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Found a Middle Stick Kit from ~1969

#41
You are doing great for your first build. Correction; you're doing great for any build. (y)
You should buy the whole roll of white. It's a very useful color and hopefully this will be the first of many more builds in the years to come. You might build a white airplane with red trim. :)
Jon
 

KSP_CPA

Well-known member
#42
Servos and push rods have been installed in the fuse. Did the pushrod wire to balsa rod secured with thread and CA method; unfortunately, I did not get any photos before closing up the fuselage back cover plate.

I found my Achilles heel; cable push/pull rods. The install of the front gear steering cable was a flipping nightmare. From cutting the cable, to the tracking tube, to both sides of the connection, nothing went right. Several hours and the wheel barely pivots, but it is better than a fixed position gear and will provide some ground steering control. I’m not fooling with that again right now.

More weighing showed I am actually trending down towards 1,400 grams all up weight. The gear has been attached and I decided to see how it looks on its feet. And.... it sits right on its tail even after the battery and motor are thrown in the fuse front-trunk (the “frunk” if you prefer). I’ll have to counter balance with quite a bit of weight, but I have budget for it.

Covering has started on the wing with bottom half of one side was completed tonight. More to do this week!
 

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KSP_CPA

Well-known member
#43
Wing covering was completed last night, I was so excited, I had my wife take a picture with me holding it. Ailerons, hinges, and control horns is all that’s needed to complete the wing now.

Weight and balance is going to be an issue I’m afraid. While I was so happy to be under weight, I did not take the balance point into consideration. I believe the primary reason I’m under weight is the huge difference in weight between the gas and electric motor. The .30 rotary engine it was designed for weighs around 375 grams with the fuel load up to 280 grams for a powerplant load of 475 to 655 grams. The electric motor, ESC, and battery I have slated is 275 grams with the majority of it behind the firewall. This is pushing the current COG far aft. Adding ballast weight to the front would correct, but I'm looking at adding around 400 grams (nearly 1 pound) just behind the firewall to balance.

It looks like an extended front motor mount and cowling will be part of the answer to save weight and correct COG. I found a great article about making custom cowlings which would seem to work (See article here) but I would opt for a fully balsa style covered in MonoKote instead of trying to learn how to use fiberglass.

EB222531-9477-4905-BD6B-13AE8D466B8A.jpeg

A56D3867-33ED-4B63-AE93-3CDCCAB589D9.jpeg
 

KSP_CPA

Well-known member
#44
attempted to form a longer nose to the front, horrible idea, looked terrible and took the whole look of the plane away, after nearly a whole day working on it I ended up just ripping it off and keeping with what I had. I was so disgusted, I refused to take any pictures and hope out of the thousands of things I forgot in my life, that nose extension is one of them.

Mounted the motor, gear hold clips, and took it around for some taxi testing. The front gear control cable comes back to haunt me as I found it was mounted mirror, so left is right and right is left. I have no idea how I am going to fix without replacing since it is firm fixed to the rudder servo. More work on that another time.

On to weigh out. I weighed it again today and the results were as follows:
wing- 403 grams
Fuse - 926 grams
Battery- 166 grams
Additional nose weight - 210grams
Current all in- 1,705 grams

I think with more nose weight necessary and some other odds and ends it will end up at a max flying weight of 1,800 or roughly 4 pounds. That presents a new problem. I currently have an FT2218B 1180KV with a 35 amp ESC installed. I only have a 3S battery and max 3S charger. Stats on the FT2218B motor are difficult to find but assuming that it runs at about 75% of max recommended ESC amperage with the recommended 10x4.7 at 3S voltage estimates could put out around 300 watts of "power". Everything I can find recommends 80-100W per pound therefore it looks like I'm going to have to upgrade to 4S voltage which would put out 416 watts.

However, I have doubts that just upgrading to 4S on this motor will solve all my problems. Looking at other power pack C enabled aircraft shows their weights are roughly half of what I'm pulling. For example, the master series P-47 weighs only 1,000 grams and the recommended battery is 4S on the powerpack C.

Going to need help from the builders out there, if this was a foamie, who cares, just throw it up and see if it goes, but I am a fully grown adult male who is not ashamed to say if this thing crashes, I'm going to sob like I'm watching the first 15 minutes of the movie "Up". Would a 4S battery powering an FT2218B going to be enough to put 1,800 grams or 4 pounds in the air and keep it there?
 
#45
In my opinion 100W per lb is a lot of thrust. You should pull unlimited vertical with that much power. 50W per lb is for the trainer/scale airplane category. If your motor can put out 300W on a 3s battery you should be okay. 300W in a 3.9 lb airplane is in the 80W per lb range. It should have a healthy climb rate and enough power to pull itself out of trouble. I think you will be safe and can always get a 4s later.
Jon
 

The Hangar

Fly harder!
Mentor
#46
attempted to form a longer nose to the front, horrible idea, looked terrible and took the whole look of the plane away, after nearly a whole day working on it I ended up just ripping it off and keeping with what I had. I was so disgusted, I refused to take any pictures and hope out of the thousands of things I forgot in my life, that nose extension is one of them.

Mounted the motor, gear hold clips, and took it around for some taxi testing. The front gear control cable comes back to haunt me as I found it was mounted mirror, so left is right and right is left. I have no idea how I am going to fix without replacing since it is firm fixed to the rudder servo. More work on that another time.

On to weigh out. I weighed it again today and the results were as follows:
wing- 403 grams
Fuse - 926 grams
Battery- 166 grams
Additional nose weight - 210grams
Current all in- 1,705 grams

I think with more nose weight necessary and some other odds and ends it will end up at a max flying weight of 1,800 or roughly 4 pounds. That presents a new problem. I currently have an FT2218B 1180KV with a 35 amp ESC installed. I only have a 3S battery and max 3S charger. Stats on the FT2218B motor are difficult to find but assuming that it runs at about 75% of max recommended ESC amperage with the recommended 10x4.7 at 3S voltage estimates could put out around 300 watts of "power". Everything I can find recommends 80-100W per pound therefore it looks like I'm going to have to upgrade to 4S voltage which would put out 416 watts.

However, I have doubts that just upgrading to 4S on this motor will solve all my problems. Looking at other power pack C enabled aircraft shows their weights are roughly half of what I'm pulling. For example, the master series P-47 weighs only 1,000 grams and the recommended battery is 4S on the powerpack C.

Going to need help from the builders out there, if this was a foamie, who cares, just throw it up and see if it goes, but I am a fully grown adult male who is not ashamed to say if this thing crashes, I'm going to sob like I'm watching the first 15 minutes of the movie "Up". Would a 4S battery powering an FT2218B going to be enough to put 1,800 grams or 4 pounds in the air and keep it there?
I've heard that the P-47 flies just fine on a 9 inch prop on 3s. My guess is that you'll be fine, but if you do need to upgrade the motor I'd reccomend this one: https://www.horizonhobby.com/product/motor-extra-300-1.3m/EFL11596.html
 

The Hangar

Fly harder!
Mentor
#47
Wing covering was completed last night, I was so excited, I had my wife take a picture with me holding it. Ailerons, hinges, and control horns is all that’s needed to complete the wing now.

Weight and balance is going to be an issue I’m afraid. While I was so happy to be under weight, I did not take the balance point into consideration. I believe the primary reason I’m under weight is the huge difference in weight between the gas and electric motor. The .30 rotary engine it was designed for weighs around 375 grams with the fuel load up to 280 grams for a powerplant load of 475 to 655 grams. The electric motor, ESC, and battery I have slated is 275 grams with the majority of it behind the firewall. This is pushing the current COG far aft. Adding ballast weight to the front would correct, but I'm looking at adding around 400 grams (nearly 1 pound) just behind the firewall to balance.

It looks like an extended front motor mount and cowling will be part of the answer to save weight and correct COG. I found a great article about making custom cowlings which would seem to work (See article here) but I would opt for a fully balsa style covered in MonoKote instead of trying to learn how to use fiberglass.

View attachment 175968
View attachment 175970
That looks really really good!
 

L Edge

Elite member
#48
Thanks @TooJung2Die. Looks like that was too easy. I'll need to come up with a harder question!
Here is a "DasUglyStik" that my son(age 7) used in pattern competition and blew away the 16 men(including me) to win first place. I built it without any dihedral and it would track and hold it's line with little imput. Notice the plane's length and my son's height is the same. Ended up, we had to get Curares' to compete with the big boys.

DasUglyStick.jpg
 

Monte.C

Legendary member
#49
Here is a "DasUglyStik" that my son(age 7) used in pattern competition and blew away the 16 men(including me) to win first place. I built it without any dihedral and it would track and hold it's line with little imput. Notice the plane's length and my son's height is the same. Ended up, we had to get Curares' to compete with the big boys.

View attachment 177598
Wow! Wow to a lot of things right there!
 

KSP_CPA

Well-known member
#50
OK! Finally re-installed the front gear steering control cable. I didn’t give it much motion and was hoping for minimum turning, but just 15-20 degrees of movement and it nearly pivots around the end of the wing, very pleased with that. Did some taxi tests around my neighborhood and you can tell this wing really provides a lot of lift. Going at a brisk jogging pace, it has some “suspension“ when hitting small bumps that is absent at walking speed.

The final pre-maiden test was conducted today was an electrical system cooling test. Flight setup, 2 minutes at full throttle, held down, in the sun. The motor was quite hot, but the battery, ESC, and interior were warm so I think it should be ok.

And with that, I think it is ready to maiden. I have a willing camera operator in my wife to document the event and if I can figure out how to edit and upload, I promise to post. This weekend is out as the remnant of hurricane Laura is causing breezy conditions all weekend in East TN.

I really appreciate everyone who posted their memories, pictures, and knowledge throughout this project thus far. I have read every post, mostly out loud to my wife, unprompted and without permission.
 

Attachments

BATTLEAXE

Legendary member
#51
OK! Finally re-installed the front gear steering control cable. I didn’t give it much motion and was hoping for minimum turning, but just 15-20 degrees of movement and it nearly pivots around the end of the wing, very pleased with that. Did some taxi tests around my neighborhood and you can tell this wing really provides a lot of lift. Going at a brisk jogging pace, it has some “suspension“ when hitting small bumps that is absent at walking speed.

The final pre-maiden test was conducted today was an electrical system cooling test. Flight setup, 2 minutes at full throttle, held down, in the sun. The motor was quite hot, but the battery, ESC, and interior were warm so I think it should be ok.

And with that, I think it is ready to maiden. I have a willing camera operator in my wife to document the event and if I can figure out how to edit and upload, I promise to post. This weekend is out as the remnant of hurricane Laura is causing breezy conditions all weekend in East TN.

I really appreciate everyone who posted their memories, pictures, and knowledge throughout this project thus far. I have read every post, mostly out loud to my wife, unprompted and without permission.
I am jealous, you have a beautiful build and good luck on the maiden
 

KSP_CPA

Well-known member
#52
Maiden flight was successful! It is a tad underpowered and has a bit of roll tendency that will need adjusting on the aileron control rods but it flies. Only pictures for now but my camerawoman / spouse got some really good video. I’ll figure out how to edit and post as promised.

Pretty good considering a maiden can be summed up as “first flight is the worst flight”!
 

Attachments

The Hangar

Fly harder!
Mentor
#53
Maiden flight was successful! It is a tad underpowered and has a bit of roll tendency that will need adjusting on the aileron control rods but it flies. Only pictures for now but my camerawoman / spouse got some really good video. I’ll figure out how to edit and post as promised.

Pretty good considering a maiden can be summed up as “first flight is the worst flight”!
Awesome!!