SG2100 motor failed.

[walrus1957]

Curious if anyone else has had the SG2100 motor fail, where it drives one direction only even after reset?

My SG2100 motor that I purchased three or four years ago has really received a work out. This is my test motor that I have abused and received 1000 times the normal usage. It finally failed, drives one direction (west) only. That is unless you tap on the mechanical relays that switch east and west drive functions. The relay is sticking, you can tap on it and it will function normally for a while then stick again allowing for drive west functions only. Apparently they have a limited life and now must be replaced. The relays are manufactured by Shori and the part number is S2-12B. I have downloaded the pdf file for the relay with all specifications from Shori. Now just have to find a supplier or replacement relay. Even if I can not procure the Shori relay, armed with the specifications for the relay I should be able to find a replacement.

I removed the motor control board so that I could measure the voltages and switching functions. The relays are definately failing and intermittently stick. I'm sure the mechanical realys could have been replaced with solid state technology, wonder why they choose mechanical realys for this motor. Attached photos of the motor control board.

 

[Anole]

Reasons?
I'd say: cost
And maybe: reliability
A good relay can perform well if properly chosen for a task.
And not used outside its ratings.
Sounds like yours did a heck of a job for a long time.

One thing I've seen done is to re-polish the relay contacts.
That would not be done on such a small unit, and they may not be readily accessible.
I only mention it as a temporary fix, or if you fail to find replacements.

Have you tried DigiKey and Mouser?

 

[Fizbi]

I removed the motor control board so that I could measure the voltages and switching functions. The relays are definately failing and intermittently stick. I'm sure the mechanical realys could have been replaced with solid state technology, wonder why they choose mechanical realys for this motor. Attached photos of the motor control board.

Nice macro shots...

Can you show a picture of the back side?

It looks like you could easily adapt a suitable replacement set of relays.

I would also be looking for cold solder connections on the solder side. Temperature changes can open solder connections if there is no stress relief for thermal expansion/contraction.

 

[walrus1957]

Yes I should be able to fit a replacemnent relay to the board, there is plenty of clearance between the board and the motor housing.

I looked at the solder connections very carefully and could not find a cold solder joint. Attached a photo of the back side of the board.

 

[Jim S.]

Did you ever find replacement relays? I have a PowerTech DG-280 with the same problem, and the same relays.

Sorry for dragging up an old thread, but your inbox is full!

 

[Bongu]

Have you tried spraying some contact cleaner in the relays? This should help, but is a temporary fix that would need to be repeated.

Sent from my Timex Sinclair using SatelliteGuys

 

[Jim S.]

Don't know as if I can, the relay appears to be a sealed box.

 

[zwarder]

Hi I have a dark motor with same symptoms & relays.
Some available on ebay