RCU Forums

RCU Forums (https://www.rcuniverse.com/forum/)
-   ARF or RTF (https://www.rcuniverse.com/forum/arf-rtf-75/)
-   -   Top Flite B-25 ARF (Tecnical, tips, suggestions) (https://www.rcuniverse.com/forum/arf-rtf-75/6494380-top-flite-b-25-arf-tecnical-tips-suggestions.html)

Speedracer2112 02-28-2010 10:08 PM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
BTW. In case your wondering how many flights can you make without the wing bolts in and survive?

Answer. Three. On the third flight last week in was taxing back to the pit and saw both of the wing bolts hanging out the front of the plane. I had done rolls and loops over and over in those three flights. The little screws in the back were in. About 33 minutes of flight time total.

SR

mechanicalfailures 03-02-2010 06:29 PM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
Has anyone compared the twinsync and gyro system in the event of engine loss? Twin sync is supposed to slow the other engine to idle, thus preventing a sudden stall, however the gyro allows easier control the on the approach after an engine failure. Anyone have any suggestions as to whether I should pick one, the other, or both? I would like to make my B-25 as safe as poosible as I've now lost two planes to mechanical failures. (The twinsync system can be found here: http://magnumrc.com/index.php?main_p...products_id=86)

I was also wondering about usng fewer channels. I only have a 7 channel radio, and I don't see why some channels can't be combined. This is a setup I found:

Channels Used: 9 total. Throttle - 2 channels, Flaps -1 channels, Rudder - 2 channels (1 Rudder & 1 Nose Wheel Steering), Ailerons - 1 channel w/Y-harness, Elevator - 1 channel, Retracts - 1 channel

( http://www.rcuniverse.com/magazine/a...rticle_id=1011 ) I figured that I could combine the rudder channels and throttle channels and only have 7, including the retracts. Is there anything wrong with this plan?

Thanks in advance,
Dalton

norm 03-02-2010 08:32 PM

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

You can easily work off 7 channels. The rudder should use only one channel. use a inverter "Y" if necessary on the noze wheel. As for the throttle you need to indepently be able to set electronically fine tune your settings, ie: idle and Full throttle and only after making the best mechanical set up on the throttle. You can electronically set the throttle using a JR Match box or similar device available at smartfly.com, but only after making the best mechanical set up!!!

Use the JR Match box on your flaps as well is highly recomended since this will set them perefectly to the same position closed and full.

As for the engines tune them as best as possible idling on their own for a full tank if necessary without quitting and transiting from idle to full throttle without failing. Once this is acheived your best next step is to install a glow driver, the best so far is the McDaniels MCD472TE available at sonictronics.com, or better call Hank directly at sonic tronics and he will make you one custom with the correct lenght leads at no extra cost.

As for the twin sinc...I'm not a firm beleiver since you can do the same and throttle back once you have an engine failure. The B-25 is a good glider. Your best bet is a Gyro for the job and it will home this plane no sweat. I have picked up a placrtic ribbon on take off 2 years back and from lift off I was able to bring it up 50 feet in the air slowly and go around for a safe landing on one engine. The plane flew nicely but I was more nervous than the plane reacted to the single engine flight and control...The gyro settings has to be well understood and the site describes it well. If you have any questions on how to set it do not hesitate to PM and lots of guys on this site had succes with it and will assist you with your set up.

Hope this help you.

Cheers,

Normand

RCGuy41 03-03-2010 08:10 AM

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

After reading your post and the post from Normand; I agree with his comments and recommendations he made. I'm currently flying with a spread spektrum DX7, the nose wheel steering and rudders are all on one channel to include a gyro that Normand recommended to put in. My gyro is on CH 7 for sensativity but needs to be set up in accordance to your radio manual and the gyro manual when installed in your aircraft.

So far I'm flying my B-25 with the smallest recommeded engine size (OS AX 46 TS) and achieving great results from my grass field that I fly from. As Normand has put out, if you have any questions, comments, and or concerns please post, there are quiet a few guys on this thread who are willing to help.

mechanicalfailures 03-03-2010 07:30 PM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
Thanks for the quick reply guys. Well I'm relieved to hear I can run it on 7 channels... that'll save me a little money :) So I will need 2 matchboxes (1 for flaps and 1 for engines) is that correct? I will definately be back for help with the gyro, but I'll wait until I get close to that stage in the build. RCGuy you mentioned you're running the OS AX 46 TS, is there a big difference between the sound of two four strokes and dual two strokes? Is a four stroke worth the investment? Any engine recommendations? My initial was a saito as that's personally my favorite engine. I think what I fear most about this plane is the dual engines. I've heard story after story of crashes after an engine failure, including a recent one from my close friend. I'm not willing to buy a new plane just to have it crash... Especially one of this magnitude. I know a glow driver is extremely convienent... just the prriiicccee.... I need some more money, but don't we all? ;)

norm 03-03-2010 08:49 PM

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

2 match box it is. As for the engines how can I voice my opinion...Like a beautiful women is to a nice car with a big big engine...or the difference between a blonde and a brunette or a better example some guys only swears by a Harley motorcycle and others prefer racers...I guess it is only a question of choice. All I can say the 2 cycle harmonic is a whole lot different when running a pair. The difference is really only a matter of choice but a pair of 4 strokes sure sounds nice to my hears. I would personally go with a pair of OS81 w/pump instead of the Saitos. I got a pair of Saito 82's but back then the OS81's w/pump did not exist.

All in all the reliability of 2 cycles and 4 strokes is almost the same but when budget is a question the answer is: as long as you can fly is what matters most.

Good luck and enjoy this build it is a very good one and twins are not so bad...I'm busy now putting together a Lancaster @#$% a whole lot of headhaches! 4 engines take a look at the threadn it is mostly all scratch build multi engines is a sickness once you start... :

http://www.rcuniverse.com/forum/m_80...tm.htm#8051097

Cheers,

Normand


RCGuy41 03-03-2010 09:09 PM

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

As for cost the Saito 72 FS to 82 FS is $280.00 to $300.00 per engine new from Horizon, through Tower the OS AX 55 is $160.00 and the 46 AX is $140.00 per engine. There is no measure, the sound from a four stroke engine sounds better, were as two TS engines have a higher pitch. If one is on a budget go for the OS two stroke engines, they are reliable and will turn a 12X6 to 8 prop between 9800 to 10200 RPM. My OS AX 46 engines are turning two 11X8 APC props at 10500 RPM and she has no problems taking off from my grass field, but I do take 3/4s of the field for my take off run.

Dalton I understand your situation, before I bought my B-25 I did a lot of research to determine the best course of action to be taken. In this hobby we build and fly our aircraft and then there are those unfortunate incidents were we lose an aircraft, whether it's through pilot error or a mechanical failure it's part of the hobby. I have lost a number of aircraft, but never a complete loss; I have been able to salvage the majority of gear. Right now I have about two grand invested in my B-25, and that's conservative to say the least.

As for an engine selection, buy what you can afford and is reliable at the same time, any four stroke engine I would add a glow driver and Normands recommendation I would take. Any further questions please feel free to ask.

djstar39 03-04-2010 03:38 PM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
I'm with Normand. I have two Saito 82's with McDaniel Glow drivers (except I used two of the MCD 466's mounted in the engine pylons. I'm using a 9 channel JR 9503 so my throttles are on different channels. I do have a gyro as well. The matchbox makes flap setup a breeze!

The differnce is that Normand is running Perry Pumps with his and no mufflers. That has got to sound absolutely awesome! :D I set mine up this way initially but our club rules require mufflers so I had to put them back on. [>:]

This may sound really weird but this B-25 is my least stressful airplane to fly. I prefer it to my giant scale P-51 because I don't worry about it pulling to the left on takeoff, it can't nose over, takeoffs and landings are VERY predictable and it just flys great in the air! Attention to detail on engine break in, intallation, setup, needle settings, etc. are absolutely required if you want to lower your risk of an engine out. I did come very close last year because after I landed, I only pulled about 5 seconds of fuel out of the tanks with my electric fuel pump. My fault as I'm still running a tad rich and flew at 3/4 to full throttle most of the flight.

This winter I've added a rotating top turrent and bomb bay and 6 bombs + release from Wingspan Models. I've also added landing lights. All of these extra goodies are running off a second receiver and my buddy will use my other transmitter to run them. I'll be pilot and he'll be bombadier! :)

Can't wait until it warms up more!

Dave

norm 03-04-2010 09:23 PM

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

Post some pictures!

jdhughen 03-04-2010 10:59 PM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
Norman,
Really enjoying the Lancaster build. How do you like the Proxxon table saw. I'm in the market and it's between it, the microlux (they look the same ??) and the Byrnes (a little more pricey). Have you have good experience with your Proxxon ??

Joel

norm 03-05-2010 06:45 AM

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

The Proxon saw is probably the best buy for a shop tool so far. It is a bit pricey but it makes clean cut through plywood, and balsa. It has variable speed and you can tilt the blade making precise angle cut and make your own stock, grooves... The savings are there but the work you do with it surpass all savings.

I'm not familiar with other brands but they should be very similar, I also found that Proxon is a little over priced but the retailers opinion is that they are the best in the market for miniature woodworking tools. I beleive him so far it is true.

Normand

jdhughen 03-05-2010 08:12 AM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
I like what I've seen/heard about the Proxxon and in the mid $300s it's more in my price range than the Byrnes which when complete will run around $540 ( [link=http://www.byrnesmodelmachines.com/tablesaw.html]Byrnes Table Saw[/link] ) . I appreciate the value of good tools but think that the byrnes might be overkill for my needs, but then you never know sometimes. Anyway thanks for your imput. I'll put another mark in the Proxxon column, and we'll get back to the B-25 here. ;)

Joel

djstar39 03-05-2010 07:33 PM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
1 Attachment(s)
Here are some pictures of my B-25 and the Bomb Bay addon from Wingspan models. The Bomb Bay mod isn't done yet... need to paint the bombs bright orange and tidy things up a bit. So far this add on kit from Wingspan is working out great! Can't wait to do a bomb run over my field!!!


norm 03-06-2010 10:10 AM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
Very Nice [sm=thumbup.gif][sm=thumbup.gif][sm=thumbup.gif][sm=thumbup.gif]

Normand

djstar39 03-06-2010 10:45 AM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
Thanks Normand! Like I said, I'm running a second 2.4 receiver and my buddy will use my other transmitter to turn on and off the landing lights, turn the rotating turrent on and off, open and close the bomb bay doors, and release the bombs. My job will be to just fly. :D

It's mid-40's here in Indiana... When does it warm up enough for you to get the big stuff out up there? Don't you fly some of your stuff on skis? Me and my buddy will fly EDF Jets off parking lots throughout the Winter but that's about it.

Dave

Speedracer2112 03-11-2010 08:53 PM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
My B25 has made it to the Big Show. She will be in the McDill Air Force Base Air Show next weekend with the Blue Angels as her side show. Well .....maybe the other way around but she will be there for two days flying for the crowd.

SR

http://i145.photobucket.com/albums/r...la/airfest.jpg

fytrjok 03-19-2010 12:16 AM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
Speaking of "Big Shows", this may be the last time that anyone will have the chance to experience the awe of at least 20 full scale B25's flying together. My wife and I are going...I'll post video and pics when we get back. Click on the link for the press release.

http://www.nationalmuseum.af.mil/new...p?id=123194616


Speedracer2112 03-23-2010 03:48 PM

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


ORIGINAL: Speedracer2112

My B25 has made it to the Big Show. She will be in the McDill Air Force Base Air Show next weekend with the Blue Angels as her side show. Well .....maybe the other way around but she will be there for two days flying for the crowd.

SR

http://i145.photobucket.com/albums/r...la/airfest.jpg


So i go there and they had a very nice 5 acre plot for me to fly on. [X(](snicker) I tried to fly in it twice. It was too tight so I landed. Its a little scary flying in between million/billion $$$$ aircraft.

The RC helis had a blast tho.

SR

krproton 03-24-2010 10:02 PM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
Sorry to hear that SR. Glad you did the right thing and got your baby back in one piece. Thanks for "representin.' "

Tim

krproton 04-05-2010 07:12 AM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
1 Attachment(s)
Well, here's my latest effort. Was trying to finish it for Toledo, but not gonna make it. Got started a little too late. If I had just another week!!!

RCGuy41 04-05-2010 07:44 AM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
Saaaaaaweet, great job Tim, so what engines are you putting into this new B-25? Also having sequenced doors would be awesome.

krproton 04-05-2010 09:48 PM

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

Thanks for the compliment. I'm putting in the new .72FSa's. Originally, I had .81's fitted, but found out the .72's are about 5mm smaller in every dimension, so I went with those. I'll post some pics of them mounted up.

Sequencing doors would have been great, but I wanted to keep the mechanicals pretty much stock. At the time I was rushing to get it done for Toledo, but now the pressure is off. I did add landing lights.

Tim

norm 04-06-2010 07:45 PM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
This is so nice Tim. Well done

Normand

krproton 04-07-2010 06:02 AM

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

Thanks, but my B-25 is not yet done! :D

Nice to chat with you. Thank you for all of your posts on this model. You have shared much information and provided much assistance with the B-25 and I'm sure it is appreciated by many. Are you still enjoying yours?

Be well.

Tim

norm 04-07-2010 08:33 AM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
1 Attachment(s)
Tim,

Yeah still screaming an flying, it has got well over 150 flights (i presume +/- 15) i dont keep a written count since october 2007 but all in great shape. My only problem is the perry pumps tend to deteriorate over the winter and end up costing me 120$ a year. The Saito 82's are great but the OS81's w pump did not exist then... and I will never settle for muffler pressure. Maybe in 10 years I'll realise it may have been better to buy the new engines.

Cant wait to see flying pictures.

Normand


All times are GMT -8. The time now is 05:48 AM.


Copyright © 2022 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.