The Definitive Servo Testing thread (Brands, Discussion)

[Carlisler]

I am glad that I am on the learning curve here with ya Joe!!!

Unlike me, I believe there are a lot of guys here using the units.
Maybe a new set of tests with one or both of these types of machines may be in order.
Do you agree?


Your explanation helped yes, Thank You.

I did not know that you could use 3 and 4S batts on these things tho. Thats Awesome!

[Alberta1]

Thanks for all the dedicated testing. It is surprising how some servos play out during a controlled test. Thanks for sharing.

[JoeT]

I am glad that I am on the learning curve here with ya Joe!!!

Unlike me, I believe there are a lot of guys here using the units.
Maybe a new set of tests with one or both of these types of machines may be in order.
Do you agree?


Your explanation helped yes, Thank You.

I did not know that you could use 3 and 4S batts on these things tho. Thats Awesome!

Hi Scott,

Not all units can take 3S or 4S as a power source. Off the top of my head, CB400, Booma Smart Bus Extreme, and a couple of other off brands (RCCSKJ).
Plus there are a couple of popular types of voltage regulators, analog using the tried and true fashion of resitors heat sinks and capacitors, the other one is switching type which involves a bit more complicated circuitry. Both have their plusses and minuses.

[Cosmith]

Nice to see the Hitec's out performing their specs. I love my 7954s. I'm a little disappointed in the MKS and Savox results though. Especially seeing the HV777s making less torque than the 7954s at a price, weight and size premium. The 1270tg has always seemed too good to be true to me so I'm not too surprised.

Now what I wonder is how consistently these servos are manufactured...wonder what the variance would be if you were too test a half dozen of the same model from different batches.

[JoeT]

Nice to see the Hitec's out performing their specs. I love my 7954s. I'm a little disappointed in the MKS and Savox results though. Especially seeing the HV777s making less torque than the 7954s at a price, weight and size premium. The 1270tg has always seemed too good to be true to me so I'm not too surprised.

Now what I wonder is how consistently these servos are manufactured...wonder what the variance would be if you were too test a half dozen of the same model from different batches.

I'm happy to test the same servos from different batches, I'm also happy to lend out the rig so people can test their stuff.

I'll be testing some more servos this evening and posting, I've got some odds and ends laying around, might as well. Steve and Ed are bringing over some Rockstars and others this afternoon too.

[JoeT]

I added a chart right from the spreadsheet on the first post. More information / data and a comparison that does Oz in / Dollar comparison. When compared side by side, the Savox 2290SG is quite a beast of a servo too, with a really good price performance factor, at 2.99 Oz / Dollar.

[JoeT]

This one does not center reliably, then again, I'm using a 13" pointer. The video shows some undershoot and overshoot from center.

Brand: Trackstar TS0900
Test Voltage under load: 7.90
Stable Amperage at stall: 4.41 Amps
Max Torque: 299 Oz In
Price: $36.40 USD or $50.96 CDN

https://hobbyking.com/en_us/tracksta...___store=en_us

Heeeres the video: https://youtu.be/PxE4EoAkhSw

[itizme]

Good job Joe

looks like the Pornstar did better than I thought, 300 ounces and almost centers, not bad.

[JoeT]

Good job Joe

looks like the Pornstar did better than I thought, 300 ounces and almost centers, not bad.

hahahahah yeah, Almost!!! Chika bow wow..

[Jwl]

Yes, they are rated at 3 amps. At 250 volts!

Which, doing the math, translates to over 90 amps at 8 volts. (3 amps X 250 volts = 750 watts ÷ 8 volts = 93.75 amps.)

So, nothing to worry about.

They are known as "dupont" connectors. Here's the specs on them: http://images02.cdn86.net/kps01/M00/...CEYVF0Q563.pdf

No, No, No!!!!!

Sorry Jim. Current is current. The rating of the pin is 3A and it does not matter what is "pushing" the current. It can handle up to 250V pushing. You are not dropping 250V across the connector at 3A for a power rating of 750W. The pin contact is rated at 20 milliohms. Therefore, you are dropping 60 millivolts at 3A across the connector regardless of the voltage. If you have 8V as the supply, than the load sees 7.94V. If you have a 250V supply, the load sees 249.94V The load determines the current necessary from the supply. Anything in between the supply and load needs to rated to handle the current the load needs to operate (wire, connectors, housings, etc). If the voltage is high on the load causing too much current to be safely drawn (load power=Watts), then a decrease of the supply voltage is necessary to decrease the current sourced (load Watts decreases). But in turn, this causes less work to be performed because the power is correspondingly reduced. Therefore, less torque.