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 09-07-2010 01:25 PM

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

ORIGINAL: lfierro1

I have had my B-25 ready sinse Christmas but just got around to flying it. Great flying plane but my nose gear is bending on very soft landings. Anyone got a fix for me? Robart gear by the way.
First make sure the assembly in in tight together without any gaps between the pieces. Next, you have to land on the main gear. Especially if your on grass. You have to learn to hold the elevator after you touch down to keep the nose wheel off the ground. Look at the video above by "christophe31". He keeps the wheel off of the ground as long as possible. Perfect landing.

You can bend the gear back into position about 3-4 times depending on how bad you bend it. More than that and you will shear the pin off.

I think the Robart systen is near perfect. I would rather bend the pin than replace the nose of the plane. I quit counting but I am near 300 flights now and have used about 12-14 nose pins. Most were when I was first learning to land. I use the Robart wheels with inserts also. The foam tires in the kit are too hard.

Dont give up! Its worth it in the long run. Learn to land correctly. If you look back in these pages you will see my posts asking for the same help on how to fly and land this plane.

This is one of my early landings. Its not a pin failure but a sand in the mechanism failure.

[youtube]http://www.youtube.com/watch?v=A31lDAB3qfs[/youtube]

Speedracer2112 09-07-2010 02:11 PM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
Almost forgot........Last weekend I was shocked to find a third pilot in my B-25. A large wolf spider was sitting between the pilots. He flew three times that day. I hate killing things so I left him be thinking he would have enough and bail out. This weekend......there he is. Right between the pilots again looking out the window and he has grown. He took 4 flights and made it back to the house. Cant tell the wife, for she would surly kill him as the plane lives in the house also. I dont know what he is eating but he is eating well!!

SR

Termites Dream 09-07-2010 02:24 PM

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


ORIGINAL: Speedracer2112

Almost forgot........Last weekend I was shocked to find a third pilot in my B-25. A large wolf spider was sitting between the pilots. He flew three times that day. I hate killing things so I left him be thinking he would have enough and bail out. This weekend......there he is. Right between the pilots again looking out the window and he has grown. He took 4 flights and made it back to the house. Cant tell the wife, for she would surly kill him as the plane lives in the house also. I dont know what he is eating but he is eating well!!

SR
How does the spider affect the CG? If he crawled to the back while in flight would you crash? Maybe you should keep him, you can be sure your B-25 will be insect-free. Do you think he could be trained to operate the landing gear in an emergency? Arachnids have a 6th sense- if he leaves the plane or puts on a parachute, you shouldn't fly that day. OK, I'm done :)

Lifer 09-07-2010 02:26 PM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
Perhaps you now have a new nose-art logo?????????

Mustang Fever 09-07-2010 02:56 PM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
Very bad Karma to evict the spider. Very, very bad.

Lifer 09-07-2010 02:59 PM

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

Are you the Bob Hunt of control-line aerobatics renown?

Mustang Fever 09-07-2010 04:32 PM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
Not guilty.

lfierro1 09-07-2010 08:15 PM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
thanks for the replies but i don't need landing advice just wanted to know about strengthening the nose gear

Speedracer2112 09-08-2010 06:53 PM

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


ORIGINAL: lfierro1

thanks for the replies but i don't need landing advice just wanted to know about strengthening the nose gear

No problem. Remove the retract and strut. Drill them out on a press to fit a 1/4" rod. It will never bend again. However, you will need to order a new fusalage instead of a pin every time you land. You were asking for advise. You received three great responces. Two from guys with retracts and one from a guy with fixed gear. The retract guys say land on the mains and you will be fine. The fixed gear guy has placed a wire spring that gives a lot to absorb the force. I have landed this plane hundreds of times. I know for a fact that the pin does not bend unless I have done something wrong. Please understand that something has to give under pressure. Better the pin than the fusalage. The force will find the weakest point.

You might even try to insert the wire gear "MustangFever" showed into the retract mech.

SR

Speedracer2112 09-08-2010 07:00 PM

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


ORIGINAL: Mustang Fever

Very bad Karma to evict the spider. Very, very bad.

EXACTLY!!! I peeped into my hanger with my camera tonight to try to catch him. There he was between the pilots. He ran off before I could get a photo. Ill get it. You wait and watch.

SR

RCGuy41 09-08-2010 08:21 PM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
Ifierro1,

Hi follow this link it tells you how to treat steel, http://www.ehow.com/how_4575979_heat-treat-steel.html

djstar39 09-08-2010 08:52 PM

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


ORIGINAL: Speedracer2112



ORIGINAL: lfierro1

thanks for the replies but i don't need landing advice just wanted to know about strengthening the nose gear

No problem. Remove the retract and strut. Drill them out on a press to fit a 1/4'' rod. It will never bend again. However, you will need to order a new fusalage instead of a pin every time you land. You were asking for advise. You received three great responces. Two from guys with retracts and one from a guy with fixed gear. The retract guys say land on the mains and you will be fine. The fixed gear guy has placed a wire spring that gives a lot to absorb the force. I have landed this plane hundreds of times. I know for a fact that the pin does not bend unless I have done something wrong. Please understand that something has to give under pressure. Better the pin than the fusalage. The force will find the weakest point.

You might even try to insert the wire gear ''MustangFever'' showed into the retract mech.

SR
+1 on the response SR! Wow, interesting picture... and no nose gear showing to boot. I have nightmares that look something like this. [:o]

Mustang Fever 09-09-2010 08:03 AM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
1 Attachment(s)
Just so there's no misunderstanding, I have never once landed my 25 on the nose wheel. The factory supplied nose gear bent during taxi before the maiden flight. As sure as I'm sitting here, I know the retract would have also bent under the conditions at that field.

This is not meant to deride the guys who are trying hard for a scale appearance in every way possible. Just a statement that I like to fly more than I like to do repairs. If I have to spend a lot of time working on a bird (after completion), I tend to put it on the shelf or get rid of it. This attitude comes from my years in the trucking industry- if something is a PITA, sell it and get something else. Keep em rolling.

One thing I may have failed to mention here- the nose gear mounting blocks in this aircraft are too high up in the fuse for use with the factory supplied fixed gear- the bird will sit nose down. I screwed and expoxied some hardwood blocks over the factory ones to get the gear mount lower, and reinforced as much of the area as I could with a mix of epoxy and milled fiberglass. (Liquid steel, in my book.) This is necessary when using the Fults, as it gets the springs mostly outside the fuse. I did have to hog out the sides of the gear opening a little, tho.

Speedracer2112 09-09-2010 02:28 PM

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


ORIGINAL: RCGuy41

Ifierro1,

Hi follow this link it tells you how to treat steel, http://www.ehow.com/how_4575979_heat-treat-steel.html

Thats way cool! Ever tried it? Did it work? Looks like a cook out is in my future. Id love to harden some axels on my P-51D.

Thanks!

SR

Speedracer2112 09-09-2010 03:13 PM

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


ORIGINAL: djstar39

Wow, interesting picture... and no nose gear showing to boot. I have nightmares that look something like this. [:o]
I truley believe my B-25 loves me. Shes a big park flyer. She looks brand new even tho she has been in multiple bad situations. Every time she pulls through. I have had three no nose wheel landings, one no left main wheel landing, two nose wheel failures and one left motor out death roll. She landed every time with out a scratch except for the time in the video above. That time it used the landing gear door as a skid. Easy fix.

Here is the death spiral. Engine fails at about 2:47 in and rolls over at about 3:07. I landed with a 20mph wind in the wrong direction.

[youtube]http://www.youtube.com/watch?v=8Qu7W-nHMvc[/youtube]



ORIGINAL: Mustang Fever
Just a statement that I like to fly more than I like to do repairs. If I have to spend a lot of time working on a bird (after completion), I tend to put it on the shelf or get rid of it.

You got that right! I hate a plane or engine that breaks nonstop. Out of all of my planes this one has the least problems. The occasional nose pin replacement and I had to replace the stock fuel lines in the tanks that split. I do tear her down every 50 flights or so to check for problems or wear but thats it. I am on my 4th set of tires however!

SR

Speedracer2112 09-13-2010 01:34 PM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
If your going to wreck your plane I prefer to do it in the air. I wrecked my B-25 this weekend on the ground. Boy I was mad at myself. I accidently left on my receiver and hit my retract switch to reset my transmitter for another program. I heard the air rush but was too late. It popped off two doors and broke the wood door levers off all three mechs. I remember someone making aluminum replacements. Ill have too look that up. Bummer.

SR

Mustang Fever 09-13-2010 01:51 PM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
1 Attachment(s)
That's a drag. I had retracts on a P-51 and an F-4, and did that a couple times.

I was looking at the ESM (Troy Built Models) retracts for their 95" B-25. I don't know anything about them, but they sure look a lot nicer and tougher than the Robarts, and gobs less expensive. Would probably fit with little modification, as there's less than 1% difference in size between the TF and the ESM.

http://www.troybuiltmodels.com/items...CHELL95LG.html


Speedracer2112 09-13-2010 06:28 PM

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


ORIGINAL: Mustang Fever

That's a drag. I had retracts on a P-51 and an F-4, and did that a couple times.

I was looking at the ESM (Troy Built Models) retracts for their 95'' B-25. I don't know anything about them, but they sure look a lot nicer and tougher than the Robarts, and gobs less expensive. Would probably fit with little modification, as there's less than 1% difference in size between the TF and the ESM.

http://www.troybuiltmodels.com/items...CHELL95LG.html


I have them for the ESM B-25 I have still in the box. They are way too big. She it quite a bit bigger. I have two Saito FA125's for her. I just havent had time to build her yet.

SR

Mustang Fever 09-13-2010 07:26 PM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
Another idea down the tubes.

Mustang Fever 09-15-2010 10:05 PM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
I "counter torque weighted" my B-25, and it made a huge difference in the handling. (2x.55=1.1x2=2.2 ounces of weight in the right wing tip.)

Before this, the bird needed a lot of right aileron trim to fly wings level, and it definitely did not want to turn right. The weighting eliminated the right turn problems, and the right aileron trim is no longer necessary.

This idea came from an article in Model Aviation from last year. I was very skeptical, and didn't try it until this year, on a 60 size P-51 ARF. It made so much difference in the handling that I'm doing it to almost all my birds.

One other item: this airplane takes off much better with flaps. I had been using them for all takeoffs until yesterday, when I tried one with flaps up, and the takeoff roll was much longer, and the airplane was struggling to climb after liftoff. I did another with flaps down, and the difference was dramatic.

Mustang Fever 10-05-2010 04:32 PM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
Got a chance to fly her again today, and I now think this is going to be one of my all time favorite airplanes- right up there with my Joe Beshar Shrike 40, and my Laddie Mikulasko Arrow flying boat.

The counter torque weighting has really cured all the handling problems- she turns equally well to the left or the right, and does not try to overbank in either direction.

I've founding that holding one click of throttle above idle on final (approx 3000 rpm with the 12x6 3 bladers) is the key to good landings. Once she's slowed down, I can pull some back stick and get a nose high touch down every time, with no tendency to balloon.

The 55s provide sufficient power for aerobatics with this 18 pound airplane: she does the most beautiful stall turns you ever saw. Comes to a complete stop after a vertical blast of about 75 feet, and left rudder at full throttle rotates her about the CG. Then I just pull back on the gas, and let her build speed back up in a vertical dive. :D

The wind started getting goofy before I could completely wring her out, but I did a half Cuban 8 (or a sloppy Immelman) and she had plenty of power going over the top of the outside loop part.

Can't wait to try a spin.

mechanicalfailures 10-07-2010 09:29 PM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
After months of saving and bribing, I finally put in the first order tonight consisting of the B-25 ARF and all required servos. Can't wait to get it! Should keep me busy for a few weekends before I order engines and retracts. This forum's been a great help and I hope to incorporate all of the tips that I've seen here. Thanks to everyone who's posted!

Mustang Fever 10-07-2010 09:49 PM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
You'll love it.

mechanicalfailures 10-07-2010 10:14 PM

RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
 
I know I will! I've been into B-25s since I was just a little kid but I've never done anything but look at pictures and read about them until now. To finally get the chance to do something like this is just awesome. Hopefully I'll be able to find some guys at the field to fly formatation with me when it's all done.

Speedracer2112 10-13-2010 07:54 PM

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


ORIGINAL: Mustang Fever

I ''counter torque weighted'' my B-25, and it made a huge difference in the handling. (2x.55=1.1x2=2.2 ounces of weight in the right wing tip.)

Before this, the bird needed a lot of right aileron trim to fly wings level, and it definitely did not want to turn right. The weighting eliminated the right turn problems, and the right aileron trim is no longer necessary.

This idea came from an article in Model Aviation from last year. I was very skeptical, and didn't try it until this year, on a 60 size P-51 ARF. It made so much difference in the handling that I'm doing it to almost all my birds.

I tried this last weekend. I didnt see a difference although I didnt have any issue with right hand turns prior? Wierd how we have such different planes. I tried it because I do have to have a lot right aileron to fly level. I was told last week that I was useing the wrong surface to pull this out and I should be mixing rudder with throttle to counter the motor torque. I tried to mix the ailerons with the throttle and nearly lost my plane three times in death spirals before I got her to the ground I one piece. VERY POOR THINKING ON MY PART. It makes total sense now. [&:] Next time I will try mixing the rudders with the throttles on a condition switch so I can disarm the mixing if it goes bad again. It was UGLY!!

My problem that I have is trim at high speed vs trim at landing speed. I have her trimmed at mid-throttle but I have to hold my sticks at the extremes of speed. She tries to roll right when landing and rolls left at high speed. Yes, I know its the motors BTW. Rudder will fix it. I just need to find the proper mix.

I'm well over 300 flights now an have kind of quit counting. If fact, I think I lost the front seal last week on my left motor shes run so much. I had just gotten used to her minor quirks as normal. Now I want it trimmed out.

SR


All times are GMT -8. The time now is 09:11 PM.


Copyright 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.