1450 FMS P51 Motor upgrade

[Pheonix]

RE: 1450 FMS P51 Motor upgrade

Thanks and I will recheck mine.

[jetlag]

RE: 1450 FMS P51 Motor upgrade

Flies great and much more linear than stock esc

[Konrad]

RE: 1450 FMS P51 Motor upgrade

Flies great and much more linear than stock esc

Good to hear. But I thought that the FMS ESC was a rebranded ZTW ESC.

I thought that the ZTW Gecko ESC was basically their Mantis series but with a much larger BEC. Aimed at the Castle Creation Talon series ESC

I will say that the ZTW ESCs have some of the best throttle response. They make good 3D ESC. One of the worst for throttle response is the E-flite  ESC.

Maybe Motion RC can set my perception straight without alienating a vendor.

[RCcruz]

RE: 1450 FMS P51 Motor upgrade

Jetlag glad you got it going , from wut I'm reading. If not hope you do . Hope to see it flying on YouTube. I'm running stock esc dnt wunt to go thru this trouble. I have no heat issues. I run 8 mins straight 3/4 throttle with no issues. Have flown mine 6 times already

[Grossman56]

RE: 1450 FMS P51 Motor upgrade

Have had my Big Beautiful Doll up 7 times now and what a great plane.  I have the stock motor/ESC and its great for me.  I think when I'm ready for more speed, I'll try the zip tie trick, see what happens.  Also, I've noticed that the prop on my Freewing P51 has fatter blades, maybe a little more aggressive since the FW Mustang weighs more than the FMS due to the sound system.  I'm wondering if anyone has tried swapping props on the FMS Mustang?

Grossman56

[jetlag]

RE: 1450 FMS P51 Motor upgrade

Flies great and much more linear than stock esc

Good to hear. But I thought that the FMS ESC was a rebranded ZTW ESC.

I thought that the ZTW Gecko ESC was basically their Mantis series but with a much larger BEC. Aimed at the Castle Creation Talon series ESC

I will say that the ZTW ESCs have some of the best throttle response. They make good 3D ESC. One of the worst for throttle response is the E-flite  ESC.

Maybe Motion RC can set my perception straight without alienating a vendor.

Could be but actually in reading the fms esc manual is what tipped me off about the start up rate. The Gecko has Aluminum heat ribbing and a few other goodies im not exactly sure on. Ive ordered a program card so ill try to hook it up to fms esc and see if your correct
[hr]

Have had my Big Beautiful Doll up 7 times now and what a great plane.  I have the stock motor/ESC and its great for me.  I think when I'm ready for more speed, I'll try the zip tie trick, see what happens.  Also, I've noticed that the prop on my Freewing P51 has fatter blades, maybe a little more aggressive since the FW Mustang weighs more than the FMS due to the sound system.  I'm wondering if anyone has tried swapping props on the FMS Mustang?

Grossman56

What exactly is this zip tie trick

[Konrad]

RE: 1450 FMS P51 Motor upgrade

The wire tie is used to change the angle at which the blades are mounted to the spinner back plate.
Putting the wire tie under the leading edges of the prop blades adds about 50mm (2") to the prop pitch. This is a lot! I think the FMS prop stock has around 8" of pitch. With the wire ties it can go to 10" of pitch. This will up the amp draw significantly. One might safely get away with it using the low KV motor. But as the prop absorbs power by the cube of the RPM. Adding this extra pitch and a higher KV motor might overload the power system. If you try this do use an amp meter and check your motor temps after a 2 minute flight.


As to ZTW and FMS esc there is a relationship. Don't know if all firmware is compatible between the ESCs and programing cards.
http://www.motionrc.com/ztw-air-esc-programming-card-for-fms-and-rochobby-escs/


That heat sink is there to help dissipate the heat from the large BEC. Nice feature that adds a great deal to one's pieces of mind, even if it adds weight.

P.S.
I see that the ZTW OEM brand ESC is called Beatles

[Grossman56]

RE: 1450 FMS P51 Motor upgrade

yes, that's true, there is a thread where one of the guys did a zip tie thickness/prop pitch ratio.  So you knew how much you were increasing the pitch by the thickness of the zip tie.
I'll have to see if I can find it again.  I should know by now that I should print things like that out when I see them, but what can I say, old guy brains I guess!

Grossman56

[jetlag]

RE: 1450 FMS P51 Motor upgrade

Ptop pitch question, if you have as an example 12 x 8 prop does it means your vehicle will travel 8" in 1 foot?

[Pheonix]

RE: 1450 FMS P51 Motor upgrade

There was a good article about a year ago (January I believe) in Model Aviation on the aerodynamics of the zip ties using the FMS P-51 Mustang. I simply use the ties from Radio Shack to increase the prop pitch. I used on my Iron Ass and there was a noticeable difference in performance, as there was with other planes that fit the modifications.

[Lon]

RE: 1450 FMS P51 Motor upgrade

There was a good article about a year ago (January I believe) in Model Aviation on the aerodynamics of the zip ties using the FMS P-51 Mustang.  I simply use the ties from Radio Shack to increase the prop pitch.  I used on my Iron Ass and there was a noticeable difference in performance, as there was with other planes that fit the modifications.

I use the Mod on my Iron Ass too. Yes, significant difference. 

[Konrad]

RE: 1450 FMS P51 Motor upgrade

Ptop pitch question, if you have as an example 12 x 8 prop does it means your vehicle will travel 8" in 1 foot?

NO

For our model airplanes we generally define a prop by its diameter (the first number) then its pitch (the second number) and some times the there will be this "(3)". The number in the parenthesis is the number of blade of the prop. No designation by default means 2 bladed.

OK the "Diameter" is what defines the prop disk area. It is usually measured tip to tip (actually it should be measured as a radius x 2).

"Pitch" is the distance the prop would move forward with no slip in a fluid in one revolution.  

So a 12x8 prop has blades that are 6 inches long (center to tip) and would move forward 8" for each revolution.  So going from an  8" pitch prop to a 10" would result in the model going 25% faster for the same rpm. (this isn't totally true  but close enough for this discussion)

We are ignoring the concept of power. But let me state that the ability of a 2 bladed prop to absorb power (standing still) is 
Power= K x D(4th power) x P x RPM(3power)
(K) is a constant to describe things like blade shape (aspect ratio), blade area airfoil etc. For our toys 1.11 to 1.31 works well. 

BTW, Power is in watts, D and P are in feet and RPM is in thousands

I hope this helps,
Konrad

[Grossman56]

RE: 1450 FMS P51 Motor upgrade

Thanks Konrad, great to have guys like you around to explain these things to us old guys.

Have to print that one

Grossman56

[Konrad]

RE: 1450 FMS P51 Motor upgrade

Thanks Konrad, great to have guys like you around to explain these things to us old guys.

Have to print that one

Grossman56

Thank you,

I'm not sure it is worth printing out. I got it from Bob Boucher's book The Electric Motor Handbook.

Now all us old guys need to look out  and help each other. And if some new guys learn a thing or two so much the better.