Could you take a measurement from the cranck centerline to the fuse? I have been thinking that a couple of RCV 90sp's would be great in this airframe along with a Kelo (sp) exhaust system. They swing a big prop at lower rpm's, but the props that they want (3 blade) may actually be too big. If not the 90sp then maybe the normal RCV 91 as it still has a short crank-to-head dimention due to the rotary valve system that they use and as such could possibley be totally cowled in. Thanks!

Hi "nemesis4u."

No, we did not make provisions for bomb bay doors in the Top Flite B-25 ARF. However, Greg Hahn (who was given a leftover prototype from early in the development of the project) added bomb bay doors to his with a bomb-dropping mechanism. One of the other guys I work with (who was the primary test pilot on this project) is also building a B-25 (finishing it in glass cloth and resin!) and is adding bomb bay doors and the dropping mechanism to his too. Maybe I can get some photos and write up brief instructions some time.

JoeyCoates, the distance from the crankshaft centerline to the fuse side is...(while I run upstairs to take the measurement off mine)... about 9-7/8". Those RCVs are intriguing. Hmm.......

Tim

hey tim,
did you get a chance to fly it with those new props yet???

you said that the kit maybe going out friday or early next week, that is just the distributors right like tower hobbies??

do you know how many planes were in the first shipment??? and when will the next shipment be coming in??

thanks
dan

Man....
You have to give him a break!!
You are going to chase him of with all those questions like that!!!

listen if he dont wanna answer the question he dont have too. im not making him. they are just some simple question.

so i think you need to relax and enjoy!!!!

Hey Dan!

No sweat man!

I did have an opportunity to fly the props today, but got to working on my van (heater won't work and winter is nearing!), then the firewood guy came by and I spent the afternoon carrying firewood from my front yard to the back! We finally got some descent weather today (overcast and gray, but calm), but that other stuff came up so I didn't get out.

I did run the engines on the ground after work last week and "tacked" them with all the different props. I have all the RPMs written down and am going to post them, but was going to wait until I got to fly them too. Hopefully tomorrow. I can tell you that I don't know if those Graupner 12 x 8s are going to work. They take the RPM down to like 8,200 and that seems too low to me. They were spinning about 8,600 with the Master Airscrews in the same size. I'll be sure to give a complete report about all the props after I get to fly them.

The first shipment of kits did come in. We finished our Q.C. check on Friday and everything looks swell. The hold up now is with the decals (I guess that sounds like an excuse, but it's true).

I don't think I should divulge the quantities of kits that came in, but it is almost (but not quite) enough to fill back orders, so most everybody should get theirs from this first shipment. I don't know what the allocation breakdown is between dealers (hobby shops who have purchased them through Great Planes Distribution) and Tower Hobbies. I do believe this first shipment is only about half of our first order, so the other half of the order is probably close behind (I think that's the case, but not certain--I can check).

I have also developed a list of suggestions for building/setting up/flying your B-25. These are simple hop-ups and other things I've learned after spending more time with my own (some I have already mentioned earlier in this thread). I'll post that stuff (with a few photos) soon.

In the mean time, feel free to ask whatever you want. I'll gladly answer what I can!


Tim

tim,
thanks again. looking forward to getting a great looking and flying plane soon. thanks for all your help!!!

dan

Yea Tim, the RCV engines are actually pretty neat. I have had a 60sp (the funny looking ones!) for about 4 years now and I swear it has more time on it then any other engine that I currently own. It took a while to break in, but it swings a 16x12 or 17x10 two blade prop very happily, and it is dead reliable. The only time it quits is if I tell it to, it runs out of fuel, or I have the idle set too low (and it will go low). I will have to look at what size three blade prop people are using on the 90sp, but if it is what I need then they would be awsome on the B-25.

On a side note, I have NEVER seen someone in your position spend as much time relaying your experiences on an airplane that they helped develope. Normally a manufacture does not even come on here much less come forth with all of the information that you have. I think that everyone following this thread appreciates it and I appreciate your taking the time to get that measurement for me.

Hi Joey.

I've seen those RCV engines in the magazines, but have never seen one "in-person." Maybe if I go to Toledo I'll check one out there. Your endorsement of the RCV is commendable.

My "position" isn't that big of a deal. I'm just a guy same as anyone else who's into R/C but happens to work in the industry. Like I said earlier when I joined in on this thread, although I've been into R/C for many years, I haven't been doing much modeling on my personal time the last few years until I got back into it this summer. I have a Venus II ARF that I converted to electric and now the B-25. For some reason the B-25 has really stirred my passion and I'm hopeful that everybody else (who gets one) enjoys it the same as me. And I'm just a bit "ahead of the curve" since I already have one, so the more info I can disperse the more likely it will be that others enjoy success too. Of course, I'm hopeful that the B-25 is a successful (profitable) release for the company, but on the other hand, that's not really my concern--my part is building, testing and writing manuals.

Tim

do the bomb bays open like they do on realflight, great spot for the lipopack and really easy access. ill make them if i have to.

Hi timothy thompson.

I don't know how the bomb bay doors open (you're referring to the ones I was talking about in recent posts where Greg Hahn and another R&D engineer at Hobbico are modifying their B-25s and retro fitting them, right?). I haven't seen either of these two planes nor have I seen Real Flight. I'll try to get some pictures later and post them.

If you end up getting a B-25, there will be PLENTY of work to do before you need to work on the fuselage and retro fit your bomb bay doors (should you decide to). About 80% of the work on this model is in the inboard wing panels where you have the nacelles with the engines, fuel tanks, throttle servos, landing gear (retracts), gear doors, cowls, replica engines and finally the inboard flaps. When you get the inboard wing panels completed the rest of assembly goes really fast.

Tim

Just got in a few more flights this morning. The winds were about 5-10 mph, but closer to 5 most of the time, so it was pretty nice (although the skies were gray).

First flight was with the tried-and-true Master Airscrew 12 x 8 3-blades. No problems. Then I mounted the Graupner 12 x 8s (3-blades). After "tacking" the engines with these props the other day I was a little leery because they pulled the RPMs down from about 8,600 with the Master Airscrews to about 8,300. Anyway, I flew the plane with the Graupner's and I couldn't really notice a difference in performance--other than the engines seemed to run a little smoother. In fact, if anything, the plane flew a bit slower. I didn't bother trying the 12.5 x 7 Graupners because on the ground, the engines "tacked" at only about 7,400 RPM (at full throttle). I don't know for sure, but that seems really low (considering the O.S. specifications say the engines make 1.1 hp at about 11,000 RPM I believe).

Then I put in another flight with the Master Airscrews (12 x 8 3-blades) and I think that's where I'll stay.

Next thing I need to do is some back-to-back flights with the APC 13 x 6 2-blades and the Master Airscrew 12 x 8 3-blades.

So, until further notice, I'd recommend the Master Airscrew 12 x 8 3-blade props if you want to go with 3-bladers.

I also experimented with some engine-out scenarios today. With the flip of a switch (on my 9Z) I can decouple the engines and have the throttle stick work the left engine and the right slider work the right engine. In flight, I flipped the switch to decouple the engines and pulled one back to about 1/4 power. Then the other. In both cases, I gotta tell you the plane seemed to move along pretty well and just required rudder to maintain heading. The manual has more information about engine out flying, but right now, I don't foresee any major problems as long as one doesn't quit on takeoff. (This is all "old territory" covered when we were test flying, but as I wrote earlier one of our more-experienced pilots was the primary test pilot on this bird so I didn't do any engine out testing, so it's a little new to me).

That's all for now and I'll write more later.

Tim

KRPROTON

This model really interests me. I would love to own and fly one. However, I am a little nervous about buying one.
I consider myself to be an intermediate flyer, or better. But I have never owned a warbird, or a twin.
What would be your opion of someone like myself attempting to fly such a bird?

Craig

Hi Craig.

Thanks for your interest and your candor in your R/C and flight experience.

The B-25 is a honey to fly. It's gentle and smooth like a trainer--well, actually probably even more gentle and smoother than a typical .40-size trainer due to its size, weight and wing loading. And since it's designed to be nothing but stable (as opposed to unstable like an aerobatic plane), it really isn't supposed to do anything but simply fly around.

However, with a model like this the stakes are higher. The plane itself is expensive (albeit a marvelous value in my opinion). Then you add the expense of two engines, twelve servos, retracts (optional), and about ten miles worth of servo extensions, you've got a lot of money tied up into something like this. Then you consider all the time and effort required to assemble and prepare it for flight, even though it's easy to fly, there are just a lot of systems for someone who doesn't have experience setting up models. So, it shouldn't be the flight characteristics of a model like this, its just the expense and technical nature that one must consider most. And even though this is an easy model to fly, you need moderate (considerable) experience in setup and flight to have the confidence to fly a model like this that will allow you to focus on flying rather than being distracted by apprehension or nervousness.

I guess I'm rambling, but it might be a good idea for you to start with any single-engine warbird--just to get a little scale experience. This will build your confidence in preparation for something a little more complicated like the B-25.

Restated, it's a dream to fly, but there's just a lot of money tied up and more complication for someone who has little experience.

This is just my opinion. Stand by and see if anybody else chimes in and consider their recommendations as well.

Tim

tim and craig,
this plane will be my first really twin that i will build and fly. i do have a PBY which is a twin. it was an electric kit that i had turned into glow. it did crash it on the first flight. only b/c the CG was really wrong. also it was kind of windy for how small the plane was too. the crash was not bad. the plane was fixed in about 3 hours or less. but the set up on the engines is kind of hard. but im getting there. just need a lot of time and calm set of nerves. i think of myself as a pretty good pilot. i many types of planes from h-9 corsair, piper cub, f-18 prop jet, foamies, helis, 33% suhkio and a cmp p-40 which had a mid air with this year. so i did fly 3D aerobatics to scale warbirds. so i think i am ready for the next step in my flight.

i did read the manual already that i printed off from top flites web site when it was first released. the set up does not seem to hard. it will just take time. out of all the arfs that i put together the manuals are very helpful. they almost always have some type of tips in them to help the builder out.

i would agree with tim craig. you should get yourself some type of scale warbird and fly that. also i talked with a lot of more experinced warbird pilots to help me understand what to expect from warbirds and how the fly. most war planes like to fly fast. so slow take offs and landings are not a good idea with any fighter warbird. you need to learn rudder i think. to me this is a must for take offs and landings. some may say other wise. ask around and see what other pilots at your field have to say.

dan

I was actually joking!!
I guess my tone and facial expresions are not seen when I type what I am thinking!!

Justin

Hi Craig. I was doing more thinking about your question and went back and read your post again. If you consider yourself an intermediate (or better) pilot, you may be halfway there. But the other thing you have to ask yourself is how capable and thorough you are at assembling/setting up R/C airplanes. Are you the type of guy who always seems to forget something like using threadlocker on bolts, or forget to check your Rx battery Voltage before you fly, or do you always seem to have trouble with your engines? If this is you, time on a single-engine warbird or simply time on more models wouldn't be a bad idea. It comes down to "crossing your t's and dotting your i's." If you seem to make it to the flying field, fuel up your models, put in several flights without mechanical issues, and if you can keep an airplane "alive" for a while, maybe you'd be okay with something like the B-25. But again, even though it is a baby to fly, the stakes are higher (with all the expense and higher complexity), so you should be really confident in your skills before getting something like the B-25.

Okay, more food for thought.

Tim

No sweat Justin. You're A-okay!

Tim

Tim and Dan,

I wish to thank you guys for your input and honest opinons. Particularly you Tim. Being a rep for TF and warning a potential buyer of what to be aware of, possibly looseing a sale in the process, speaks volumes.

With that being said, maybe more explanation is in order. I have been flying and "assembleing" ARF's for many years. I have been involved in the hobby for approx. 30yrs. though only full time for about 10yrs. I pride myself on setting up my arf's right the first time. If I take a bird to the field for a maiden flight, and everything does not work perfect, or with only minor tweeks, I am very embaresed and upset with myself. In fact makeing the details perfect is half the fun in arf's, flying is the other half.

I read with interest your posts about your co-workers putting bomb bays in their B-25's, this is something I thought would be fun to try.

When I call myself an intermediate pilot, I mean I am not an expert. I can not wring out a 3D plane like some of the guys at my field. I can however do good realistic areobatics with my GP super stearman running a 2.4cc gasser. Or my 120 size 4-star, also with same size gasser. Or GP Pitts special 50cc, though I have ground looped that a couple of times, so short coupled ya know.

I could go on, but I won't. Suffice to say, I think there are 3 classification of flyers. Beginers, Intermediate, and Expert.
Maybe that leaves to much room for guessing. Thanks again for your honest input, and I am in no way offended by your reply.

Craig

Hi Craig.

Whatever you decide to do (to purchase a B-25 or not to purchase a B-25), you may be interested to follow the new thread I started. It's titled "Top Flite B-25 ARF (Technical, tips, suggestions)". It's in this same "ARF or RTF" category as this thread. I've listed many new suggestions/hints and some covering tips as well.

Keep in touch!

Tim

I have only been flying R/C planes for the past year and a half and full scale for the past 17yrs. My first was the Hawk P6E for the first month then the Hangar 9 P47 150 with a Brisson 3.2 for the next 3 months then I decided to buy the Top Flite DC3. The DC3 was my first twin and still fly's today, its a great flyer with one engine. Last winter I built the KMP B25 with RCV 90's ( Great Engines) and I also installed bomb bay doors and flew it this year and it fly's great also, the only thing is that with my current B25 it lands fast and the power must be kept a little over a quarter untill the B25 is on the ground. The Top Flite B25 will be my next after I finish my Tigercat. Anyway I am very happy I now fly the twins even with the bigger expence and I also have had no problems going from singles to twins. I treat all my RC planes like full scale. I have backups on my electronics, I bench run then break my engines in for twins on a Big Stick and when I mount the engines on the Big Stick I mount the engines at the same angle that they will be mounted on the twin. Once mounted on the twin I take the time and properly sync the engines and I use onboard glow. After every flight I double check everything and before the next flight I re check both engine RPM, after 211 flights on my twins I had one time when I checked the RPM on both engines and found them to be off, I pulled the cowls off and after alot of searching I found a pin whole leak in one new fuel line. I guess what I am saying is that if you perform pre flight inspections and run ups before every flight chances are you will always go home with the airplane. If I were flying a Giant Areo Master with a gasser I would not think twice about the Top Flite B25. One last thing, before I flew my DC3 and had an engine out I flew the DC3 on the Real Flight sim with one engine only for many hours, when I lost the engine on the flying model I kept flying then made one of the best landings.

I noticed last night that Tower Hobbies were showing limited stock of the B25 then this morning it said on order. Still it does not matter now I noticed that Tower will not ship this model to the UK because of the weight/size. I am gutted !!

I find this strange as they shipped the Cessna 310 to me box size 68x21x17 and 38llbs, the B25 is smaller and lighter 68x20x13 and only 31 llbs.

Does anyone know if there is another dealer that will ship to the UK

Hey Tim,

I was probably a little late in ordering my plane, also I ordered it from my LHS . Any word yet on when to expect the next shipment?

well just seen on towers web site, late oct!!!! wow that sucks.

hopefully the second shipment comes in soon. cant wait to see the beauty in my living room!!!!

The Tower Hobby site said "Mid-December" this AM, but says "Late October" now.

That means that whatever kits came in on the first shipment, went out to the pre-ordered buyers.

I hope I was one of those folks.