RE: New Hangar 9 B-25  
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RE: New Hangar 9 B-25 - 8/5/2008 3:30:26 PM   
rc74


 

Posts: 60
Joined: 5/26/2004
From: west chester, OH, USA
Status: offline 		Here is a pic of six B25 for are annual Flying Circus. Left to right, first is a Top flight, 3 H-9, a KMP, and then another H-9. Check out more at www.gcrcc.net

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(in reply to Corsair 29)
       Post #: 401

RE: New Hangar 9 B-25 - 8/7/2008 4:14:03 PM   
raveon


 

Posts: 17
Joined: 3/10/2007
From: WIGAN, UNITED KINGDOM
Status: offline 		can anyone tell me how i can get round this problem ive got i want to install two sc52 four strokes in my hangar 9 b25 mitchell but when i try and fit them the prop driver sticks out much to far ive got os40fxs in at the moment and i find them under powered and not reliable this is my second b25 first one crashed when i lost a engine at low altitude would be grateful for any advice or input many thanks Ray

(in reply to bbrundle)
       Post #: 402

RE: New Hangar 9 B-25 - 8/7/2008 4:52:57 PM   
lesliehowell


 

Posts: 21
Joined: 10/11/2002
From: Des Plaines, IL, USA
Status: offline 		Raviun,

I installed two Saito 56's in a friend of mines and they fit, but I had to make a small light plywood tray for the throttle arm to clear. It was very easy to do and it has tremdous power. I seen one at a local field flying with two Saito 40's in it with 11 X 5 two blade props on it and it appeared to fly alright. Well anyway he was happy with it, but of course he is an old fart like me.

Sincerely yours,
Les

(in reply to raveon)
       Post #: 403

RE: New Hangar 9 B-25 - 8/7/2008 5:07:54 PM   
modawg73


 

Posts: 53
Joined: 1/18/2008
From: Mason, OH, USA
Status: offline 		Ray,
I mounted two saito 62s and had the same problem. My workaround was to mount the cowlings further forward. I used a 1/2" square hardwood stock and cut off 8 pieces about 3/4" long. Then I epoxied them onto the front of the firewall. Then i marked the positions of these blocks with tape and cardboard, set the cowlings where i wanted, and drilled using the cardboard templates as a guide. I used the included mounts for the engines, but had to move the engines forward on the mounts to have clearance for the carb and throttle arm. All in all it turned out pretty well. The hardest part for me was lining up the cowling and holding it in place long enough to drill the holes. I used the dummy radial to hold the cowling in place. I don't think I can leave them on because I can't get the cowling on over the rocker arm covers with the dummy radial in place. I'll try to get pix on if you wouldnlike of my final setup.

Good luck.

Ken

(in reply to raveon)
       Post #: 404

RE: New Hangar 9 B-25 - 8/7/2008 5:12:47 PM   
lesliehowell


 

Posts: 21
Joined: 10/11/2002
From: Des Plaines, IL, USA
Status: offline 		Shoot Ray,

I had to do that with mine anyway because there was nothing to screw to at the recomeded locations, just hollow behind them. They have been the standby for cowling mounting for many years and I think still the best method.

Les

(in reply to modawg73)
       Post #: 405

RE: New Hangar 9 B-25 - 8/7/2008 5:57:59 PM   
blemoine30


 

Posts: 3
Joined: 11/15/2007
From: collisville, TX, USA
Status: offline 		i put two thunder tiger 75 s in mine and did not have to modify any thing ,because of there phyical size, turn a they turn a graupner 3 blad prop about 9200 rpm 11 7 prop

< Message edited by blemoine30 -- 8/7/2008 6:03:30 PM >

(in reply to raveon)
       Post #: 406

RE: New Hangar 9 B-25 - 8/7/2008 7:05:20 PM   
raveon


 

Posts: 17
Joined: 3/10/2007
From: WIGAN, UNITED KINGDOM
Status: offline 		Dear Ken would love to see pictures of final set up of your engines and cowls thanks very much for your feedback regards Ray

(in reply to modawg73)
       Post #: 407

RE: New Hangar 9 B-25 - 8/8/2008 2:36:57 AM   
mobyal


 

Posts: 816
Joined: 1/2/2006
From: Lexington, VA, USA
Status: offline 		Don't know if anyone's looking for one of these it's been on backorder from Horizon since last Fall but I was in Hobby Hanger in Chantilly VA yesterday morning and they have two for sale, one NIB and one completely built. Their phone number is 703/631-8820.
Al

_____________________________

MobyAl

(in reply to raveon)
       Post #: 408

RE: New Hangar 9 B-25 - 8/11/2008 1:24:44 AM   
modawg73


 

Posts: 53
Joined: 1/18/2008
From: Mason, OH, USA
Status: offline
quote:

ORIGINAL: raveon

Dear Ken would love to see pictures of final set up of your engines and cowls thanks very much for your feedback regards Ray


Ray,

Was hoping to get them done this weekend, but had a snafu with the mufflers. Here are pictures of the mounting of the engines. I'm out of town, but hope to finish the bird by the end of the week. Cowls look good on it, the spacing is about a gap of 1/2" between the shortest part of the cowl (where the nacelle scoop is) and the firewall. the short blocks of wood in the picture are for mounting the cowling. The longer blocks do double duty. They mount the cowl and also are used to secure the flex pipe muffler.

FYI, as shown in the first picture, the small block on the top (it is actually the bottom since the plane was turned upside down) doesn't align properly. I am going to have to cut it off and re-align. If you notice that the original mounting points on the nacelle firewall stick out about 1/8", so I aligned them all with the outer edge of the firewall and they turned out perfect. The top/(bottom) one i mounted even with the edge of the firewall, but didn't take into account that it wasn't sticking out like the other mounting points. The only reason I didn't use the original mounting point on that firewall is because I need to strap down my flex pipe, and I couldn't secure a long enough piece because of the cutout for the muffler in the nacelle.

If you need more pix quickly, I can try to get them by Wednesday, but it will probably be the weekend before I get it all done.

Ken

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< Message edited by modawg73 -- 8/11/2008 1:31:21 AM >

(in reply to raveon)
       Post #: 409

RE: New Hangar 9 B-25 - 8/11/2008 1:42:33 AM   
modawg73


 

Posts: 53
Joined: 1/18/2008
From: Mason, OH, USA
Status: offline 		COG help please!

I was trying to get her ready to maiden this weekend, but had an unexpected thing happen with the center of gravity. I put her on a great planes balancer at 3 3/4" like specified, and she was significantly nose heavy. I had to add 5 1/2 oz. of lead to the tail to get her to balance. Since I had a temporary setup (i didn't have the final mufflers, so was using the factory muffler for the saito 62s) i didn't feel like adding the lead until I was at the final setup.

A couple of quick questions that I would love your perspectives on.

First, I balanced her with retracts in the up position and with gas tanks empty. Is this the best way to do it? (first model with retracts that fold front to back) The manual doesn't specify whether to do it with the retracts up or down.

Second, i have 2 5-cell AA packs in the nose. Has anyone mounted the batteries anywhere else. I am thinking of moving the packs back to the wing center section. I am thinking it is best to balance without adding weight if you can.

Third, I am of the opinion that a COG too far forward is a livable situation, but too far back makes for hairy flights. How far would I have to go in front of the specified COG before I would be in trouble? Is it possible to have it too far forward to be flyable?

Thanks for any help you might be able to provide.

Ken

(in reply to modawg73)
       Post #: 410

RE: New Hangar 9 B-25 - 8/11/2008 12:24:02 PM   
da Rock



Posts: 6968
Joined: 10/11/2005
From: western, NC, USA
Status: offline
quote:

ORIGINAL: modawg73

COG help please!

I was trying to get her ready to maiden this weekend, but had an unexpected thing happen with the center of gravity. I put her on a great planes balancer at 3 3/4" like specified, and she was significantly nose heavy. I had to add 5 1/2 oz. of lead to the tail to get her to balance. Since I had a temporary setup (i didn't have the final mufflers, so was using the factory muffler for the saito 62s) i didn't feel like adding the lead until I was at the final setup.

A couple of quick questions that I would love your perspectives on.

First, I balanced her with retracts in the up position and with gas tanks empty. Is this the best way to do it? (first model with retracts that fold front to back) The manual doesn't specify whether to do it with the retracts up or down.


Yes, you balance with the wheels up and tanks empty.

quote:


Second, i have 2 5-cell AA packs in the nose. Has anyone mounted the batteries anywhere else. I am thinking of moving the packs back to the wing center section. I am thinking it is best to balance without adding weight if you can.


Move the packs as far back as needed. Use heavy wire extensions. You're absolutely correct about dead weight.

quote:


Third, I am of the opinion that a COG too far forward is a livable situation, but too far back makes for hairy flights. How far would I have to go in front of the specified COG before I would be in trouble? Is it possible to have it too far forward to be flyable?

Ken


Find out where the CG range goes. Best way to do that is to measure the model, plug the measurements into the application listed, and run the application a couple of times. Using 5% margin will tell you how far back the CG can go, and 20% will tell you how far forward. The CG location affects the elevator sensitivity. If you choose to move the CG forward of the mfg's suggested, then rig your elevator to have more throw than the mfg's suggested throw. If you move the CG aft, then rig the elevator to have less throw. As long as the CG is in the range the airplane should fly reasonably well. But in your case, moving the batteries back will help quite a bit. Using geistware will reliably predict what can be done to help also.
http://www.geistware.com/rcmodeling/cg_super_calc.htm

(in reply to modawg73)
       Post #: 411

RE: New Hangar 9 B-25 - 8/11/2008 2:58:44 PM   
modawg73


 

Posts: 53
Joined: 1/18/2008
From: Mason, OH, USA
Status: offline 		Rock,

thanks so much for the help! much appreciated

Ken

(in reply to da Rock)
       Post #: 412

RE: New Hangar 9 B-25 - 8/14/2008 6:25:26 PM   
modawg73


 

Posts: 53
Joined: 1/18/2008
From: Mason, OH, USA
Status: offline
quote:

ORIGINAL: raveon

Dear Ken would love to see pictures of final set up of your engines and cowls thanks very much for your feedback regards Ray


Ray,

Here are the shots of the cowlings. I still have two small holes to drill, one for the needle valve, and one for the fueling T.

Other than that, the cowls are done.

Ken

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