KMP / Kondor P-38
11-27-2008, 12:24 PM
#1
KMP / Kondor P-38
Well, I searched and searched for a related thread in this forum, but could not locate one so I will start one.
I just recieved my 'N.I.B.' KMP P-38F/ 'Shark Mouth' version. I purchased it second hand from a RC Universe Market Place seller for $450 shipped (GreyHound) minus the KMP retracts. Altho these kits (ARFs) have been discontinued, Chief Aircraft still has them in stock for $590 shipped WITH the KMP retracts:
http://www.chiefaircraft.com/rcmsec/...harkmouth.html
I will power mine with a pair of AXI 4130/16 brushless motors, thus I will have an Electric Lightning. Using E-power will enable me to keep those streamlined cowls hole free, except where there are SUPPOSED to be holes. Also, by using electric power, I will be able to use contra-rotating Master Airscrew 3 blade 14 x 7 props, just as the full scales have contra-rotating props.
Full scale wheels BTW are 36" diameter for mains, 27" diameter for the nose. As this ARF is about 1/7.5 scale, I will round it off to 1/8 scale and attempt to install wheels for that scale ( 4 1/2", 3 3/8" )
A pair of CB associates 3 1/2" P-40 style spinners are on their way to my house, being shipped from MECOA:
http://www.mecoa.com/
While I did NOT find a thread in this forum, I DID find one in the 'Twin Engine' forum:
http://www.rcuniverse.com/forum/m_2543010/tm.htm
And in RC Groups:
http://www.rcgroups.com/forums/showthread.php?t=684920
I will use the stock, olive and gray paint scheme, but would like to use a differnt full scale as my model. Being a dirty old man, I kinda like this one:
I just recieved my 'N.I.B.' KMP P-38F/ 'Shark Mouth' version. I purchased it second hand from a RC Universe Market Place seller for $450 shipped (GreyHound) minus the KMP retracts. Altho these kits (ARFs) have been discontinued, Chief Aircraft still has them in stock for $590 shipped WITH the KMP retracts:
http://www.chiefaircraft.com/rcmsec/...harkmouth.html
I will power mine with a pair of AXI 4130/16 brushless motors, thus I will have an Electric Lightning. Using E-power will enable me to keep those streamlined cowls hole free, except where there are SUPPOSED to be holes. Also, by using electric power, I will be able to use contra-rotating Master Airscrew 3 blade 14 x 7 props, just as the full scales have contra-rotating props.
Full scale wheels BTW are 36" diameter for mains, 27" diameter for the nose. As this ARF is about 1/7.5 scale, I will round it off to 1/8 scale and attempt to install wheels for that scale ( 4 1/2", 3 3/8" )
A pair of CB associates 3 1/2" P-40 style spinners are on their way to my house, being shipped from MECOA:
http://www.mecoa.com/
While I did NOT find a thread in this forum, I DID find one in the 'Twin Engine' forum:
http://www.rcuniverse.com/forum/m_2543010/tm.htm
And in RC Groups:
http://www.rcgroups.com/forums/showthread.php?t=684920
I will use the stock, olive and gray paint scheme, but would like to use a differnt full scale as my model. Being a dirty old man, I kinda like this one:
11-27-2008, 01:20 PM
#2
RE: KMP / Kondor P-38
There are a few large threads:
http://www.rcuniverse.com/forum/m_22...Cp%2D38/tm.htm
http://www.rcuniverse.com/forum/m_25...Cp%2D38/tm.htm
http://www.rcuniverse.com/forum/m_22...Cp%2D38/tm.htm
http://www.rcuniverse.com/forum/m_25...Cp%2D38/tm.htm
11-27-2008, 07:01 PM
#3
RE: KMP / Kondor P-38
Niether of the above threads are in the WarBirds forum.
I think of the P-38 as a warbird first, and since this is the forum that I spend 95% of my RC internet surfing in, I chose to open this thread in the forum that I feel is most appropriate for a P-38.
I think of the P-38 as a warbird first, and since this is the forum that I spend 95% of my RC internet surfing in, I chose to open this thread in the forum that I feel is most appropriate for a P-38.
11-28-2008, 09:52 AM
#4
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RE: KMP / Kondor P-38
I have the same plane and never finished it because I just could not decide what would be best for power. I like the electric lightning approach to reducing the engine out issues that generally kill P38's. I bought the same spinners from Mecoa at Toledo last year, I have Robart gear in mine as well. The warbird thread is where I spend the most of my time as well and it always has something going on with P38's so why not put yours here. This might be what what I need to finish mine.
11-30-2008, 12:21 PM
#6
RE: KMP / Kondor P-38
After doing a LOT of research on retracts these past few days, I discovered something VERY INTERESTING: SOME models of the Robart retracts actually retract (go up) higher than normal. In other words, the struts go up at an angle which is past the mounting rail plain.
Case in point: "Robart 540RS 105 Degree Nose Robostrut Ready". Altho this is a nosewheel, they make mains with the same specs (minus the steerable parts). If you look up the Robart drawing, you will see what I mean.
http://www.robart.com/retracts/drawings/540RS.pdf
Now how does that apply to the KMP P-38? WELL, I had intended all along to use larger, closer to scale size wheels. The biggest problem tho is that even if I made room for them in the booms (by removing servo tray), the wheels would 'hang out' of the bottom because the gear rails are too close to the bottom.. Alternate solutions would be to fabricate new rails, which would have to be mounted higher in the booms. That that would mean that I would have to use longer struts as well, which would in turn add more weight, AND shift the CG more when retracting.
SO, retracts such as these provide the best solution. I may have to shim them a little, so that there is a 5 deg forward 'rake' when down, and 10 deg farther up when up, but that would seem to be a minor problem.
Since Tower does not stock any of the mains with retraction over 90 deg, I ordered 3 of the nosewheel retracts mentioned above. They can easily be converted to mains, by removing the steering parts and installing RoboStruts. Using their $60 off coupon (expires after today), I basically got all 3 retract units (identical), 2 straight 7/16" RoboStruts, and a needed prop adapter for about $245 shipped. I still need the nose gear RoboStrut, but that can come later.
Case in point: "Robart 540RS 105 Degree Nose Robostrut Ready". Altho this is a nosewheel, they make mains with the same specs (minus the steerable parts). If you look up the Robart drawing, you will see what I mean.
http://www.robart.com/retracts/drawings/540RS.pdf
Now how does that apply to the KMP P-38? WELL, I had intended all along to use larger, closer to scale size wheels. The biggest problem tho is that even if I made room for them in the booms (by removing servo tray), the wheels would 'hang out' of the bottom because the gear rails are too close to the bottom.. Alternate solutions would be to fabricate new rails, which would have to be mounted higher in the booms. That that would mean that I would have to use longer struts as well, which would in turn add more weight, AND shift the CG more when retracting.
SO, retracts such as these provide the best solution. I may have to shim them a little, so that there is a 5 deg forward 'rake' when down, and 10 deg farther up when up, but that would seem to be a minor problem.
Since Tower does not stock any of the mains with retraction over 90 deg, I ordered 3 of the nosewheel retracts mentioned above. They can easily be converted to mains, by removing the steering parts and installing RoboStruts. Using their $60 off coupon (expires after today), I basically got all 3 retract units (identical), 2 straight 7/16" RoboStruts, and a needed prop adapter for about $245 shipped. I still need the nose gear RoboStrut, but that can come later.
12-11-2008, 10:36 PM
#7
My Feedback: (48)
RE: KMP / Kondor P-38
Looking forward to your build thread I had put off buying this P38 until I saw this thread. Checked Chiefaircraft and they still had a couple left so I made purchase before they were all gone. I too will go electric, as I have in several of my other warbirds up to the 160 size. Keep up the information. Mine shoud be here in a few days.
PS: The theory of flying twins on a common battery so that the drain is equal is not fool proof. Found this out on friends smaller E-Flight P38. He pushed battery to limit thinking that both motors would act the same at low battery warning bad idea. The two seperate ESC's (required) sense low voltage different enough that one engine shut down first. So same condition can exist as on gas/glow etc. Moral of story do not push batteries to edge on electrics - Yes the P38 was repaired.
I have sinced used seperate batteries for each motor on twins and limit my flying time to allow reserve battery power and charge between flights
PS: The theory of flying twins on a common battery so that the drain is equal is not fool proof. Found this out on friends smaller E-Flight P38. He pushed battery to limit thinking that both motors would act the same at low battery warning bad idea. The two seperate ESC's (required) sense low voltage different enough that one engine shut down first. So same condition can exist as on gas/glow etc. Moral of story do not push batteries to edge on electrics - Yes the P38 was repaired.
I have sinced used seperate batteries for each motor on twins and limit my flying time to allow reserve battery power and charge between flights
12-13-2008, 05:07 AM
#12
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RE: KMP / Kondor P-38
Thanks! 
The model have 2 Saito 125 4 stroke with 15x8 G-Sonic Propeller.
Weight: 9,5Kg without fuel (2 fuel tanks of 500cc).
All servos are Hitec Hs225Mg.
Inflight is good, I have landing 3-4 times with only one engine without big problems.
Bye,
Massimo.
The model have 2 Saito 125 4 stroke with 15x8 G-Sonic Propeller.
Weight: 9,5Kg without fuel (2 fuel tanks of 500cc).
All servos are Hitec Hs225Mg.
Inflight is good, I have landing 3-4 times with only one engine without big problems.
Bye,
Massimo.
12-13-2008, 08:37 AM
#13
RE: KMP / Kondor P-38
Great looking Lightning, and nice flying to boot!
It's re-assuring to know that there is still SOME interest in this plane, now that they are dis-continued it appears that not too many are interested.
One thing that I noted, is something that I referred to earlier: there appears to be very little dihedral. And, it may be difficult to add some because the booms have the fins attached, and adding dihedrawl will cant the fins toward easch other. Oh well, I'll see what I can do.
I have all the parts for mine now: Robart 105 deg retracts all the way around, contra-rotating Master Airscrew 3 blade 14 x 7s, C.B. associates 3 1/2" spinners, etc. I need to re-do the main gear mounts, as I want the gear to retract a little deeper into the fuslage. I will have to fabricate new mounting rails which will be canted 5 deg.. The mains currently extend 100 deg, and retract 95. I want to make them extend 95 and retract 100, which is why I need to re-do the rails.
Thanks for the inspiration, 2M86
It's re-assuring to know that there is still SOME interest in this plane, now that they are dis-continued it appears that not too many are interested.
One thing that I noted, is something that I referred to earlier: there appears to be very little dihedral. And, it may be difficult to add some because the booms have the fins attached, and adding dihedrawl will cant the fins toward easch other. Oh well, I'll see what I can do.
I have all the parts for mine now: Robart 105 deg retracts all the way around, contra-rotating Master Airscrew 3 blade 14 x 7s, C.B. associates 3 1/2" spinners, etc. I need to re-do the main gear mounts, as I want the gear to retract a little deeper into the fuslage. I will have to fabricate new mounting rails which will be canted 5 deg.. The mains currently extend 100 deg, and retract 95. I want to make them extend 95 and retract 100, which is why I need to re-do the rails.
Thanks for the inspiration, 2M86
