Jammed capstan sleeve - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

DMcMahon · 4th Jun 2020, 9:27 am

Quote:

Originally Posted by red16v

Various ways of fitting the resized capstan to the original. This website has some useful info.

http://www.oaktreevintage.com/Akai_R...eplacement.htm

Very interesting.

DMcMahon · 4th Jun 2020, 9:30 am

Quote:

Originally Posted by red16v

Quote:

Originally Posted by DMcMahon

Interesting, I have not seen the keyed/notched type before on Akai.

David, looking back this is a kit I bought for the X201D I recently passed on to you. But, it did not fit and the hifi shop I bought it from was most embarrassed! Note that the pinchwheel is a smaller diameter than the OEM one - that is probably the one I found and gave you, the capstan is long gone - it was nearly 50 years ago!

https://www.ebay.co.uk/itm/Genuine-A...-/113961240009

I assume it did not fit because as far as I can see the X-201D never had a removable capstan sleeve.

PaulR · 4th Jun 2020, 9:38 am

I had - still have somewhere actually - a 4000DS. The capstan sleeve used to stick on this sometimes. I assumed it was due to a build up of tape debris. Lighter fluid or penetrating oil would loosen it. There was always lighter fluid around in those days of fairly universal smoking!

I am not sure whether WD40 had been invented in the early 1970s but I imagine it would penetrate sufficiently to loosen it. The lighter fluid would then come in useful to get rid of the WD40!

Restoration73 · 4th Jun 2020, 10:19 am

The X-2000 (reel/cassette/8-track) recorder had a keyed push on capstan.

The smaller capstan should always be kept free of oxide.

Interestingly, the X-1900 reel/cassette was supplied with both extra capstan and also reduced diameter pinch roller for 15 ips. The latter was stored on the wooden lid.

DMcMahon · 4th Jun 2020, 11:42 am

Quote:

Originally Posted by Radio Wrangler

4000GS is a facelifted version with their Glass and Xtal head. Track switch moved out of head box as well.

Tha Akai sleeves are not keyed an any way, but what most people don't notice is that the bottom end of the capstan had a conical flare as it steps up to a larger diameter. The sleeve has a slight conical rebate on its opening, so when it sits on the capstan cone-on-cone gives accurate centring The underside of the nut is flat and faces onto the flat face of the outer end of the sleeve. It takes decent precision to not have terrible flutter with a sleeve adaptor, and it's the 7.5IPS speed that bears the brunt.

David

I do not think I have seen the conical flare/rebate version, the various 4000 machines I have, both ends of the sleeve are flat. GX-4000D photos attached.

Radio Wrangler · 4th Jun 2020, 11:55 am

My 4000DS looked just like that except yours shows a deliberate undercut to remove any radius effect at the root end of the & 3/4 IPS capstan. Mine had a deliberate but very small cone in the root, just a little bit larger than the clearance on the bore of the sleeve.

The sleeve has a slight chamfer to the entry to the bore at each end, so it didn't matter which way round it was fitted.

I wonder if they did a change? Going to a simple cylinder bore on a cylinder inner capstan with flat faces to the ends of the sleeve would work, but there would be a nasty compromise between any clearance allowing the sleeve to tighten up slightly off centre, giving flutter, or not enough clearance causing it to stick in place?

I never had problems with the sleeve sticking.

My problem was I kept wearing out the bearing bushes of the spool spindles.

I enjoyed my old 4000DS it did a lot of work for me. and took an A77 to replace it.

David

ms660 · 4th Jun 2020, 12:17 pm

I got lost with the model number given in the first post, but I'm guessing it's the usual type of capstan sleeve, unscrew top nut/cap and pull sleeve off, if jammed try plus gas or similar or heat or both.

Lawrence.

DMcMahon · 4th Jun 2020, 1:32 pm

The standard non keyed sleeves can be a bit tight, but generally when tight holding the flywheel and CW/ACW twisting the sleeve plus pulling at same time normally gets them off. Have never had to use heat or penetrating lubricant.

TALKINGWITHPYE · 5th Jun 2020, 2:31 pm

Hi all, got the problem sorted,I held the pointed end of my smoothing iron against the sleeve while the iron was still hot after ironing laundry. Then gripped the top part of the sleeve with adjustable grips and switched the machine on while holding the grips,lifted the auto stop lever and the sleeve released.
Mods this thread can now be closed.

DMcMahon · 5th Jun 2020, 4:03 pm

So is 4000GS the correct model number ?

Ted Kendall · 5th Jun 2020, 4:18 pm

Not good practice to put mole grips on a capstan shaft!

TALKINGWITHPYE · 6th Jun 2020, 2:39 pm

Yes I got the model wrong it is a gx4000d and as to using the molegrips I made sure they were only on the tip of the sleeve furthest from the deck itself and with just enough grip to hold it against the force of the capstan spin.

4th Jun 2020, 9:38 am	#23
PaulR Dekatron Join Date: Oct 2003 Location: Southport Lancashire, UK. Posts: 3,233	Re: Jammed capstan sleeve I had - still have somewhere actually - a 4000DS. The capstan sleeve used to stick on this sometimes. I assumed it was due to a build up of tape debris. Lighter fluid or penetrating oil would loosen it. There was always lighter fluid around in those days of fairly universal smoking! I am not sure whether WD40 had been invented in the early 1970s but I imagine it would penetrate sufficiently to loosen it. The lighter fluid would then come in useful to get rid of the WD40! __________________ Paul

4th Jun 2020, 10:19 am	#24
Restoration73 Nonode Join Date: Jun 2013 Location: Surbiton, SW London, UK. Posts: 2,801	Re: Jammed capstan sleeve The X-2000 (reel/cassette/8-track) recorder had a keyed push on capstan. The smaller capstan should always be kept free of oxide. Interestingly, the X-1900 reel/cassette was supplied with both extra capstan and also reduced diameter pinch roller for 15 ips. The latter was stored on the wooden lid.

4th Jun 2020, 11:55 am	#26
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,871	Re: Jammed capstan sleeve My 4000DS looked just like that except yours shows a deliberate undercut to remove any radius effect at the root end of the & 3/4 IPS capstan. Mine had a deliberate but very small cone in the root, just a little bit larger than the clearance on the bore of the sleeve. The sleeve has a slight chamfer to the entry to the bore at each end, so it didn't matter which way round it was fitted. I wonder if they did a change? Going to a simple cylinder bore on a cylinder inner capstan with flat faces to the ends of the sleeve would work, but there would be a nasty compromise between any clearance allowing the sleeve to tighten up slightly off centre, giving flutter, or not enough clearance causing it to stick in place? I never had problems with the sleeve sticking. My problem was I kept wearing out the bearing bushes of the spool spindles. I enjoyed my old 4000DS it did a lot of work for me. and took an A77 to replace it. David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

4th Jun 2020, 12:17 pm	#27
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Jammed capstan sleeve I got lost with the model number given in the first post, but I'm guessing it's the usual type of capstan sleeve, unscrew top nut/cap and pull sleeve off, if jammed try plus gas or similar or heat or both. Lawrence.

4th Jun 2020, 1:32 pm	#28
DMcMahon Dekatron Join Date: Apr 2019 Location: Worthing, West Sussex, UK. Posts: 6,600	Re: Jammed capstan sleeve The standard non keyed sleeves can be a bit tight, but generally when tight holding the flywheel and CW/ACW twisting the sleeve plus pulling at same time normally gets them off. Have never had to use heat or penetrating lubricant.

5th Jun 2020, 2:31 pm	#29
TALKINGWITHPYE Pentode Join Date: Oct 2018 Location: Carrickfergus, County Antrim, Northern Ireland, UK. Posts: 126	Re: Jammed capstan sleeve Hi all, got the problem sorted,I held the pointed end of my smoothing iron against the sleeve while the iron was still hot after ironing laundry. Then gripped the top part of the sleeve with adjustable grips and switched the machine on while holding the grips,lifted the auto stop lever and the sleeve released. Mods this thread can now be closed.

5th Jun 2020, 4:03 pm	#30
DMcMahon Dekatron Join Date: Apr 2019 Location: Worthing, West Sussex, UK. Posts: 6,600	Re: Jammed capstan sleeve So is 4000GS the correct model number ?

5th Jun 2020, 4:18 pm	#31
Ted Kendall Dekatron Join Date: Jul 2008 Location: Kington, Herefordshire, UK. Posts: 3,670	Re: Jammed capstan sleeve Not good practice to put mole grips on a capstan shaft!

6th Jun 2020, 2:39 pm	#32
TALKINGWITHPYE Pentode Join Date: Oct 2018 Location: Carrickfergus, County Antrim, Northern Ireland, UK. Posts: 126	Re: Jammed capstan sleeve Yes I got the model wrong it is a gx4000d and as to using the molegrips I made sure they were only on the tip of the sleeve furthest from the deck itself and with just enough grip to hold it against the force of the capstan spin.