RC B-25 Problem

T

Tom Burnside

Charter Member
Im having a problem with Roy Chaffins B-25 everytime I engage autopilot the rudder goes to the right everytime. I emailed Roy and asked about it and he told me to look at the manual and zero the speery but for some reason my laptop will not let me open the manual. Can anyone tell me how to zero the speery.
 
Glad (?) to see I am not the only one!! Love the lines of that B-25 - potentially awesome freeware BUT mine too flies crooked with the AP switched. Stays in the hangar . .
 
expat said:
Glad (?) to see I am not the only one!! Love the lines of that B-25 - potentially awesome freeware BUT mine too flies crooked with the AP switched. Stays in the hangar . .
Click to expand...

Same here I love it and its always been a must have for me now that its does that its staying at duxford for the moment so can anyone give us a hand please.
 
Never had any problems with it. It is one of my favourite bombers in fsx. Even done some Multiplayer sessions with it. Such a great feeling to see several of these birds take off.

I will have to open the manual when I get home from work tonight. I asume the Sperry works the same on FS9 and FSX.

Will let you know, unless someone beats me to it ;)

Update: Gonna be running late at work. Will have to wait till the morning, but....

I found this fix on Roy Chaffins' website:
Sperry Autopilot acts strangely
Do one of the following :-
To fix this problem manually, just open the "Aircraft.cfg" file with a text editor.
Look in the [Autopilot] section of the "Aircraft.cfg" file and remover the two "//" before each line of the two lines below.
//use_no_default_pitch=1
//use_no_default_bank=1

Will check the manual in the morning to be sure,
 
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Let us know if that solved the problem.

The manual will not load in Windows 7, because that OS is missing the "Windows Help Program". I downloaded that from the Microsoft website, and now the manual will open.

This is what the manual states:
Servo Speed Regulators
Usage:
Before using the autopilot make sure that "auto coordination" in FS is switched off. It is also important to achieve a good trim especially with MS Flight Simulator default aircraft. The SPERRY-PILOT MARK III was made to hold heading and attitude, it was not built to turn automatically to the desired heading.
- Turn upper rudder knob ("RUD") on directional gyro unit, and align upper card with lower card.
- Turn aileron knob ("AIL") until its follow-up index matches the zero point on the banking scale at the top of the autopilot artificial horizon (see detail).
- Turn elevator knob ("ELE") until following-up index matches the elevator alignment index at the side of the artificial horizon (see detail).
CAUTION: Don't align follow-up index with horizon bar.
- Set sensitivities to "3" (average ) (see detail).
- Switch autopilot on by pressing key 'z' or use the autopilot mainswitch 1.

(Taken from the original manual)
If you want to change your course, select the new course with knob "RUD". The aircraft will be turned slowly in the new direction only with the rudder.To turn faster, bank the aircraft with the help of knob "AIL", or switch the autopilot off and turn manually. To end the turn reduce the bank degrees with knob "AIL". To climb or fall you can select a new pitch with knob "ELE". The original way to achieve a new course and pitch was to disengage the autopilot and turn manually.
If you think your aircraft reacts not fast enough or too fast on changes of course, bank or pitch, modify the settings on the Servo-Speed-Regulators. Regulator 2 steers the reaction of the rudder, regulator 3 is for the aileron and 4 for the elevator.

To start this "Help File" from MS Flight Simulator "Left Click" your mouse in the top left hand corner of the "Sperry" gauge.
You should not use the default MS Flight Simulator autopilot functions together with the SPERRY-PILOT MARK III.

The servo-speed-regulators are used to adapt the steering reaction to your aircraft. All regulators can be tuned from 0 to 6 in 1/8 increments. The left regulator controls the rudder, the middle one controls the aileron and the right one controls the elevator.
If the reaction is to slow, increase the respective regulator. If the aircraft is unstable (especially at high speeds and/or high simulation rates) decrease the regulator. Remember that setting to '0' locks the autopilot.
This package is Copyrighted to RCS Panels & Arne Bartels

These are the knobs on the bottom of the Sperry, and will only show in the 2D view.

I hope this helped.
 
I have removed the two // and no luck I have read the previous comment and I cant find anything to do with it. Im going to be honest this is really annoying me as ive always wanted to fly a mitchell.
 
Hi,
I just downloaded this bird and found the autopilot works fine (!) once you change the little wheels under it to Zero and be flying straight and level; then engaging the A/P should just means the plane carries on !

To turn I found using the Aileron button worked OK and if you look carefully at the Horizon dial you will see a tiny yellow square which moves either left or right as you turn the button and the aircraft follows that; adjusting the control wheel at the bottom will make it turn harder.
Andy.
 
manfred's post above about covered it and yes, it's a bit complicated at first.

I haven't installed the B-25 (yet) but the AP is probably the same, or modified from the one Roy did for the 2002/2004 R4D (DC-3). It is actually a dual AP in that it has the standard Sperry system and a more modern (set-it-and-forget-it) interface.
The manual is important (aren't they all?) and it explains what to do and why it has to be done. If the B-25 AP manual is done in a Windows Help format and you can't read it I've attached the R4D manual folder. Unzip it (the HTML doc usually won't work within a .zip file), read the 'read-me' text docs and then open the "apmanual" folder and click on apmanual.htm which should open a browser page with the images so you can study.

Yes, the key is to adjust the three "trim" wheels on the AP but there's a bit more to it. Basically though, the reason the rudder goes right is because the AP is telling to do so via the 'AP trim' settings. IIRC the WOP B-17 had a similar system.

attachment.php

Also note that you may, if you installed a stock AP like the Bendix-King, experience coding conflicts because of the special code Roy used to create the Sperry.
 
I commented out the two entries in the air.cfg. I can now use the Sperry AP and she flies straight. I did NOT **** first (!) so now I see you need to adjust the little trim wheels to zero but that didn't seem to matter. I think when I tried it a while ago I must have modded a modern AP (King) and that's when it would not fly straight with AP. Think I will stick with the Sperry as it is historically correct and more or less holds alt and hdg. The plane with AP off trims up so nicely you almost don't need an AP. Mostly doing patrols around the Solomons - great scenery done by Mark!
 
Hi,
I didn't find the need to change anything in the cfg.....in fact, of course, I never read the Manual to begin with !
The AIR file doesn't seem to match up with the one in the Model folder, but perhaps that doesn't matter too much.
Andy.
 
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Expat,
Glad to see you got the issue sorted out. I love flying this bird. After trimming ti for level flight I activate the Sperry and the adjustments in the sperry make for smooth turns.

Tom, Don't loose your patience with this bird. It is certainly worth the effort.

Can you provide some additional information, like:

What Operating System are you running,
What controls do you use
Are you running FSX or FS9
Do you use FSUIPC for your calibration/asignments or just FSX?

I'll be more than happy to further assist you, where I can, and if you want me to.
 
manfredc3 said:
Expat,
Glad to see you got the issue sorted out. I love flying this bird. After trimming ti for level flight I activate the Sperry and the adjustments in the sperry make for smooth turns.

Tom, Don't loose your patience with this bird. It is certainly worth the effort.

Can you provide some additional information, like:

What Operating System are you running,
What controls do you use
Are you running FSX or FS9
Do you use FSUIPC for your calibration/asignments or just FSX?

I'll be more than happy to further assist you, where I can, and if you want me to.
Click to expand...

I have windows 7 if it helps I have a lenovo g560e I use a joystick and rudder pedals im running fs9 and I dont have FSUIPC.
 
Tom, it's all in the picture posted by sirgalahad above.

Although personally I never use the autopilot on older aeroplanes, set control assignments for trim properly,
trim out to keep heading and alt, use trim to gain/ lose height at constant throttle...etc etc


Ttfn

Pete
 
Tom, if your joystick has a twist axis, make sure it is not assigned to anything, as you are using the rudder pedals. With the B25J on the runway, make sure to dial the knobs at the bottom of the Sperry to zero, as mentioned above and that the Sperry is "un-caged". Then just follow the instructions above.
It will take some practice, but once you get the hang of it, it actually works great.

I used the Sperry in the Douglas DC-2 "Uiver: during last years London to Melbourne Race. And it's working great.

Roy Chaffin's B25J is really easy to fly with and without the Sperry, I just use the Sperry for the longer legs, or when in multiplayer to give other warbirds the chance for some formation flying.

Let us know how you get along.
 
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