rc74

My Feedback: (6)

Thomas Here is a couple pics

RCGuy41

Lt. (jg) Narly

Welcome Shipmate; I have been flying Spektrum 2.4 system for over a year now, one of the better radio systems on the market today. The Spread Spektrum line of 2.4 GHz systems got their start with cars and moved into park fliers. Their claim to fame is (Model Match) can't fly without the TX and RX bound together, it's fact, I tried flying another bird set in my TX and the neither would bind. Normand gave some great advice, the McDaniel’s glow driver will not affect a 2.4 GHz system where as in a 72 MHz system you will get feedback from the glow driver, it will affect your radio system. A fix for that problem will be to install inline filters due to the length of the leads and proximity of the glow driver leads in an 72 MHz system. http://www.spektrumrc.com/giveaway/ this is Spektrums website, they hae a great FAQ site which will answer alot of your questions concerning 2.4 GHz, to include informative video's.

Brad

RCGuy41

Ron,

Some great detail work on your TF B-25J, any build pics of the bomb bay?

Brad

RCGuy41

Thomas,

Welcome, you will find the TF B-25J challenging, but a very rewarding build and initial flight. Tom is a wealth of information and their are plenty of modelers who have built this bird who can give expert advice. Post some build pics if you can, we would like to see your progress.

Brad

RCGuy41

The build thread for the KMP B-25 is good, but KMP has a problem with their initial production run, called droopy wings. Both outer wing panels sagged down approximately 1-2 inches at the wingtips, but KMPs working on a fix for the problem, didn't make a nice scale looking aircraft.

Brad

Thomas B

My Feedback: (4)

Not worried about the build at all....looks very straightforward to me and most of the probable glitches have been encountered in the build threads.

rnordeck

Brad & Normand,

Thanks for your input. I never woulda thunk that my Futaba 9c or 9 channels wouldn't be 'nuf!! Man, I don't wanna buy nother $600 radio. I would have to put this project on the "Five Year" budget plan!! (instead of the 2 Year Plan!). What's a bomber without a bomb bay; ie. the need for 10 channels.....I just don't wanna Y everything, ie. the engines, ailerons & flaps and set-up like a Trainer.

I have a Futaba 9/10? channel 1024 PCM receiver, think it's the R149DP on 72 MHz (it's at home & I not). Anyone know if I will get RF interference from the long McDaniel Glow Driver leads with PCM receiver??

Also, Anyone willing to share their Futaba 9C programming set-up? especially for separate engine channels.

Thanks,
Totally Confused
aka Lt. (jg) I.B. Narly

fytrjok

My Feedback: (2)

Lt.,
I use a Futaba 9c with an XPS 2.4 module. Because the xmitter must be in ppm mode to operate the 2.4 module, I loose the 9th channel...wierd. Here's how I set up my bird:

ch1 - ailerons (y'd)
ch2 - elevators
ch3 - throttle (y'd, mechanically sync'd)
ch4 - rudders (y'd)
ch5 - gear
ch6 - flaps (all y'd but soldered connectors except for the outboard flap)
ch7 - bomb bay
ch8 - nose wheel servo slaved to ch4

One other thing I learned early on...if your retract system is pressurized, hold the nose up enough to keep the gear from retracting if the servos jump when you power up the plane. Those doors are a pain to reattach at the field!!

rnordeck

fytrjok,

Thanks for the 9C set-up; now I'm encouraged. Man I got depressed after reading "Twinmans" posts on forum mentioned not far above...."Don't do twinns....Dont Do IT..."

Anyhow, Are U going to "Warbirds Over da Rockies"?? I think this deep gas well will be finally finished 'round 23rd & I be drivin rite toit!! Be only a spectator but hope to see U and U'r B-25 and pick up retract set from Things w/... and see kids in Longmont.

"....we could have bought a new car" ... "Nah, it doesn't Fly"

BadBob

flaviosi

Fytrjok,

The best way to avoid the gears to come up when you turn the radio on is to bind it again, with the lever on the gear-down position.

Flavio

norm

Bob

You can even save another channel using the Match Box by JR, This unit is simply fantastic you can connect all flaps and adjust the throw of each flap so they spread open precisely: closed, 1/2 and full flap. You can do the same using a match box on the rudder channel connecting both rudders ans noze wheel servo to it it will enable you to avoid the reversed situation... . You pay approx 40$ for a match box and about 4 x 7$ for Y harness... only a little more and you can reverse and adhust the throw of each servos separately.

I would also be tempted to go further with the Match Box and use it for the throttle servos...somnetimes the Y is upside down %$#@#$% bugging your @$$... the match box will enable you to acheive a precise throw and reverse that servo and enable you to place it in the desired place. Specially if you intend to use the Saito 82's. Check the link...I think they just increased the price.

http://www.horizonhobby.com/Products...ProdID=JRPA901

As Twinman said if you read between the lines be prepared to be 8 times more involved on a plane if you whant to fly twins. It is only "8 times more captivating" and you will enjoy every moment of it. "Multi Norm" think that way: It is a big step further and only the ones who did it are fortunate enough to know it.

You are definitely on the right track if you did not understand the first recommendation of twinman!

Open the box!


Normand

camdyson

If you "Y" the rudders AND the nosewheel steering, you'll also free up a channel so you can have separate throttle channels - handy if your radio will allow it.

See my earlier post re isolating the retract servo - it's dead easy and works perfectly. I wouldn't put the plug near the prop arc if I did it again though...[:@]

Cam

jdhughen

My Feedback: (1)

Norman,

Norman,

A couple of match box questions.

1.If using a match box to couple rudder and steering, if you are also using a gyro would you put the match box upstream or down stream of the gyro ?
2. Could a match box be use to setup aileron Differential by adjusting the end points?

ANYONE Using aileron diff on the B-25 ??

3 How is the "memory" in the matchbox maintained ? ie batt or ROM, I guess what I'm getting at is it volatile??

I really like the flap application, that's a no brainer. Ailerons also if I can get Diff, that would free-up one for bombay, yea. I'm still leaning toward seperate CH for steering just so I can tie rudder mix conditional to gear down. Also seperate channels for engines for throttle curve sync mixing and run-up control. I did the door setup like RCdon but am using a door sequencer instead of a radio mix. I'm not happy with the amount of "closed" holding pressure I can get with the servo setup he used without getting servo binding, conderned with posiable door chatter during flight, so I think I'm going to convert doors to air cylinders. Have you ever used the little small cylinders for doors you can get from Bob Violet Jets ??

Is everyone using servos for bombay doors?

Thanks

Joel

jdhughen

My Feedback: (1)

ALL,

I have some nose art that I want to use on this plane. I thought about trying to make my own decal but after doing some checking it might be a bigger pain than I thought and the results might not be what I what, so I was wondering if anyone knows of a vender that does that kind of thing from your furnished artwork ??

Thanks

Joel

MANFRED

My Feedback: (27)

callie graphics, just google it

norm

Joel,

To answer your 2 questions,

1- the Gyro must be used upstream from the match box but there is no real need for a match box there. What I did is connect the gyro in the rudder channel and the gain in the Aux2. I Y'd from the gyro to the noze wheel and to the tail. The only thing left to do is to reverse the connectors to the servos in the tail for them to turn with the wheel. Some prefer to reduce the servo action on the noze wheel and you can do this using the matchbox instead of using Y's.

2- The second question is the better one for you. Yes you can adjust for differential ailerons using a matchbox. I use it on a corsair. the lifting wing need more travel and the dipping wing need less travel. so what I did is reduced the up ailreon trave using the matchbox in order to reduced the dipping effect on the wing giving me a better turn coordination.

On the B-25 this may be a good thing since the wing tend to drop when in a turn, you must also mix at least 20% rudder in your ailerons to maintain a coordinated turn. I habe 22% turning right and 18% turning left.

BTW servos on the bombbay door is a better idea since the buzzing sound of the servo sounds like a hydraulic pump when it is activated on static display.

For small air cylinders check out those: http://www.sierragiant.com/prod17.html

Normand

jdhughen

My Feedback: (1)

As many in the "Twin" forum have suggested, I've been practicing a lot flying with the rudder/ailerons on my turns. does the mixing of the rudder into the ailerons to keep the gyro happy and make it more of a Aileron/elev turn ?? or is rudder still need on a normal "Scale" turn. With 20% rudder mix with ailerons what happens if you do a roll ?? (I know a roll is not really a "Scale" manuver for a B-25, but what the hey)

thanks

Joel

norm

Joel,

No problem for the Gyro, you can even leave the gyro on for the whole duration of the flight. The gyro think you are using the rudder and is being overridden for the same percentage.

I use a mix switch to disable the aileron rudder mix on demand as well as the aux 2 to disable the gyro.

Disabling the gyro in flight is desirable since this unit is power hungry on your batteries. You really only need it on take-off and landing for overshoot purpose. Those are the only times you really need a gyro...slow speed, climbing, when the plane is under torque. Otherwise an engine failure is manageable in the air and if the plane has momentum, the engine out is less dramatic you can then switch on the gyro for help and come in to land unless you like it!

Normand

elojim

Hi all,

a question regarding the servos you're using. Are you following the Topflite recommandations ? or what type of servos have you got ?

thanks

jdhughen

My Feedback: (1)

I'm using hitec digitals on Ailerons (5245MG), Elev (5645MG), Rudder (5085MG - with futaba GYA352), and BB / metal gear analog on Flaps (225MG), steering (645MG), gear (82MG), gear doors (85MG). That said I'm still in contstruction and haven't flown yet, but that's what I'm going with.

Joel

Thomas B

My Feedback: (4)

I am leaning towards using the Jr/Spektrum DS 821 for ailerons and Hitec 85MGs or 5085MGs for the rudder. Still undecided on the elevator servo, but will be something digital. Have been thinking about spliting the elevator halves and using two DS 821 for some redundancy back there. Will likely use Futaba S-148s or S3003s for flaps, retract valve and nose gear steering.

norm

Thomas
Great choice of servos I have DS821 all over and the hitec 85MG in the rudders, just trust them better than the JR341. I use the Hitec 5645MG on the elevator great servo and I trust it a lot. I would tend to beleive that you are better off using the TF split U for the elevator it is very good and effective.

The DS821 are plenty for the flaps @ 72oz for the size of those flaps you have plenty of power in the servo to hold the flap in place without forcing it at all.

Normand

elojim

Hi,

does the HS-5245mg support 6.0 Volt ?

slamdance64

Bonjour Elojim,

Yes the 5245MG servo supports 6.0 v packs.

Here are the specs:
Torque: 61.10 / 76.37 oz.in (4.8v/6v) 4.4 / 5.5 kg.cm

I have bought these too for the ailerons for my B-25.

Happy building!
A+

Brent

jdhughen

My Feedback: (1)

Norman,

I had originally bought a Sullivan twin glow driver but after setting it up in the test stand I wasn't really particularly excited by its performance/features when compared to the features of the McDaniel twin Glow driver you used. I noticed an older post of yours you suggested getting the 40" plug leads. Is that because of where you were placing your driver, were you using it to help balance your plane? I thought about going with singles in the nacelles but when I added it all up doing so would be a +8oz in weight. I'm already pushing the envelope on weight so decided to deal with the extra wiring. I order one today (42"). Where did you put your driver and Batt ??

Also I looked back through those that tried magnets for holding on the canopy, Turret and the "pod" on the belly. between those that went that way what seemed to work best ?? I've seen the rare earth magnet in disk and block shapes rated a different strengths. How much force in how many locations is sufficient to hold it on ??

Thanks

Joel Hughen