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-   -   KMP New Spitfire Mk XIV (https://www.rcuniverse.com/forum/rc-warbirds-warplanes-200/2671070-kmp-new-spitfire-mk-xiv.html)

Chris Nicastro 08-05-2009 10:24 AM

RE: KMP New Spitfire Mk XIV
 
Oh ok how are you liking that set up?

For me the Thunder Tiger 120 Pro and Slimline wrap around pitts seems a little weak for this size plane. I thought it was less than scale speed. The engine makes good power and runs at a good temp and all is fine its just not doing it with authority.
I'm starting to think of going bigger and just fly the heck out of this plane until its gone! lol

tevans55 08-06-2009 03:14 PM

RE: KMP New Spitfire Mk XIV
 
Venomous-
I like the setup alot. Mine flys a little faster than what appears scale to me. Most of the comments at the field are that it flys fast but I think that is just the result of low flybys. I have to plan for climbing maneuvers because you can run out of speed but I don't think it is outside of scale. I really like the way this plane flys at speed and at idle.

Shihtzutan 08-10-2009 11:54 AM

RE: KMP New Spitfire Mk XIV
 
Good looking field tevans55. T/O on pavement and land on grass, it nice to have that option. My Spit is all upgraded with the Satio 1.50, ran the engine. I'm waiting for ideal conditions for the maiden. We have a closed airport nearby and I'm thinking of maidening her there, was there a particular reason you choose to land in the grass?

tevans55 08-11-2009 07:07 AM

RE: KMP New Spitfire Mk XIV
 
Shihzutan-
The first several flights I landed on the asphalt and it ran off the end of the runway. My plane rolls out a long way for some reason. I land by cutting to idle about 200 feet before the threshold. The plane lands great but rolls forever. I thought maybe the idle was a little to high but the plane sits still on the pavement at idle. I always land my B-25 on the runway with plenty of room but the Spitfire seems to like to roll. I've just resigned my self to land it on the grass which is probably just as scale as these planes often landed on grass and dirt during the war.

We do have a nice field that is in E.P. Tom Sawyer State Park in Louisville, KY. Our club, River City RC developed and maintains the entire facility and we rent the space from the State Park. The runways are 500'.

Shihtzutan 08-11-2009 11:47 AM

RE: KMP New Spitfire Mk XIV
 
Hmmm, I'll prepare for that. It probably has something to do with that 17lb mass.

tevans55 08-11-2009 12:34 PM

RE: KMP New Spitfire Mk XIV
 
I'll bet your right! Just pay attention to the elevator when you land...I gradually increase the up elevator as the plane begins to slow to keep that tail down especially in the grass.

Chris Nicastro 08-18-2009 02:49 PM

RE: KMP New Spitfire Mk XIV
 
OK going bigger on the engine. I'm putting an OS 160FX with a wrap around Pittts style Slimline muffler in my Spit. OS claims 3.7HP and can swing up to a 20in prop. Thats kind of interesting for multi blade prop options and a closer to scale dia as well. I hope that makes her fly with authority and thanks to the added weight I can remove some of the lead from the nose too.
I beefed up the gear this time as well and will probably add glass and resin in there as an extra measure.

Chris

tevans55 08-18-2009 03:14 PM

RE: KMP New Spitfire Mk XIV
 
Chris-
You may be the smartest of all. It certainly needs the weight in the nose so you might as well make it useful weight. I'll be interested to hear how this works out...keep us posted!

Chris Nicastro 08-18-2009 06:55 PM

RE: KMP New Spitfire Mk XIV
 
Hahahah lets hope so, like I said earlier I'm going to fly the heck out of this one since I'm over it being any kind of scale attempt now its a sport scale rocket Spit! lol I'll giver all she's got captain!

Chris

tevans55 08-19-2009 09:57 AM

RE: KMP New Spitfire Mk XIV
 
And on the weekends you can go pylon racing! Actually, I still think it makes good sense to use a heavy engine as useful weight.

Shihtzutan 08-19-2009 12:08 PM

RE: KMP New Spitfire Mk XIV
 
Well the Spit maidened without incident. Everything worked, gear came down, flaps, . . . no bad behaviors at all. I ran the engine rich so maximum speeds were not obtained, but she pulled a nice authoritative round loop very nicely. The paint sheme I choose proved to be difficult to see in certain attitudes. A grey cloudy day would not be a good idea with this plane; something to keep in mind when you guys pick out your colors. I thought the white would be enough, but was surprised on how well she blends into her background.

Here’s the t/o technique I used to get off my grass field. First off, forget about taxing on grass! Drink at three coffee's and if you smoke, smoke a cigarette! Walk it out with a few clicks of throttle to maintain a very high idol, hold the tail with your left hand. Holding the box with your right hand with your thumb holding the elevator full up, let go or push it off slightly to break the resistance of the grass and left it roll out. As the plane builds speed and you’ve reestablished directional control, ease off the elevator and lift her gently.

tevans55 08-19-2009 03:16 PM

RE: KMP New Spitfire Mk XIV
 
Shihtzutan-
Congratulations...glad to hear that 1.50 worked well. No substitute for a litle more power. By the way how was the landing on grass. Did your Spit have any tendency toward nose over with the flaps deployed once you got into ground effect?

oriole 08-19-2009 03:47 PM

RE: KMP New Spitfire Mk XIV
 

ORIGINAL: tevans55

Shihtzutan-
Congratulations...glad to hear that 1.50 worked well. No substitute for a litle more power. By the way how was the landing on grass. Did your Spit have any tendency toward nose over with the flaps deployed once you got into ground effect?

I have the original ARF with the included retracts and wire gear. I ended up, enlarging the retract wells in the wing and angling the gear forward dramatically to keep from nosing over.

Chris Nicastro 08-20-2009 11:23 AM

RE: KMP New Spitfire Mk XIV
 
Congrats on the maiden.
Did you have the CG set at 95mm as well?

Shihtzutan 08-20-2009 11:46 AM

RE: KMP New Spitfire Mk XIV
 
Interesting, my instructions said to put it @ 105 if I recall, or about 4.25 inches. Where does the 95mm come from? A later release?

Chris Nicastro 08-21-2009 01:16 PM

RE: KMP New Spitfire Mk XIV
 
No actually I got that crossed with my Me 109E, sorry for the confusion.
So yours flew fine at the 105mm mark then?

Shihtzutan 08-24-2009 04:37 PM

RE: KMP New Spitfire Mk XIV
 
Correction, 107mm (I checked). Nice glide at idol. Several flights on it now. It would be fun to chase that 109 of yours around with.

WarbirdPilots 09-13-2009 09:18 PM

RE: KMP New Spitfire Mk XIV
 
1 Attachment(s)
Pics of my retract blocks mods, my friend helped me do. My friend is a long time warbird builder and he was absolutely disgusted with how KMP/ESM did the retract blocks in the first version of the spitfire. So after I ripped them out on a bad landing (yes the landing was bad, a dead stick, that just barely made it back to the runway, totally my fault) my friend got to take a good look at how they were built. He was so pissed at where they were located, how little foward sweep there was, and how week the blocks were, that he had me cut open the wing and rip out every piece of the original retract blocks.

He then proceeded to teach me how to properly build a retract plate and blocks, and how to beef up the surrounding ribs and epoxy the living hell out of it. We moved the retracts almost 1" close to the middle of the wing and put the proper angle and pitch the gear needed to bring the wheels in front of the leading edge of the wing. Whats also nice is because the gear blocks have the proper pitch and angle, the wheels lay flat in the wheel wells. I can taxi this thing all over the place now and it has no tendancy of nosing over at all. I don't even have to give it up elevator.

I have attached pictures of the almost finished mod. I just have to paint the solartex. But the plane has flown a couple of times and lands, takes off, and taxi's like a dream. I also am not worried to bring the plane in under power and have a nice rollout.

If you have the time, definitally open up the wing and fix this issue. I believe it is still an issue with the newer versions as well, because I have read about individuals having to shim the gear to get them further forward. Enjoy the pics.

Adam


WarbirdPilots 09-13-2009 09:21 PM

RE: KMP New Spitfire Mk XIV
 
1 Attachment(s)
One more

George C 09-14-2009 07:04 AM

RE: KMP New Spitfire Mk XIV
 
Nice work! TT I had thought something similar myself but i didn't have enough room to install the gear doors so I left it as it was. My plane has a huge problem with nosing over upon take off but I thought of mixing throttle to elevator to compensate. It wants to nose over even with a 1/4 throttle if I don't hold full up elevator, no matter how gentle you are with the left stick. I havent tried the mix at the field yet so we will see.
What size wheels are you using? Cause I'm using the 4" Robats and they are a tight fit.
Has anyone else tried mixing throttle to elevator?

Thanks

George.

tevans55 09-14-2009 08:25 AM

RE: KMP New Spitfire Mk XIV
 
George-

Do you have any idea what the source of the nose over problem is...is it down trim in the elevator or perhaps flaps? I have this problem from a little bit of down trim in the elevator. It also helped to not use flaps on takeoff. I hold the tail down on takeoff with the elevator.

I would be concerned with mixing throttle because what happens when the plane leaves the ground? It would have a tendency to want to fly into a slow speed stall if you didn't jump on the elevator. Tough decision!

George C 09-14-2009 03:45 PM

RE: KMP New Spitfire Mk XIV
 
I do have about 3 degrees down trim and I suspect that is the main cause of the nose over. Further more I have the robart wheels which have very soft tires even with the foam inserts installed, and they had flat spots where they touched the ground for a long time. What happened is the flat spots touched the oleos creating a breaking effect. Now I have brought the tires back to normal using heat and I only set the plane down on a stand. Yet it still wants to nose over. I have also tried take offs without flaps but that didn't have any significant difference either. Some people have suggested reducing down thrust but that would compromise the scale line of the spinner and the cowling so I ruled that one out. The mix I have programmed is 25% up elevator which gradually reduces to 0% just below half throttle. I just have to figure out the correct analogy for a smooth and not a 3D take off. Weather permitting I will spend this weekend doing that.

WarbirdPilots 09-14-2009 05:32 PM

RE: KMP New Spitfire Mk XIV
 
What I originally did, before I moved the gear blocks was to use the high rate switch on the elevator during taxiing and just before takeoffs. I programmed the high rate on the elevator to be at an absolutely extreme (almost 3D) angle. With that much insane up elevator it did a pretty good job at keeping the tail down.

Now you will also have to program in some exponential because once the plane starts rolling for take off, you are going to have to level off the elevator and then gradually apply a little elevator to climb away. As soon as I was up, I would turn off the high rate switch, so that I wouldn't accidentally snap the plane by accidentally giving it full up elevator with the high rates on.

For landing, once the plane is on the ground and finishing its rollout, flip the switch to high rates on the elevator and taxi it back.

I also bent up the tail wheel so it allowed the tail to sit as low as possible.

Another thing you must do is shim the retracts to get the wheels as close to the leading edge as possible when in the down position.
Unfortunately the more you shim the retracts, the less likely the wheels will sit flat in the wheel wells. So you should also get rid of the plastic wheel wells that come with the kit. Cut open the wheel wells larger and sheet them. This allows the wheels to sit deeper in the wing. The wheels that I used were smaller 3 3/4" wheels.

Now if none of this works, you have no other option but to open up the wing and correct the angles.

Good luck

tevans55 09-15-2009 08:29 AM

RE: KMP New Spitfire Mk XIV
 
1 Attachment(s)
George-

If your tires flat spot under compression just sitting still I can image that they deform enough under the load of takeoff and landing to create enough drag for a noseover. Much like a flat tire on a car slows a car down. I am using Sullivan tires with the aluminum hub which stay firm and are very light without being made out of foam. (And they don't look half bad either.)

Good Luck this weekend!

transatlanticflight 09-16-2009 07:42 AM

RE: KMP New Spitfire Mk XIV
 
TwinTurbo...how about pics of the inside of that retract retrofit? ...with some dimensions. Your install looks good, but your pics are not helping me. Not everyone has a warbird building buddy. ;)


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