Official FMS 1400mm P-51D V8 Thread

[Grossman56]

I hear you there Wrongroad, I've got plenty of 4s between the 4000's and the 3600's that I'd rather use and put money into other things. Now, what I haven't tried is using the 4000's in the Mustang. To my way of thinking, I'd just gain more flight time with a marginal increase in weight. Am I right in this and if you've tried it, I'd be interested to know if you changed the battery position slightly or was it that much of a difference.
Yep, the bolt pattern on the back of the 650kv is different than the 580kv. You could possibly drill it out, but its one of those pita things where its so close, but no cigar!
I guess the wise thing to do, and maybe I'll heed my own advice here, is to order a couple with the next order and to have a couple of spares and then remember to order one with each motor.
By the way, I hate to change the subject, but has anyone tried flite metal??

Grossman56

[xviper]

Actually, going from a 650kv motor on 4s to a 550kv motor on 6s is a difference of nearly 3000 max rpm. That's a lot in terms of %rpm increase. I'm still going to give the 650 motor a try when it gets here. I'm just hoping to be able to go back to the 4-blade prop and achieve a satisfactory level of performance (which the stock 540 or even 580 motors don't achieve for me).

[OV10]

Now, what I haven't tried is using the 4000's in the Mustang. To my way of thinking, I'd just gain more flight time with a marginal increase in weight. Am I right in this and if you've tried it, I'd be interested to know if you changed the battery position slightly or was it that much of a difference.

Hello Dan,
Almost my whole fleet uses 4000's including both the FMS and FW stangs. As you said, there is a marginal increase in weight which is offset by a slight shift aft of the battery to keep the CG correct and you do gain some extra flight time with the larger capacity battery. The very interesting aspect about the P-51 is that the CG envelope range is a lot more forgiving than other 1/8 scale warbirds.
Best regards,

[Mizer67]

G'day Mizer,
Hope this clears up what I am getting at.
Regards and respect
Daryl

Yes, I suppose I wasn't following.

On 4S, the 650kv is the ticket. I'm really pleased with that motor on 4S in my P-40B. While I'd like a little more top end speed, it's great all around and keeps the all-up weight lighter.

On 5S or 6S, the 550kv is the ticket, but you have to have the batts. to go with or it is significantly more expensive route to go.

[Dewey H Lee]

Hey Alpha I just have one quick question. I noticed that MOTION is out of all the P51 ARFs and was wondering if they would be back in stock any time soon or would they be discontinued.

[Grossman56]

Thanks Charlie, good to know as my little incident last Monday also took a 3600 to the grave with it as well. The battery is still holding a charge, but the butt end of it (which was closest to the nose) got a little crumpled in the crash, so now its relegated to the bench, leaving me with 5x3600s. I have 2x4000s that I got for the P40, so its good news that they can be used in the Mustangs as well.

Grossman56

[Grossman56]

FW Iron Ass is discontinued, but as for everything else, certain color schemes have gone, but the planes themselves are available, what were you looking for?

Grossman56

[Dewey H Lee]

Hey Gman. I was referring to the 1450 kits. I've noticed that MOTION list them as ARFs. There are 3 on page 3 in wardirds section I was interested in purchasing and then putting my own electronics in. Thanks

[Dewey H Lee]

Sorry that was 2 on page 3 and the red tail on page 4.

[KiwiRod]

I have a zippy 4000 4s 20c and have added 30grams of stick on mag wheel weights to the front end of it and it's pushed hard up into the nose to achieve CG.

[Grossman56]

Ah, the kit form, yeah, I noticed that too, they dropped those for some reason. Guess you could do it by ordering spare parts, but I don't know how the price would work out.
I see your point though, That's what I'm in the process of doing since the FW Mustang lawn darted, I just ordered all the foam parts and will use the old electronics sans the receiver as I don't trust the old one.

Grossman56

[KiwiRod]

What c rating on batteries are you guys using? I'm going to pick a couple up at the weekend and can get 20 or 30 c and am currently using 20c. I'm thinking 30 c is more peppy but don't know if it's necessary as the 20c I'm running is ok

Rod

[fhhuber]

20C is really all you NEED. I've run a 5000 watt EDF on 12S 4400 mah 20C rated. Actually pulling closer to 25C peak...

Most non-EDF flying we don't pull even close to 20C. The slight difference in power due to the lower internal resistance of a higher C rating is hard to measure with a wattmeter.

[wrongroad]

G'day gang,
Took my Duchess out for a day of flying yesterday and I was trying to get her to her one hundred flights but fell one short when one of the bearings let go in the motor during the 99th flight. The overload took care of the battery as well and it looks like a puffer fish now and most likely it is cactus.
It is not often that one has a fair dinkum dead stick with our machines but this was one and I was a long way out to boot.
I did not lower the gear until I was sure that I would make the runway as an out landing at our field is not pretty. It is a serious cow paddock.
I have spare bearings but going on my attempt to see how long the original parts lasted....based on one motor, the FMS 580kv motor lasts 98 flight to fail on flight 99. :p
Of course basing anything of a test unit of one is open for argument:D
The big 100 next Sunday now and that will put all my Mustangs with over 100 flights. Three 'Stangs, three hundred sorties without loss and nine kills between them. [I love 'shooting down' unsuspecting Cubs and Bixlers and Zeros...if it aint got a star and bar, it is fair game!]
Time for bed blokes.
Regards and respect
Daryl

[OV10]

I love 'shooting down' unsuspecting Cubs and Bixlers and Zeros...if it aint got a star and bar, it is fair game!
Time for bed blokes.
Regards and respect
Daryl

Hello Daryl,
Couldn't agree more!!. When ever someone at the club does a showNtell of a non warbird airframe, another warbird pilot in the club and myself look at each other and say "TARGETS" :p
Best regards,

[Shirty]

What c rating on batteries are you guys using? I'm going to pick a couple up at the weekend and can get 20 or 30 c and am currently using 20c. I'm thinking 30 c is more peppy but don't know if it's necessary as the 20c I'm running is ok

Rod

I use 30-40c in these personally, though 20-25c is sufficient. I much prefer a higher c rating (specially with light 3D foamies where it is more noticable), but for warbirds it's not a biggie as the gains are slight. :)

[Dewey H Lee]

Congrats on the 298 flights. Very impressive. I guess that could be rated in car miles at least 100,000 each. Shows good maintenance practices also. Great work.

[KiwiRod]

Thanks Shirty. Looks like I'm a bit limited here at present for what I can get. I'm heading to the U.S. later in the year so will pick up some higher rated ones over there.
It's great to be able to get info like this from you guys, I appreciate the help!

Rod

[wrongroad]

G'day Rod,
Will you be taking orders???????:D
I am not sure how the airline will react to four tonnes of LIPOS on board:p
I have not had time to check out the motor issues in DA yet as, by the time I am getting home from work it almost dark. These eleven hour days are paying well but, boy, am I tired.
I did not think I would would get to be 53 and be working so damn hard. I thought I was smarter than that.....apparently not!
At least I know I am not a bludger.:cool:
Hope you have weather for the weekend.
Regards and respect
Daryl

[olwarbirds]

G-man thats impressive brother, Congrats.... I wouldnt trust that lipo either !
Rod you have been getting some good advice here for sure....but I am going to disagree with the C rating...depending on manufacturer and which series, lipo battery c ratings can really become an issue. A 4S 4000mah 20c only gives you 80 amps output, if you go above that you could experience a brown out aka loss of power to the reciever. The FMS 650kv with stock 4 blade on 4S does show spikes above 90amps. So two reasons I would go with a 30c, first more available spike/burst amperage, secondly longer battery life. So for me getting more life is worth the few dollars more and a bit more insurance too. Most of my lipos are 40c and up. Alot of them I have been using for close to 3 years. I am a bit anal about storage voltages and how I handle my lipos too...happy flyn guys.. DJ