Tascam 34B with a noisy capstan motor

[Fte New]

Hi all,

I recently got a well conditioned 34B in full working condition. I had it serviced for SM 911 and it runs well. Only thing that should be replaced is the capstan Motor. It consistently makes a running noise, esp. on 15ips. I assume the motor has it‘s best years behind, and is now running on its teeth. Sounds a little like the small baby brother of a high pressure cleaner’s or air compressor’s sound.

I would like to exchange it for a spare part.

Does anyone know which exact model I should look for? Also, is it a very complex job of repair? I’m not inexperienced fixing gear, but not on the extent that I directly know what is what as soon the machine is dismantled. I had to figure out every step in advance. If it turns out to be a very sofisticated pro job, maybe I will leave my hand off it.
But I can solder…

Thanks in advance, have a great day. I’m happy about any recommendations.

Best

 

[sweetbeats]

Is the machine upright or laying on its back?

Does the sound change when you change the machine’s position?

Can you post a video demonstration the sound?

You may just need to remove, disassemble, clean and lubricate the capstan shaft (which is separate from the motor, and coupled by a belt).

Does it pull tape okay, it’s just noisy? Or does it struggle to pull tape?

 

[Fte New]

Is the machine upright or laying on its back?

Does the sound change when you change the machine’s position?

Can you post a video demonstration the sound?

You may just need to remove, disassemble, clean and lubricate the capstan shaft (which is separate from the motor, and coupled by a belt).

Does it pull tape okay, it’s just noisy? Or does it struggle to pull tape?

Hey, thanks for your reply!
I tried both, upright and flat aswell, it doesn’t alter the noise at all.
The person who measured the heads to the material said, he assumes the motor to be worn out. He already tried to lube with this specialized motor oil according the service manual but didn’t achieve any difference. But he couldn’t figure out more and didn’t want to exchange it by himself, cause he was unsure if he would be capable of. That’s my „knowledge start off“ point from now. He gave me the advice to work with it until it will stopping to work. I don’t know if I want that because when it on some day blows up, mabe then ther‘s more damage aswell…

The tape runs perfectly, though. Aswell as everything else.

I’m not at home, but I will try to post a video as soon as I am.

 

[Fte New]

Edit: the noise appears independently from transport. also when tape is stopped and not running but as soon as the machine is powered and the right tension arm is lifted to engage the capstan

 

[Fte New]

Hey, here’s a video of the capstan motor noise. direct Video upload didn’t work somehow, maybe because it‘s a .mov
I attached it as a .zip file below.

In the video you can hear the sound (even it‘s not the best audio quality. In reality it’s louder and bleeds into microphone recordings).

 

[sweetbeats]

Video is really short…hard to actually hear the sound. But what I hear sounds like maybe the capstan thrust needs adjusted, and I know you said it was lubricated, but was the capstan shaft actually disassembled and cleaned and relubricated? If not I wouldn’t rule out that’s still a problem. You can’t necessarily expect some oil applied to the nose will make it to the tail and to the thrust bearing. Also, was the capstan belt replaced? And if so was the replacement belt absolutely positively the correct size and spec? I’ve seen some belts that were supposedly correct and were NOT…way too thick of a cross section, put too much tension on the motor pulley and capstan pulley. There’s two noises I hear, one is some squeaking, sounds like dry metal-to-metal contact, and the other sounds like the motor is under too much tension.

 

[Fte New]

Video is really short…hard to actually hear the sound. But what I hear sounds like maybe the capstan thrust needs adjusted, and I know you said it was lubricated, but was the capstan shaft actually disassembled and cleaned and relubricated? If not I wouldn’t rule out that’s still a problem. You can’t necessarily expect some oil applied to the nose will make it to the tail and to the thrust bearing. Also, was the capstan belt replaced? And if so was the replacement belt absolutely positively the correct size and spec? I’ve seen some belts that were supposedly correct and were NOT…way too thick of a cross section, put too much tension on the motor pulley and capstan pulley. There’s two noises I hear, one is some squeaking, sounds like dry metal-to-metal contact, and the other sounds like the motor is under too much tension.

Hey Sweetbeats, thanks for listening and your evaluation! I will ask the person who calibrated the machine: what he actually did, as far the capstan lubricating. The belt was replaced for a new one, I will look up and post the exact description. Maybe I load up a better video, too.

Would you say I can work with the machine for now, though? Or would that rather be too risky?

 

[sweetbeats]

I can’t tell you that. I don’t know what is truly going on with your machine. What we know is that something is not right. So use your best judgment. I know if it was me, and I’d just come into possession of the machine and didn’t have answers yet but knew the capstan belt was replaced but it didn’t sound right I’d be holding off using it until I had answers. I’d be removing what I’d need to remove to view the capstan belt and visually comparing with a correct belt.

 

[sweetbeats]

The replacement belt should be 382mm internal circumference, 8mm wide and 1mm thick.