Hi Tec HS-785HB Servo gets stuck on initilization

dbb · December 29, 2015, 1:09am

Hi All

I am having an issue where the servo motor gets stuck while setting the initial phase. Actually it seems to be getting stuck even if I use the Lynx Terminal Slider. I have changed the motor but still the problem persists.

I have attached a link to a small video showing the issue

https://www.youtube.com/watch?v=youtu.be/aq5LxEfC49U

Appreciate any help I can get.

Here are some additional pics of the connection. The current connection is with the SSC 32 board but the issue occurs even with SSC 32 U board.

scharette · December 29, 2015, 4:13pm

Hi,

Are you using the SSC-32 or the SSC-32U?

Please provide us with one or more pictures clearly showing all connections, jumpers and any other components on your SSC-32(U), including any power sources/connections.

You can attach pictures (and other files) using the full editor mode. Simply expand the Attachments bar above the Preview/Submit/Save draft/Cancel buttons (see the attached image for details).

Sincerely,

dbb · December 29, 2015, 6:30pm

Hi I have added the pictures. Thanks.

scharette · December 29, 2015, 6:36pm

Thanks for the pictures.

The only problem we noticed in your wiring would be the VS1=VL jumper being in place with (what seems to be) two independent power sources. See our attached image.

What power sources are you using on VS1 and on VL? Please provide as many details as possible.

Sincerely,

dbb · December 29, 2015, 7:21pm

HI so I am trying to use two different power sources. If I do end up removing the jumper then the the servo completely The thing that bothers me is that even the SSC 32 U which has the right jumpers removed shows the same problem. The power soureces for VS1 is directly through an adapter and power supply that outputs 9V while for VL is through a switch. The switch gets power from 6V adapter.

dbb · December 29, 2015, 7:25pm

The original system was suppose to run with SSC 32 U but since that was giving an issue and we had an extra SSC 32, we decided to switch and make sure that the board is not broken in anyway.

scharette · December 29, 2015, 7:32pm

Hi,

The VL input on the SSC-32U should not be used, as stated in the manual. Also, on the SSC-32U, the VS=VL jumper should always be removed.

Make sure to provide 6 V DC (most RC servomotor only run at 4.8-6.0 V DC, if you use a higher voltage, make sure your servomotors are able to function with it) to the VS1 input and the board will be powered properly. The VL power input on the SSC-32U is only required in certain special cases and unlike the SSC-32 is no longer needed in nearly all cases.

We hope this clears up some confusion about wiring the board.

From what we understand, the HS-785HB is a 4.8-6.0 V DC servomotor and cannot run with a 9 V DC input. Please note that voltage input on VS1 is fed directly into the servomotors.

Sincerely,

dbb · December 29, 2015, 8:11pm

Hi now the voltages are fine and the jumper for Vl = VS1 has been removed. The servo seems to be having the same issue of getting stuck but it occurs when I change the angle from 750 to 2250 using the slider. If you go from 2250 to 750 it seems to be working fine.

scharette · December 30, 2015, 1:38pm

Do you have another servomotor to test this with? It is possible your servomotor is defective/damaged (maybe from the use with 9 V DC).

Sincerely,

dbb · January 4, 2016, 5:39pm

Hi I tested it with the SSC 32 U and the system works fine. Not sure whats the issue with the SSC 32 board

dbb · January 11, 2016, 8:25pm

HI I just wanted to follow up with the issue of the SSC 32 board. When I go from 750 to 2250 the servo seems to getting stuck and seems to work fine from 2250 to 750. Now as I replied before that the servo works fine with SSC 32 U. We want to end up using the SS 32 as well and so it would be great if we can get it up and working.

scharette · January 11, 2016, 9:26pm

Hi,

We are still unsure why this is happening only with your SSC-32. We have been unable to reproduce this problem here so it is rather hard to figure out on our end.

If you have an oscilloscope or logic analyzer available to you, we recommend that you monitor the RC signal sent from the SSC-32 to your servomotor to see if there is any irregularities in the signal sent.

If you can provide us with any other details it may help us get an idea of what could be wrong.

Sincerely,

dbb · January 21, 2016, 7:35pm

Hi

Just wanted to give you an update. We figured out that we were driving the Servo using a 6v power supply. when we switched to a 5V supply the issue got resolved. Thanks for your help.

Regards
Dhaval