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Guillows SE5a Kit 202 Rubber Power to RC Conversion

TooJung2Die

Well-known member
#1
I haven't built a Guillows kit in over 45 years. The last Guillows kit I built as a boy was this SE5a. It was rubber powered and covered with the green tissue that came in the kit. I remember it wasn't a great flier. The rubber and prop didn't have enough thrust for it to climb well. The landing gear was weak and every landing resulted in a repair. But it looked good. It was proudly displayed on my desk until a baseball crashed through the plate glass window above the desk and big shards of broken glass came crashing down on top of it. :mad:

Last winter I picked up an old Guillows SE5a kit on eBay. It's just like the one I built back in the '70s. It may even be as old as the first kit. The instructions are yellowed with age. :) It is good old die-crunched balsa. It wasn't evident in the eBay photos but someone started popping out the pieces without sanding first or using a razor blade. :eek: Two balsa sheets of parts were a pile of scraps in the bottom of the box. The first thing I did was take inventory of the pieces. Remarkably every single piece is there. Nothing is missing but some of the balsa cracked and the delicate tips and such are broken off. Finding the broken bits and putting them back together was like solving a jigsaw puzzle. Happily I found every little scrap and using CA glue got every piece whole again.

That's enough yacking. Let's get started. Here's the kit.

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Here's what was in the box. Loose pieces on the left. I'm glad the scrap balsa was included. That's where the missing bits were found.

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Some pieces fit back into the scrap and were glued. Others had to be pinned down and glued.

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The notches for the side keels and stringers on the bulkheads will be cut out later in case there's some misalignment that needs correcting.

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The side keel fit loosely in the bulkhead notches so shims were cut from scrap to fill the gaps.

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I don't know anything about balsa grading. I use what comes in the box. Compared to the balsa in the "Contest Commercial" kit this balsa is HARD. It is dense. I swear there's a knot in one of the fuselage keel pieces. Hey, it's what came in the kit so I'm gonna use it. I'll just have to sharpen the blades more often. By the way, this is the sixth airplane I've built using the same Xacto blade, foam board included. I'm not cheap, it's that I can quickly sharpen the blade to a better edge than new. I'm still using the same snap-off blade for the same reason. The trick is to use a razor strop like a barber. The back of my left hand is almost hairless from testing the edge. It's hair shaving sharp.

Jon
 
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Seahunter

Active member
#2
Nice work! I've been uploading photos for a couple of days now of a Guillow's Piper Cherokee build I built back a few years ago. I will be posting a thread on it in a few days. I have the photos in an album in the media section. Will be opening it for everybody to see soon as I get all the pictures together. Waiting on some more pictures from my daughter out in Sante Fe where the model is. Kit # 307, build log and album soon. I have that SE5 kit out in my storeroom, so I'm watching this build with great interest!

P5200004.JPG Here's a sample, completed model of my daughter's Cherokee 180, Display Only.
 

TooJung2Die

Well-known member
#3
I don't think I've ever seen a Guillows kit turn out that nice, Seahunter. The Cherokee is static only? It's beautiful.
I'm reading up on some Guillows RC conversions to get ideas of where and how to mount the electronics. The "Contest Commercial" fuselage was big and roomy inside but the SE5a is just the opposite. Lots of bulkheads taking up space. "Keep it simple" is my motto. Since the plans show a Cox .020 as an alternate power plant I'm going to use this motor, a similar size motor to the one used in the "So-Long" RC conversion; 1806/2100KV (19g). Other builders have used lighter motors but I want enough thrust to do more than get off the ground.


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Jon
 
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Seahunter

Active member
#4
Great story to go with that Cherokee. It's built using 1/16" lite ply formers and completely covered in sheet balsa and then Iron on vinyl. I have a bit more to do on the photos and descriptions, will post soon. That motor should do fine, using about a 12A ESC? That will save space. I have an older18A ESC in the Fokker DVII I built, big and cramped it up a bit.
What are your plans for covering the SE5 ? I like the tissue, but not when I go electric. Tears and punches out much too easily with the extra weight. Just a suggestion, but I have had real good luck with coverite 21st century micro lite. That's what's on the Dumas Ercoupe I built. Its a lot thinner than regular monocote thus saves weight. don't remember any olive though. Looking good, keep us posted :D
 

rockyboy

Skill Collector
Mentor
#5
Love this project! :D

For the ESC I'd say look into multi-rotor ESC's - those are getting much smaller and lighter than the traditional airplane ones, and with direct soldering you should be able to save a good bit of weight.

For your razor strop, are you just using an unfinished chunk of leather with some polishing compound? I've tried stropping a couple times but haven't had much success with it. I really do want to learn though - especially for covering. Some of the best covering experts I've read about always run their razor across a strop a few times between every cut and it turns out great work.
 

Seahunter

Active member
#6
I have been stretching out my blade life for several years using a worksharp field sharpener, it has two grades of diamond plates, two ceramic rods and a leather strop built on. Handy angle guides at each end of the diamond plate and ceramic rod to start your angle right. I keep it in the kitchen knife drawer until I start a build. I also have the Work-sharp electric model so I seldom throw away blades. Don't know about links yet, I tried one below

https://www.cabelas.com/product/Work-Sharp-Guided-Field-Sharpener/1434522.uts?slotId=0
 

TooJung2Die

Well-known member
#7
Love this project! :D

For the ESC I'd say look into multi-rotor ESC's - those are getting much smaller and lighter than the traditional airplane ones, and with direct soldering you should be able to save a good bit of weight.

For your razor strop, are you just using an unfinished chunk of leather with some polishing compound? I've tried stropping a couple times but haven't had much success with it. I really do want to learn though - especially for covering. Some of the best covering experts I've read about always run their razor across a strop a few times between every cut and it turns out great work.
Before I started the SE5a I was going to use a Rx/servo/ESC brick and a geared brushed motor. That idea flew out the window as soon as I saw the Cox .020 glow engine in the Guillows SE5a plan for an alternate power plant. The "So-Long" old timer is a Cox .020 engine free flight design. I used an 1806/2300KV motor in the "So-Long" RC conversion and it was a good choice. Barely crack the throttle open to maintain altitude. Wide open throttle and it climbs like crazy.

Before beginning a new build I put a fresh edge on the blade with an Arkansas oil stone. You only have to sharpen once. For a strop I glued a leather belt rough side out to a paint stirrer. First I rubbed in some Mother's Mag & Aluminum Polish. Now I have a brick of white metal polish and rub it on the strop once in a while. I can't believe it took me sixty years to learn this trick. Even if you don't want to resharpen blades you should use a strop on your new blades. When the blade seems to be losing the edge hit the strop again. If you hate sharpening a strop will make blades last longer between replacements. Ask any barber.

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Here's another trick I learned from BobK, another Flite Test forum member. Ever hear the expression "like a hot knife through butter"? That's how this covering film gadget works. It's a 25W soldering iron with a #11 Xacto blade riveted to the tip. It won't scorch the balsa. Sometimes it does double-duty as an extra fine trim iron.

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Jon
 
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TooJung2Die

Well-known member
#13
A few other projects came along but it gave me some time to think about this step. The plans had the plywood firewall for the Cox .020 glued to a 1/16" balsa bulkhead. That doesn't seem strong enough.

There's no way to get a firewall in the fuselage where it belongs without cutting one of the keels. I tried. The motor is mounted in the same position and angle as the Cox .020 engine. Splints are glued on either side of where the bottom keel was cut out. This looked good so splints were added to the top keel.

The firewall shape.

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Bottom keel cut and firewall positioned at the correct angle.

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Balsa splints added to the top and bottom keels. Fuselage placed on top of the plan to check the position and angle of the motor.

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Front view. There's good airflow through and around the firewall.

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The close ups show how rough the die cut pieces come out. Sanding will clean that up.
Jon
 
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TooJung2Die

Well-known member
#14
The 3.7 gram servos are in the cockpit. The front fuselage top will be removable. Here you can see the frame for the removable part. The bulkheads are doubled at the front and rear of the removable top. The top keel will remain uncut until all the stringers are in place. Then the removable top will be cut free. Toothpicks are used for alignment. Magnets will hold it in place.

I don't know where the battery will go for CG but with the weight of the motor up front I have a hunch the battery will go on top of the bottom wing. The removable part is long enough to allow ample room to play around with the position of the electronics. More balsa can be cut out of the inside of the bulkheads to make more space.

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Jon
 
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TooJung2Die

Well-known member
#17
This is one of those steps that always makes me think hard because there are so many ways to install control linkage. Where is the best place for the push rods to exit the fuselage? Bamboo skewers, wire and heat shrink tubing used again. This way the length of the push rods can be adjusted after the elevator and rudder are hooked up to the control horns. When the length is just right a couple of drops of CA glue on the heat shrink locks the wire in position. The rear bulkhead the wires pass through is hardened with CA glue.

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Jon
 

TooJung2Die

Well-known member
#18
Putting the stringers on the fuselage. Invariably the die-cut notches for the stringers are too big or misaligned. The notches that have fallen out by themselves get shims to fill the gaps. The notches that at still in bulkhead get glued with CA and cut with a notching saw. It slows down progress but I enjoy building and this is not a race to complete. Alternating stringers right side and left side so the fuselage remains straight.

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With all the corrections that have to be made there isn't much advantage to die-cut kits over printed balsa. Laser cutting is a tremendous advancement in kit building when the laser is programmed right.

Jon
 

TooJung2Die

Well-known member
#20
There are a lot of pieces in this fuselage! All the main stringers are done but there is still much to be done on the fuselage. I needed to look at something else for a change so began building the tail surfaces. The plans call for 1/16"x3/32" strips but there are none in the kit. No problem, there are lots of balsa scraps from the last three kits and 1/16" seems flimsy. Since the tail surfaces will be hinged larger cross section strips were used for more strength. The elevator and rudder were also beefed up where the control horns will mount. .060" wire is used to connect the elevator halves.

You can see the plan view of the tail surfaces and the resulting modified parts.

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Jon