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cbdane · 10-09-2008, 06:43 PM

Quote:

Originally Posted by Mercuriell

The devil's in the detail and it all depends on how you define servo speed - I wouldn't be surprised if manufacturers set travel limits >60° to take into account acceleration time then measured the 60° sector once the servo had reached steady velocity - that doesn't seem a realistic test to me and I like the ability to incorporate the acceleration segment.

I agree, since in a typical flight, a lot of the movements are small and quick meaning that the servo is probably never getting out of the acceleration portion of the motion, i.e. never reaching peak linear rotational speed.

Finless · 10-09-2008, 07:06 PM

cbdane, whats is the possibility of me getting one for some of my own tests on servos?

This thing look great and I wonder why it has not really been done before?

Bob

fogger · 10-09-2008, 08:12 PM

cbdane, very cool , nice work.

another interesting test to add in the next firmware would be a back and forth test that measures the transition time for the servo to oscillate between two points "x" degrees apart for "y" settable cycles...

Funny you mention derivatives, that's what I'm learning (again, after 14 some odd years since the last time I "learned" it) in calc 1... I think the endpoints of the velocity curve should be "s" shaped though Jared

... It should start with zero slope, increase in slope until it hits a point of inflection at the same point in time that your acceleration curve hits a local maximum, (IE it should switch from concave up to concave down at that point) and then should level out to a constant vel. Correct me if I'm wrong though.

-Fog

Mercuriell · 10-10-2008, 05:07 AM

Quote:

Originally Posted by jared_of_atlanta

8717 please :-)

Here you go

Finless · 10-10-2008, 05:16 AM

On 8V

Will this run on 8V?

Bob

Mercuriell · 10-10-2008, 05:32 AM

Quote:

Originally Posted by Finless

On 8V

Will this run on 8V?

Bob

In Canada in winter I believe Bob

- seriously I think there's a whole swag of servos able to be run on 8V esp those with aluminium heatsinks - my hunch is that it's heat dissipation from the motor gonna be the rate limiting step here and flights of 8 mins with cycles of <0.5 Hz are probably gonna be OK - our 7 yr old club stick-banging protege is onto about his 10th flight now on the T700 with Align DS620s on 8V and the servos are hardly warm - I'd guess around 45°C

Assuming Brent's tester is the real deal (and I'm quite sure it is

) there's a whole load of work to be done in and out of installations to check out various aspects of these servos !

Finless · 10-10-2008, 05:36 AM

Yes and no John... It depends on the chips used in the amp board. Take the servo apart and look. MOST chips these days run in 12V but older stuff doesn't! If you check the circuits components and they are OK for 12 THEN they may work and YES the motor is the next thing to worry about. The BLS servos handle this GREAT! They are brushless and thus voltage doesn't hurt them like a brushed motor!

Will this tester handle 8V?

Bob

Mercuriell · 10-10-2008, 05:50 AM

Quote:

Originally Posted by Finless

The BLS servos handle this GREAT! They are brushless and thus voltage doesn't hurt them like a brushed motor!

Will this tester handle 8V?

Bob

Brent says its good for 16V ! - I put 12V into an ALign servo yesterday by accident for about a second and althoug it smelt a bit char-grilled it seems to run good

I don't think it's so much a voltage prob with the motors but heat - the ALign servo ran OK up to 70°C but died pretty quick over 90 and I think the rotor just bound up in the magnets from heat expansion - lucky I didn't burn out the Servo Tester !

jared_of_atlanta · 10-10-2008, 06:32 AM

Are these all new servos? I think you should note that in the chart.
Futaba fan-boys claim that JR servos loose their center. Can you test this?

jared_of_atlanta · 10-10-2008, 06:35 AM

Quote:

Originally Posted by fogger

cbdane, very cool , nice work.

another interesting test to add in the next firmware would be a back and forth test that measures the transition time for the servo to oscillate between two points "x" degrees apart for "y" settable cycles...

Funny you mention derivatives, that's what I'm learning (again, after 14 some odd years since the last time I "learned" it) in calc 1... I think the endpoints of the velocity curve should be "s" shaped though Jared

... It should start with zero slope, increase in slope until it hits a point of inflection at the same point in time that your acceleration curve hits a local maximum, (IE it should switch from concave up to concave down at that point) and then should level out to a constant vel. Correct me if I'm wrong though.

-Fog

Yea I guess you're right.

Mercuriell · 10-10-2008, 06:54 AM

Quote:

Originally Posted by jared_of_atlanta

Are these all new servos? I think you should note that in the chart.
Futaba fan-boys claim that JR servos loose their center. Can you test this?

All new apart from the 9256 and 8717 which have had around 30 flights on my Stratus

Funky · 10-10-2008, 06:45 PM

Great videos

How much are these testers going to cost? I have a LOT of different servos to check

Grant_beltcp · 10-12-2008, 07:24 AM

Excellent, now you just need to add a simple torque tester plug in module for it

Tom Burgess · 10-15-2008, 07:58 AM

yes these test are all under no load. I guess we will see even higher temps with load?

uffe40 · 11-11-2008, 11:28 AM

Hi wonder if there are any news
Thanku
Uffe

Mercuriell · 11-19-2008, 03:11 PM

Quote:

Originally Posted by uffe40

Hi wonder if there are any news
Thanku
Uffe

I've been busy getting the fleet in flying order and dialling in the Logo 400 but plan to do some more under load tests soon - I think cbdane is checking out various manufacturers to see about production but if you want one and ask him nicely he may make one up for you

trickybit · 12-12-2008, 01:22 PM

I wish you would have beat on the S9257 with 6v to see if it held up.

Note the response from vendor is this post https://www.helifreak.com/showthread.php?t=107667

To wit, it can handle 6v if regulated, and 5.8v is "recommended."

Cool stuff. Thanks.
Jim

Finless · 12-12-2008, 01:52 PM

After going through 2 9257's running at 6V as a tail servo on my 500, I decided to use a drop down for the 3rd one. I started this way but pulled it for the heck of it to see. In the end the 9257 can run 6v for things like cyclic but with the duty cycle a tail servo gets in makes for a short life... My experience anyway....
Oh and this is WITH Chinese weight mod on the tail....

Bob

Mercuriell · 12-12-2008, 03:58 PM

That's useful experience Bob - that's pretty much the same experience I have with the 9254/6 - they will run at regulated "6V" but cark it after ~50 flights

ayash · 12-13-2008, 05:28 PM

MKS have a few interesting servos that aren't being talked about a lot.

MKS 9660 - a Futaba 9650 with Metal Gears & faster
MKS 9670 - a faster one less torque
MKS 8910 - seems like a perfect tail servo for the price.

Maybe they can be tested as well?

10-09-2008, 07:06 PM	#22 (permalink)
Finless Team Taco VP My HF Map location Join Date: Nov 2005	cbdane, whats is the possibility of me getting one for some of my own tests on servos? This thing look great and I wonder why it has not really been done before? Bob __________________ "Don't Taco My Pack Dude!" NEW Video Link -> Safety Video #1 Video Link -> CAUTION using powerful tools! Video Link -> How to CRASH TWICE in one flight! Video Link -> Don't Taco! Last edited by Finless; 10-09-2008 at 08:22 PM..

10-09-2008, 08:12 PM	#23 (permalink)
fogger Registered Users My HF Map location Join Date: Jul 2006	cbdane, very cool , nice work. another interesting test to add in the next firmware would be a back and forth test that measures the transition time for the servo to oscillate between two points "x" degrees apart for "y" settable cycles... Funny you mention derivatives, that's what I'm learning (again, after 14 some odd years since the last time I "learned" it) in calc 1... I think the endpoints of the velocity curve should be "s" shaped though Jared ... It should start with zero slope, increase in slope until it hits a point of inflection at the same point in time that your acceleration curve hits a local maximum, (IE it should switch from concave up to concave down at that point) and then should level out to a constant vel. Correct me if I'm wrong though. -Fog __________________ This heli stuff is a pretty deep Rabbit hole, you just have to decide how deep you are willing to go...

10-10-2008, 05:16 AM	#25 (permalink)
Finless Team Taco VP My HF Map location Join Date: Nov 2005	On 8V Will this run on 8V? Bob __________________ "Don't Taco My Pack Dude!" NEW Video Link -> Safety Video #1 Video Link -> CAUTION using powerful tools! Video Link -> How to CRASH TWICE in one flight! Video Link -> Don't Taco!

10-10-2008, 05:36 AM	#27 (permalink)
Finless Team Taco VP My HF Map location Join Date: Nov 2005	Yes and no John... It depends on the chips used in the amp board. Take the servo apart and look. MOST chips these days run in 12V but older stuff doesn't! If you check the circuits components and they are OK for 12 THEN they may work and YES the motor is the next thing to worry about. The BLS servos handle this GREAT! They are brushless and thus voltage doesn't hurt them like a brushed motor! Will this tester handle 8V? Bob __________________ "Don't Taco My Pack Dude!" NEW Video Link -> Safety Video #1 Video Link -> CAUTION using powerful tools! Video Link -> How to CRASH TWICE in one flight! Video Link -> Don't Taco!

10-10-2008, 06:45 PM	#32 (permalink)
Funky Registered Users My HF Map location Join Date: May 2006	Great videos How much are these testers going to cost? I have a LOT of different servos to check __________________ More helis than brains

10-10-2008, 06:32 AM	#29 (permalink)
jared_of_atlanta Registered Users My HF Map location Join Date: Apr 2007	Are these all new servos? I think you should note that in the chart. Futaba fan-boys claim that JR servos loose their center. Can you test this?

10-12-2008, 07:24 AM	#33 (permalink)
Grant_beltcp Registered Users Join Date: Apr 2008	Excellent, now you just need to add a simple torque tester plug in module for it __________________ Sponsored by - Team Align UK- CSM - MKS Servo's UK - Kontronik Drives T-rex 700E v2 - 700E DFC

10-15-2008, 07:58 AM	#34 (permalink)
Tom Burgess Registered Users My HF Map location Join Date: Oct 2007	yes these test are all under no load. I guess we will see even higher temps with load?

11-11-2008, 11:28 AM	#35 (permalink)
uffe40 Registered Users Join Date: Apr 2007	Hi wonder if there are any news Thanku Uffe

12-12-2008, 01:22 PM	#37 (permalink)
trickybit Registered Users My HF Map location Join Date: Sep 2007	I wish you would have beat on the S9257 with 6v to see if it held up. Note the response from vendor is this post https://www.helifreak.com/showthread.php?t=107667 To wit, it can handle 6v if regulated, and 5.8v is "recommended." Cool stuff. Thanks. Jim __________________ PRÔTOS 500 Plastic, Logo 550SX/600SX, PRÔTOS Max2 up and flying! Team MSH USA, Team Cyclone, Team Xnova

12-12-2008, 01:52 PM	#38 (permalink)
Finless Team Taco VP My HF Map location Join Date: Nov 2005	After going through 2 9257's running at 6V as a tail servo on my 500, I decided to use a drop down for the 3rd one. I started this way but pulled it for the heck of it to see. In the end the 9257 can run 6v for things like cyclic but with the duty cycle a tail servo gets in makes for a short life... My experience anyway.... Oh and this is WITH Chinese weight mod on the tail.... Bob __________________ "Don't Taco My Pack Dude!" NEW Video Link -> Safety Video #1 Video Link -> CAUTION using powerful tools! Video Link -> How to CRASH TWICE in one flight! Video Link -> Don't Taco!

12-12-2008, 03:58 PM	#39 (permalink)
Mercuriell HF Support Thread Starter Join Date: Sep 2006	That's useful experience Bob - that's pretty much the same experience I have with the 9254/6 - they will run at regulated "6V" but cark it after ~50 flights __________________ John

12-13-2008, 05:28 PM	#40 (permalink)
ayash Registered Users Join Date: Jul 2008	MKS have a few interesting servos that aren't being talked about a lot. MKS 9660 - a Futaba 9650 with Metal Gears & faster MKS 9670 - a faster one less torque MKS 8910 - seems like a perfect tail servo for the price. Maybe they can be tested as well?

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