Futaba S9254 / S9252 question

Detailed Specifications

Control System: +Pulse Width Control 1520usec Neutral Required Pulse: 3-5 Volt Peak to Peak Square Wave Operating Voltage: 4.8 Volts Only Operating Temperature Range: -20 to +60 Degree C Operating Speed (4.8V): 0.08sec/60 degrees at no load Stall Torque (4.8V): 28 oz/in. (2.0kg.cm) Operating Angle: 45 Deg. one side pulse traveling 400usec 360 Modifiable: Yes Direction: Counter Clockwise/Pulse Traveling 1520-1900usec Motor Type: Coreless Motor Potentiometer Drive: Indirect Drive Bearing Type: Dual Ball Bearing Gear Type: All Nylon Gears Connector Wire Length: 12" Dimensions: 1.6" x 0.8"x 1.4" (41 x 20 x 37mm) Weight: 1.7oz. (49g)

Detailed Specifications

Control System: +Pulse Width Control 1520usec Neutral Required Pulse: 3-5 Volt Peak to Peak Square Wave Operating Voltage: 4.8 Volts Only Operating Temperature Range: -20 to +60 Degree C Operating Speed (4.8V): 0.14sec/60 degrees at no load Stall Torque (4.8V): 92 oz/in. (5.5kg.cm) Operating Angle: 45 Deg. one side pulse traveling 400usec 360 Modifiable: Yes Direction: Counter Clockwise/Pulse Traveling 1520-1900usec Motor Type: Coreless Motor Potentiometer Drive: Indirect Drive Bearing Type: Dual Ball Bearing Gear Type: All Nylon Gears Connector Wire Length: 12" Dimensions: 1.6" x 0.8"x 1.5" (41 x 20 x 38mm) Weight: 1.8oz. (50g)

...snip....

Detailed spec.

Unfortunately I don't have any equipment that will allow me to discriminate between the 2 servo specs you posted. Details like 1 gramme difference in weight and 1 mm difference in height depend upon what you measure. The speed and torque ratings are just not viable to test either AFAICS. I also don't have any S9252s to hand so can't directly compare the two types. I read on Tower Hobbies website that the S9254 has a unique output spline pattern (this is offset somewhat by the fact that they recommend the S9253 accessory packet :-) does anyone here know what the difference is in this department ? Or failing that is there a difference in the servo internals ?

Thanks for your reply anyway though MK,

Seems to me even uncalibrated fingers should be able to distinguish between

Sure, if you had the two of them in front of you to compare the torque, you could tell, but i think he wants to know how to tell them apart by looking at them.

Boat hints at a good point though. If "Boo" applies some fundamental knowledge about torque and can use the web to look up the specs for the two servos in question, he *should* be able to test the servo he received to see which spec it is closest too.

If he can operate the servo then he can time how fast it moves and how much torque it creates. If he cannot operate the servo then how is it going to fly his plane?!?

According to the table at those figures should be 47.2 and 92 oz-in ?

But...

...see my post below :

Unfortunately they are indistinmguishable :-)

Correct, and I don't think my original post was sufficiently clear, but I wanted to be able to positively identify the servos as being S9254, not merely to distinguish them from 9252s.

Anyway, I'm very grateful for the replies and obviously I don't blame anyone for not knowing what they look like inside.

I've since received a triplet of S9252s as well as my pair of S9254s and the two types are identical in external size, appearance and weight. I've been able to compare speeds and torques as suggested and the S9254s are definitely not S9252s as they are quicker and less strong (S9252s are monsters torquewise !).

Thanks again for the replies,

But it doesn't matter does it? You ordered the "weaker" of the 2 but you MAY have received the "stronger" of the 2, so you can't have lost out even if they ARE the "other" ones can you? If you want SPEED, then you've lost out a little bit, but as you've bought more than one, I'm thinking "not for your tail rotor have you bought them" so the SLIGHT less rapidity probably won't be noticed, but the extra strength could well come in handy.

I also don't have any S9252s to hand so can't

One has more torque, so it's a fair assumption that it's got a slightly more powerful motor, but I'm willing to bet that either will do the job although the stronger one will do it for longer.

But if he ordered the "54" which is the weaker of them, and he got the stronger "52" he's ahead of the game.

Well, the price difference is significant...

Anyway, I also ordered some '52s at the same time and having them side-by-side it's pretty easy to see which is quicker/stronger. I haven't taken them apart and they're visually and dimensionally identical but I'm pretty sure I've been sent the right bits.

Haven't seen a post by you for months btw, bin on holiday ? Or just taking time off of usenet ?

Hmm Rapidity............. is there such a word.......Hmm

SNIP Hmm Rapidity............. is there such a word.......Hmm

This URL gives you the definition.......

David