TOPIC:

Hi,

Decided to start a topic about how different brand servos have interchangeable servo horns.
Mostly because I never seem to remember myself...
And there isn't a complete overview on the net that I could easily find.

Would be a great source of info if the members share their knowledge here. I'll start with what I know...
Don't think polarity is an issue anymore nowadays but we might extend to connector type?

M2.6 x 10 screw - and identical servo horn mesh
Tamiya
Futaba
Hitec
GWS

M3 x 10 screw - and identical servo horn mesh
Acoms
Sanwa

I wouldn't fancy that myself! I find most of the modern popular makes appear to be interchangeable, some can be a little tight/loose & screw holes can be enlarged. What I do find infuriating though, is the way the arm hole pitches always seem to be either side of the position you actually want, or the supplied arm isn't quite long enough (Not so much of an issue if you've moved away from MSCs)

eddrick wrote:

...What I do find infuriating though, is the way the arm hole pitches always seem to be either side of the position you actually want...

That winds me up too - & I've never found a satisfactory answer to it ... you can either use up pretty much all of the TX trim adjustment & have the servo saver straight, or have the TX trim tab correct and the servo saver on the slant & make the steering straight by ajusting the arm length ... bearing in mind just about every Tamiya has asymetric steering rod arms & therefore different amounts of steering lock on each side neither method is a good one

Great idea here is something to read and than you can sort it out for us

but can say that hitec and tamiya aint the same fit

found this on rctech.net VladVY

Servo output shafts

23 tooth spline - Sanwa / Airtronics / KO / JR
24 tooth spline - Hitec
25 tooth spline - Futaba / TT / ACE / HPI

+

Spline (teeth (gear Mesh) on Servo's output shaft)
==================
23 teeth on the spline
-Sanwa
-Airtronics
-KO Propo
-JR Propo
-Graupner
-Multiplex
-Volz
-Cox
==================
24 teeth on the spline
-Hitec
-Hobbico
-Tower (System 2000)
==================
25 teeth on the spline
-Futaba
-Keil
-FMA
-Cirrus
-Vortex
-Duratrax
-HPI
-Tamiya
-Tower (System 3000)
-Traxxas
-Orion

servo spline teeth and size are a thing that can drive one crazy

This guy wrote a lot on the subject - Alan Tong
here are some links
rcuniverse
rcgroups
Servo Horn Arm Spline Count and Inter Brand Compatibility
his homepage

Thanks a bunch, that's probably about all the info we'll need.
I'll see if I can make an overview of it...
But I could swear I took a Tamiya horn off a Hitec yesterday. That's why I added it. Gonna sort that out.

Yep, I've had a Tamiya servo saver on a Hitec micro servo, & a Bycmo one. Both Acoms & Futaba (Depending on which version) fit on Traxxas TRX1.5 & Shengqi Hummer. Hextronic HX12k high torque seros can only use their own horns - the spindle is a bigger diameter, despite the servo being standard size. I've also got one of thos blue sub-micro servos (That are always all over Ebay) & again, despite its size, the spindle is standard & later Acoms/Futaba fit it. I think spindle diameter might need to be noted on the list too (Just where different to standard)

well as tamiya has three different servo saver horns it might well be that one of these fits another brand. horn 1 small sanwa, horn 2 sanwa/acoms horn 3 tamiya/futaba.

I can't say I've ever had one of these servo saver kits that hasn't fitted, but I tend not to look at the markings & just use whatever fits the servo I have in my hand

Oh my, seems like I've stepped into a bit of a swamp.
But a good overview of all this would definitely be a great source of info. I'll give it a go...
Might take a few stages though.

Btw - Q1 is the one I took off the Hitec.

oh a swamp it is

now this is a cool infosite :
Hitec servo splines
Futaba Servo Splines