Is my Capstan supposed to be turning when the take up arm is down???

SteveM

SteveM

New member
haha I just moved and re set up all my equipment and when I powered on the Ampex 440, with no tape on it I found the capstan is turning. I'm pretty sure it never did that before and only engaged when the take up arm was up!!
 
SteveM said:
haha I just moved and re set up all my equipment and when I powered on the Ampex 440, with no tape on it I found the capstan is turning. I'm pretty sure it never did that before and only engaged when the take up arm was up!!
Click to expand...

I don't know that particular model but I think that's generally how it is.
The capstan is engaged when the take up arms are lifted.
There's usually a very delicate microswitch in there and it's not uncommon for them to get stuck.

Are you handy enough to investigate?
 
Yeah...very possibly a stuck micro-switch.

"Bounce/flip" the take up arm lightly with your finger...it might come unstuck.
Otherwise, you probably have to remove the faceplate (which can be a PITA, but not a big deal) to get at it.

There might be some kind of grease on those parts...and with old equipment, that grease can turn pretty thick and sticky.
If that's the case you want to Q-tip that gunk away...but replace with appropriate(?) lubricant...not sure what they used back in the day on those decks.

The guy who would know for sure...is most likely sweetbeats/Corey. :)
 
Thanks for the replies. There's a lever that engages when the take up arm moves up. It's it's own removable part below the take up arm. I disconnected the wires on that before and the capstan kept moving. So I'm thinking something went haywire in the capstan itself. Or in it's network of wiring. But I believe you're right that it shouldn't be moving. Otherwise I guess there wouldn't be a switch.
 
SteveM said:
I disconnected the wires on that before and the capstan kept moving. So
Click to expand...

Well, that depends which way the switch operates.
It's entirely possible that lifting the arm opens, or closes, the switch.

If it's the latter and the switch is failing to close, disconnecting it wouldn't prove anything.
Are the switch and it's connectors visible to you? If you can literally see a switch and a 2 connector plug, and you're sure there's nothing else to it, bridge the connections to simulate closing the switch.

That said, it may not be your problem but it's worth ruling out fully.
 
If I'm reading the transport description and schematics correctly, the 'safety switch' on the tension arm should provide or cut power to most of the transport, i.e. the capstan and reel motors and possibly the brakes as well. So that might be an interesting test... See if rewind/fast forward works with no tape. If so, it's definitely the microswitch.

I'm not seeing a huge amount of logic involved so I'd be a bit surprised if it wasn't the switch.
 
Is it a 440C with a servo motor? If so you can run the motor continuously by removing the relay on the servo chassis, usually mounted on the back of the machine.
 
radardoug said:
Is it a 440C with a servo motor? If so you can run the motor continuously by removing the relay on the servo chassis, usually mounted on the back of the machine.
Click to expand...

So logically, if it is the servo version, that relay could fail and cause the motor to run continuously...
 
Steenamaroo said:
Well, that depends which way the switch operates.
It's entirely possible that lifting the arm opens, or closes, the switch.

If it's the latter and the switch is failing to close, disconnecting it wouldn't prove anything.
Are the switch and it's connectors visible to you? If you can literally see a switch and a 2 connector plug, and you're sure there's nothing else to it, bridge the connections to simulate closing the switch.

That said, it may not be your problem but it's worth ruling out fully.
Click to expand...

Good point! Thank you!
 
Yup, was the switch after all. I just removed it and shook it around then when I saw it worked with a buzz test put it back and it's working again. Must have been something stuck in there. Thanks for the help!
 
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