lbarnes

Good idea, I wish I would have done that instead of using the linkage supplied with the kit.

If I was going to do it I would use a micro servo. Since it doesnt take much torque to operate any of the .15 or .25 throttles the small Hitec 55 servos or even the smaller micro servos would work.

Larry

Johnny C!

Showtime,
Throttle bodies need very little torque to
move them, so anything will do. I have just
revived an old twin project & I have pulled
the micro servo's out of a dead Venom
Night Ranger Heli. I don't know what
size they are, but they're very small.

Oh, my revived project is a .25
size Wart Hog...

Good Luck!

Johnny C!

FA82Showtime

Yea, i no they dont need much, i never used a micro servo. this will be smallest plane i got, i figure something with like 20 ounces of torque would be lots

lbarnes

Way too much. There is room for large full size servo's.

I do want to caution you on this plane. KEEP THE WEIGHT DOWN.

I have 2 Magnum .25xls, Macs tuned pipes and 9x6 APC props.

My finished fly weight is 5.5lbs and even with the .25's it is not a hot rod in the sky. Loops are just barely done and I haven't even tried a roll yet. When you cut back on the power for landing it will sink like a rock.

If you have the ability to program flaperons then this does help.

Most builders have experienced this plane as nose heavy. When I built mine I sheeted the elevator (which added some weight to the tail) and the Macs pipes were much lighter than the stock mufflers (which reduced the nose weight).

Other than that it really looks and sounds cool in the air, but lacks the speed and aerobatics of my other planes.

Practice low passes over the landing filed so when it does come time to land you can come in at about 3/4 throttle and cut and touch down when about 6" off the runway.

Good luck.

Larry

Johnny C!

Barnes,
That's interesting. I bashed a Dazzler Arf into
a twin with two OS .25's, and it's a bullet. It
seems that with a much sleaker airframe, the
P-38 ought to go like stink...

Johnny C

lbarnes

That was my thoughts too, but was kinda disappointed with the performance.

I guess it may be the way I have the throttles set up. I dont want to lean them out too much and get a flame out on one engine[:-]

I could most likely get another 500 rpm out of each engine if I leaned them out another click but dont want to try to fly and land with one engine out.. I hear that bad things can happen

Larry

FA82Showtime

Has anyone had trouble with the nose gear bracket, IE strength of the ply its bolted to. Any reinforcments nessesary?
What about the engine mounts any upgrade done there? seems rather thin. What about putting fiber glass inbetween?

lbarnes

Yeah, you will need to beef it up. See my post and pics at this thread

http://www.rcuniverse.com/forum/m_89..._4/key_/tm.htm

Used 1/4 ply for the nose gear mounting and gussets (F2B, F2A, F1). It hasent broke yet.

You will also see that I laminated the lite ply (item #4 and 5) with 1/8 ply behind the nose gear.

If your still in the build mode try using 1/4 x 1/4 spruce for the upper and lower boom frame (PAGE 20, STEP #6).

Use 1/4 ply for the engine mounts and not the laminated lite ply that comes with the kit (page 22, step #3).

What till happen is the lite ply will crush when tightening the engine mounting screws, you will never get them and keep them tight with the lite ply.

Last suggestion is sheet the elevator with 1/16 balsa top and bottom. This will keep it from flexing and also add some weight to the tail, because this plane is nose heavy to begin with.

Happy flying

larry

tony0707

HI how much flying time are you getting on the 25 size engines ???-as we are limited to 6 oz tanks here- i am sure you need to run as small an engine as is possible to keep fuel consumption down-and nose weight down-to have any flying time on this plane so you can have fun with itpart of the problem with fuel is you have to start on of the engines first- and have it running while you start the other- so the first engine you started will be the one that determines your actual time in the air
-based on how fast it burns the fuel- bigger the enginethe less your flying timeyou get my point
do tell me the actual times you have to fly the 25's

tony0707

hi can anyone tell me the most powerful 15 size engines out there- i have read the entire thread-and do understand that the TT25 and the os 25 FX seem to be the engines most usedif a real strong 15 could be used -that may have some good merit in fuel use and flying times

lbarnes

I never timed the flight but I will do low fly-by and with the clear tanks you can see how much fuel you got left. And your correct about one side having less fuel by the time you get the other engine started. This can be remedied by add the 3rd fuel line to each tank and top them off just before take off.

I would guess my flights are about 5 min.

As for a .15 size engine, I dont think i would go that route. I have 2, OS .25 and tuned pipes running about 15,500 Rpm and I'm at full throttle 90% of the time, and it's no speed demon.

Larry

tony0707

HI OK ready for my p-38 story-my plan was to use two 40 FP"s i had-i did decide to use 1/4 inch balsa for my stab and elevator from the start- felt it would make the back of the plan more rigid- i new i would need some tail weight with the engines i was trying to use- happy i did this plane does not have a lot of wing area- so it needs to be built as light as is possiblei did the engine linkages as per the plans if you use EZ' s on the engine throttle arms it helps get the engines to run within the 200 RPMSsuggested in the plans -was not a problem -and is lighter than any two servos you just must be sure to solidify the joints of the engine linkages as it is hidden once the wing is builtand you cannot afford to have it loosenEVER!!- this can be done by grinding a flat on the rod -and using locktight on the joint
the 40FPSdid not work out at all -the major reason being they consumed fuel to quickly on a 6 oz tank - so i gave up on them- no flying time- the set up made no sense to meso you can see were i am going with this from my prior posts
had no problem putting my battery-rx-and switch in the lower plastic pod-the rudder rod does need to be made more ridged than the 2-56 rod suggested
. i have built many kits i 20 years -i find this kit time consumming-as you are building some parts twiceYOUMUSTTAKETHETIMETOBUILDTHISKITLIGHTbut the P38 "FORKWINGDEVIL" is one awsome flying machine to duplicate
the 1/ 16 balsa wing sheeting must be handled with some care but keeps the weight down
the G/PP-38 in my opinion does fly a lot better than it looks like it mightthe wing area has always appeared on the small side to methis thread shows great results with flying the plane -i built one because i saw it fly so well at my fieldANDOHWHATASOUND !!
i had pulled my engines out and had the plane for sale-S0000 glad i did not sell it- i am now VERYEXCITED to get smaller engines in her and fly my first twin engine plane after reading the info herei am now all warm and fuzzy about getting her up and running and in the air again THANKYOUALLREGARDSTONY

tony0707

HI IBARNES-thanks for your input never though about filling fuel tanks with the engines running-  need to figure how to do that-i know how to add a third fuel line-if i may i would like to suggest you get a count down timer at radio shack-   you then can calculate you flying time down to the minute-and a beeper lets you know it is time to land-may make the flight more relaxing-prevents you from running out of fuel-  or going dead stick- thank you

tony0707

HI IF the 15 size engine is to light on horse power-  what is the most powerful 25 out there these days-just do not think i would use more than a 25-( i did try to use a 40NO GOOD )-again because of fuel consumtion issues-nice to fly for as long as is possible -but with good power and authority -is a must-after all this is  one of-THE MOST POWERFUL PROP   planes that was ever built-

lbarnes

WOW, 2, .40 size. Now that would be fun!

You are correct about the small size wing area. If I throttle back to about 25% it drops llike a rock even with flapperons.

Dont make the mistake I made on my first flight. I had dual rates set up on my madien flight. My elevator was set at 50% travel and during my landing I did not have enough elevator to flair out. That's when i needed to beef up the nose gear and former with 1/4" ply, due to the hard landing.

Now i use all the elevator and only dual rate the airerons.

Practice comming in for landing at 50 - 75% throttle get a low as you can before cutting power for touch down.

As for the countdown timer, Due to my hunting and military action I am tone deaf at the timer frequency. I cant even hear my beeper on my watch. Someone has to tell me it's beeping.

It also helps me ignore my wife......

Have fun

Larry

tony0707

hi i would like to add -if anyone is so inclined to make the wing larger by a bay or two (or even making a very large extended wing tip )-i am quite sure it would stop this plane from dropping in like a rock on landing  - and then might handle a 32 more easily- i have added bays and clipped wings over the years sometimes both on the same plane  ( clipped it then put it back )-adding wing will give more float on landingjust my two centsthis wing always did look a bit small to me to be carring two engines-  as i have said before

tony0707

HI IBARNEShow about having high rate on elevator -to flip on on your final approachonly-  that should give you all the elevator you might need  on touch down     -but do not stall the plan-  you can fly the plane on low rate elevator  on take off and in the sky just a thought

tony0707

HI ibarnes you might try to add 1/2 oz of lead to the rear of the plane (  1/2  oz at a time -to see if it improves your rotation of the nose on landing )- it is  making  you more tail heavyand makes your elevator more sensative  than it was beforeat the same time-but should help the plane fly more and drop  in less-might be worth a try

tony0707

HI  like to add -3 blade props look good scalebut they have very little low end torque-the plane will perform much better at lower speeds with a two blade prop  -my prop of choice is APC- have done a lot of testing with props do you want the plane to fly ggod or look good the choice is always yours-prop performance is based on vertical performance  -best vertical -  best prop-

tony0707

HI I am thinking- if you are using a 3 blade proptry a two blade to see if the added torque is just what you are lacking atthe reduced throttle -you need to land the plane- might help prevent it from dropping out like a rock on landing as it is doing now- worth a try if it will keep you flying and in control more -on final and touch down-i just put 2and 2 together from what i hve already learnedlove to know the results of that testTONY

tony0707

hi would you believe i think i could have kept the two 40 FP"s -in the p-38-if i new i could refuel the tanks before take off-    sold those two great engines   -had them  running great together within the 200 RPMS -as recommended -oh well we live and learn - do we not had it balanced very goodtook the engines out thought i had  much to little flight time in the air to enjoy the plane- bummmer-it might have been the beast i was looking for-never know now

lbarnes

Been there done that.

The plane lands alot better with the elevator at full rate, 3 bladed props were worse on the performance. I made 1 flight on 3 blades took them off and never to be bput back on again. The next one was with my trusty APC, 2 blade props.

Maybe a .32, with pipes would perk it up, but I'm not really going to do anything with it. It only gets maybe 3 - 4 flights a year.

I got 16 other planes that I try to rotate during the year.

Larry

tony0707

hi did some engine research the GMS 32 is 10.8 oz engine at  1.2 HP-the 46 la is 9.6 oz at 1.2 HPthe GMS is 63.00 plus s&hthe la is 80.00 plus S&H-GMS is a bearing motor -the la is a brass sleeve  but fuel consumption s/b much more with the 46 la will limit flight times a great deal-they are from tower
    were is the best place to purchase the thunder tiger 25i saw one selling for 109.00is that the going price for that engine- the engines above    seem to be the best   engine choices for the -P38 LIGHTNINGas best i can see
    the OS 25 FX is another choise  -but  HP is rated at .84-and seems low-  also it is 95.00
     my conclusion is the GMS 32 looks very promising of the engines above- but i never used this brand engine
    the old OS 25 SF might be a good choice -but might be hard to find these days-not sure of the engines weight -    but the SF series puts out good power

tony0707

hi how do i add a picture to this thread-thank you

lbarnes

at the bottom of the post screen you will see: "click here to upload images and files"

When you click on it a pop up wil appear and you can then browse you filews and select them to upload and post.

Larry