View Full Version : Teac 6300 tape roll off pinch roller Problem


russ1965
11-27-2007, 12:20 PM
While using one of my Teac A-6300 decks on Auto reverse using a 10" reel the tape rolls off the top of the pinch roller, 5 seconds after it hits the sensing foil. It doesn't happen with 7" reels. I switch out the pinch rollers on the decks, same result. It only happens at the end of the tape.

Is there any adjustment that can be made. I didn't notice any problem, before.

Bob

russ1965
11-28-2007, 02:52 PM
While using one of my Teac A-6300 decks on Auto reverse using a 10" reel the tape rolls off the top of the pinch roller, 5 seconds after it hits the sensing foil. It doesn't happen with 7" reels. I switched out the pinch rollers on the decks, same result. It only happens at the end of the tape. This just stated over night, on one machine not the other. I noticed that on both machines the tape "currels" in reverse play at very end of the 10" reel. On one machine it sides up and out, the other machine it doesn't, the "currelling" stops and everthing looks the same in Forward Play. The machine the tape slides up and out, if yoou are not at the end of the tape say 1/16" to1/8" tape left on the 10"and Reverse Play no problem.

With 7" reels no problem or tape "currelling" reverses perfectly.

Is there an adjustment that can resolved this problem.

Rjs

cabinover
11-28-2007, 03:18 PM
Try a PM to VintageTX. He's the guy on most things reel to reel.

Sorry I cannot help you.

jblmar
11-28-2007, 03:47 PM
Adjustments on these decks are interelated. You need to check each adjustment point using the proper spring scales to be on specification.

What's the condition of the pinch roller(s)?
Are they 'flat black' or shiny? They should be flat or dull black color.

Ron

russ1965
11-28-2007, 09:01 PM
Adjustments on these decks are interelated. You need to check each adjustment point using the proper spring scales to be on specification.

What's the condition of the pinch roller(s)?
Are they 'flat black' or shiny? They should be flat or dull black color.

Ron

Ron,

The pinch rollers are flat black, when I switched pinch rollers from 1 deck to the other, there was no difference, the same deck still had the problem with tape slipping out at the top. Since it doesn't happen with 7" reels, I am thinking the pinch roller adjustment is OK. The other thing I noticed if I set the deck for small reels, the 10" reel will auto reverse, at the end tape, without slipping out 3 of 5 times. Is the "currelling" between capstan and heads normal, since both machines do it, at start of auto reverse, and last until there is about 1/8" to 1/4" tape on the left reel.

Fred Longworth
11-29-2007, 01:56 AM
Check to make sure that the pinch roller arm assemblies have not gotten slightly tweaked, so that even a fresh pinch roller surface is not exactly parallel to the capstan shaft.

Make sure the tension arms are not sticky and that they haven't been tweaked so as to pull the tape either toward the frontpanel or away from it relative to the lead-out tape guide(s).

Use a spring gauge to verify forward and reverse play reel tensions are close to or at spec.

Use a heavier spring gauge to make sure the pressure of pinch rollers against capstans is close to or at spec.

Fred

jblmar
11-29-2007, 09:45 AM
Could be the circuit that controls the reels size since you say that the deck works with 7" reels.
Difficult to pin point without taking torque measurements.

Ron

Mopic5
11-29-2007, 12:47 PM
Had a similar problem with an AN series Teac and only presented itself with full reel "pay out" in reverse play. Turned out to be insufficient hold-back tension.

A quick & dirty test for this is to add a slight bit of drag to the payout reel with a finger and see if the tape holds its path through the capstan.

- Mario

jblmar
11-29-2007, 12:51 PM
Had a similar problem with an AN series Teac and only presented itself with full reel "pay out" in reverse play. Turned out to be insufficient hold-back tension.

A quick & dirty test for this is to add a slight bit of drag to the payout reel with a finger and see if the tape holds its path through the capstan.

- Mario

Holding back with your finger will work, but setting the back tension too tight (high) will slow the tape down as it reaches its end.

The only way to determine the exact cause is to make all tension measurements to mfg specification.

Ron

russ1965
11-29-2007, 01:46 PM
Check to make sure that the pinch roller arm assemblies have not gotten slightly tweaked, so that even a fresh pinch roller surface is not exactly parallel to the capstan shaft.

Make sure the tension arms are not sticky and that they haven't been so as to pull the tape either toward the frontpanel or away from it relative to the lead-out tape guide(s).

Use a spring gauge to verify forward and reverse play reel tensions are close to or at spec.

Use a heavier spring gauge to make sure the pressure of pinch rollers against capstans is close to or at spec.

Fred

Fred,

The entire tape path is clean and not sticky. The only thing I noticed about the tension arms, is the auto shutoff arm seems to move back and forth, like vibrate during playback in either direction, and really moves back and forth a lot more during fast forward and reverse. On my Teac 4300sx the auto shutoff does not do that kind of movement. My 1st thought was auto shutoff tension arm is out of alignment with the pinch roller, tape guides. How do you tell if it is, tweaked, it looks like it is lined up.

Where would I get the proper spring gauges to check the tensions/

Bob

russ1965
11-29-2007, 02:29 PM
Holding back with your finger will work, but setting the back tension too tight (high) will slow the tape down as it reaches its end.

The only way to determine the exact cause is to make all tension measurements to mfg specification.

Ron

Ron,

I added drag with my finger to payout reel in playback revese, no "currelling" and the tape ran OK, released drag after, 1/32 tape on takeup reel tape started "currelling", but didn't come out between the capstan and pinch roller, after several more turns the "currelling" stopped.

So from this test, I think, and correct me if I am wrong, check all the tensions, starting with the back tension, and adjust. Or do I start with the pinch roller, and adjust? Since the other thing I noticed is that the leader tape moves OK no "currelling", as soon as it hits the recording tape the "currelling" starts, and if there isn't enough tape on the take up reel the tape comes out between the capstan and the pinch roller.

Where can I get the proper scales and aprox. how much do they cost.

Thanks,
Bob

russ1965
11-29-2007, 02:38 PM
Had a similar problem with an AN series Teac and only presented itself with full reel "pay out" in reverse play. Turned out to be insufficient hold-back tension.

A quick & dirty test for this is to add a slight bit of drag to the payout reel with a finger and see if the tape holds its path through the capstan.

- Mario

Mario,

Thanks, it seems that is problem. Now all I need is to find the proper scales, and where to get them at a reasonable price.

Mopic5
11-29-2007, 03:08 PM
Hi Bob,
As Ron is quick to caution - my trouleshoot doesn't fix the problem. I hear you on sourcing a spring scale of sufficient sensitivity to measure the x value in ounces. I wasted $20 on a digital fish scale that specified ounce increments. Trouble was that this started out after a min. threshhold of 4 oz. is met - too gross for holdback tension readings. Guess anything under 4 oz. gets thrown back.
Anyway, I'm beginning to think constructing something homebrew may be the way to go - to keep from spending an arm or a leg or both. In the meantime, the offending TEAC plays by my basement workbench spinninging lightly filled pre-records.
Good luck, and when I get around to making up the tension scale, I'll post it.

- Mario

jblmar
11-29-2007, 03:21 PM
At this point, we're just checking that all tension parameters are on specification. Please, don't adjust anything.

Another possibility aside from the condition of the pinch roller is the condition of the capstan. Overtime the shaft can and does wear. It can also become slick and not grab the tape. The later Teac decks used a ceramic type capstan. It offered better performance than the eariler metal shafts.

The down side of the 4300/6300 and for that matter any of the Auto-Reverse decks that use a single capstan/pinch roller is that in forward play the tape is pulled past the heads. In reverse play the tape is 'pushed' past the heads. If the capstan/pinch roller is less than perfect, these problems happen.

Ron

pustelniakr
11-29-2007, 03:30 PM
OK. What you want is one of these (not this one, get the right range and scale):

http://cgi.ebay.com/Collectable-Chatillon-DPP-25-Torque-Compression-Gauge_W0QQitemZ290186660531QQihZ019QQcategoryZ1387 6QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

This is a Chatillon Force gage. The one pictured is not the size you want, but one like it is what you should hold out for. Don't just buy the force gage, but hold out for the wooden case, with the accessories. the gage is about useless without the extender and tips.

The specific one you want is the Chatillon DPP-.5Kg, which provides a scale of 500g, in 5g increments (.5g x 5g is what is written on the scale dial)). The gage is able to accurately do a little over 1.5 rotations of the scale, so it is plenty for any tape deck task I have so far encountered. With the accessories, you will be able to do R2R and cassette pinch roller pressures, as well as R2R reel and brake torques. For cassette reel torques you will need special torque gages in cassette shells ($$$). For R2R reel and brake torques, you will also need a length of string with a big knot on one end (to go in the empty reel slot) and a loop on the other (to fit the gage accessory hook).

For the force gage, do not pay the high prices for new ones the the bay stores have. Hold out for a decent one, at $50 or less. I got mine for significantly less.

This one might be the one you want, but you will have to get more info from the seller: http://cgi.ebay.com/VINTAGE-CHATILLON-DIAL-PUSH-PULL-MODEL-FORCE-TESTER_W0QQitemZ160183886869QQihZ006QQcategoryZ150 4QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Enjoy,
Rich P

Enjoy,
Rich P

russ1965
11-29-2007, 04:34 PM
Since I going to be adjusting tension, I got two other questions on the the brake response for the 6300, and going from stop to play functions. The 6300 takes about 10 tape counter digits to stop when in FF or reverse with a 10" reel the tapeout reel is 3/4" full is that normal. I never thought it was that loose. Comparing it to 4300SX, it stops within 1 tape counter digit, like immediately.
When activating reverse play, 3-4 seconds before the pinch roller engages, forward play pinch roller engages immediately. Is this all do to back tension.

pustelniakr
11-29-2007, 05:33 PM
Brake tension and motor torques are different animals, but measured in a similar way. Motor torque is measured by putting the unit in the mode to provide the torque to measure (be careful to have the string wrapped in the right direction for the reel and torque direction). Brake torque is typically measured putting the unit in a play mode and hitting stop, then pulling on the string via force gage, and seeing what the gage reads at the instand the reel starts to turn.

Brake force is sypically adjusted by spring force and position, while motor torques are typically adjusted via pots or tapped resistors.

The proper way to stop an R2R that is going in FF or REW (fast reeling modes) is to hit the reverse fast mode, and when the reels come near to stopping hit "stop". (Example: going in FF, to stop hit REW, and wait till just about stopped, then hit "stop"). That way the motor torque is smoothly used to bring the reels to near stop. When you get good, you can time the "stop" so that the brakes drop on to a stopped set of reels. Higher quality decks will do this for you automatically. Older ones require you to do it yourself.

Enjoy,
Rich P

russ1965
11-29-2007, 06:59 PM
OK. What you want is one of these (not this one, get the right range and scale):

http://cgi.ebay.com/Collectable-Chatillon-DPP-25-Torque-Compression-Gauge_W0QQitemZ290186660531QQihZ019QQcategoryZ1387 6QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

This is a Chatillon Force gage. The one pictured is not the size you want, but one like it is what you should hold out for. Don't just buy the force gage, but hold out for the wooden case, with the accessories. the gage is about useless without the extender and tips.

The specific one you want is the Chatillon DPP-.5Kg, which provides a scale of 500g, in 5g increments (.5g x 5g is what is written on the scale dial)). The gage is able to accurately do a little over 1.5 rotations of the scale, so it is plenty for any tape deck task I have so far encountered. With the accessories, you will be able to do R2R and cassette pinch roller pressures, as well as R2R reel and brake torques. For cassette reel torques you will need special torque gages in cassette shells ($$$). For R2R reel and brake torques, you will also need a length of string with a big knot on one end (to go in the empty reel slot) and a loop on the other (to fit the gage accessory hook).

For the force gage, do not pay the high prices for new ones the the bay stores have. Hold out for a decent one, at $50 or less. I got mine for significantly less.

This one might be the one you want, but you will have to get more info from the seller: http://cgi.ebay.com/VINTAGE-CHATILLON-DIAL-PUSH-PULL-MODEL-FORCE-TESTER_W0QQitemZ160183886869QQihZ006QQcategoryZ150 4QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Enjoy,
Rich P

Enjoy,
Rich P

Thanks Rich,

Looking at the Service Manual
Pinch Roller adjustment, "the scale should indicate 2.2 to 2.5kg, Optimum vaule is 2.4kg, +/- 0.1kg.

The Brake Torque should be 1000 g-cm +/-200 g-cm.

Back Tenson and Takeup Torque
Foward Play
Large reel takeup 800-820 g-cm, small reel takeup 370-410 g-cm,
Large reel back tension 300-320 g-cm small reel back tension 170-210 g-cm

Reverse Play
large reel takeup 800-900 g-cm, small reel takeup 430-470 g-cm,
large reel back tension 310-330g-cm, small reel back tension 200-210g-cm.

So it looks like I'll need several gages, or one that goes 2.5kg, and is 5g increments. Am I correct

Bob

russ1965
11-29-2007, 07:42 PM
Brake tension and motor torques are different animals, but measured in a similar way. Motor torque is measured by putting the unit in the mode to provide the torque to measure (be careful to have the string wrapped in the right direction for the reel and torque direction). Brake torque is typically measured putting the unit in a play mode and hitting stop, then pulling on the string via force gage, and seeing what the gage reads at the instand the reel starts to turn.

Brake force is sypically adjusted by spring force and position, while motor torques are typically adjusted via pots or tapped resistors.

The proper way to stop an R2R that is going in FF or REW (fast reeling modes) is to hit the reverse fast mode, and when the reels come near to stopping hit "stop". (Example: going in FF, to stop hit REW, and wait till just about stopped, then hit "stop"). That way the motor torque is smoothly used to bring the reels to near stop. When you get good, you can time the "stop" so that the brakes drop on to a stopped set of reels. Higher quality decks will do this for you automatically. Older ones require you to do it yourself.

Enjoy,
Rich P

Thanks Rich,
That is exactly what the 7010 manul says to do. The 6300 says nothing about it except to stop any function press stop. The 4300SX recommends not to do it, just press stop.

Ozric
11-29-2007, 09:56 PM
I too am suffering this same problem with my A-6300. I have tried to make sure the alingment of the right side tension arm is correct and have made adjustments for back tension, it still does not work properly. The window of specifications is so small, that if everything is not absolutly perfect it just will not work properly, there is no room for error.

The down side of the 4300/6300 and for that matter any of the Auto-Reverse decks that use a single capstan/pinch roller is that in forward play the tape is pulled past the heads. In reverse play the tape is 'pushed' past the heads. If the capstan/pinch roller is less than perfect, these problems happen.

This is a major design problem for these type of decks. I think that Teac knew that this was an issue near the end of the run for these types. I also have a A-2300SR. Teac added a stationery tape guide to the 2300SX to keep the tape better inline with the pinch roller & capstan and prevent this issue. It is also seen on the newer X-3R that I have as well. (See Attached Pics).

I am in the process of trying to make one these, I am removing the guide from my 2300SX and a friend of mine is going to try and dupiclate it on a metal lathe. It will be made from stainless steel and the surface that the tape rides on will be completely polished. This will take a while, probably will not be done until after Christmas. If it works well, I will install one on my A-6300 as well as my A-4300SX.

russ1965
11-30-2007, 07:49 AM
At this point, we're just checking that all tension parameters are on specification. Please, don't adjust anything.

Another possibility aside from the condition of the pinch roller is the condition of the capstan. Overtime the shaft can and does wear. It can also become slick and not grab the tape. The later Teac decks used a ceramic type capstan. It offered better performance than the eariler metal shafts.

The down side of the 4300/6300 and for that matter any of the Auto-Reverse decks that use a single capstan/pinch roller is that in forward play the tape is pulled past the heads. In reverse play the tape is 'pushed' past the heads. If the capstan/pinch roller is less than perfect, these problems happen.

Ron

Thanks Ron,
I don't think it is the capstan since after every 10 hours of use I clean the entire tape path, and I lightly brush it with nylon pad.

Bob

russ1965
11-30-2007, 07:56 AM
I too am suffering this same problem with my A-6300. I have tried to make sure the alingment of the right side tension arm is correct and have made adjustments for back tension, it still does not work properly. The window of specifications is so small, that if everything is not absolutly perfect it just will not work properly, there is no room for error.



This is a major design problem for these type of decks. I think that Teac knew that this was an issue near the end of the run for these types. I also have a A-2300SR. Teac added a stationery tape guide to the 2300SX to keep the tape better inline with the pinch roller & capstan and prevent this issue. It is also seen on the newer X-3R that I have as well. (See Attached Pics).

I am in the process of trying to make one these, I am removing the guide from my 2300SX and a friend of mine is going to try and dupiclate it on a metal lathe. It will be made from stainless steel and the surface that the tape rides on will be completely polished. This will take a while, probably will not be done until after Christmas. If it works well, I will install one on my A-6300 as well as my A-4300SX.

The is a site that I came accross that sells tape guides, it might save your a lot time. http://www.magneticheadcompany.com/ Down load the catalog it is on page 31.

russ1965
11-30-2007, 08:32 AM
I switched tapes from Maxell 35-180b gold box and went to another Maxell 35-180 white box, now the tape rolls off the bottom between the capstan and the pinch roller, not the top, but if you engage reverse playback when the tape is 6 inches from the leader no problem. After several times doing this, the length of 6 inches was shorten to 1 inch from the leader the tape started to roll to the bottom but recovered.

I am going to switch back to the 180b tape to see if roll has changed, checking the distance from the leader, and ifn the roll off is still at the top.

russ1965
11-30-2007, 09:26 AM
I switched tapes from Maxell 35-180b gold box and went to another Maxell 35-180 white box, now the tape rolls off the bottom between the capstan and the pinch roller, not the top, but if you engage reverse playback when the tape is 6 inches from the leader no problem. After several times doing this, the length of 6 inches was shorten to 1 inch from the leader the tape started to roll to the bottom but recovered.

I am going to switch back to the 180b tape to see if roll has changed, checking the distance from the leader, and if the roll off is still at the top.

Switched back to the 180b, roll off is now at the bottom, and doesn't occur, at 6 counter turns from the leader.

The only thing, I think, that changed from yesterday might be is the tape up reel. So I am now thinking that it might be the auto shut off arm is not in proper adjustment, as Fred stated earlier.

russ1965
11-30-2007, 11:49 AM
I too am suffering this same problem with my A-6300. I have tried to make sure the alingment of the right side tension arm is correct and have made adjustments for back tension, it still does not work properly. The window of specifications is so small, that if everything is not absolutly perfect it just will not work properly, there is no room for error.



This is a major design problem for these type of decks. I think that Teac knew that this was an issue near the end of the run for these types. I also have a A-2300SR. Teac added a stationery tape guide to the 2300SX to keep the tape better inline with the pinch roller & capstan and prevent this issue. It is also seen on the newer X-3R that I have as well. (See Attached Pics).

I am in the process of trying to make one these, I am removing the guide from my 2300SX and a friend of mine is going to try and dupiclate it on a metal lathe. It will be made from stainless steel and the surface that the tape rides on will be completely polished. This will take a while, probably will not be done until after Christmas. If it works well, I will install one on my A-6300 as well as my A-4300SX.


Hi,

Did your problem just start suddenly? On your 6300 does the right arm tension arm vibrate during playback. By vibrate I mean moves back and fourth in a jerky fashion, not a smooth movement, like the 4300SX. Also comparing the 6300 to the 4300SX the 4300SX right arm seems to be stiffer, more resistence to movement. Comparing my two 6300's, I can't really feel any difference, between the tension of the two arms. They both have the jerking action.

How did you check the spring tension and the alignment of the right arm?

What I am thinking is that the tension on the arm is not enough and when the deck goes into reverse playback the arm jerks just enough knocking the tape out of alignment casuing the tape to slide between the roller and capstan. Yesterday, the tape was rolling off the top every time, not today, the tape is rolling off the bottom every time. I think the only thing that changed is reel itself, that I am using for the tape up reel, right reel. The back tension is now different, the arm adjusts the tension, and jerks slightly causing tape path misalignment, then the tape slides to the bottom. The length of tape required on the left reel is far less than yesterday, to stop roll off.

Ozric
11-30-2007, 01:56 PM
Russ1965

Thanks for the link to Magnetic Head Company. I spoke to Joe and he is sending me two of the TG-7 Tape Guide Posts. I will mount these and report back on my findings, hopefully sometime next week. They look almost identical to the one used on my A-2300SR

As far as my A-6300, unfortunately I can't tell you when it started, as I acquired the machine about 8 weeks ago and it already had the problem. As far as checking the spring tension on the right arm, I do not have any way of testing that because I do not have a tension gauge, but I tried moving back or forth when playing the tape and it made no difference. As far as alignment, I first tried doing it by sight, adjusting it so that the tape ran dead center of the in the pinch roller and the tape guide at the right edge of the head stack, but the problem persisted. I can put my finger on the edge of the right reel, add some extra back tension and the problem goes away. I then marked the variable resistor that controls back tension, and tried to make some adjustments to it, but I still could not stop the issue, so I returned the resistor back to its original setting. The pinch roller is new, and the capstan and tape path is perfectly clean. As far as the arm moving back & forth, it varies depending on type of tape used, how well the tape is packed on the reel, and how well the reel is centered on the spindle. I am going to give these extra guides a try and see what happens. My 2300SR and my X-3R do not suffer from this issue at all. The 6300 does it every time and my 4300SX does it occasionally.

jblmar
11-30-2007, 03:55 PM
Thanks Ron,
I don't think it is the capstan since after every 10 hours of use I clean the entire tape path, and I lightly brush it with nylon pad.

Bob

Hi Bob,
Cleaning isn't the issue I was referring to. The capstan wears over time. As a result it doesn't grab the tape as well as it did.

Ron

pustelniakr
11-30-2007, 04:16 PM
Hi Bob,
Cleaning isn't the issue I was referring to. The capstan wears over time. As a result it doesn't grab the tape as well as it did.

Ron
One significant note: The capstan drives the pinch roller. The pinch roller drives the tape. Therefore, you must be sure that the pinch roller has significant meat exposed to the capstan, on both sides of the tape.

Enjoy,
Rich P

jblmar
11-30-2007, 04:44 PM
One significant note: The capstan drives the pinch roller. The pinch roller drives the tape. Therefore, you must be sure that the pinch roller has significant meat exposed to the capstan, on both sides of the tape.

Enjoy,
Rich P

Hey rich,
That's why I think he has a hardened pinch roller.

I stated a few post back that the deck pulls the tape in forward and pushes the tape in reverse. A compromise design having the capstan/pinch roller on one side only. The pinch roller must be in good working order.

If IPA is used as a cleaner (not saying you did) the rubber will harden and shrink resulting in poor performance.

I would order a new pinch roller from Teac. It might just cure your problem.:yes:

Ron

russ1965
11-30-2007, 09:41 PM
Hi Bob,
Cleaning isn't the issue I was referring to. The capstan wears over time. As a result it doesn't grab the tape as well as it did.

Ron

Ron,

Just measured all 4 machines capstans with micrometer all four are the same front to back. The nylon pad brushing I hope stops the tape travel from polishing the capstan.

russ1965
12-01-2007, 12:47 AM
Hi Ron,

I can order pinch roller or have mine rebuilt (if Teac doesn't have any) it would good to have spare. But when I put the pinch roller from the Teac 6300 with no roll off, in the problem machine, the roll off still exits. The pinch roller from the problem machine causes no roll off on the machine with no roll off problems. The 4300 that I used for parts had roll off 3 out of 4 times any where on the tape, when put in reverse play. That pinch roller is shinny and is hard compared to these rollers.

Like you said earlier everything is interrelated. I thought the switch of the pinch rollers test would have eliminated the pinch roller. The next test was the finger on the reel to see if that stops the problem, it did. The tape path from the right tension arm looks like it is aligned, tape in center of the pinch roller and the notches on the arm line up with notches on the on first tape guide. However the arm moves, and does that jerky movement, and when it does that it may not line up with the tape guides.

If I had a gauge I would check the pinch roller pressure and then check Back tension, take up torque, and make the adjustments, starting in the order the manual states.

Fred also said to check for any sticky surface on the right tension arm. Knowing the problems with back coated tapes, and this was a back coated tape, I cleaned the tape path and tried it again, same problem. I then tried a non back coated tape. This is where I think I changed take up reels (right reel) from a Maxell to Ampex, the tape still rolled off put this time from the bottom, not the top, and would not roll off six inches form leader when engaging reverse play. 20 times in row no roll off at 1". Engaging reverse play less than 1" from the leader or on the leader, roll off occurred, and I noticed the right tension arm acted differently before roll off occurred. Switched back to 180b tape, roll off did not occur when engaging reverse play after six counter marks from the leader, yesterday I need like 1/4 " on take up reel (left reel) to stop the roll off and it was at the top, not the bottom.

Why the change from yesterday? I don't know. It could be the reel change, or the machine got more exercise going in reverse play than it did in 6 months, maybe everything was just stiff. I don't know. I would like to get the deck running so I can continue transferring the tapes from the Scotch tapes, that are starting to go bad, to Maxell.

Bob

Ozric
12-01-2007, 01:03 AM
russ1965,

Teac does have new pinch rollers for this machine, they are the same ones used on all the X-Series machines. I have a new one on my A-6300, the problem still exists. As far as older pinch rollers, I usually take a piece of fine sandpaper and sand the surface of the roller and expose some fresh rubber, then I thoroughly clean it with Techspray Rubber Rejuvenator and finally wipe it off with a little Windex to get rid of the slippery residue left by the rubber conditioner.

russ1965
12-01-2007, 08:46 PM
russ1965,

Teac does have new pinch rollers for this machine, they are the same ones used on all the X-Series machines. I have a new one on my A-6300, the problem still exists. As far as older pinch rollers, I usually take a piece of fine sandpaper and sand the surface of the roller and expose some fresh rubber, then I thoroughly clean it with Techspray Rubber Rejuvenator and finally wipe it off with a little Windex to get rid of the slippery residue left by the rubber conditioner.

Just a thought on the installation of the guide. When you use 10" reels and engage the switch for large reels the right tension arm shifts to a different positon then were the tension arm is at with 7" reels. The shift changes the tape path to change were you intend to mount the guide. Just playing with the good 6300 1/3 of tape on the left reel 2/3 on the right reel. The arm moves all the way to the left stop in reverse play, in the forward play about 15 degrees to the right of center. Engaging the small reel switch, in reverse play the arm is 1/2 to the left of center from the stop, and in forward play the arm is less than 15 degrees of right of center around 10 degrees. So the mounting of the guide would have to close to the capstan cap about 1/4 " from it. I would temp. mount it with double sided tape to test where it preforms best, before drilling.

Bob

russ1965
12-01-2007, 08:51 PM
Just a thought on the installation of the guide. When you use 10" reels and engage the switch for large reels the right tension arm shifts to a different positon then were the tension arm is at with 7" reels. The shift changes the tape path to change were you intend to mount the guide. Just playing with the good 6300 1/3 of tape on the left reel 2/3 on the right reel. The arm moves all the way to the left stop in reverse play, in the forward play about 15 degrees to the right of center. Engaging the small reel switch, in reverse play the arm is 1/2 to the left of center from the stop, and in forward play the arm is less than 15 degrees of right of center around 10 degrees. So the mounting of the guide would have to close to the capstan cap about 1/4 " from it. I would temp. mount it with double sided tape to test where it preforms best, before drilling.

Bob

I use the nylon pad to rough it up. It is similar to the ones used for pots, I got 1/2 dozen from a furniture refinisher.

Ozric
12-01-2007, 09:56 PM
I will definitally try different positions for the extra guide post. I will not drill any holes until I have picked the optium position that works with 7" and 10.5" reels at all stages of tape play (full reel, half reel, end of reel). The parts should arrive on Monday or Tuesday and I will start experimenting with them and report back.

russ1965
12-02-2007, 11:53 AM
I will definitally try different positions for the extra guide post. I will not drill any holes until I have picked the optium position that works with 7" and 10.5" reels at all stages of tape play (full reel, half reel, end of reel). The parts should arrive on Monday or Tuesday and I will start experimenting with them and report back.



Thanks for the info on the roller. In my post 31 the Reel “switchout”, is reversed, (from a Ampex Reel to a Maxell Reel). I am currently using both Maxell Reels.

This may sound ridiculous, but after sending the right tension arm report to you, I put the “tape set” (both Maxell reels, left reel 1/3 tape, right reel 2/3 tape) back on the deck with problems. I noticed that the right reel with 2/3 tape, after engaging the forward play, had a noticeable ridge build up, to the top of the reel. I ran the tape all the way to the leader and engaged reverse play, the tape rolled off the bottom. 1” from the leader the tape did not roll off, same as before. I then examined the height adjustment of the right reel platter with the tape at where the ridge started, and adjusted the height of the reel platter so there was no ridge build up, that I could tell. The platter was very hard to move with the set screws almost fully out. When I tightened the set screws, it appeared to me that I got then set deeper the before. Then I tested it, about 20 times last night with about 3” of leader as the start point, no roll off, Going beyond the 3”, roll off. Tested again this morning 5 times no roll off at 3”, at 4” started to roll off, but recovered. Again the roll off was to the bottom, and beyond 4” roll off occurred. I do not know what adjustment you really start with. The service manual says height adjustment is only necessary if the motor is changed or excessive reel rub. It doesn’t address the roll off problem in the manual, which appears to be major problem.

Like Ron stated with his 4300 everything is very interrelated. With the 6300 more so, since the tension is adjusted with the small / large wheel switch. It is not like my Bell Sound Labs T-347, tape roll off, operators manual says adjust the tape guide 1 with xxx size allen wrench, opposite direction of roll off, make sure to tighten lock screw, after adjustment. Oh for the old days when the quality stuff was made in the US, (This sounds like my father) and manuals were not literally translated five times before you got the English version, which may or may not be correct. When, the biggest thing Honda imported in the US was 90 CC motorcycles (1965). That operators manual was joke, The Honorable Honda Motorcycle adjustment xxxx , what it meant was, The Honda is a precision motorcycle, and the adjustment xxxx. The Honorable starter requires xxxx. Everything that was high quality, precision, the best quality was translated as honorable.

Bob

Ozric
12-08-2007, 01:58 AM
I received my tape guides a couple of days ago from Joe at the Magnetic Head Company (great guy by the way) and have had some time to play around with the mounting location on my A-6300. First off putting it in the position that is similar to my A-2300SR did not work well, the tape still slipped off the roller and the extra guide, so I started moving the guide around into different places until I found one that worked. Unfortunately I am not quite thrilled with the location that works. It is down about two thirds of the height of the pinch roller which brings the tape down the front surface of the pinch roller. I do not know that this is a bad thing, but it works perfect, tape will not slip off at all. One drawback is that it causes the pinch roller to rotate during FF and RWD as it keeps the tape in contact with the roller even when the roller is down away from the heads. I don’t think this will cause any harm. The beauty of this location is that you can choose to use or not to use it. If you choose not to use it, just thread the tape the normal way and it will also work fine as the extra post does not interfere with regular operation or the tape tensioner. It can just sit there as a dummy if not needed. For the time being, I still have it mounted to the mounting bracket that came with it and have taped into place with masking tape until I am 100% sure that is where I want it. When I decide the absolute final mounting position, I will the drill a hole on the face of the deck and mount it on its post by itself. The guide is adjustable on the shaft and has an allen set screw in the center to lock it down, adjusting this to the other guides is very easy after it is installed.

Please let me know what you think of this modification, do you think it is going to cause any harm ? Tape and transport operation seem to work perfectly so far. :scratch2:

Ozric
12-10-2007, 06:32 PM
Anybody have any thoughts on this modification before I go drilling into this machine ? I have not been able to make any adjustments (back tension or torque) that will affect this issue and it seem to be the only thing that I can get to work.