F-100 Super Sabre 1/8th Build (70")
- Thread starter thenated0g
- Start date
If you look back at post 98 you can see aluminum bungee launcher that I started a couple years back and never finished. It has about an eight to nine foot rail so I did is to finish that or I'm going to make a rolling cart that takes off from.
While waiting for paint to dry.....
As shown in the post above i got all the Callie graphics vinyl put on the plane. They are the largest stickers i have applied so it was a little scary trying to keep everything straight on each side of the plane. At first i tried the soapy water trick, but on this paint it just doesnt work at all, like it lost all stickyness and i had to dry the plane and the sticker and just stick it on. Also, trying to get the stripe had me worried but it came out close enough that you cant really tell if its not totally the same on both sides.
After i applied the stickers i applied one coat of Helms Urethane on the entire fuselage and 2 more coats on the bottom (belly lander). This will help protect the paint and stickers.
I had a problem painting the wings which i didnt have on the fuselage. Fortunately i painted the bottom of the wing first. What happened is everytime i would put a coat down the wood grain of the paper would raise up and i would have to sand it down. After 2 coats i decided to seal the top of the wing with urethane and see if that helped, which totally did. If i do this again, the first thing i will do is seal the paper before painting. In all i used 2 cans of paint on the fuselage and 2 cans of paint on the wing. The paint and urethane added about 200g of weight to the wing.
I added some Bass wood pieces to the FPV canopy to let it key into place and a canopy lock in the back to lock it down.
Plane is ready for electronics. I CA glued the motor in place to hold it while i predrill and get some wood screws installed. After weighing i am guessing flying weight is going to be somewhere between 4.5kg and 5kg
After i applied the stickers i applied one coat of Helms Urethane on the entire fuselage and 2 more coats on the bottom (belly lander). This will help protect the paint and stickers.
I had a problem painting the wings which i didnt have on the fuselage. Fortunately i painted the bottom of the wing first. What happened is everytime i would put a coat down the wood grain of the paper would raise up and i would have to sand it down. After 2 coats i decided to seal the top of the wing with urethane and see if that helped, which totally did. If i do this again, the first thing i will do is seal the paper before painting. In all i used 2 cans of paint on the fuselage and 2 cans of paint on the wing. The paint and urethane added about 200g of weight to the wing.
I added some Bass wood pieces to the FPV canopy to let it key into place and a canopy lock in the back to lock it down.
Plane is ready for electronics. I CA glued the motor in place to hold it while i predrill and get some wood screws installed. After weighing i am guessing flying weight is going to be somewhere between 4.5kg and 5kg
Jetcrafter_2000
Member
Nice!
My buddy was over this weekend and picked it up, he seems confident that he can toss it. Will just give him a glove, the motor wont beable to spinup with his hand in the way if i accidentally start it up. We have a spot with some tall grass we can do initial toss.Mash it all up - a rolling cart pulled down the field by a bungee!
I totally understand. I just meant that a prop "strike" where it causes damage is cause its spinning. They dont have the torque/power to push your hand out of the way and once his hand is right there it will just tap him if i did accidentally hit it.
Namactual
Elite member
I know. I was not trying to imply anything brother. I am sure you guys will take every precaution.
I just cringe at the thought of hand launching that beast with the prop in the back as big as it is. I just don't want to see anyone hurt is all. I guess I am just trying to say "stuff" happens no matter how well things are planned or thought out.
I can't wait to see this beast in the air though.
I just cringe at the thought of hand launching that beast with the prop in the back as big as it is. I just don't want to see anyone hurt is all. I guess I am just trying to say "stuff" happens no matter how well things are planned or thought out.
I can't wait to see this beast in the air though.
It is definitely not the goal, to hand launch, but maybe for just getting it trimmed up.
If there is any question about the hand launch safety I would definitely go the bungee route for early flights. It can be a bit nerve-racking since its going "up" no matter what once you hit the lever, but my experience with pusher jets and rolling carts is that they don't mix well. You have NO steering (long fuselage gliders with large rudders in the prop wash have enough leverage to at least suggest a change in direction while on a cart. Your rudder won't do that, especially since it is not in the prop wash). Compared to other cart-launched airframes your wing loading will likely be a lot higher and as such you'll need a LOT of ground speed to rotate. Rotation is also more challenging on a cart as there is some friction on the leading edge of the wing where the wing is pushing the cart. I could never get a pusher jet to rotate smoothly off of a cart.
You can see a few attempts on video below. I have a smaller glider cart as well but made this one for 2 reasons. I found I needed more clearance for the larger jet to rotate without striking the prop on the ground and found that the smaller wheels didn't like our field and would bounce too hard and knock the jet off the cart.
Good luck!
You can see a few attempts on video below. I have a smaller glider cart as well but made this one for 2 reasons. I found I needed more clearance for the larger jet to rotate without striking the prop on the ground and found that the smaller wheels didn't like our field and would bounce too hard and knock the jet off the cart.
Good luck!
Thanks for the suggestion. I remember that video. My maximum flying weight is going to be 5kg, which makes it 21.17 oz/sq.ft wing loading. Calculator says 22mph stall speed. I have watched a bunch of really bad launch dolly videos lol. I guess i will focus on the bungee launch for now.
3d printed Pilot ready.
Using a general rule of thumb for 5-7lbs of pull per lb of airplane I'd look for a setup that will give you at least 55lbs of pull, although I'd feel better with 60+. I use a dog tie-out to secure the bungee. Get one rated up to 100lb dogs so can handle a lot more pull than you'll need. I also use a long section of rope between the bungee elastic and the airplane. The reason being that if something snaps and the bungee comes screaming at you it isn't likely to make it to you. I use about 20' to give myself a safe buffer.
There is debate about the best location to put the launch hook. For jets I like about 35%-45% of the distance from the tip of the nose to the CG. Further forward and she wont want to climb when she comes off the rails. Further back and she may climb faster than you want. Too far back and she may try to go vertical or rip the wings off (not likely with a jet but it can happen with gliders).
I'd recommend not throttling up until she is well off the rails, perhaps not even until the hook is away. If you gun it as soon as she comes off the rails she may not yet have enough airspeed to counter the torque.
It sounds like a lot, but honestly bungee launching is tons of fun. Its just a bit of a pain to setup and break down.
There is debate about the best location to put the launch hook. For jets I like about 35%-45% of the distance from the tip of the nose to the CG. Further forward and she wont want to climb when she comes off the rails. Further back and she may climb faster than you want. Too far back and she may try to go vertical or rip the wings off (not likely with a jet but it can happen with gliders).
I'd recommend not throttling up until she is well off the rails, perhaps not even until the hook is away. If you gun it as soon as she comes off the rails she may not yet have enough airspeed to counter the torque.
It sounds like a lot, but honestly bungee launching is tons of fun. Its just a bit of a pain to setup and break down.
I picked up 2 of the blue hobbyking bungee cords on a sale last year. .
That will do it!
Lots of wiring this weekend
Motor and 80 amp esc installed.
150a meter will send telemetry data to my x8 for audio notifications on my taranis. I will have it on a 3 way switch. One position will non stop announce amps being used and the other will do the same for pack voltage. This will also allow me to set automatic warnings as well so if i hit the max amps of my motor or the pack is getting low it will just tell me no matter what the stick position is. Even for fpv i personally like audio warnings over OSD for these things. I get tunnel vision when flying and forget to look. Also installed is a 12v ubec for wingtip lights and anything else like fpv gear. A 5v ubec will power the servos.
On the wingtips i am installing these 5050 leds. Meant for 16v but they are still bright enough on 12v to see them in daylight. They have 3 dip switches to change the color to whatever you want. Also used some 6 pin connectors to make a quick connection for the 2 servos and lighting.
frsky X8 receiver in place. Using 7 channels at the moment. All 4 control servos are on separate channels. This will allow individual adjustments for alignment and will allow some mixes if i want. Such as mixing ailerons into the elevators and adding flapperons and such.
While i was working i printed out this fpv pan/tilt for a gopro3 and fpv camera. Uses a 9g servo for tilt and a regular size winch servo that turns about 310 degrees or so for pan.
This morning i installed the control rods for the ailerons. They use a metal 2mm threaded clevis screwed onto a 4mm metal control rod. You cut 4mm carbon fiber tubes to size and epoxy in place. I used these on my 90" wing and they are super strong and very clean looking. Best setup i have seen yet. Being that this wing is a clark-y (bottom is flat) it was very easy to install them in the correct position as seen in the picture.
Motor and 80 amp esc installed.
150a meter will send telemetry data to my x8 for audio notifications on my taranis. I will have it on a 3 way switch. One position will non stop announce amps being used and the other will do the same for pack voltage. This will also allow me to set automatic warnings as well so if i hit the max amps of my motor or the pack is getting low it will just tell me no matter what the stick position is. Even for fpv i personally like audio warnings over OSD for these things. I get tunnel vision when flying and forget to look. Also installed is a 12v ubec for wingtip lights and anything else like fpv gear. A 5v ubec will power the servos.
On the wingtips i am installing these 5050 leds. Meant for 16v but they are still bright enough on 12v to see them in daylight. They have 3 dip switches to change the color to whatever you want. Also used some 6 pin connectors to make a quick connection for the 2 servos and lighting.
frsky X8 receiver in place. Using 7 channels at the moment. All 4 control servos are on separate channels. This will allow individual adjustments for alignment and will allow some mixes if i want. Such as mixing ailerons into the elevators and adding flapperons and such.
While i was working i printed out this fpv pan/tilt for a gopro3 and fpv camera. Uses a 9g servo for tilt and a regular size winch servo that turns about 310 degrees or so for pan.
This morning i installed the control rods for the ailerons. They use a metal 2mm threaded clevis screwed onto a 4mm metal control rod. You cut 4mm carbon fiber tubes to size and epoxy in place. I used these on my 90" wing and they are super strong and very clean looking. Best setup i have seen yet. Being that this wing is a clark-y (bottom is flat) it was very easy to install them in the correct position as seen in the picture.
