RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

Yes I am, Just using Saito .82's because O.S. canceled the greatest engine ever made! .70 surpass II.
Steph..

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

Still building mine a little at a time. I am really sorry now that I did not go with the Saito's. I was one of the dummys who purchased the new OS 82s at the very high price. They must not be selling well because they are now offering a gift certicate with the purchase. However, when I requested one they told me I was not entitled because I purchased mine in January and February and therefore am not elegible. Great customer relations for a good customer. I was going to purchase one of the new Futaba 10c radio systems. But now................................

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

Hold out for the JR 12ch 2.4 - with one of those new dual-battery Rx's it'll be the duck's guts.:D

I've finished all the "build" and have added alot of aluminium tape and litho' to mine - currently airbrushing bits and pieces. Still haven't found a nice alternative scheme that has those stripes on the fuz.....

Cam

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

Tim
I have ordered this plane, still a question on the motors. Will the OS 55's fit inside the cowel as they do on the T/F 310. I have these motors on my 310 pulling a 12 x 8 graupner getting over 10000 RPMS. This plane is about the same size and weight as the 310 and it is like a rocket. So I am very sure it will pull this plane with no problem. I may go with the Saito 82 I want to stay as clsoe to scale as I can with out cutting up the cowel very much.

Walt

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

Hello Walt. Thanks for ordering your B-25!

About the fit of the engines, here's what I did. Since we haven't actually fit one of these engines on a B-25, I took measurements from an engine and compared them to the drawing of the cowl I have in my AutoCAD files. So the cowl, in the approximate area where the head of the engine would be, is approximately 161mm dia. The engine, from the base of the engine mounting lugs to the fins is 73mm. Therefore, it looks like you would have approximately 7mm clearance between the cowl and the head of the engine (160mm / 2 - 73mm = 7mm).

So it looks like the 55 ' s will fit, but please understand this is based on measurements from drawings, not an actual test fit.

I hope this helps.

Thanks again.

Tim Lampe

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

Tim
Thanks for the quick reply. I am still going to kick this around a bit. The four strokes are the better way to go but we will see. I will keep you posted. Thanks again.

Walt

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

Walt,

I would be tempted to tell you to go with the 1 Saito FA100T flat twin in this plane if you are still debating engine choice, 2 Saito 82 head @ 9 O'clock or the 3 OS 70 Ultimate positioned at 3 O clock. I have flown the plane with saito 82's and sounds great. I am now completing a second B-25 full scale project and installing bomb bay, release bombs brakes and all details except for pilots...this is a rc aircraft... and installing the saito Fa 100T flat twin and changing the colors to make it into the canadian colors "Grumpy".

Hope I'm not confusing you...

Normand

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

Normand
Now I am really confused. Not really, Will the FA 100 fit inside the cowl or will you have to cut it up. Like I told Tim, I plan to build this plane to scale and don't really want to cut up the cowl at all if I can still get the power. I know the 55's will pull this plane with no problem and they should fit inside the cowl. The FA 100 do sound good, a pair would sound even better then the 70's. They have a different sound to them.

I will keep you posted on what I go with.
Thanks Again
Walt

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

OK Guys,

I am in an absolute panic. I've recently started building my B-25 in earnest. I was attempting to hook up the throttle control linkages to my O.S FS-70 Ultimate (yes the ones with the pump). Turns out the carb arm needs to be reversed (as was also true for the FS 70 Surpass II). Problem is, I see no way possible to reverse the arm on this engine. I removed the one mount screw, but the carb is asymmetric. It seems impossible to reverse. If this is true, then I really need to to complain to both top flite and Tower Hobbies. This was the engine that was recommended by Tower Hobbies as the replacement for the Surpass II for this ARF. I am hoping that I am absolutely wrong on this. I cant be the only one using the ultimate FS 70 on this plane. Please someone put my mind at ease. I am hoping KProton, will chime in here, or norm will chime in here..or anyone. Do I have two brand new useless FS 70 Ultimates? Say it isnt so...

thanks guys.

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

Walt,

I am talking about the FA100T, not the FA100 there is a difference one is a 2 cylinder and the other is a larger single cylinder. check it out: http://www.horizonhobby.com/Products...rodID=SAIE100T

Just imagine the sick sound of a pair of those...

The engine will fit and you only have to cut out the 2 holes for the exhaust pipes, expensive option but why what makes planes fly? Only answer is Money!

Normand

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

That is the one am talking about, sorry I forgot to add my T. One of the guys at the field has one and it sounds great. I agree a pair would have a sound of its on. If they fit I may go with them and just use a short pipe as you did on your 82's. That would really bring out the sound. Agree they are pricey but what the hell.........

Walt

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

Morganew,

Relax buddy, just take 3 pictures of each engines. top view left and right side of the engines installed in the nacelle 1 & 2. Your only problem is to reach the throttle lever, there is numerous ways to adress this detail. I cannot call it a problem because this is a common situation. Keep your engine assembled as is. There is a variety of belcrank system available to reach your throttle lever, for example great plane make one: http://www3.towerhobbies.com/cgi-bin...EARCH=gpmq3920 you can use ball link to minimize loose movement and get a precise movement and multiply the amount of belcrank. My buddy building me a P-47 designed a throttle linkage to reach around a tank and is another interesting system, take a look: http://www.rcuniverse.com/forum/fb.asp?m=7268725

this is a simple solution and numerous other solution may be there for you to encounter this situation. I will gladly help you design a linkage to reach your throttle lever.
You also have an alternative servo tray in the nacelle to position the linkage in a preferable position. You will get it!


Normand

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

Walt

Way to go [sm=thumbup.gif]

Normand

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

go leccy no throttle hookup :Dtrouble

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

Hi morganew.

First, sorry to put you in a panic. I don't have the resolution here at my fingertips as I have read your message from home, but I can troubleshoot from work tomorrow. But here are a few things...several reviews were done on the B-25 with the same engine as you. I don't know what they did with the throttles, but no mention was made of the situation, so presumably they figured out a reasonable solution.

Second, have you considered the alternate throttle servo location? The one on the bottom of the wood nacelle? This may put your throttle servo in proper alignment with the carb arm.

That's all I can think of for now. Tomorrow from work I'll get an Ultimate and look into this for you.

Please stand by.

Sorry.

Thanks.

Tim

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

Hey Guys
I talked to Darrell with Sierra Precision Retracts. In May he will also start building and selling the retracts for the TF B25. I have his retracts on all my big planes and I will be getting a set for this plane as well. I don't know what the price will be yet. They will be a little more then the Robart but the quality of his retracts next to the Robart there is no comparison.

Also if you are still looking for WWII pilots, go to KMP models they have 1/6 scale painted pilots for $19.95 that will fit in their B25. They will also fit in the TF B25, they look really well. They are only half body not full body pilots.

Walt

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

Hi again morganew. I was just checking out your engine mounting/throttle hookup situation with your B-25. So yes, the throttle arm is on the right side of the engine. I did not examine an actual engine personally, but I looked at the photos on O.S.'s web site. As you already stated, it appears as though the carb cannot be reversed. So then, my recommendation would be to mount the throttle servo in the alternat location on the bottom of the nacelle next to the retract mount. Your pushrod will have to clear the fuel tank, but you should be able to do this with ball links (that will elevate the pushrod above the servo arm and the carb arm) and bending the pushrod.

Let me know if you cannot achieve this.

Thank you.

Tim

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

I'll definitely give this a try when I get a chance to resume building this weekend. Thanks for the prompt response. On another note, I know its off topic, but any idea when the shortage of Top Flite Cessna 310 wing replacement sets will become available? I cant find them in stock anywhere...just thought you could shout over the cubicle at the 310 guys while at work :)

Thanks again

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

Well Guy's I finished the plane at the end of last yr and run in the motors on a bench. Last night between the rain showers I fired them up for the first time in the Model. They need a little tweaking as one of them was really rich but the Twyn sync kept them in sync.
Weather here in the UK looks good today so who knows !!

http://www.youtube.com/watch?v=pPoOkZ4QVI8

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

asnook,

good luck on your maiden! I'll be watching the thread to see how it went.

Good luck! :D

Tim

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

Asnook. Looks and sounds great. Just one question. What are you using for crew figures?
Bill. [&o]

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

Test Flight Report,
Typical the grass was not cut and was very long, we have a short grass strip so it was always going to be marginal! Assembled the model and the engines were really on song with the aid of the twynsync.
The wind was all over the place but only around 12mph, first take off was aborted as it was never going to get off. I dare not lean the engines as they were so reliable although a little rich.
Second attempt looked more promising but again aborted as a good up elevator command made no difference.
Ok last chance, try a little flap. Not ideal on a first flight, at this stage the video camera was put away.
Now here is a little advice, dont try and level the elevators with the rear top moulding line before flight. It will give you too much up!
She ran the whole length of the runway and with a pull on the Elevator she shot up like a rocket, anyway several clicks of down and she was in control. Took out the flaps and boy she flies fast!
Throttle back a little and a couple of clicks of right rudder she's trimmed, retract the wheels and she accelerated into top gear!
Half a dozen laps and a couple of low flybys and the smile is growing until i realize with all those aborted take offs it must be time to land.
I pushed the switch to bring down the wheels, now ive cycled these retracts hundreds of times without a fail and to my amazement they come down very scale like.
A little flap and a half circuit she comes in fast, the wind changes, and a little rudder command soon has her in line. She's down safe and sound, all we got was a 10 second video inflight and her taxing back to the pits.
What a wonderful plane. Bill i have 1/5 scale pete's pilots in the plane. I need a drink!
http://www.youtube.com/watch?v=lma5RspoAsA
http://www.youtube.com/watch?v=17SN6AfjrJg

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

Let me be the first to say CONGRATULATIONS!!!

This model has been out for a little while now and my focus has moved onto other, new models that we are working on here at work, but I still have my personal B-25 ready to go (as soon as I get done practicing for an upcoming IMAC contest). Never-the-less asnook, your report made my day and I'm relieved you got in a successful maiden.

I could have told you to use flaps - especially in long grass, but yes, you usually don't want to mess with the flaps on the first flight (especially on takeoff) until you know how the model is going to behave. Last fall I was flying my B-25 from a grass field somewhere else and I always used the flaps for takeoff - they REALLY work!!!

And your model looks great too! But in the tall grass you were talking about I bet you got lots of clippings up inside the wheel wells!

Well, keep 'er flyin' and give us updates when you have more news.

Congratulations.

Tim

P.S. What engines are you using again?

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

Tim, I am using os 70 Surpass engines a little on the rich side, no grass clippings inside the engine bays but plenty of grass stain on the Fuss.
Once the grass is cut short I plan to shoot a video !
Alan

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 

Just for fun, here is a link to a short flight on my TF B25. It is power with OS FS70ii. I guess the last two FS 70 sold, but as you can see from the video there is more than enough power.

[link=http://www.circlecityflyers.com/images/ethan042708.wmv]TF B25 Flight[/link]