europatc74

My Feedback: (6)

Danrc2,
Something is amiss. They should not be that far off at full throttle. My transmitter is set to channel 3 and 6. 3 is the master, 6 is the slave. Be sure that channel 8 is set to 100% throws both up and down on your transmitter. Test and set each engine individually. Then adjust 3 for correct idle and full throttle. Once that is accomplished move to 8. Balance 8 engine speed to 3 using the dial. You can adjust idle for 8 with end point adjustment in the transmitter. My engines are never more that a 100 or two off from one another.

europatc74

My Feedback: (6)

I'm presently using MAS 13/6 2 blade props on OS 70 Surpass engines. Plane seems slugglish in the air. Wondering what props others with the same engines are using. Thinking of trying 13/8 as recommended in the engine manual... Any recommendations???

krproton

Hi europatc74.

Assuming both of your throttle setups are mechanically identical (both pushrods in the same holes in the servo arms and in the carburetor arms and both servos are centered and the arms are in the same position) and assuming both throttle curves are the same electronically in your Tx, it sounds like you just need to adjust the needles.

Make sure the engine with the slower RPM is needled correctly, then richen the fast one to bring it down to the RPM of the slow onedon't lean the slow one to "catch up" with the fast one, otherwise, you will over lean it (becasue you have already set the slow one correctly - right?). If you feel you are over richening the fast one to the point of running rough, you may have to program in a throttle curve to get the engines to match betterthis is what I have done with my model.

Tim

krproton

Hi again europatc74.

Try to make sure your expectations are correct remember, this is a WWII bomber, not a P-47. The best way I can describe how mine flies (power wise), is I usually cruise somewhere around 3/4 throttle, but always use full throttle for takeoff and often throttle up when executing turns. Just as I expect a full-size B-25 would flysometimes it really needs full-throttle which makes it realistic to me.

About the propellers, in R&D, we always experience a noticeable increase in performance when we switch from wood Top Flite propellers to APC propellers. Could be the same for your Master Airscrew propellers. If you feel your engines are running well, maybe try APC props.

Tim

rc74

My Feedback: (6)

Tim I just didn't care for the stripes that came on it. They were quite a pain to get off but well worth it. The invasion strips that are on it now make it really show up good in the air. Thanks for your comments. Ron

danrc2

my low and high rpms are only 1 or 2 hundred rpm different. its the mid range that off by about 1000 or so. it that okay?????

dan

krproton

Dan,

I honestly can't say for a fact whether 1000rpm difference in the mid range is okay or not. I'll give my best opinion; As long as both engines are performing well - idling reliably for extended periods, transition to mid and full throttle reliably, and run reliably at all other throttle settings, I think you'll be okay. It may not be optimum, but as long as both engines are happy nothing bad is going to happen in flight - other than perhaps minor rudder trim changes. If your engines are running well, there's no risk in flying it just because the rpm's don't match at certain throttle settings. Then, you can see for your self if this is something you can actually notice in flight.

I do have a throttle curve programmed into one of my engines to get it to somewhat match the other engine throughout the rpm range, so this may be something you need to do as well.

My vote is don't sweat it as long as you are confident in the engines.

Tim

norm

Yeah I second that little rpm difference is no big deal.

Danrc2

Most of the time the midrange rpm difference is due to the low setting that may be rich on one engine, the low needle valve may cause one engine to run rich and slower up to the midrange.

In that case count the # of turns on the low setting needle and compare it to your other engine. You may find your answer there. The slower engine in midrange may be richer at the low end. Fine tuning experience is needed here.

Another cause is often the difference in servo response, your servos may not travel equally and in that case a throttle curve adjustable radio may solve that problem. A better and simple solution is to install new servos for the throttle and preferably digital servos.

1000rpm difference at mid power +/- 6000 rpm may cause undesired yaw and a "wabling" plane, but up to 500 at high end is not noticeable (+/- 9500 rpm)

Hope that may help you resolve this enigma!

Normand

danrc2

okay guys,
well i got three great flights on it today. i didnt have any major problems. the plane only needed a little right aileron and a little rubber trim. at half throttle the plane was nice and straight. the only thing i got to work on are the landings. it comes in a little on the hot side. i was playing a little with the flaps, but being this was my first twin i was a little nervous. all the landings were smooth and soft. i just was waiting for the plane to slow down more. does anyone know how the stall speed is??? when i make my left turn cut the power it seems hairy to me. i dont wanna stall at that point.

i think i just need a few more flights on it to get the bugs worked out.

but all in all i wanna thank Tim and the rest of the R&D department for build such a great plane. again this is my 1st twin and everything went great!!!!! thanks guys!!!!


dan

rc74

My Feedback: (6)

Dan On my TF B25 landings. On my down wind leg I stay extra high @ 1/2 throttle with full flaps and then start cutting power to (1/4 throttle) on the turn. Keeping the nose down, (Her decend rate is good). Then after clearing the end of the runway I pull the nose up (and hold) in a nice flare about 2ft off the runway and cut all power. Thats when it really slown down into a nice float. Apply down elevator on the roll out to help slow it down. If it ever gets too slow just add power a fly it with the rudder and keep the wings level with the aleirons. Hope this helps Ron

danrc2

sure
ill give that a try.

i think just a little getting used to it. thats all

krproton

Hi Dan.

Congratulations on your maden - glad all seems to be well.

Here's how I land my B-25;

Cut the power all the way (to idle) on the down wind leg, allow the model to slow a bit, then extend your flaps and gear (I forget which one I do first - doesn't matter I guess). I have my flaps on a switch, but with a delay so they extend slowly. Turn the model onto base (crosswind), then onto the final - all the while she should be nose down maintaining air speed even though she is descending. You should be making a nice, big half-circle (180 - degree turn). When you're on final if you look like you're coming in a bit short just power up a bit to extend your approach. Gradually feed up elevator to slow the model even more, yet not so much elevator that the model ascends. You can maintain airspeed with the throttle too. Keep feeding in up elevator until you finally flair and land basically with full up elevator - at which point the model will be going about as slowly as possible.

I think the main thing for you is to get used to the flaps - they work superbly - you just need to use them more to get a good feel for them and gain confidence. Another good idea is to practice slow fly bys with flaps. After you make your pass apply full throttle and retract the flaps - you can even retract the gear for more realism. Just play around with the flaps to get a feel for them.

Tim

danrc2

thanks tim.

i will give that a try tomorrow.

everyone love the plane at my field. thanks again for the great plane!


dan

europatc74

My Feedback: (6)

Tim
In your response regarding using flaps you state that your flaps are on a switch with a delay. My flaps are switched as well with two positions. How did you establish a Delay..? I like the idea. Is the delay something in programing the transmitter?? Dave.

krproton

Hi Dave.

I am using a Futaba 9ZHP radio. You can program a delay on any chanel you want - it's under the ATV function. In the ATV menu, select "NXT" and it will bring up the delay function. You can program in how much delay you want.

If you don't have a 9Z (you probably don't - it's pretty antiquated), I'm sure other, higher - end computer radios can do the same thing.

Tim

rc74

My Feedback: (6)

Dave I doing the same delay and slowing the servo down on the flaps and bomb bay doors using the new JR 9303. Works great. Ron

toreo

I WIN,WIN,WIN!!!!!!!
I win Russian competiton of semi-scale rc plane with TF B25!!!
It was so difficult, so strongest contestant, but TF B25 flyed like really B25!!!
There was 27 contstant semi scale, and 22 F4C from all Russia
After scale assesment i take 5th place
Flyght days was unbeliveble cold, strong 9-11(m/s) wind , 90 degree runway crosswind.
In this conditions i and my executive sweet can do absolutly perfect, scale fligt, with so diffucult manevr like touch and go!! Whitout any gyro!
I absolytly impressed of this plane!!
Thanks TF, thanks all!!!

Some pictires of event you can see this

http://forum.rcdesign.ru/index.php?s...dpost&p=856987
http://forum.rcdesign.ru/index.php?s...dpost&p=854260
http://akirill.tushino.com/index-14.html
http://akirill.tushino.com/displayimage-49-43.html
http://akirill.tushino.com/thumbnails-50-page-7.html


F15C win competition of scale F4C

krproton

Congratulations toreo!!!

Great job and even better, I'm glad you enjoy your B-25! Thank you for posting in this thread and thank you for all the photographs. Looks like it was cold weather at the contest - that is no fun for me.

Thank you again and keep us informed on new developments on your B-25.

Tim

camdyson

Well done Toreo!

Looks like you've added wing lights with anti glare shields, external aerials, and extra nose gun to your plane - any close-up photos of the modifications?

Everyone huddling under blankets and not smiling though - you gotta come to Australia!

Cheers,

Cam

BTW - some of those in-flight photos were EXCELLENT, you have a very talented photographer there too.

rnordeck

Way to Go Toreo!

Nice Legs...I mean Hat!! You would Fit right in, here in Wyoming! Xcept you will need Stampede Strings. I think we are now going on 30+ days of 30+ mph (48 kps).....planes getting "road rash" from just unloading... reloading.

"Keep it Up'
BadBob [[aka Lt. (jg) I. B. Narley ]]

nemesis4u

My Feedback: (77)

GUYS AND GALS,,,,

Mike at WINGSPAN MODELS has updated his site w/ the videos and photos of the "OPERATIONAL TURRET" conversion and WORKING BOMB BAY, BOMB RELEASE MECHANISMs....

CHECK THEM OUT!!

http://www.wingspanmodels.com/Produc...25%20Conv.html

WAY TO GO MIKE!!!!!!!!!!!!!! Making modeling "FUN-ctional"

-TOMAS
www.vqwarbirds.com
[email protected]
www.bomberfieldusa.com

RCKen

My Feedback: (9)

Now that I have my review of the TF B-25 finished and submitted, and back home from covering the XFC for RCU I'm going to get started on the review of Wingspan's additions for this plane. I'm going to do a review and hopefully a build thread as well. Will keep everybody posted as I get going on these.

Ken

MLDELARUELLE

Hi guys,
She's almost done, but I discovered that the yellow bolts to hold the propeller is too large for my 2 OS 46 AX.
Does exist an adapter ? Or does anyone with a good tip to solve this issue ?

BTW, I'm frightened by the weight[X(] compared to my Giles 202 1m80 of wing span which is lighter lighter .....

Thanks
ML

norm

I'm affrad that your only solution is to install thje "harry higley" safety spinners. you can install the lite lock and the spinner with the proper filets. here is a link to harry higley and they are popular, just a link that i found but displays well the safety spinner: http://www.gohobbies.com/RA_APS_HIG.html

The gold ones are heavy and the silver ones are light. You probably whant to go with the silver ones. Also there is a lock nut that sells separately and is strongly suggested.

Hope it helps you,

Normand

c550

My Feedback: (16)

Tru turn also makes a very good spinner nut, but I would second the recomendation to use the lite lock with the spinner nut. Here is the website: http://www.tru-turn.com/