How to prevent the nose over problem on the World Model Spitfire Warbird Racer
09-06-2016, 10:07 PM
#26
Thread Starter
Got the first and second flights on this Spitfire. Yes I have video and will upload as soon as I can.
The ground handling showed no tendency to nose over at all and required no more than the normal attention you'd normally give any other warbird taildrager.
The takeoffs both happened with no drama at all with a bit of a crosswind in my face. The plane accelerated to flight speed with just the slightest back pressure and lifted off on its own once flight speed was acquired.
The first landing came up about three feet short of the runway on the south end as I cut power a bit too early. The mains contacting the grass caused the plane to nose over enough to have the prop contact the ground just as it came onto the asphalt. Once on the smooth surface the nose came back up and the tail down, and it rolled off into the grass as it weather vaned from the crosswind off to the left side of the runway where the friction of the grass on the small diameter wheels caused it to stop nose down.
The second landing, I came in a little hotter and cut power a little later. This landing, all on the smooth paved runway, showed that I had made the correct decision for my own interests in moving the gear forward.
This Spitfire handles like a low wing aerobatic sport plane and now that I have an idea of what my approach speed should be, I see no reason at all for concern in using this as a Gold racer.
I had set the control surfaces to the throws shown in the instructions and I have reduced the throws on the ailerons and elevator quite a bit after the first flight.
Also, the dimensions called out in the instructions for spacing the prop drive washer from the firewall are not easily met with the stock mounts and fasteners if you are using a YS mid block, (.91-1.15)
To get as close to this dimension as I possibly could, I counter bored the bolt hole in the engine mount that sits behind the throttle arm and then trimmed the inside upper corner off the mount to prevent interference of the mount with the throttle arm.
https://goo.gl/photos/bd7fR6365SLEmyM97
The ground handling showed no tendency to nose over at all and required no more than the normal attention you'd normally give any other warbird taildrager.
The takeoffs both happened with no drama at all with a bit of a crosswind in my face. The plane accelerated to flight speed with just the slightest back pressure and lifted off on its own once flight speed was acquired.
The first landing came up about three feet short of the runway on the south end as I cut power a bit too early. The mains contacting the grass caused the plane to nose over enough to have the prop contact the ground just as it came onto the asphalt. Once on the smooth surface the nose came back up and the tail down, and it rolled off into the grass as it weather vaned from the crosswind off to the left side of the runway where the friction of the grass on the small diameter wheels caused it to stop nose down.
The second landing, I came in a little hotter and cut power a little later. This landing, all on the smooth paved runway, showed that I had made the correct decision for my own interests in moving the gear forward.
This Spitfire handles like a low wing aerobatic sport plane and now that I have an idea of what my approach speed should be, I see no reason at all for concern in using this as a Gold racer.
I had set the control surfaces to the throws shown in the instructions and I have reduced the throws on the ailerons and elevator quite a bit after the first flight.
Also, the dimensions called out in the instructions for spacing the prop drive washer from the firewall are not easily met with the stock mounts and fasteners if you are using a YS mid block, (.91-1.15)
To get as close to this dimension as I possibly could, I counter bored the bolt hole in the engine mount that sits behind the throttle arm and then trimmed the inside upper corner off the mount to prevent interference of the mount with the throttle arm.
https://goo.gl/photos/bd7fR6365SLEmyM97
09-07-2016, 04:44 AM
#27
Thanks for the update! I too have moved the gear forward but have not yet flown it, I am looking forward to the same results. Wow, you totally stripped your plane down and recovered it, the chrome covering looks good, I am sure you can see that when the sun hits it.
09-07-2016, 07:25 AM
#28
Thread Starter
Yes, I stripped it to allow me to reinforce the wing structure and sheet the open bays.
To be fair, the wing on mine was of very sound and strong construction and probably did not require my attention in this manner.
I also changed the plane in that I prefer to use dual elevator servos on separate channels. So I cut out the stock servo tray and installed my own rails to move the elevator and rudder servos as far back as possible. I then installed the throttle servo ahead of them. I used a tetra 16 oz tank and it fit with just minor dremel sanding drum work on the bottom of the opening in the former at the front of the bay.
I know this plane has been beat up a bit in here with regards to the landing gear location.
But, I have noticed that there are quite a few of them out there racing in a successful manner.
I just preferred to mod mine to prevent the drama I have seen a few other racing pilots have. I feel that it was worth it for the time I invested.
In all, this is a very good racer to assemble right out of the box.
To be fair, the wing on mine was of very sound and strong construction and probably did not require my attention in this manner.
I also changed the plane in that I prefer to use dual elevator servos on separate channels. So I cut out the stock servo tray and installed my own rails to move the elevator and rudder servos as far back as possible. I then installed the throttle servo ahead of them. I used a tetra 16 oz tank and it fit with just minor dremel sanding drum work on the bottom of the opening in the former at the front of the bay.
I know this plane has been beat up a bit in here with regards to the landing gear location.
But, I have noticed that there are quite a few of them out there racing in a successful manner.
I just preferred to mod mine to prevent the drama I have seen a few other racing pilots have. I feel that it was worth it for the time I invested.
In all, this is a very good racer to assemble right out of the box.
09-07-2016, 08:56 AM
#30
Thread Starter
I'll get you a picture up later.
But for now, picture the rear servo screws on the three servos for the tail, positioned such that you have a straight drop down in front of the rear wing hold down plate that gives JUST enough clearance to drill and install the servo screws.
Then I used a slightly smaller servo in front of those three, installed laterally across the fuselage to run the throttle.
I have a 1450 mah 2 cell LiFe installed just behind the fuel tank.
I forgot to mention earlier, I reduced the overall dimensions on all the tail surfaces by tracing a line about 3/8" inside of the existing shape and cutting that part off.
With the engine mount work and all the other changes I made, and using an aluminum spinner of the proper diameter, the plane balanced on the factory CG location with no ballast required. The flight behavior gives me no reason to feel the need to alter the CG location at all.
But for now, picture the rear servo screws on the three servos for the tail, positioned such that you have a straight drop down in front of the rear wing hold down plate that gives JUST enough clearance to drill and install the servo screws.
Then I used a slightly smaller servo in front of those three, installed laterally across the fuselage to run the throttle.
I have a 1450 mah 2 cell LiFe installed just behind the fuel tank.
I forgot to mention earlier, I reduced the overall dimensions on all the tail surfaces by tracing a line about 3/8" inside of the existing shape and cutting that part off.
With the engine mount work and all the other changes I made, and using an aluminum spinner of the proper diameter, the plane balanced on the factory CG location with no ballast required. The flight behavior gives me no reason to feel the need to alter the CG location at all.
09-14-2016, 08:53 PM
#33
Thread Starter
