Akai X-1800SD capstan sleeves and pinch wheels...

[thebeez85]

alrighty guys, Im slowly getting back into my R2R world and have questions:

I lost my capstan sleeve (i only have the chunkier one), and need another for recording/playing 7.5 IPS tapes.

As far as the rubber pinch wheel/combination goes, I've always been able to use either no capstan sleeve or the large one for, if I'm correct, playing 1 7/8, 3 3/4, 7.5 and 15 IPS.

I have the manual on-hand in my google drive for quick reference.

below, on the left, was the only capstan sleeve I had...

per the manual, the one on the right is what is to be used for 7.5 IPS yet, I was able to use the large one with the speed switch set to LOW. Does that mean that with the large capstan sleeve and the speed switch on HIGH, i'm getting 15IPS?


The combination of the speed switch, two different capstan sleeves available, and apparently two different rubber pinch wheels, has me befuddled. Can you get the same speeds with different sleeve/speed switch/pinch wheel combinations?

 

[dhnash]

Does that mean that with the large capstan sleeve and the speed switch on HIGH, i'm getting 15IPS?

The combination of the speed switch, two different capstan sleeves available, and apparently two different rubber pinch wheels, has me befuddled. Can you get the same speeds with different sleeve/speed switch/pinch wheel combinations?

Pages 6 and 7 of the instructions/owners manual provide information that may help answer your questions. The tape speed switch has two positions LOW and HIGH. According to the chart, the 3.75 IPS speed is normally achieved by placing the speed switch is the LOW position and using the smaller capstan bushing (the one on the right in the photo in your post). If the bushing is not used, operation at 3.75 IPS can also be achieved with the speed switch moved to the HIGH position. Operation at 7.5 IPS is normally achieved by using the smaller capstan bushing and placing the speed switch in the HIGH position. If you use the larger bushing (the one on left in the photo) along with the pinch roller designed for use with that bushing, you can achieve operation at 7.5 IPS with the speed switch moved to the LOW position.

 

[thebeez85]

hey dhnash!

correct - sooo...is the (smaller?) rubber pinch wheel and smaller capstan sleeve absolutely necessary to achieve all 4 speeds?

 

[dhnash]

1.875 IPS can be achieved using the LOW speed switch position and NO capstan bushing.
3.75 IPS can be achieved using the HIGH speed switch position and NO capstan bushing.
7.5 IPS can be achieved using the LOW speed switch position and the LARGE capstan bushing w/SMALL pinch roller.
15 IPS can be achieved using the HIGH speed switch position and the LARGE capstan bushing w/SMALL pinch roller.

 

[thebeez85]

so follow up question then: since I was able to play 15IPS tapes before, assuming the pinch roller is correct for that speed, what diameter/part number, etc is the larger pinch wheel to be used with the smaller capstan bushing?

edit: maybe Im missing something...there should be two different pinch wheel sizes available, correct? Still confusing seeing as im using the (i think) smaller pinch wheel for 15IPS but can also use the same pinch wheel with NO bushing at all, just the bare capstan

 

[MRL_Audio]

I believe OakTree Village seems the smaller sleeve your looking for. eBay sometimes has both of these.

 

[thebeez85]

MRL_Audio, correct: I'll be ordering one soon, maybe along with the smaller capstan sleeve (if its even necessary)

I guess my question Im trying to answer is: Why two different pinch wheels and bushings?

What's the other pinch wheel size, that is used with the normal bushing/no bushing?

I was previously able to achieve all 4 speeds (i think), with the one (smaller?) pinch wheel and either no bushing or my 15IPS large bushing

edit: this is the only pinch wheel I have (at least im pretty sure)
https://i.ebayimg.com/images/g/CTgAAOSwNWhbwlQE/s-l1600.jpg

 

[dhnash]

Reviewing this earlier thread on the same topic may provide an answer to some of your questions.

http://audiokarma.org/forums/index.php?threads/akai-x-1800sd-15ips.737238/#post-9987692

Why two different pinch wheels and bushings?

The larger capstan bushing was required to achieve the 15 IPS speed. The use of a different (smaller) pinch roller with the larger capstan bushing was probably necessary in order to maintain proper pinch roller pressure. I'm not sure why Akai chose to use the smaller capstan bushing since it should have been possible to achieve all four speeds using either no bushing and the normal pinch roller or the larger bushing with its corresponding (smaller) pinch roller. Perhaps they felt that since the most common operating speeds would be 3.75 and 7.5 IPS, it made more sense to provide a bushing that would allow these speeds to be achieved using a single bushing and the tape speed switch to switch between these two speeds. This would also eliminate the need to change the pinch roller.

 

[thebeez85]

so my next question: why would I need a different pinch roller and the 7.5 capstan bushing, when I can use my current pinch roller with the 15IPS bushing and NO bushing?

 

[thebeez85]

If I re-read post #4, it sounds like 7.5 IPS can be achieved with two different bushings/pinch rollers/switch settings.

It sounds as though using the actual 7.5IPS bushing would help produce less W&F, correct?

 

[dhnash]

so my next question: why would I need a different pinch roller and the 7.5 capstan bushing, when I can use my current pinch roller with the 15IPS bushing and NO bushing?

This is certainly an option as I indicated. The use of the pinch roller designed for use with each capstan bushing (or no bushing) is recommended in order to provide proper pinch roller pressure which helps to maintain good contact between the tape and the capstan shaft.

It sounds as though using the actual 7.5IPS bushing would help produce less W&F, correct?

Most likely, but this can only be confirmed through appropriate testing.

 

[thebeez85]

This is certainly an option as I indicated. The use of the pinch roller designed for use with each capstan bushing (or no bushing) is recommended in order to provide proper pinch roller pressure which helps to maintain good contact between the tape and the capstan shaft.
Most likely, but this can only be confirmed through appropriate testing.

Thanks again for your patience dhnash and others! I kinda get how you can kludge your way to different speeds with different settings,parts, adaptors.

Just ordered a splice kit with leader and all for making some custom tapes of some of my vinyl collection

 

[corpblues]

I'm looking for one of these sleeves without any luck. Let me know if you can help.

 

[corpblues]

I found one at http://www.oaktreevintage.com for $38.50
They have newly made capstan sleeves made for many models.

Described on site as

AKAI / ROBERTS-Rheem
7.5ips "SHORT" SPEED SLEEVE

REEL TO REEL TAPE DECK
CAPSTAN BUSHING / SPEED CHANGE SLEEVE ADAPTOR
FOR DECKS WITH AN OUTER
'RIDGE' / 'LIP'
ON THE PINCH ROLLER
MADE OF "HARD, NON-MAGNETIC 7075 ALUMINUM ALLOY" IN THE USA!
for sale
This is a new capstan bushing / speed change sleeve adapter for certain Akai & Roberts-Rheem Reel to Reel Tape decks, whose rubber pinch roller has a small ridge or lip on the outside edge (the 'edge' or 'lip' was originally designed into these pinch rollers to keep the speed sleeve and I suppose the tape 'in place' but was really un-necessary, as the speed sleeve generally stays in place by it's own pressure), such as the; ​

FITS:
Akai M9 / M-9, 1800 series, X-1800SD, 1800-DSS X-2000S, X-2000SD models and
Robert's / Rheem model 770X-SS, 771X SS, 778X and maybe others .