilot
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if it weighs more than 5 oz its gonna fly like a speeding brick. not like i learned that from experence, but if your a good flyer yeah sure you could fly it.

check into finding a formula for wing area , weight and speed. those are important factors to looks for in a plane that you wanna fly or gonna try flying.
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Old Dec 31, 2005, 12:20 PM
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6.5 oz/sq-ft is not speeding brick wingloading

Quote:
Originally Posted by PrOtRoN
if it weighs more than 5 oz its gonna fly like a speeding brick. not like i learned that from experence, but if your a good flyer yeah sure you could fly it.

check into finding a formula for wing area , weight and speed. those are important factors to looks for in a plane that you wanna fly or gonna try flying.
That's what I had previously stated, concerning wing area. As always, again RMC. The plane has 1 SQ-FT of wing area. At 6.5 ounces, that's 6.5oz per SQ-FT. That is not a speeding brick wingloading. This is why bipes and tripes make such appealing micros. The small size is obviously misleading here.

Still always looking for useful info and advice,
Bill
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Old Dec 31, 2005, 01:55 PM
Time wounds all heels.
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Guillows wood is dense and heavy, I almost never use the stock wood anymore.

I have built almost every kit they make, since I like the plans. I have built as light as 50g and up. 50g was a 17" 9 series Mustang with 2s2p 145 Lipo on Cirrus MJ gear with lots of carbon, contest wood, and EDP50 DD. And it was the best of the bunch by far, surprisingly crash resistant. The airframe is still flyable, although the gear has moved on.

As far as tips, I would tell you to cut out half the stringers, shave the formers (or redo them in depron), replace the built up tail with depron, drill lightening holes in everything, and use a light covering. The geared GWS edp50 (i think its called an A) should be plenty, and use a prop that is a bit faster for the first flights, the slower props seem to torque effect these birds pretty hard.

Guillows kits are one of the hardest conversions, Dumas is much easier. Mainly due to wood quality issues. Dont be misled by the wingloading, at 6.5oz that tri is gonna be a handful. The saving grace for you is that you chose the 20" model (5 series?) which can carry a bit more. One of the biggest hurdles to making the transition to building micro is gettign a feel for how much every gram matters. If something looks strong enough, its overbuilt. Light weight crashes light, too.
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Old Dec 31, 2005, 03:11 PM
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Quote:
Originally Posted by watersharer
Guillows wood is dense and heavy, I almost never use the stock wood anymore.

I have built almost every kit they make, since I like the plans. I have built as light as 50g and up. 50g was a 17" 9 series Mustang with 2s2p 145 Lipo on Cirrus MJ gear with lots of carbon, contest wood, and EDP50 DD. And it was the best of the bunch by far, surprisingly crash resistant. The airframe is still flyable, although the gear has moved on.

As far as tips, I would tell you to cut out half the stringers, shave the formers (or redo them in depron), replace the built up tail with depron, drill lightening holes in everything, and use a light covering. The geared GWS edp50 (i think its called an A) should be plenty, and use a prop that is a bit faster for the first flights, the slower props seem to torque effect these birds pretty hard.

Guillows kits are one of the hardest conversions, Dumas is much easier. Mainly due to wood quality issues. Dont be misled by the wingloading, at 6.5oz that tri is gonna be a handful. The saving grace for you is that you chose the 20" model (5 series?) which can carry a bit more. One of the biggest hurdles to making the transition to building micro is gettign a feel for how much every gram matters. If something looks strong enough, its overbuilt. Light weight crashes light, too.
I've built a number of Guillows in the past. I would love to use the Cirrucs MJ setup, but they blew it with me, releasing JUNK early, where 3 out of 4 servos were defective. Home plate ump says "YOUR OUT!!!" of my micro business. This conv does have a GWS geared IPS setup. Shaved formers down, etc, on Guillows builds. On this plane, if you eliminated half the stringers, you would hardly have any. Buying a laser cut kit, and then throwing away all the parts, to recut by hand, is not something I would ever do.
As for crashes light does crash light. The best thing you can do is what I've done hear. All of the major weight (Servos, batt, motor of course, and rec are basically directly against the firewall, where the weight transfers to the very front, in a crash. The worst crashers are planes with servo trays, where the mounting is loose and does not transfer its loading to the front through rigid fuse keels or added reinforcement. Same goes for batteries further back. In a crash, their inertia takes out everything in their path, on their way to the front. Alfa, for example, has done a good job with this by mounting everything on a plate which butts the firewall, where the surrounding foam of the rest of the plane is light. They crash well in direct nose ins, from direct experience.
Not to sound smart, but can I please get some specific info on This plane, from previous builders. Well aware of general building/light building info and tips.

Guillows conversions and kits built so far:
Hellcat 16"
FW-190 16"
P-51 17"
Skyraider 17"
Piper Cub 20"
B-25
P-51 27"
FW-190 25" (2 of them)
Zero 25"
Spitfire 25"
Dauntless 30"
P-47" 30"
Hellcat 30"
PBY Catalina (true e-conversion, not display)
DC-3
I'm sure I still missed a few
Not all even close to successful. That's the learning experience.

Nitrocharged, you were right. I looked more carefully at the tailplane setup. I had already made tapered shims for the rear, to allow for the elevator pivot to rotate without interfering with the top rear of the fuse frame. Still looked pretty negative. I've added another tapered shim to each side, made from light 16th inch spar. I think Guillows added the notch to the fuse keel to recess the elevator, giving clearance for the top of the rudder's front portion, which hangs over the plane. They did not look closely enough to the changes to the incidence. I imagine you were having trim problems, with the plane wanting to dive, needing pos elevator to keep flying?
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Old Dec 31, 2005, 03:54 PM
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nice job so far. looks like a winner.
have you decided on a color scheme and covering?
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Old Dec 31, 2005, 05:34 PM
Team30 Micro EDF
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Adelaide, Australia
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Not dive but nose straight up as the tailplane pushed the tail down hard. start with what you have in the way of incidence and increase if necessary. Try and at least match the positive incidence of the top wing.
I have a thread going on about all the hiccups with the model. I put my r/c gear too far back and ended up having to add a full ounce of weight to get the cg I stacked it and have yet to repair it - while it sat there I scavenged all the gear out of it for other projects - which is good because I can now relocate all the gear up the front. I posted also how I connected the lower wing with magnets and could access everything from underneath.

I used a 17t cdrom motor as the gws couldnt cut it even close. I used the stock wood and covered in heavy film. Basically, I did everything absolutely wrong! I have another kit still in the box and sealed that I hope to make the right way but am concentrating on micro fokkers as that is too much of a buzz for me to ignore.

BTW, fokker triplanes usually are gliding bricks - its their nature. Power up and they are fine. Making them out of foam of course gets around this. jmscw
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Old Dec 31, 2005, 06:19 PM
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Nitrocharged, the cg issue was one of the first things I dealt with on this plane, fortunately. The servo mounting in the side keels in the very front of the plane was a bit tricky, but worth it now, knowing anything further back won't cut it. One lesson I learned in the past is that even if weight is added to make a plane balance, it is still not the same thing as removing weight from anywhere behind the cg, thus needing less ballast. This is why my battery compartment is my "everything compartment". Its tight, but fits well. Worked out very well, with no wasted space. I thought about using an access panel under the wing, but it is hard to access under the landing gear, and the components really need to all be in the very front bay, to set cg without ballast. I even used .015" pushrods, to lessen tail weight. Probably should go to an even lighter covering. Econokote is not that light, but the Coverite is too transparent for me. Still better that standard weight covering. Put lightening holes in the covering? Now that I just got a digi-cam, hopefully I'll be able to post even better pics of the batt/servo/esc/rec compartment soon.
What gearing, prop, and batt did you use? Like to know more about your first build.
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Old Dec 31, 2005, 07:15 PM
Team30 Micro EDF
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direct drive, 8x4 EP GWS Prop, kokam 340.
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Old Dec 31, 2005, 10:48 PM
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Sgtdirt, going with the box scheme of the good 'ol Richtofen Red Baron. Can't put Snoopy in, however, due to cg concerns.

Watersharer, you talked me into giving this thing a major shaving and Swiss cheese drilling operaton. In reality, drilling center holes in all of the beams, shaving fuse former centers, and drilling holes in fuse formers only saves a few grams to many people's amazement. The real weight is the components, motor and battery. The few grams saved are still worth it, however, as a gram shaved is a gram saved. In this case, I shaved about 2 grams, with extensive lightening. Gradually reduced the size of the main fuse keels from behind the wing, to the tail end, as the strength required progressively decreases. Also drilled lightening holes along the center of the fuse keels, in addition to the fuse formers. The landing gear platform already had large lightening holes, although I did a second operation, adding more smaller holes. The struts attach to the front portion of the platform, rendering most of it dead weight. It only needs enough cross section to not break, as I am not running the axle across the entire platform, to save weight. The wheels will be superlight spoked, with paper center hubs to look scale. Much lighter than the Guillows wheels, which do look nice, but are simply too heavy for a plane this size. Definitely not using the nylon firewall gas engine motor mount Guillows supplies, as it is not necessary for a plane like this, and is very heavy. Since my GWS IPS gearbox is mounted in the simulated radial, there are no point loads from the gearbox mounting on the firewall, making it even more damage resistant. The large circular rear thin plastic engine surface will give a nice evenly distributed load.

The smaller prop is also a good idea. I bought the gearing they had (S2 I believe) which I may change. Not thrilled with a 10" reccomended prop, past the wheels, and the torque effect. Also, a smaller prop with higher pitch speed may be a better first flight prop, as the plane may need the speed to stay in the air. All the thrust in the world won't work if it can't go fast enough.
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Old Jan 01, 2006, 07:18 PM
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Got the fuse and tail feathers covered last night. The best feature of this build is that all of the components and battery are in the first fuse bay. Experimenting with cg, this is a must for this plane, if you don't want to add nose weight. The picture is not very clear, but I drew a diagram also. The 2s-lipo fits in the slot seen in front of the wing opening, with the gearbox, receiver, and Pixie-7 esc in front of it. There is just enough room to mount the GWS Pico rec with double sided foam tape, between the motor cutout and the servos, against the firewall. Square stock is ran lengthwise in the compartment, to keep the batt in the center, off of the pushrod wires. The servos are mounted on cuts in the fuse side keels, against the fuse sides, with the pushrods running next to the batt on either side, which makes the square stops necessary. The .015" music wire pushrods runt through guide holes in the fuse formers, keeping them from flexing. A lightweight hinged cover will be made for the batt compartment. There actually is ample room for everything, leaving room for padding between the motor end and battery, and a door that can actually fully close when the battery is installed.

UPDATE: For the naysayers, just found a 20" DR1 offered by Billy Hell, that is 6.5oz. This is EXACTLY the same overall spec as this build. Always inspiring to see someone else has done it.
http://www.billyhellrc.com/fokker.html
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