Official FMS 1400mm P-51D V8 Thread

[WintrSol]

I don't know if this has been covered before, but I found this out yesterday. If you have the older style multiport connector (http://www.motionrc.com/fms-1450mm-a...nector-part-2/), you should pop the shell off and inspect the wires. Mine shorted out the power and ground leads, intermittently, and was probably the cause of a bad crash. I had blamed the crash on a damaged CC ESC, since it reported it had restarted twice during the fatal flight. After replacing the fuselage, wing, cockpit, motor shaft, and ESC, I was preparing to fly, and while checking the model out, the power at the receiver went out, then came back on. So, I didn't fly it that day. Yesterday, I was making measurements of the power system, looking for the problem, and discovered that when I moved that connector, the power went out and came back on. With the shell off, I could see that the gap from the solder joint to the insulation was rather wide, allowing the wires to flex and meet. I checked out my spare connector, and it is better made, so I replaced the defective one. Assembly problems are probably the reason for the newer design, but maybe that one could fail, too; worth checking, anyway.

[OV10]

Hello WintrSol,
Thanx for bringing that to our attention. I've got a handful of that style multiport in various birds including my Seagull Skyraider. Am definitely putting that bird on my checklist for that connector cause I certainly don't want to lose it for that failure mode.
Best regards,

[WintrSol]

Even though the replacement was better made, I added some circuit-safe RTV, squeezing it between the wires, to make sure it doesn't fail over time. Looking at the photo of the newer style connector, I suspect it could develop the same problem; worth checking them, too.

[Grossman56]

Well, the new parts are here and the Flite Metal is here....and now I have to work 12 hour days right through Saturday. It's going to be sweet though. I'll keep a running documentary on the flite metal, so watch for it .

Grossman56

[olwarbirds]

Wintrsol, tks and nice idea for the fix...could you post pics of the prob and what you did please.
Gman looking forward to seeing what you do..I have been wanting to try that and hoping to get this look

[KiwiRod]

Hey Daryl, guess you guys have the same problem we do here. Seems that on the under side of the planet it's just hard work getting lipos sent out. DJ thanks for the update, I will try to find some higher c rated batteries. I believe the guy I'm getting some off can get them in for me so will see how that works out. It's hard getting flight time up when you've just got the 1 battery. Do you "run in" your lipos? I've had guys suggest that they are used sparingly for a start so they are cycled a few times before running them a big harder bug can't find the logic in that ( I'm not that electrickerally minded though...!) ...

Rod

[Shirty]

There's lots of different stuff on lipos, theories etc but I know one thing to be true. Don't run them down below 3.75 a cell and they'll last a lot longer. :)

[olwarbirds]

Rod, like my brother downunder Shirty said there is endless "Theories" about lipos....and 3.75 is the number, I try to never go below. A couple of proven "for me" practices ....use 3.8v per cell as the storage voltage...never charge a warm/hot lipo. .never leave lipos charged above the 3.80 per cell for extended periods of time...I always balance charge my lipos...I normally cycle my NEW lipos a couple of times before first use, this seems to keep them more balanced during first discharge...Spend the monies and get a good quality charger...If you have doubts about a lipo, dont use it. Get a field lipo tester, I always check my cell voltages before I use a lipo, this practice has saved me numerous times. Most important, handle lipos with respect for their potential danger is huge if you dont. Hope this helped and have fun.... DJ

[WintrSol]

Wintrsol, tks and nice idea for the fix...could you post pics of the prob and what you did please.

This is what the defective one looks like - note how the wires are exposed past the circuit board:

The 'good' one has very little wire exposed, and the insulation almost touches the edge of the circuit board, so the wires flex very little. I just pushed some RTV between the wires, so it will harden and keep them from flexing. You can't see where the insulation ends, but it doesn't matter - the RTV is solidly between and over the wires:

[xviper]

I just ordered the 650kv motor myself. I wish to go back to 4s. I did not order any motor mount. Are you talking about the X-mount? I've got both the stock P-51 X-mount and the Olympus 550kv motor X-mount. Is the "motor mount" for the P-40 motor different from these two?

My P-40 650kv motor arrived today and I'm pleased to say that the Olympus 550kv motor X-mount fits perfectly. In fact, both motors are designated "4258". So those who wish to go from the Olympus 6s motor to the P-40 4s motor can simply transfer the X-mount.

[olwarbirds]

Wintrsol, tks ! nice work brother. X, tks and I will add that info to the first page, along with WintrSol circuit board fix....again tks much, this is what makes this forum rock :)

I am planning on using liquid electrical tape on my circuit boards.

[Grossman56]

My P-40 650kv motor arrived today and I'm pleased to say that the Olympus 550kv motor X-mount fits perfectly. In fact, both motors are designated "4258". So those who wish to go from the Olympus 6s motor to the P-40 4s motor can simply transfer the X-mount.

Good to know Viper, I know I was disappointed when I couldn't fit it on the 580 motor mount, so any info about what does and doesn't work is very helpful

Grossman56

[xviper]

We've got a few days of rain and overcast so I'm taking advantage of it to do some mods to a few of my planes. I'll throw the 650kv motor on the P-51 today and fly it on 4s. It'll be a good comparison to the 6s set up with the Olympus motor.

[wrongroad]

G'day gang,
Viper, I did not know that you moved house next to me. Or it might be the fact that right now it is raining and blowing the dog off the chain so there was no flying for me today.
I woke at 0600 and looked out the window and went back to bed for a sleep in.
This afternoon I replaced the motor bearings in the 580 fitted to DA and tested the same in the drive way. No more growling noise.
The front bearing was really bad and had heaps of movement and was 'gritty' when I rolled it in my fingers.
The front bearing does take most of the heavy load so it was no surprise to me to see, feel and hear what I did.
I also took the time to replace the blue shrink wrapped landing gear sequencer with an older style six second unit that I had in my spare parts stock.
I was getting to the point where I was starting to mistrust the original unit.
My other other two Mustangs have the older style sequencer and have never missed a beat so it is logical to get the unreliable unit out before it lets me down. Even though I was trying to get the 100 flights up without changing any parts from out of the box. I nearly got there. I just thought that while I had to replace the bearings I may as well change the sequencer as well. All on 99 flights.
The funny thing is that all my P-51 have had to wait on 99 flights before getting to 100 up. At least I am consistent.
Regards and respect
Daryl

[Grossman56]

Hey guys, I can tell you that he DOES live almost directly north of me, so what ever Viper is getting is what we'll get in a couple of hours. Dang, and I moved away from Vancouver BC just to get away from the rain and clouds. Looks like it took it a couple of years but it found me. On top of that, its been nice in Vancouver.
NICE IN VANCOUVER!!!!
This is rainy season there.
Oh Well
started in on covering the FW mustang in Flite Metal yesterday. It really does have a sticky backing! and its not bad to work with, its time consuming. In one video I watched, the guy said to sand it with 320 wet/dry sand paper, don't do this unless you want to spend hours polishing it by hand. I have one half of the horizontal stab done and a couple more passes with Wenol (Left over from DC3 days) which by the way is a excellent metal polish and its waterbased which saved me so many polishing pads back in the day when I was working on the DC3. In hindsight, I should complain about a tiny horizontal stab, beats being up on scaffolding.


Grossman56

[xviper]

Wrongroad, It's almost like our weather this past season has been scrambled. The winter has been particularly mild and dry. We flew almost every day in what we call "winter mode" - anytime the temp was -2C or above, we put on the double socks, boots, insulated pants, several layers of upper wear, big woolly hat and thin leather gloves or fingerless mitts and we go fly. The weather only turned fowl a couple of days ago and we should get it for a couple days more, then back to the nice weather.
Grossman, Vancouver has been my all time favorite road trip holiday but I haven't done that for a couple of years now that I don't participate in the Washington Honda S2000 annual drives anymore. Vancouver has been getting a lot of wet lately. Last weekend, a flying budding went out there for a golf event and he got dumped on. When I saw him last week, he was still drying out and I think he shrunk a couple of sizes. Usually, the wet gets stopped by the Rockies and we get dry by the time the air mass gets to us.
It's been a very productive few days. P-51 ready to go with new motor. Eurofighter ready to go with upgraded fan/motor, SebArt Mig 29 ready to go with new Rx (old AR8000 was causing a servo to twitch badly). Next, repair a couple of sailplanes and a flying wing. Awaiting new Dynam C-118 "Dusty".

[olwarbirds]

Gman, how hard do you think doing panel lines then adding rivets is going to be using that flitemetal ?

[Sky Wolf]

Grossman, I am really looking forward to seeing how your P-51 turns out. I've been considering covering my P-51 in FliteMetal as well. Still toying with whether or not I have the patience to get started and see it all the way through.

Any pics of your progress yet?

[Grossman56]

Panel lines are super easy, I just use the supplied plastic ruler and run along the existing ones, works great. They also include a dress pattern marker that will put rivets on in seconds. My eyes are a little achy today from staring at it all day yesterday. Its pretty easy actually, check out 'Goodbye to Old Iron Ass' for a complete blow by blow.

Grossman56

[Sky Wolf]

That's looking awesome Grossman! Keep up the great work. Can't wait to see the finished product...but take your time.