Thread Tools
This thread is privately moderated by Beltpilot, who may elect to delete unwanted replies.
May 12, 2010, 01:35 AM
Wilde Sau
Beltpilot's Avatar
Thread OP
Build Log

FMS P-51D modifications


THE FMS P-51D MUSTANG: GETTING AIRBORNE WITHOUT HASSLE

Sorry, the below info is mainly outdated as the present version of the Mustang is V7, which faced major improvements. Most of the below mods are unnecessary.
If you are looking for further information about any FMS warbird, please visit Gary's/Sandancer's blog (link below)




The FMS P-51D Mustang is a large and nice model, however it is not really ARF as some modifications have to be done before getting airborne. Other modifications enhance it's look or functions and can make life easier...


Overview of the kit

A very nice site about the Mustang and other things of interest connected to warbirds


Some modifications depend on the version of the plane. At the moment, there are five versions, with only the latest being currently sold:

V1: early prototype; 3S setup; only few units sold

V2: 4S setup; 540kV motor; 40A ESC; no flaps or retracts out of the box, however main&tail gears can be made retractable as they come with the mechanism; only few units sold

V3: 4S setup; 600kV motor; 40A ESC; flaps&retracts out of the box, new tailwheel sits in simple slot (red color) right underneath the rudder and is not retractable, but some units have been sold with the former retractable tailwheel at the scale location; reinforced wings; numerous units sold

V4: 4S setup; 600kV motor; 50A ESC, additional BEC, flaps&retracts out of the box, tailwheel on this one is slightly modified from V3, still not retractable; now has other foamplugs at the former retractable tailwheel location so it can not be modded to that tail retract as easy; reinforced wings; also available in yellow "Marie" scheme

V5: Same as V4 but with servoless retracts

Paintschemes available: ShangriLa (silver-red), Marie (silver-yellow); Petie 2nd (silver-blue)

Some mods have to be done before the first flight, otherwise a crash is very likely to occur. Others should be done, depending on flying style. And some can be done just to improve appearance or performance of the Mustang. The need for the different mods however depends on the version of the model that you own. If you own the latest version with etracts, obviously all the mods regarding the old mechanical retracts, as well as the elevator servo issue and the weak ESCs of older versions etc. do not apply.
Other mods like the front vent hole, the oleo struts or the forward raked gear are "evergreens" and apply to every version of this Mustang!


Make sure that you also check the blogs of other users who have worked on this model. They have done the same or even other mods and have also done great descriptions on how they did it.
Examples are Sandancer/Gary(the best of them all, also about almost every other FMS-bird!!!), TheOldGuard/Dave, JBC/John and LiCobra/Tony.
Also, a well done wing mount mod made by Topkits.



The following list shows what I have done or will do on my P-51D.


Must-dos:

- Change the elevator servo against a stronger, larger one that can handle the loads of the elevator. The 9g-servo that FMS uses for this task is too weak. Not changing this servo results in not being able to pull out of dives or even stripping the servo and therefore loosing elevator control! Work in progress, pictures coming up soon!

- Change the ESC to at least a 50A or 60A (except V4). The motor pulls around 45A at full throttle, which will result in a 40A-ESC failure sooner or later depending on flying style. This means a complete loss of throttle!
Read about motor amp draw here.

- Add a receiver battery or a BEC/UBEC (except V4) as the ESC's BEC is not capable of handling the numerous servos of this plane. Failure to do so will eventually cause the BEC to blow which will result in total loss of control!

- Reinforce or redo the hinging of at least the rudder, probably also the elevator. After a few flights, the foam hinges become loose. Make sure you check that before each flight and take corrective actions if you notice any instability in the hinges!

- Check the motor and add a collet to the backend of the shaft as there is (if at all) a little C-ring that holds the shaft in place! Work in progress, pictures coming up soon!

- Make sure the retracts lock in both up and especially down positions. Mine needed a lot of adjustments to achieve this, both on servo travel adjustment (via transmitter) and on the retract mechanism!
Read about it here, here and here.
Lots of pictures here.
Read about servo travel here.

- Make sure the "servo cable covers" (the foam pieces that cover the wiring channel) on the undersides of both wings are glued in place and hold tight as these covers are the only part that hold the central carbon fibre rod in place. If these covers are loose, the wings will break off in flight!!! Work in progress, pictures coming up soon!

- The manual suggests that you glue the tail to the fuselage instead of only using the screws. I strongly recommend that you follow that advice. I used PU-glue (Gorilla glue) for that, but Epoxy should work as well.



Should-dos:

- Get a larger 4S battery that can handle the amp draw. The stock 2200mAh 20C has a maximum (theoretical) output of 44A, which will stress it a lot at full throttle. You will get better battery performance and lifetime if you take 3000mAh or greater capacities. The plane is large and strong enough to hold any 4S battery up to 5000mAh

- Reinforce the retract strut housings, especially if your plane is heavier than normal do to your mods

- Reinforce your wings either by the use of tape on the underside or by replacing the glas fibre struts (on V3 and V4) by carbon fibre struts which are more stiff. Work in progress, pictures coming up soon!

- Main gear can be raked forward which helps with the planes tendency to nose over when on ground Work in progress, pictures coming up soon!

- Tailgear strut can be shortened and reinforced (retractable tailwheel only). This helps both with the nosing over issue as well as with bending or breaking tailwheel struts.
Read about it here.

- Cut open the cowling below the spinner to have a cooling airflow around the electric components, especially motor and ESC.
Pictures of motor and cutout here. Read about the mod here.

- Install spring-mounted oleo struts to reduce load on the main gears. Most probably these struts will be heavier than the stock ones, which results in the need for stronger retract servos like the Turnigy 380MAX MG (log in to get a price around $15 rather than $26.50) Work in progress, pictures coming up soon!

- Adjust respectively bend the elevator linkage so there is less friction at the end of the linkage guide tubes. From the factory the linkages are forced into a curve to reach the elevator horns. Just bend the linkages outward at the guide tube exits and then inward again towards the elevator control horns. Use a pair of pliers for this to get exact bends. Consider the travel of the linkage rod when elevator is deflected down. Work in progress, pictures coming up soon!



Can-dos:

- Either install the retractable tailwheel or - if you have got the right version - make the tailwheel retract that already came with the plane work.
Read about it here and here.
See how to turn the mechanism around and get it to work here

- Get a new, more scale cockpit hood

- At the same moment get a better looking pilot as the stock one is ugly

- Both mods (canopy&pilot) are described in this post by Tom Hunt
Last edited by Beltpilot; Mar 01, 2013 at 05:35 PM.
Sign up now
to remove ads between posts
May 17, 2010, 01:37 PM
Registered User

FMS Mustang


I have found the forum on the FMS Mustang very helpful and I'm looking forward to your "coming up next"!! I've recently obtained my Kit;I believe it is Version 4 as it is fitted with a 50amp ESC. It appears however that I am minus the two machine screws and nuts for attaching the landing gear, unless they have changed it to 4 very small screws, which I have in the box but no idea what else they could be for. Can you help me with this query ? I've had to send you this message to you personaly because I not able, for some reason, to post it to the Forum. Kind regards, Eric.
May 18, 2010, 01:05 AM
Wilde Sau
Beltpilot's Avatar
Thread OP
Hi Eric,

on my plane, there are no nuts for attaching the landing gear, only two small screws each that are self winding and fit the holes just tight.
If your screws fit into the holes of the strut mounts, than that is what they are for. However I wil crosscheck the manual later today.

Best regards,
Bernhard
May 18, 2010, 02:51 AM
Registered User

fms mustang


Thanks for your quick resonse Bernhard. The manual refers to long screws and nuts for attaching the LG but the small grub like screws that you have described are the same as the ones I have in the Kit. So FMS must have upgraded them as well!! Thanks again, Eric.
May 18, 2010, 05:19 PM
Wilde Sau
Beltpilot's Avatar
Thread OP
Sorry, I cannot check my manual until next week. I really wonder what FMS is showing in there (V3)
May 21, 2010, 10:11 AM
Always Fly Two Mistakes High!
RGS2010's Avatar

Retracts on v.4


Quote:
Originally Posted by Beltpilot
V4: 4S setup; 600kV motor; 50A ESC, additional BEC, flaps&retracts out of the box, tailwheel on this one is slightly modified from V3, still not retractable; now has other foamplugs at the former retractable tailwheel location so it can not be modded to that tail retract as easy; reinforced wings; also available in yellow "Marie" scheme; latest version
Can-dos:
Coming up next...
My version 4 has everything you noted but NOT flaps out of the box. It has servo tray and flap is almost cut out but I didn't want anyone to think it had ready-to-go flaps, or at least mine didn't.

Russ
May 24, 2010, 03:09 AM
Wilde Sau
Beltpilot's Avatar
Thread OP
Ok, thank you very much.
FMS seems to be a bit unconsistent about how they are equipping their versions.
Jun 01, 2010, 06:05 PM
Wilde Sau
Beltpilot's Avatar
Thread OP
Quote:
Originally Posted by ericrw
Thanks for your quick resonse Bernhard. The manual refers to long screws and nuts for attaching the LG but the small grub like screws that you have described are the same as the ones I have in the Kit. So FMS must have upgraded them as well!! Thanks again, Eric.
In my manual, there are no long screws and nuts shown. Only grub screws...
Aug 27, 2011, 07:13 AM
Registered User
All good about the airflow vent you opened up....where does it exit. I looked into this on mine and cannot find a place to open up in the back to get airflow through the plane?
Aug 28, 2011, 05:56 PM
Wilde Sau
Beltpilot's Avatar
Thread OP
My air exit is the tailgear bay, I have version 2 that had the mechanically retractable tailgear...


Quick Reply
Message:
Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion FMS P-51D to P-51B conversion Tom Hunt Electric Warbirds 237 Nov 13, 2015 11:49 AM
Question Airfield(FMS) P-51 or Parkzone P-51? stangflyer Electric Plane Talk 9 Apr 21, 2010 07:17 PM
Download New ParkZone P-51D BL (brushless) for CV/FMS ggunners Simulators 1 May 14, 2009 06:20 PM