CorsairJock

My Feedback: (90)

I stand corrected, but not entirely:
According to Saito literature, all are 104mm from thrust washer to carb bolt heads. My measurements indicate otherwise: the .62 is an even 4" (slightly less than 102mm), while the .82 is 4 1/16" (about 105mm). This is certainly less than I originally thought: I thought it was about 1/4" difference. It should be noted however: that the Saito .82 which I have has round head screws holding the carb on, while the .62 has Allen head screws. The Allen head screw have a taller head, which means that maybe another 1/32 could be removed from a .62 by replacing the Allen screws with round head Phillips screws.

But anyway we look at it: the difference is pretty slight (but there is also very little room left in the H-9 B-25 cowls).

So, if someone really feels the need for more power: I suppose .72 or .82s COULD be wedged into those cowls. But I'm betting that the .62s (or even .56s) will provide more than enough power for the way I intend to fly my bomber.

ramcfarland

My Feedback: (44)

Mustang11 those are a couple of fine full scae detail shots;very helpful as a detailing reference.

In addition I see this thread quite popular ,I get the impression these ARF B-25's are PERFORMERS??

ramcfarland

My Feedback: (44)

wildswan did you do any spot filling to conceal the Ultra coat seams/over laps/ Your sharp looking B-25 Mitchell most certainly looks like a terrific flier :so how are the flight characteristics,excuse me if I'm getting ahead of your progress ... looks ready!

The 'Hangar 9 price seems right and the looks considering all with the greatest exception I observe being the canopy frames are MUCH too pronounced.;same thing with my Top Flite Razorback P_47s ,other than that ,at a glance,the Mitchells I'm seeing in this interesting thread are eye catching indeed for an ARF or any "sport scale/fun scale R/C B-25. Again good going with your finishing techniques.

Howard Davidson

In answer to Ken's question regarding the difference in the left and right motor mount templates......................twin-engine offset! It works, don't question it, just do it! I've been flying mine on twin electrics for over a month now and it's a dream. Each flight gets better and the smile bigger. As I said in a previous post. Just do what Hangar-9 says to do and go fly, don't try to over-analyze what works. They must have figured something out as my plane never needed any trim and the rudders and engine incidences were right on.

Howard Davidson

modawg73

Howard,

thanks for the reply. I have done it, just trying to understand it. As I look at my nacelles, there is a pronounced (2-5 degrees by my eyeball) angle on the firewall of the offset template nacelle (I think it is the right one, cant remember offhand now.) So that would put the prop shaft in the center of the cowling. Just trying to learn what this does and why it is different on one engine of a twin. I understand the thrust offset on a singe, and maybe it just needs one to counteract the torque.

You have eased my mind about doing it. I am thankful that I caught the difference after i drilled my pilot holes, and not the bigger ones. I guess I need to read the packaging more carefully! Anyhow, I got the correct templates on the correct nacelles!

Ken

chistech

After reading the post about the nacelle templates I couldn't recall the left and the right, only GP and EP. I just looked at the templates and realize Hanger 9 made a mistake. I have two GP-L templates and two EP-R templates. Is this going to cause any problems with the model. I have put the two EVO 46's in already and mounted the cowlings with the plastic radial engines in. There doesn't seem to be any real difference in the locations of the motors to the cowlings or dummy engines. Also, I used the pre-drilled holes in the motor mount that ends up putting the engines 1/4" ahead of the reccomended distance of 4 3/16". Has anyone also kept the motors ahead like this. Thanks for the info Tevans 55. How far is the thrust washer from the firewall on the OS's? Also, on the cowling screws, they do not hit wood like the instructions say if you put them where reccomended.

mobyal

Chris --
Re the EVO 46s -- I have a pair of them to use on this thing. If I ever get it! -- were you saatisfied w/ the fit; the 1/4" in length doesn't seem like a big deal to me. Were you satisfied otherwise w/ the fit? How about your mufflers? Or side to side and head clearance? I'll be using Slimline Pitts style on mine. Any other hints? Beyond the template issue, that is.
Thanks
Al

modawg73

Thats funny. I had 2 GP L's and 2 GP R's. Couldn't figure out what the GP stood for until I heard there was supposed to be an EP.

I got a couple of extra GP templates if anyone needs them!

Ken

chistech

MobyAl,
The fit on the 46's is actually really good. They do fit tight in the motor mount rails even with them out all the way in the oblong mounting holes but they still fit fine. I completely opened the head area on motor thru the cowling for more cooling flow but you don't have to. You could get away with only about a third of the foward part of the cylinder head sticking out of the cowling. Actually, it doesn't really stick out but stays pretty much flush with the cowling. The push rod set up and every thing else is the same. I do like the fact that the carb opening is a little more accessible for priming because it is out more than the 36's would be. The carb is still inside the forward most edge of the cowl but not inside where you couldn't get to it, if you know what I mean. I did notice one motor is a little un-centered to the plastic radial engine center hole and it could be because of the two same engine templates I have. The plastic radial engine's center hole is really not that great anyway though. It is not completely round anyway so I assume there is some built in leeway. I have not put on the mufflers yet. We are also waiting for the pitts type mufflers to come in. I am building this for a military guy who will not be able to fly it for another 3 weeks so he is not in a hurry. The only issue I haven't tackled is the needle valve extension. You cannot remove the needle from the Evos because of the set pin so you have to drill a large enough hole to work the cowl over a L-bend in the extension. I usually like to drill a small hole and put in a long allen to tighten the set screw in the needle. I will figure out what works best today.Here is the specs below.

2 46 Evo's
2 Pitts type mufflers(soon to arrive)
2 Dubro quick fuelers
8 JR 821's (still waiting on the 2 reverse ones for flap and nose wheel. 1 week out)
3 JR 331's
1 JR 2400 mah battery
1 DX7 spectrum radio
H9 Robart retracts

My overall observations:
There is many impressive things to this plane like the way things line up like wings and tail.The covering and painting is also top notch with maybe only 2-5 small wrinkles in the whole plane. Then they go and already trim the top nacell pieces that go on top of the wing and when you go to epoxy them down the edge has a 1/8'" gap on the leading edge for about 1 1/2" up the chord. Why don't they let us trim these pieces? The stab should have 2 not one dowel to secure it. Putting in the blind nuts for the nose wheel is a lesson in dexterity. And the center hatch fits too loose and the nose of the slide pin should have a slight taper to align easier. I also put thin CA on the rear of the center hatch where the pin latch comes in contact. It will gouge the soft balsa pretty easily and I might put a small piece of thin aluminum adhesive tape there if I can just find my roll!!! Did anyone else have issues with the flap linkage slots in the wing. These were not cut very well and the torque rods would bind in many positions. It was not a big deal to go in with the Dremel and clean them up. In the instructions they show someone using a big drill to work on this plane. I don't think it could be done without the trusty Dremel. There is just not enough room to get that big drill in some places and sometimes even the Dremel is too big. I will try and post some pics of it when done and some of the motors in the nacelles. One more thing, my name is actually Ted and the chistech thing is a old web name I've had for 10+ years so why change now.
Thanks, Ted

mobyal

Ted --
Thanks a lot for your response. I'd hoped the 46s would fit in there nice and you've confirmed that.
So far as my specs are concerned, if you look at the listing in the manual for servos etc that's exactly what I've got. Plus the 46s and the Robart retracts. I was going to make this my this winter's project. But by the time I get the thing building season's gonna be over, plus I'm in the process of moving my shop. So next winter, maybe. Sounds like you're a professional "assembler". Too bad we're not closer, as I'd ask you about doing mine...
Thanks again
Al

tevans55

Ted-
My OS .46's are 4 3/16" from the firewall and that included putting a gasket between the stock engine mounts and the firewall. I also noticed the same thing you did with the cowl mounting screws not contacting wood so I cut and shaped some wood and epoxied it inside the nacelle at each of the 4 contact locations and then drilled them for the screws. That was about the only disappointing construction problem I ran into with this plane and it is an easy fix. I put a washer on the outside of the bottom hatch to catch that sliding lever and while I was breaking in the engines I found this to be a nice addition because the slide lever just snaps into place and the wood is not being damaged...the washer also makes the hatch fit better. Hope this helps!
Tim

mustang11

Ramcfarland,
I lifted those pictures off the web from somewhere…… ah-ha here it is, they came from the Mid-Atlantic Air museum or MAAM, the web site is http://www.maam.org/airshow/b25.htm and at the bottom of the page there is a link to their store, which has a CD of pix (about 500) on the B-25. Highly recommended in my humble opinion……… has some cool video’s too……… the only problem is it’ll make you want to spend way too much time detailing the bird out. I spent two weeks on the top turret for crying out loud.

Chistech,
I agree on the nacelle fit, I ended up doing the tape and putty thing on mine to get the fit to where I like it. I really need to get my butt in gear and take some pictures……… I and my little girl have been sharing a nasty bug for the last week or so and today is my first day back to work. Fittingly, I’m reading this thread rather than doing actual work……… Larry

Woodstock Hobbies

Hey Larry, you should bring yer bird out to the Chain O'Lake Eagles (COLEagles.com) air show on June 29th. I will have mine (HOPEFULLY) flight ready by then, and might even get up the nerve to fly it. I know that John Redman will be there, but do not yet know what purdee planes he will be bringing. I just finished striping mine down. I will be using some balsa filler, then I am gonna use rice papaer and some minwax for strength. I plan on painting this bird in a nice flat finish as it should be. I did notice the poor fit of not only the nacell tops but also the top turret and nose pieces. Has anyone ever tried to make their own using maybe some Plastruct for framing and maybe some .040 clear? The bottom hatch is going to get permantly mounted, since I plan on installing bomb bay doors. Since this will be my first air powered retract system, how do I slow it down for a more scale appearance? I tested the unit, and they seem to want to snap in and out too fast for my taste. Also, what would I use to make the retract doors open, wait for retracts, then close again?

dbateman

My Feedback: (31)

We were talking about a twin engine setup at the field. It appears the my H9-B25 has right thrust built into both engine mounts. When viewed from above you can see the mis-alignment in the props which is exagerated because both are pulling to the right. The concensus was the left engine should have a little left thrust or at least be neutral for engine out condition. I'm flying electric so it is not a big issue, but a good question none the less. I have two ways of correcting this if i choose. I can re-align the entire nacale or shim the motor mount. What do you guys think about all this? Doug

modawg73

Doug,

I would just use a couple of washers to adjust the mount the way you want it. Should be easy enough.



Ted,

I had a heck of a time with the flap torque rod areas....used both an exacto (sp?) knife and a dremel. Still wasn't easy, but I finally got her done. Rather than use reversed servos, I use a reversing Y harness with an neutral adjuster built in. Made it very easy to align both flaps. I am using Saito 62's so I had to drill holes in the mount to make it fit (it would fit in the pre-drilled holes in the mount, but i reversed the carbs, and the throttle control horn was blocked by the mount. Moving it out a bit gave it the clearance. Not sure how it will look finished but I'll let you know.

Ken

modawg73

This is my first retract as well. Reading the instructions, there are valves on the master air switch valve that will speed up or slow down the retract deployment time. should be as easy as adjusting those valves to slow them down.

Ken

tevans55

Jim-
I am finished except for some weathering in the near future. Engine break-in is completed. I've spent the last few months testing flat spray finishes for the UltraCote and I ended up using Valspar flat clear. It is fuel proof and looks good on all surfaces. Final weight is 13 lbs. 12 ozs. and balances at 3 7/8". (Still looking for a 1/10 scale USS Hornet) Thanks for your help with the tail and decals. Hope to see you in Toledo...I will be there Fri and Sat.

CorsairJock

My Feedback: (90)

Tim, WOW, that looks GREAT! Dulling the finish really gives it that Dolittle Raider look.
I'll be in Toledo on Friday (with my wife, to keep me from spending TOO much).
I've finally been getting some work done on mine lately: I removed the 'crossgrain' covering and replaced it with grain going the same way as the aft fuselage section. Top of wings are now covered, and am starting on the bottom side of the wings. Ailerons and flaps have been re-hinged, using Robart hinge points.
Still a long way to go, but at least Iv'e been making progress these past few weeks (not much overtime at work the past few weeks).
How about the Mint Julep: you gonna be there? I have camping reservations from Thursday nite thru Saturday nite. Hoping to have my Dolittle Raider ready by then, so I can fly it on Friday (open flying that day).

To those of you who are wondering what I am talking about: I decided to re-cover mine with CoveRite dull olive drab and dull gray covering. I discovered that these (dull) coverings have a 'grain' to them, and if you apply one piece with the grain going one way, and another piece with it going a different way: they appear to have different hues depending on how the light strikes it. I used 2 pices to cover the top of my fuselage, then had to remove one of them due to the crossgain, and re(re) cover it with grains going same way.

In retrospect, it appears that Tim has found a better way to dull the finish than I did. Easier and less time consuming.

tevans55

I still have your email about the Mint Julep. My extended family is planning a vacation that week and I am waiting to hear if it comes to pass or not...if not I will definately be at the MJ! We can't reach Tokyo from there but we could possibly bomb a few Toyotas and Hondas in the parking lot.

rnordeck

One: U still out there? How did your tests of the Evolution 36's turn out? I be flying here in Wonderful Wyoming w/ WYMOPA (http://www.wyomingmodelerspark.com/ ) ...well, not quite yet! (still Winter here!) at higher than U'r average altitude: 5400'. I just can't 'magine two 36's flyin a 15 lb. B-25? Can U give us an update?

Thanks,
"Lt. I. B. Narly"

One-O-Wonder

Yep I. B. I'm still here. I haven't flown the B-25 yet. It's still winter here also. I've got four of the engines. A friend of mine decided to put Saito 62s on his and gave me the two Evos that came with his. Testing wise as I mentioned I broke in the first two Evos by mounting and flying them separately on a H9 40 size Ultra Stick. The motor that I normally fly it with is an Evo 46. They performed well using APC 11x4 props. I then mounted them as a pair on a Hobbico Twinstar. They flew that plane well. I then mounted those two Evos on the B-25 and mounted the other two Evos on the Twinstar. I've put about thirty flights on them since then with no problems. In fact I flew the plane six times yesterday. In all of the flying none of the four engines has ever quit (where is some wood to knock on?). The two Evos are almost too powerful for the Twinstar and it will take off at half throttle. I bought one of the new Futaba 12FG spread specrum radios to fly the B-25. Each engine is on its own channel. This way I can run each engine up separately and tweak/match them as well. I've also set up a flight mode where each engine will not go below 3500 rpm in the air. I have to hit a switch to get idle once the plane is on the ground. The B-25 is ready to fly and I'm confident The Evolution 36s will fly it well even here at 5900 ft. Btw my B-25 weighs a little over 14 lbs.

One-O-Wonder

Here's a picture of my friends H9 B-25 with Saito 61s

rnordeck

One-O-Wonder-
Thanks for the report on the Evo 36's at altitude. I may opt for the great sound of two Saito 52's.... but OH the $$. I like your radio set-up with separate engine/throttle channels. Never imagined that I would run out of channels (or aeroplanes memory) on my Futaba 9CAP! How am I ever gonna have bomb bay doors and bomb drop?? But for now I'm still a wannabe B-25 pilot waiting on the next boat load to arrive.....March...delayed til April...now delayed until maybe! late May....or maybe Never.

Guess for now I just have to keep up the historical reseach reading, keep hidin $$ in the Ol Arbuckles coffee can and fly me H9 F4U "Cowboy Up"....Shoot, by then I might have 'nuf saved for the Top Flite B-25J Mitch and hav'ta jump ship/forums!

Why don't you bring your B-25 to our WYMOPA (http://www.wyomingmodelerspark.com) annual Fly-in in early June and WOW the crowd!

Lt. (jg) I. B. Narly

tevans55

Well I just got back from Toledo and decided the B-25 needed landing lights. Purchased them from Ram. I drilled a 3/8 inch hole through the wing just behind the leading edge and cut an access door on the under side of the wing to access the light. After I drilled I ran a carbon fiber tube through the holes and ran the bulb and wire through the tube. I cut a concave arch in the leading edge with a dremel drum tool and filled that area around the bulb with chrome monokote. I plan to use .005" lexan for the lense cover. I found that if I heat the wing tube that comes with the plane to 500 degrees in the oven and then lay the lexan on it the lexan will take just the right curve for the leading edge lense.

I plan to activate the lights when the flaps are down. Does anyone know where (website, book, etc.) I can find some pics of well weathered bombers?

Thanks,
Tim

One-O-Wonder

For those of you who need some inspiration, here's a link to a video shot here in the Denver area of a H9 B-25 & TF B-25 flying together. http://www.youtube.com/watch?v=hY3zMsfv-vg Both are powered by four strokes but I'm not sure of the sizes. Speaking of four strokes my friend taxi tested his H9 with the Saito 61s today. Has plenty of power and sound really cool also.