Please Help, Pioneer RT-707 pinch roller

E

e-loop

New member
Hello there. I have recently purchaced a Pioneer RT-707 reel to reel player from a chap for 20 english pounds( Bargin). The whole machine works but unfortunatly it only came with one pinch roller. I tried to make one myself bit of a bodge job out of a skateboard baring and bycycle innertube. Funnily enough it didn't work.... So i have been looking on ebay, found a couple but always out bidded. So basically im hoping that one of you fine people would be able to help me out. As i work in a school i have the oportunity to have the tec department try an knock one up for me but i would like to get the reel deal. Is anyone able to help?

Thankyou kindly

e-loop
 
Have you checked with the local Pioneer distributor if the part is still available?

Even if they're out, there are quite a few parts sellers on ebay and elsewhere who should be able to come up with something better then your current angle of attack.

Cheers! :)
 
Freaky suggestion: if you can find out what the diameter of the hole in the roller is, it's possible that a Tascam one might work. Even if the diameter of the rubber is wrong, you should be able to get someone to cut it down to size, or rebuild it from the metal core.

If you can give me the hole diameter for the roller you have, I'll try and check against my model 32 roller when I get home.

Tascam's UK parts supplier is Charles Hyde: www.chsinteractive.co.uk
 
If you can give me the hole diameter for the roller you have, I'll try and check against my model 32 roller when I get home.

Thanks for that. i wont be able to get back to you till monday but i certianly will. Thanks again.

e-loop
 
e-loop,
If you can find an old pinch roller with the same shaft diameter as your RT-707, you can have "Terry's Rubber Rollers" (he's on the net and somewhere in your country) refurbish the rubber (brand new) and match the original outside diameter, width etc. If not Terry, I'm sure there would be others. I have a guy in my town in Australia redo them for me. He's been doing it for years for printing industry rubber rollers. He just finds pinch rollers a bit small. Some of the stuff he does is measured in feet, not fractions of an inch!
Tim.
 
$.02

luckilly it doesn't really do anything besides pinch the tape so no reall need to worry about overall diameter...
 
something more than $0.02

dementedchord,
Wrong. Normally a pinch roller pinches the tape between itself and the capstan shaft.
The pressure of that roller onto the shaft has to be within a certain tolerance. Pro machines and many better amateur machines use a solenoid to actuate the pinch roller.
The adjustment of the pinch roller travel and pressure can be quite sensitive and has to be checked every so often. But if you change the diameter of the roller you've thrown out the adjustment already. The solenoid will either bottom out before the roller has pinched the tape or the solenoid will not be able to go its full travel (where all its power is) and will be too weak to give enough force. The result is the same: weak or no pinch roller engagement: in some cases, too much roller pressure, resulting in premature capstan bearing wear/failure.

On many more amateur models, the pinch roller pressure is controlled by a spring. Even there, the diameter will affect the tension of the spring and therefore the pressure, but it wont normally be as critical a change as with the solenoid type.

To complicate matters on this particular model, the RT-707 there were two rollers. The right hand one is a normal pinch roller and all of the above applies. The left hand one is not a pinch roller, more a scrape flutter filter and guide, so its function, and therefore its diameter, even its hardness, is not nearly so critical. On the model I have with me at present, it's not even a rubber tyre but hard plastic.
So in that sense, dementedchord is right, but only in that sense, related to this model, and its left roller.

Tape slowing down towards the end of the reel is a classic example of weak pinch roller pressure, often caused by one or two screws out of adjustment.
Tim
 
I should add that even if you fit a brand new pinch roller, it's normal service practice to check and adjust the pinch roller pressure, according to the service manual, as it can go out with wear.
Tim
 
This page: Where can you buy parts for reel to reel decks? has some links to places you may try to check out. If you don't see the part listed then, You may want to try to actually call (or e-mail) for an advice. good luck.
also, I've seen all sorts of pieces of rt-707/701 on e-bay. you just need to keep your eye on it. Actually if I was in your situation, I would rathher look for the 'whole' machine with OK rollers and that is being sold "as is" (or untested or non-working/for parts or repair)... you get more parts, that you actually may need, and you may also get a good deal, paying not much more (if not less) than buying a specific part. Then you can take the part you need, and keep the rest as back-up or sell it back on e-bay for parts :)
 
The dimensions of the '32 pinch roller are as follows:
Shaft diameter: 5mm
Total diameter: 31mm (?)
Shaft depth: 12mm
 
$.02

from some personal experience as a repair tech (though admittedly didn't do alot of these machines) i've found that the solenoid generally has a little bit of play in it to where this is not "that bigga deal" of course we can quibble about what constitutes "TBD" of course no-one would suggest a radically different diameter ... also let's see if we can't put in perspective that we're trying to ressurect an old consumer deck not a studer 1/2" 2-track... btw the comment about too much pressur ruining the capstan IMO is the larger problem...
 
Thanks everyone for you help and advice, just emailed some of the sites and awaiting a reply.
JPMORISS the spec of the pinch roller is:whole diameter is 29 mm
: Shaft diameter is 5mm
:shaft depth (from rubber to rubber) is 10.5mm.
So unfortunatly slightly out. Maybe a chance of using it as the shaft diameter is the same an possibly get the rubber re made.

Thanks again

e-loop
 
You must log in or register to reply here.
Back
Top