Otari MTR15 Pinch Roller Does Not Engage When Play is Pressed

RoadDawgWest

Well-Known Member
May 10, 2016
9
0
131
SoCal
Hi,
I recently purchased an Otari MTR15, and was hoping to find someone who might have experienced a pinch roller on this machine that does not engage when play is pressed.
With a light nudge it will engage, and after a few minutes of play you can press stop, and play again, and the pinch roller will engage sometimes.
The machine has been sitting idle for around 5+ years. I have downloaded the user / maintenance manual, but if anyone would have experience to share while I form a plan to troubleshoot this issue it would be appreciated.

Thank you
Don
 

cooljazz

Well-Known Member
Mar 21, 2012
28
0
76
TN
Hi Don,

I installed a new MTR-10 many, many years ago. Didn't get to do any maintenance later on it to learn anything particular. But from other models, that'd suggest to me it is just a mechanical, probably lube issue. Might be an adjustment on a solenoid that could be involved, but I'd look first to the movement and all friction points in that.

Very nice super machines! Good luck getting it going properly.

CJ
 

RoadDawgWest

Well-Known Member
May 10, 2016
9
0
131
SoCal
Thank you CJ,
I was looking over the user / maintenance manual between flights, and could not find any reference to lubrication for the pinch roller mechanical mechanism. I did see the solenoid adjustment. The pinch roller will disengage when stop is pressed. Therefore I agree new lube on the friction points. Until I open up the machine I will not know if Otari used a grease or oil. I suspect a grease, if I'm right what would be the equivalent today?
 

srs148

Well-Known Member
Jan 3, 2016
80
32
250
Hi,
I recently purchased an Otari MTR15, and was hoping to find someone who might have experienced a pinch roller on this machine that does not engage when play is pressed.
With a light nudge it will engage, and after a few minutes of play you can press stop, and play again, and the pinch roller will engage sometimes.
The machine has been sitting idle for around 5+ years. I have downloaded the user / maintenance manual, but if anyone would have experience to share while I form a plan to troubleshoot this issue it would be appreciated.

Thank you
Don

hi Don, congrats on your purchase! The MTR15 is a wonderful machine - one of my favorites.

Ok, I think you have a fairly simple issue. There is a thin foam-like pad at the resting position of the pinch roller arm that has likely begun to deteriorate making it sticky. The 'foot' of the arm rests on that pad. Since the actuator of the pinch roller arm doesn't have a lot of torque, it's not strong enough (and should not have to be) to break the foot loose of the adhesion caused by the gooey pad. The pinch roller mechanism is spring loaded to go back to its resting position when not actuated which is why it goes back to the resting position without a problem, so I don't think it's a lube issue in this case.

As such, you'll need to remove all the parts necessary to be able to take off the front panel and get to the pad at the resting position of the pinch roller arm - this will include the tension rollers, pinch roller and washer, headblock cover, and the plastic head base cover (the part that is likely a tad yellowed verses the rest of the parts on your front panel). Once in there, scrape off the gooey pad and replace it with a thin felt pad cut to size (or something similar that is not sticky and not too soft lest the arm will sink in and get stuck again). That should solve your problem and you'll be good to go.

Again, this is my hunch because I had a similar issue with my own MTR15, so I hope that's it. While you're at it and the rollers are off of the machine, polish them up with something like NuFinish or Brasso to really make them shine. :cool:

Best,
Steve
 
Last edited:

RoadDawgWest

Well-Known Member
May 10, 2016
9
0
131
SoCal
hi Don, congrats on your purchase! The MTR15 is a wonderful machine - one of my favorites.

Ok, I think you have a fairly simple issue. There is a thin foam-like pad at the resting position of the pinch roller arm that has likely begun to deteriorate making it sticky. The 'foot' of the arm rests on that pad. Since the actuator of the pinch roller arm doesn't have a lot of torque, it's not strong enough (and should not have to be) to break the foot loose of the adhesion caused by the gooey pad. The pinch roller mechanism is spring loaded to go back to its resting position when not actuated which is why it goes back to the resting position without a problem, so I don't think it's a lube issue in this case.

As such, you'll need to remove all the parts necessary to be able to take off the front panel and get to the pad at the resting position of the pinch roller arm - this will include the tension rollers, pinch roller and washer, headblock cover, and the plastic head base cover (the part that is likely a tad yellowed verses the rest of the parts on your front panel). Once in there, scrape off the gooey pad and replace it with a thin felt pad cut to size (or something similar that is not stick and not too soft lest the arm will sink in and get stuck again). That should solve your problem and you'll be good to go.

Again, this is my hunch because I had a similar issue with my own MTR15, so I hope that's it. While you're at it and the rollers are off of the machine, polish them up with something like NuFinish or Brasso to really make them shine. :cool:

Best,
Steve

Hi Steve,
I believe your hunch is correct. First thing I did when getting back to California today was opened the top cover to look around, and take some pictures of the inside. I could see a white blob of hardened material on the pinch roller linkage. When I manually moved the pinch roller by hand, the white hardened material did not appear to be the cause of the pinch roller not engaging. I closed everything back up, and decided to sleep on it until Saturday. I did see the black pad, therefore I know exactly what you are talking about.

Any recommendation on sourcing the felt? My first thought was a local craft store.

Thank you
Don
 

srs148

Well-Known Member
Jan 3, 2016
80
32
250
Any recommendation on sourcing the felt? My first thought was a local craft store.

Hey Don, I just grabbed what I had in the house which was one of those self-adhesive felt furniture pads cut to size. Not elegant by any means, but it did the job in a pinch and has worked without issue since.
 

Ki Choi

Member Sponsor
May 13, 2010
764
29
1,590
Seattle WA area
yes, pinch roller on Otari MTR-15 will get stuck in rest position due to the sticky pad. It happened to all four MTR-15s I have. One of them also had sticky pinch roller pivot due to funky lube used by the studio who owned it. The lube hardened and would let the pinch roller to move.

I used thin self-adhesive 3M furniture bumper pad after removing the sticky pad with solvent.

Ki
 

RoadDawgWest

Well-Known Member
May 10, 2016
9
0
131
SoCal
Steve & Ki,
Spent some time on the MTR15 yesterday afternoon. Your suggested fix was spot on. Thank you! The pinch roller now engages when play is pressed. The following are a few photos, and videos.

Delivery of the Otari MTR15 - Still dirty needing cleaned up.
29165103710_be0c8f2061_m.jpg

A video of the pinch roller not engaging when play is pressed.
[video]https://youtu.be/An-4rcTGBGM[/video]

The culprit of the sticking pinch roller. The black foam pad has become sticky to the touch. Also sticky residue is on the pinch roller arm (not shown in photo).
29371960571_ce44a6feaf_c.jpg

Removed the sticky foam pad, and replaced with a foam pad with similar thickness. This foam pad was sourced from Michaels craft store, and has adhesive on one side. Simply traced around the old foam pad, and used an exacto blade to cut the new foam pad.
29371955531_bd9483a913_m.jpg

A video of the pinch roller engaging when play is pressed, after replacing the foam pad.
[video]https://youtu.be/wSVjtTnbozE[/video]

Next steps in the process is to re-oil the capstan motor (waiting for the oil to arrive). Demagnetize the heads and tape path. Re-clean the heads, tape path and pinch roller.

When I cleaned under the tape deck, I removed some of the grease on the linkage and springs for the tape lifters because it was full of dust. Any recommendation on the best grease to use? Also I need to remove a rusty screw in the left reel table. This looks like it might difficult to get out.

Rusty screw head in the reel table.
29452141405_b361be1cc1_c.jpg

Another week or so, and I should have the machine ready to play tape.
 

srs148

Well-Known Member
Jan 3, 2016
80
32
250
Glad to hear we were able to help and congrats on a great pickup. That's quite a clean specimen you have there. Just curious - how many hours does it have on the heads and how many power on hours?
 

RoadDawgWest

Well-Known Member
May 10, 2016
9
0
131
SoCal
Glad to hear we were able to help and congrats on a great pickup. That's quite a clean specimen you have there. Just curious - how many hours does it have on the heads and how many power on hours?

Power On Hours - 873
Head Wear Hours - 33
Lifter Wear Hours - 5

Could not confirm if the counters have been reset.
According to the seller this machine spent the majority of its life as a back up or was in storage.
 

srs148

Well-Known Member
Jan 3, 2016
80
32
250
Power On Hours - 873
Head Wear Hours - 33
Lifter Wear Hours - 5

Could not confirm if the counters have been reset.
According to the seller this machine spent the majority of its life as a back up or was in storage.

I don't think you can reset the counters on the MTR - and judging by its cosmetic condition, the counts are probably accurate. Nice score.
 

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