Akai M-10 motor pulley - what models share this one?

[audiojones]

Hi -

I'm in the process of resurrecting a nice old Akai M-10 portable reel-to-reel machine and the last thing I need (I hope!) is a replacement for the cracked motor pulley. The pulley surface seems to be made of a hard ceramic material that has somehow cracked and become uneven, so it's hard to get a good measurement. Best I can get is roughly 22mm for the smaller 60hz pulley and 26.20mm for the 50hz pulley (which I'm not as concerned about since I doubt it will ever see 50hz use anyway).

Anyone know which other Akai models share this pulley? The 3 speed motor that it attaches to is Akai #HC-16X. The transport mechanism on this machine is the 3 motor auto-reverse type used from roughly 1968 to 1974 or so. It's the one that shifts into pause automatically at the end of play (retracting the pinch roller), and at the end of FF or REW it automatically shifts the FF/REW lever to the stop position. It looks like the same transport used on the X-201D and a few others, so if you have any info on which other machines I can find this part on it would be greatly appreciated!

Here are a couple of pics -

 

[aldena007]

Akai M-10 Motor Pulley

The material for the pulley may not be ceramic but rubber that has completely dried out and hardened. I would try to get that rebuilt by Terrys Rubber Rollers. I have sourced some rollers (pullys?) from him and it is high quality. I could be wrong however.

 

[audiojones]

The material for the pulley may not be ceramic but rubber that has completely dried out and hardened. I would try to get that rebuilt by Terrys Rubber Rollers. I have sourced some rollers (pullys?) from him and it is high quality. I could be wrong however.

Before I removed it from the motor shaft I thought it was supposed to be rubber or plastic but it's a very heavy, dense material like ceramic or some kind of metal (of course I could be wrong). All of the other rubber and plastic parts on this machine are in excellent shape, even the drive belt and circuit board connector housing (which is notorious for cracking and falling apart) so I don't think it was stored in an unconditioned area. Not sure Terry can do this one but hopefully I can find a good used one from another model. Thanks for the tip, though! :thmbsp:

 

[higgles5]

Hi -

I'm in the process of resurrecting a nice old Akai M-10 portable reel-to-reel machine and the last thing I need (I hope!) is a replacement for the cracked motor pulley. The pulley surface seems to be made of a hard ceramic material that has somehow cracked and become uneven, so it's hard to get a good measurement. Best I can get is roughly 22mm for the smaller 60hz pulley and 26.20mm for the 50hz pulley (which I'm not as concerned about since I doubt it will ever see 50hz use anyway).

Anyone know which other Akai models share this pulley? The 3 speed motor that it attaches to is Akai #HC-16X. The transport mechanism on this machine is the 3 motor auto-reverse type used from roughly 1968 to 1974 or so. It's the one that shifts into pause automatically at the end of play (retracting the pinch roller), and at the end of FF or REW it automatically shifts the FF/REW lever to the stop position. It looks like the same transport used on the X-201D and a few others, so if you have any info on which other machines I can find this part on it would be greatly appreciated!

Here are a couple of pics -

@audiojones

Resurrecting this 13 year old post in hopes you may have found an answer eventually for this. I too have the same issue with my M-10's motor pulley, hoping you eventually sourced something and can pass it along. Thanks!

 

[audiojones]

Hi -

Hard to believe it’s been 13 years! Yes I repaired my M-10 thanks to a very kind local AK’er who reached out and offered a me a parts M-10 unit that still had a good pulley and a bunch of other parts I needed. It appears that the pulley for the M-10 is somewhat specific to that machine in that the diameter is properly sized for the flywheel. I found other pulleys that fit the motor and looked similar, but the crucial diameter was wrong which of course affected the final drive speed. BTW the pulley is made of a cast metal material, but it is much more refined and a higher density than the pot metal used in some of the function lever cams. I’ve worked on many, many Akai decks of this vintage and so far yours and mine are the only ones I’ve ever heard of with this problem so I don’t know how common it is.

I wouldn’t be surprised if other machines use the same combination of drive pulley and flywheel as the M-10, but unfortunately I lost all of my Akai parts lists and manuals in a computer crash a few years ago. HiFi engine has a service manual and might have a parts list that can be looked up / cross referenced but I don’t know how complete it is.

BTW that M-10 is still going strong, it gets used quite often as a stand-alone tape deck through external speakers down in my shop. Whenever I’m working on something at my bench i like to throw a reel of tape on and let it play in the background. Amazing how great it sounds through external speakers (the built-in speakers sound awful, though).

Hope this helps, good luck with it!

 

[higgles5]

Hi -

Hard to believe it’s been 13 years! Yes I repaired my M-10 thanks to a very kind local AK’er who reached out and offered a me a parts M-10 unit that still had a good pulley and a bunch of other parts I needed. It appears that the pulley for the M-10 is somewhat specific to that machine in that the diameter is properly sized for the flywheel. I found other pulleys that fit the motor and looked similar, but the crucial diameter was wrong which of course affected the final drive speed. BTW the pulley is made of a cast metal material, but it is much more refined and a higher density than the pot metal used in some of the function lever cams. I’ve worked on many, many Akai decks of this vintage and so far yours and mine are the only ones I’ve ever heard of with this problem so I don’t know how common it is.

I wouldn’t be surprised if other machines use the same combination of drive pulley and flywheel as the M-10, but unfortunately I lost all of my Akai parts lists and manuals in a computer crash a few years ago. HiFi engine has a service manual and might have a parts list that can be looked up / cross referenced but I don’t know how complete it is.

BTW that M-10 is still going strong, it gets used quite often as a stand-alone tape deck through external speakers down in my shop. Whenever I’m working on something at my bench i like to throw a reel of tape on and let it play in the background. Amazing how great it sounds through external speakers (the built-in speakers sound awful, though).

Hope this helps, good luck with it!

Thanks for the reply! That's unfortunate for me thought. I currently can't find any "for parts" M-10's or Roberts 800x's (what I have) out there, and eBay doesn't have any motor or capstan parts currently.

I can confirm, it does appear to be a cast metal of some kind that has somehow cracked and splintered. Wonder if the casting process was known to have problems, I know the cams on these models have similar issues due to the aluminum casting that was used.

I did check out there for manuals, I am able to find Service and Owners manuals, but unfortunately not a Parts List that would give me something to go off of.

Currently my deck is working, but running a consistent 6.75% - 7% fast in all speeds. Replaced the Pinch Roller and Capstan belt, but the issue persists. This is the last know part to me that appears broken, I assume as it has cracked the diameter of the pulley has increased and therefore changed all playback speeds by the same amount, but unless I can replace it with a like OEM part, I will not know if that's the case.

Is there any chance you would be able to confirm the diameter of the 50 and 60 hertz sections of the pulley with a set of calipers? I'm considering trying something like 3D Printing or on demand CNC services to commission a replacement part, I have the rest of the dimensions that I need other than the critical ones of the proper diameters for these sections. It would also help me to know how badly out of spec my current one is, before I put in all that effort to replace it, in case it's not the reason for my speed increase. I know that's a lot to ask, as it would require you to remove the whole transport assembly to get a set of calipers into there to measure.