norm

Joel,

How you doing Flavio,

1- The pipe is the metal pipe stock with the Saito engine...I have the 82's but same as the 72'. I just cut it flush to the cowl.

2- The VP20 you should return and do use it on a twin. Simple reason it works on oscillating vibration made by the engine. the 2nd engine will off tune the vibration causing it to block or pump backward!

3- The pump to be used is the VP-30 and it works by installing a "T" in the vent line of the breather nipple...needs to be carefully installed.

4- follow the instructions in previous postings. Do not install VP-20 you will have problems or crash.

5- The brackets are from "The Hardware Store" in the hardware section you will find this attached to a nail to hold wiree it simply is a wire bracket. You shave off the portion for the nail and end up with the brackets. You glue them in place with med CA

6- I'm using 4" ten spoke aluminium wheels from robart with brakes. Simply better then anything else in my opinion for cost and support, cant go wrong with Robart.

I have over 80 flights with the B-25 and never encountered a functinal problem other then 2 minor accidents...Human error. The VP-30 installation is very reliable and the inverted engine is no issue when well tuned. In any case it is a myth that inverted engines are a problem. Once they are running they will perform the same in any position. Only wrong tuning will cause any engine to stall. I suggest that you install the MCD472TE McDaniel glow driver for twins. You can only buy it from Hank at Sonic Tronic, he is the manufacturer. will make it custom to your needs. Just ask fo 40inch leads with the rubber cap for each engines. This is a shortcut to the website /product. Call Hank @ the number indicated.
http://www.sonictronics.com/xcart/pr...cat=422&page=1

You will have no problems,

Normand

RCGuy41

Good Day Normand,

I tend to agree the B-25 nacelle may not have room, but an OS 70 4S valve cover is the only part protruding through the cowl. With the exhaust on the right side can be ported to a ringed manifold with a single exhaust just below the scale location. The ringed manifold can be mounted to the nacelle supports (either of the two screws they support.) These are just some ideas I have been tinkering around with in my head. Kelvin tends to make his exhaust systems lite weight but very strong, it's amazing how they sound and create scale exhaust while in flight. If you have any more thoughts and or ideas please post to the forum, I'm alsways interested in other modelers opinions. By the way, you have some awsome pictures of your B-25, you have done some very nice work.

Brad

jdhughen

My Feedback: (1)

Norman,

I'm using the DuBro Anti-vibration mounts, with the V-20 pumps attached directly to the engines with the offset crankcase bracket perry makes for this pump. I was told that this type of mount would actually improve the performance of this kind of vibration driven pump when attached directly to the engine AND the mounts isolate the vibrations of one engine being transmitted to the other as well as minimizing general airframe vibration. Does this logic make sense to you ?? I do plan on testing it throughly and I've built a twin engine test stand using the same mounts to break the engine in. I'll let you know how the testing goes. At the first sign of a problem I'll switch to v-30s. Thanks for the heads up.

Very cleaver about the tubbing holders, great idea.

Thanks

Joel Hughen

norm

Joel,

I looked at this option but never went ahead or tried it. Isolating the engine with the Dubro mount does not cut all countervribation that may offset the oscillating pump. Nevertheless a test is better than a theory.

I Beleive Perry Pump (Conley Precision) tested it already even with the pump mounted to the crankcase.

I contacted the fellow at Conley Precision, the makers of the Perry Pump and he convinced me not to. Maybe a call to him may be the better way to go: http://www.perrypumps.com/

Hoping that may help you,

Good Luck

Normand

norm

Brad,

Thanx for the picture compliment but it is hard to beat TOREO as we can all see!

I've been on this thread since the begining and it is awsome how many great ideas came up from many participants. It is good to share experience in what is 8 x more complicated than a normal single engine.

I always will say that my "functionality" recommendations are to be followed specially when it comes to a rudder "gyros" and the rubber groomet on the front strut are not to be overseen.

The B-25 is an awsome aircraft that had 300+ spectators in Montreal cheer and applaud after landing at a warbird funfly we held this summer. It gets the most attention and I can get used to this, specially when it took me +/- 200 hrs to put together this ARF (not 50! as pretended by TF hahaha!)

That beats the Kit builders who spent 1500hrs on their 2,3,4 or 5 year projects!!!

The quality is there and there is a lot of potential to this ARF for refinement.

Normand

CCFPILOT

Normand:

Thanks for all of your great input on this thread. I agree with you on the 50 hours to build. I think I took about 100 hours, and I just completed the build as outlined in the manual.

I don't have a gyro on the rudder, but on some of my take-offs it probably would be helpful, particularly if the tracking requires a lot of correction. After a little adjustment things work much better.

RCGuy41

Normand,

I have to agree again on the build time, I would estimate, it took me 100-150 Hr's to complete my build and that's taking into consideration missing parts and hardware from the kit. When I fit tested the carburetor intake covers I found I had 2 RH pieces, it took my hobbyshop and TF 3 weeks to get 1 LH cover.

Question for you Normand, but a little info from me, I'm flying off of grass, when the aircraft starts to rotate and the nose looses traction my bird starts to yaw left, would a gyro help? Since I've been flying warbirds for quite some time (single engine of course,) I just use some right rudder to compensate and that has worked for me. I have seen some of your recommendations for a gyro on the rudder in-case of a single engine failure. Since you have been flying you bird longer have you run into an in-flight emergency and had to land on one engine? I have also read the pro's and con's of adding a gyro to the rudder maybe even the ailerons. Just trying to get some better perspective on the subject. The majority of builders are using 4S vice a 2S engine and I'm the first builder to use 2S OS engines that I have seen so far on this forum.

So far after six flights the engines are running fine and I get great performance out them. Next month I'm heading up to the Prince George Radio Control club's annual warbird fun fly here in Southern Maryland and hope to have the only TF B-25J at the event.

Brad

norm

Brad,

The TF guys must be thinking those guys are "slow", not to mention the real expression they must be saying...! taking up to 200hrs but make me feel better when I hear others saying that it took them well over 100hrs. I must admit I'm counting some hours spent waiting for the glue to cure with a budweiser in my hand...admiring the ongoing job.

A gyro on the rudder is the way to go. As I mentionned before the take off run and the overshoot are the most critical moments. I did have a mishap and the gyro saved my plane on take off. I picked a plastic ribbon that wrapped itself on the prop and choked the right engine. The aircraft rolled to the right but the rudder prevented the yaw and I was able to control the ailerons to level the plane climb sloooooowwwwwlllllly and recuperate the plane and land safely. If the Gyro would have been on the ailerons there is noway you would react fast enough to prevent the yaw from happening and test this climb and slow fly your plane and turn the ailerons...they have no effect, the plane does not react at all or very little. Ailerons need speed and the rudder are very effective at slower speeds like take off and slow approach.

For the yaw you get on take off this is normal with 2S engines as they dont "clean" themselves and reach top rpm simultaneously. The Gyro would certainly correct this but the gyro must be installed as an insurance policy only and used on t/o and landing. It create a knife edge effect when you turn so I disable it in flight but put it on when landing and on t/o roll.

As for pros and cons I suggest you review some experts comments on this subject. They all come to a single conclusion Gyro on thye rudder 1st and if you really like Gyros you can add a 2nd one on the ailerons, then you have full recovery control. 98% of gyro control needed on the rudder 2% on the ailerons. I prefer the stick

here is something interesting: http://rcwarbirds.com/Techniques/Technigues.htm#t2

Normand

camdyson

Hi Normand,

Just a quick question about the gyro (yes, another one ). You mentioned it causing adverse effects in turns - are you using aileron only when turning? I've got rudder mixed to aileron, and was hoping that the resultant rudder input should override the gyro's attempts to resist the yaw.

I'd rather gyro on all the time if possible to help in the initial swing if an engine cuts, and also because it's one less switch to worry about when I'm flying!

Appreciate your input (and Toreo's...[8D]) - 80 flights is VERY encouraging.

Cheers,

Cam

p.s. If the sun comes out on the weekend I may be able to get my engines run-in, and do some photos - it's been a long wet winter here. Just ordered a 4m enclosed trailer, so will be able to transport it to the flying field in a few weeks. Turned into an expensive model!!

elojim

Normandouellette,

using a pump and straight seems to be the solution. About the straight pipe : is it made by yourself or do you bought it ?

norm

Elojim,

the pipe you can use is the one supplied with your engine, just cut it flush to the cowl.

Normand

elojim

Normand,

ok to cut it, but what about the noise ?

norm

Hello Cam,

I have 20% rudder mix with the ailerons but the rudder still whant to maintain its axle in a pronounced turn. As fot the extra switch, I understand. All in all it is a very short procedure when compared to a full scale operation with multi pages of task on a checklist, Taxi,Run up, before takeoff, takeoff, climb, cruise, descent, pre landing check, short final, after landing... all those steps demand multiple task to perform while flying.

The B-25 before landing procedure is: begining on the downwind leg, gyro on, reduce power as requested, gear down, flaps as requested and after touch down, brakes as required.

When you memorize this, it is quite simple and this machine deserves this attention after all. This also add to the pleasure and this plane is so easy to fly, make you feel like you did something!

Normand

norm

Elojim,

The noise? Enjoy it!

Normand

flaviosi

ROFLOL!!!

elojim

Hi Normand,
one question (one more ) : You says you have brakes : did you use a specific pressure tank (and where did you place it ?) for the brakes or do you use the same one for gear and brakes ?

norm

Elojin

I'm using a small robart tank installes in the cockpit for the brakes and a medium air tank for the retracts located in the bulkhead as per the Top Flite tech notes. Although at the time it was not published, Tim Krproton had suggested an alternate location for a larger tank. I followed his recommendation and installed the larger tank in the bulkhead (behind the cockpit).

So yes there is 2 air tank and the small air tank location is ideal for the brakes,

Normand.

Flavio,

what is the decripted meaning of : ROFLOL?

camdyson

rolling on floor laughing out loud........

(and I don't even have teenage kids!)

Thanks for the gyro advice, I'll set it up on a switch and see how it goes. I think the first flight will have to have a "caller" for this one, rather than my usual trick of sneaking out to the field when it's deserted. Officially we have to have a "large model inspector" present anyhow, for models over 7kg. Officially.....[8D]

Cam

norm

Cam,

Before you go fo the first flight, I would strongly advise to review the all the blocks holding your servos, specifically the aileron and flap servo hatch. The blocks holding the servos break off loose under vibration and the servo is then loose in the hatch. 3 out of 6 on mine came loose or at least 1 of them. Even before assembling the servos I had prepared the holes by filling the holes with thin ca and added thin ca to the blocks, they still broke off. I had an aileron servo loose and completely detached. That got my attention. The way they are assembled does not permit to hold the blocks from the other side with a screw...take a look yo will understand.

I suggest you fuel proof the servo hatch plate and place a 2 sided foam tape between the hatch plate and the servo in case the blocks break off, the tape will still hold the servo in place and at least do 1/2 a job an get the plane back. That will take you a half hour nad at least take away that fear.

I actually found out the existence of the problem when I reviewed each hatch after the aileron incident. Two flap hatch when dissasembling the servos left me with a block broken off while reviewing them.

This is the reason why I'm a little "alarmist" about the subject but I beleive i cannot be overlooked.

As for the first flight, you will laugh at yourself and maybe "ROFLOL" how well it went when well prepared.

Have a good one waiste no time!

Cheers!



Normand

toreo

Normand
do you tested 2 vp-20 pump on twin engine plane??
I think, on B25, engine is almost isolated one from other. Additionaly, engine mount is very flexible, and not provide big vibration to the airplane.
I planning to test that pumps at this week. First on the ground, offcourse.

norm

Toreo,

No I never did test 2 vp20...but it seems that your B-25 is getting a series of interesting testing!


Normand

toreo

simple - i love this plane!!

camdyson

Hi Normand,

Thanks - I saw you mention this early in the thread - all the blocks for servos now have epoxy fillets all the way around (after first soaking joints with CA), and all servos secured with servo tape as well. I'll keep a watch on them though. Naturally it's bucketing down rain here still - hopefully Sunday I will fire her up. More time to check it all over.

Anyone ever counted how many screws in this thing?! I reckon if I glued it all together I'd knock a kg off the weight!!

Toreo - I like your plane more every time I see it - wouldn't mind being the upper turret gunner.....

Cheers,

Cam

RCGuy41

Hi all,

With Normand’s suggestion, I installed a GY401 Gyro mounted in the cockpit (removed from a helicopter,) but I am flying the Spread Spektrum 2.4 GHz radio system. The Gyro gets connected to the servo leads then to my rudder channel within the receiver. I am using AUX2 for sensitivity and reduced my throws, after mounting which was easy, I picked up the aircraft and manually yawed the aircraft the rudders reacted as advertised. Right now, I will be taking my bird to the field for some flight-testing and will report my results.

norm

RCguy,

Good show,

My suggestion is to have the Gyro on at take off then "switch it off" in the air and back "on" as part of a pre landing check and the first action on the list. It is a good location at the CG location and in the middle inside the fuselage.

Try also to have the gyro coulped to your noze gear, that will make you look good (perhaps perfect) on take off roll... nice and straight t/o roll.

The Gyro might be your best insurance policy. I suggest you test the reaction at high altitude idling one engine and have the Gyro on or off and see the difference. The best testing sequence is slow flying then full throttle on a climb (always at high altitude) then you idle one engine and see how fast the plane enters a spiral dive with no gyro on the rudder. You then do the same with the gyro on.

That should convince you.

Normand