ESM Spitfire 72.5 (Full Version)

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hombresinropa -> ESM Spitfire 72.5 (1/17/2012 2:28 AM)

 Hey all I'm working on an ESM Spitfire, and have only found one forum on here so far dedicated to it, but it's in the electric conversion section.  I'm sticking with glow power, so I'm starting this thread to keep things orderly.

I'll track progress of the build and keep it as updated as I can.  I have some issues and hopefully some of you who have the bird can give some tips or insight, and if any of you are interested in getting it or are building one as well, hopefully we can share some thoughts.

I'm actually mostly done already, but I'll post some of the pictures as I built it.  Right now I'm just trying to figure out the best placement of certain components.  This is also my largest glow warbird (had 2 phoenix spitfires before and currently am tweaking a top flite P51).  It's also the first pull-pull setup I've done.

I'm trying to be deliberate and not "just get it in the air," although I'm severely itching to get it up soon.

I'm open to any discussion topics that would apply to finishing or streamlining the setup on this plane.

If you haven't seen it yet, it is one of the most beautiful models I've owned.  My TF P-51 is darn-near bullet proof, so I don't know if this one is quite as sturdy, but it seems close.  It's very well-made, and the optional pneumatic retracts that come with it are outstanding (once you put in a Robart adjustable valve and loctite all of the set screws).  My wife and brother plotted together and bought me this plane from Tom at VQ Warbirds, and I have to say again, it's beautiful.



hombresinropa -> RE: ESM Spitfire 72.5 (1/17/2012 2:35 AM)

 Here it is, getting much love and attention, straight out of the box and "test fit" for a little looking-at action.  I have to do this, it's a disease.  My brother can attest.




hombresinropa -> RE: ESM Spitfire 72.5 (1/17/2012 2:39 AM)

 Ooops, here they are.



hombresinropa -> RE: ESM Spitfire 72.5 (1/17/2012 2:43 AM)

With the spilt flaps, I had to recess the inside area of the flap to get them to shut all the way.  I loose "all the way" loosely, since they didn't shut all the way without hardware at all, but it's barely noticeable.  It shouldn't affect flight.  They actually shut more than in the picture, they are flush except in one or two spots on the edges.  I plan on attempting to flatten them.  Tips would be appreciated.

I didn't use the supplied hardware.  I'm trying to avoid the supplied hardware as much as possible.  Not sure I trust it, since three of the screws snapped before I even got them screwed all of the way in.  More of them stripped.



hombresinropa -> RE: ESM Spitfire 72.5 (1/17/2012 2:52 AM)

 Pull-pull was a pain, as it is my first.  I think I have it figured out.  I don't have a bell-crank.  Not sure if I need to look into redoing this.  I am sure that I need to straighten out the cables and possibly take out the cross-over.  Servos were just hastily mounted so I could work with them a bit and I will move the rudder servo out toward the skin of the aircraft to reduce the friction on the ends of the tubes.

Tailwheel setup required me to cut more than I wanted to, but I loctited the hardware and reworked the steering arm on the tailwheel.  The supplied steering arm had crappy set screws; I stripped 3 before I went and bought a new setup, which worked great.

Pull-pull works well here, keeping the tail lighter, which I feel will be important when balancing.  My last spitfires had a nasty tendency to nose over on my grass field, and I'm sure this will be worse, since the engine and cowl seem to be about 160mm from the firewall.  The cowl is like a dang front end of a '75 Lincoln Continental.

Anyhow, the tailwheel setup works well now, I'm just trying to reduce friction to lighten the servo load.  I have a 2000mah 6.v RX battery with Voltwatch, but you can never be too careful.  I lost both of my Phoenix Spitfires due to brownouts.  I have to figure out what I was doing wrong, this might be part of it.

I'll clean up the slot I cut in the fiberglass once I get it ready to balance.



hombresinropa -> RE: ESM Spitfire 72.5 (1/17/2012 3:01 AM)

 Engine mounted.  Cowl cut and cleaned a little.  Will need more cleanup on the cowl... that's another thing I'm getting better at.  Finally got some good Dremel attachments for the job.  Lexan scissors work pretty well for certain parts of the cutting and don't crack the paint.  Finished off holes with dremel sander attachment.  I still need to finish centering the holes.  I cut them large so the cowl can be fit on, that's the smallest the holes would allow for the pitts muffler to stay on while sliding on the cowl.

Mounted the engine sideways, otherwise the muffler would have to be almost entirely out of the cowl, to include the power box muffler.  I don't know anything about tuned pipes, so maybe that would be a better option for some of you.
Using the hole for the cylinder head as my intake hole for cooling, I still have to cut an exit hole behind the pipes for the cooling air.  I've been told that using the pipe holes, even if I make them larger, wouldn't be a good idea.





tevans55 -> RE: ESM Spitfire 72.5 (1/17/2012 3:02 AM)

Hombre-

I have built 2 of these...the first one hit a bird and didn't survive. I have an OS 120 ax with a JTEC wraparound pitts muffler and Century Jet retracts. Including the battery in the nose I still had to add about 2 lbs of nose weight. Sounds like alot but the plane flys great. I also have a double pull-pull setup for rudder and elevator. I did not use most of the ESM hardware either. On the flaps I had a similar situation with the control horn and I hollowed out the balsa above the horn so that it closed flush.



hombresinropa -> RE: ESM Spitfire 72.5 (1/17/2012 3:03 AM)

 Some  more photos of the beautifulness.  Again, I need to clean up some of the marks I made while cutting.  All in all, I think the holes in the cowl are pretty  well-done... I've seen far worse at the field.

Let me know if any of you have some tips on cowl-hole-cutting.





hombresinropa -> RE: ESM Spitfire 72.5 (1/17/2012 3:09 AM)


quote:

ORIGINAL: tevans55

Hombre-

I have built 2 of these...the first one hit a bird and didn't survive. I have an OS 120 ax with a JTEC wraparound pitts muffler and Century Jet retracts. Including the battery in the nose I still had to add about 2 lbs of nose weight. Sounds like alot but the plane flys great. I also have a double pull-pull setup for rudder and elevator. I did not use most of the ESM hardware either. On the flaps I had a similar situation with the control horn and I hollowed out the balsa above the horn so that it closed flush.



Tevan, My god, that is gorgeous.  Wish I'd have known about that type of muffler.  I suppose I can try and track down another cowl and do it up later in the game.

I also like what you did with the mounting locations for your retract servo and air tank.

Did you run into any big issues with the plane before you maidened it?  How correct is the CG in the directions?  This set of directions looks strikingly similar to a set on my electric B-17 I built last year... which is scary.  The CG was off on that model's directions by quite a bit, which made a horrifying maiden.  Got it figured out by the 3rd flight.



tevans55 -> RE: ESM Spitfire 72.5 (1/17/2012 3:09 AM)

http://youtu.be/xpTW87KRNzc

Here is a video of the first plane. I also soaked my gear doors in water and put a more scale curve on them. I will also include drawings that were sent to me from a fellow ESM Spit owner in Norway.



hombresinropa -> RE: ESM Spitfire 72.5 (1/17/2012 3:10 AM)

Where did you get the cockpit kit? Did you make it yourself from scratch?



tevans55 -> RE: ESM Spitfire 72.5 (1/17/2012 3:17 AM)

The CG was close enough but I remember it changed from the first plane to the second. I figured that was due to the move from push rods to pull-pull. The second plane is even more tail heavy than the first primarily due to the heavy wire on the stock landing gear. I modified a DuBro tail gear and set up the steering almost exactly the way you have. You will need to make sure the plane is nose heavy for the maiden and stay on the elevator when landing...just like the full scale Spit! You will see in my video the tail almost comes up and over on landing. You can use a lot of flap on this plane and it is a great help when landing...very scale looking, especially on grass.



tevans55 -> RE: ESM Spitfire 72.5 (1/17/2012 3:20 AM)

Cockpit kit is from Dynamic Balsa and is easy to build and install. I was only able to put in about half of it due to the pull-pull cables but you cannot see the bottom half real well due to the canopy. The pilot is a British pilot from Century Jet.



Beechbum -> RE: ESM Spitfire 72.5 (1/17/2012 3:21 AM)

I thought there was a thread on here somewhere. I posted pictures of mine to it a few years ago. Mine flew great. Landing it was a challenge at first. I took advice and shimmed the gear so the axles were out closer to the leading edge of the wing which helped a lot. The flaps worked well, and it slowed down nicely. Mine weighed 14.5 pounds and had a Saito 1.20. I just recently sold it and kind of wish I had it back.



hombresinropa -> RE: ESM Spitfire 72.5 (1/17/2012 3:30 AM)


quote:

ORIGINAL: tevans55

Cockpit kit is from Dynamic Balsa and is easy to build and install. I was only able to put in about half of it due to the pull-pull cables but you cannot see the bottom half real well due to the canopy. The pilot is a British pilot from Century Jet.


Thanks Tevan, I just looked it up and saw that Magnum RC sells a kit as well.  After I maiden it, I'll definitely look into getting once.  This is going to be a plane I keep around.  That video is great, and great job on the cowl... looks awesome.  Did you have to mix in a lot of elevator for the flaps?  

Beechbum, your comments and Tevans vid make me realize that ESM Spitfire = KMP / YT Spitfire.  Didn't know that.  I'm sure I can find some threads on there now.  I wonder why the change...

On my last 2 Spits and my B-17 electric, I had to rake the wheels forward about 15 degrees or so to keep the tail down on the grass.  With the size of this plane, hopefully it won't be as much of an issue on short grass.  The last spit was a .46 size (had a 55 AX in it) and the wheels were much smaller.




tevans55 -> RE: ESM Spitfire 72.5 (1/17/2012 3:42 AM)

You definately don't want to mix elevator and flaps for this plane. Mine actually just slows down and has no unusual tendancies at all. On the second plane I doubled the amount of flap, about 65 degrees. It lands nice and slow (scale). I have to admit none of my scale warbirds have flap/elevator mix. I just slow the plane down and there is no tendancy to balloon. Most of my planes are at idle when I turn on final and as long as I keep the nose down it is pretty difficult to stall it even with a lot of flap.



hombresinropa -> RE: ESM Spitfire 72.5 (1/17/2012 3:45 AM)

 Receiver mounting, trying to get away from directly mounting with sticky tape... using foam to reduce vibration; something I've overlooked in the past.  Glued some plywood blocks with holes drilled into them and screws to hold a medium-tension rubber band.



hombresinropa -> RE: ESM Spitfire 72.5 (1/17/2012 3:51 AM)


quote:

ORIGINAL: tevans55

You definately don't want to mix elevator and flaps for this plane. Mine actually just slows down and has no unusual tendancies at all. On the second plane I doubled the amount of flap, about 65 degrees. It lands nice and slow (scale). I have to admit none of my scale warbirds have flap/elevator mix. I just slow the plane down and there is no tendancy to balloon. Most of my planes are at idle when I turn on final and as long as I keep the nose down it is pretty difficult to stall it even with a lot of flap.


I'll have to remember that.  I've been told in the past to always mix flaps with elevator, and other planes really needed it, although they were lighter electrics.  On a plane this size it very well may be unneccesary.  I can always give it a whirl.

Were the throws correct in the directions?  I know I already asked you about the CG; just having nightmares about poorly translated directions.






hombresinropa -> RE: ESM Spitfire 72.5 (1/17/2012 3:56 AM)

Note on the retracts... the ESM ones are pretty nice.  The machined aluminum wheels look great, and I've cycled the gear about 10 times on one tank, 85 psi.  It's my first set of pneumatics and I'm pleased.  Not too bouncy, either.  I may work a mounting solution similar to the receiver.  Looks like the battery will go up on the engine, in the cowl if I can fit it, like you guys did.



Firepower R/C -> RE: ESM Spitfire 72.5 (1/17/2012 4:06 AM)

Hombresinropa, did you get your DX-7 converted to DSMX? You might consider it, but it's not essential. it would be a little safer. A bigger battery wouldn't hurt as well- maybe a 2500-3000 Mah. This is a big plane and it will need some real juice. [X(][8|]

I need to bring My ESM FW-190 to NC and tangle it up with you sometime this year! We just need to take care and not "Randy" our planes![:D]

heh heh heh, inside joke... no offense, Randy!



tevans55 -> RE: ESM Spitfire 72.5 (1/17/2012 4:07 AM)

You can use the recommended throws...they are now my high rate throws. I have backed off on those for my low rate. I always fly on low rate and occasionally switch elevator to high rate for landing when it is windy.

I just checked the CG's. The KMP plans recommended CG at 120mm and the ESM plans recommend the CG at 107mm. I balanced mine at 110mm and have added additional weight after the first several flights. I would go with the 107mm and make it a little nose heavy for the first flight and have a helper with you on that first flight to feed in some down elevator...just in case. You won't have any trouble the plane flys great it just takes a minute or two to get the plane trimmed. Just know that the tail will try to lift when you get into ground effect and it does it on both grass and pavement. Both of my planes had this tendancy and I just learned how to control it by working the elevator and using a lot of flap.



jjkirby -> RE: ESM Spitfire 72.5 (1/17/2012 4:19 AM)

Looks good man im about to pull the plug on the ESM P-47 silver version.



Firepower R/C -> RE: ESM Spitfire 72.5 (1/17/2012 4:24 AM)

Oh, I can attest to the "look-at-it disease", as I suffer from this also. Hobby enthusiasts suffering from this will always need to quickly throw together and ARF just to see how cool it will look when done. Maybe an airplane sound or two as well...

jjkirby, I have the ESM P-47 drab version, and they are great airplanes. I made scale pylons for mine and am using a 33cc chainsaw conversion engine. You will not be disappointed.



propicts -> RE: ESM Spitfire 72.5 (1/17/2012 3:03 PM)

I have one of the original KMP Spits....also be aware if using the ESM air retracts ! If you have the pump with the gauge on it, to check the time after filling the air tank to see if you have air leaks. ESM is very prone to this problem on their air retracts. Also, the plane
will be nose heavy once you have the CG worked out, but once in the air, because the retracts fold a little rearward, it changes the CG
toward tail heavy. This can be corrected with a little down trim on elevators. Mine is hauling a Zenoah 26, one of the heaviest engines
and I still have almost a pound of lead in the nose. Good Luck with your Spits !!



flycatch -> RE: ESM Spitfire 72.5 (1/17/2012 3:51 PM)

You always balance airframes with the gear retracted and adding weight is dead weight. If possible use a larger displacement engine in leiu of adding dead weight.



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