Belt sizes or manual for JVC RC-880? Restoration supplies and tools?

[amoorey]

Hello from Canada,

I just acquired my first restoration project, an RC-880 that I’m restoring for my 19 year old son so he can understand the world of tapes and music beyond his phone. I’ve looked through the wonderful resources within the site here but can’t find a PDF service manual or the belt specs. I just got the box today and haven’t started opening it up yet but thought I’d try and get a jump in things and order the belts. Failing the exact specs, I read somewhere that I should perhaps buy a universal belt kit? Are there any other cleaning or lube supplies and tools I should start pulling together? Thanks!

 

[robitaille03]

I'd probably grab this: https://www.ebay.com/itm/335156841405

 

[amoorey]

I'd probably grab this: https://www.ebay.com/itm/335156841405

Yes, I saw that. I’m asking if they will ship to Canada. I also have a lead on a PDF version. Thanks for flagging though!

 

[robitaille03]

Also this is the lube that was recommended to me when I was restoring my GE 3-5259A, and it seems to be doing the trick:

https://www.amazon.com/dp/B000XBH9HI

 

[amoorey]

Also this is the lube that was recommended to me when I was restoring my GE 3-5259A, and it seems to be doing the trick:

https://www.amazon.com/dp/B000XBH9HI

Oh nice, thanks!

 

[amoorey]

Ok, I have purchased a PDF service manual and the belts are JVC part numbers VKB3001-021 (Capstan belt) and VKB3000-070 (belt). I can’t find any direct matches for replacements online but ChatGPT is suggesting SBM11.5 and SBM6.5. I’d be happy to try a universal type package of belts but the service manual doesn’t state the belt lengths or diameter so I’m not sure which pack to get. I have emailed KP Components which are based in Canada, same as me. I haven’t got into the box yet, trying to order the belts ahead of time but maybe the easiest solution is opening it up and measuring the belts?

 

[caution]

SBM6.5 is correct for VKB300070, it's here (link)
I see no information about VKB3001021

 

[amoorey]

SBM6.5 is correct for VKB300070, it's here (link)
I see no information about VKB3001021

Thanks! Here is a snip from the manual.

 

[Superduper]

Interestingly, I just serviced one of these about 3 months ago. It did have some cracked gears so that meant it could only run in fwd direction, reverse wouldn't work right. Sometimes, you just have to remove the deck, take out the belt and measure it, and order the correct size. Factory belts do tend to stretch over time so you might want to order it ~ .2 or .3 inches shorter.

 

[amoorey]

Interestingly, I just serviced one of these about 3 months ago. It did have some cracked gears so that meant it could only run in fwd direction, reverse wouldn't work right. Sometimes, you just have to remove the deck, take out the belt and measure it, and order the correct size. Factory belts do tend to stretch over time so you might want to order it ~ .2 or .3 inches shorter.

Very interesting that you just worked on one. Currently the tuner and speakers are fine but tape deck is stuck in play position so door won’t open. I understand that this might be a belt issue. I will open it up this week and see what’s up. This is my first restoration of a box so excitedly nervous…. Where is your favourite place for replacement parts? Where did you find replacement gears?

 

[Superduper]

Didn’t fix the gears, replacement gears are non existent. Sadly not everything in a malfunctioning boombox can be restored without replacement parts. If high demand item, sometimes ingenious folks can recreate parts but this boombox isn’t that common and by extension, replacement gear demand isn’t high on the list of things that would end up being created. It’s a supply and demand thing.

 

[Superduper]

If you look closely, one cracked (split) gear is visible. There is another one that isn’t visible due to moving assembly and smallish size. When played in reverse position, there is obvious clicking as the cracked gear tries to mesh and other issues were present. So unfortunately, can only play this in the fwd position and it would be fine. If you really want to fix this, and are able to extricate the gears, you can mold your own and cast it using resin. Lots of YouTube videos showing how to cast parts with resin, go investigate that if yours ends up being cracked and you want to address those.

 

[amoorey]

If you look closely, one cracked (split) gear is visible. There is another one that isn’t visible due to moving assembly and smallish size. When played in reverse position, there is obvious clicking as the cracked gear tries to mesh and other issues were present. So unfortunately, can only play this in the fwd position and it would be fine. If you really want to fix this, and are able to extricate the gears, you can mold your own and cast it using resin. Lots of YouTube videos showing how to cast parts with resin, go investigate that if yours ends up being cracked and you want to address those.

Yikes, keeping my fingers crossed. What about 3D printing?

 

[amoorey]

Interestingly, I just serviced one of these about 3 months ago. It did have some cracked gears so that meant it could only run in fwd direction, reverse wouldn't work right. Sometimes, you just have to remove the deck, take out the belt and measure it, and order the correct size. Factory belts do tend to stretch over time so you might want to order it ~ .2 or .3 inches shorter.

Hi, can I ask what the trick is to get the capstan belt out of the RC-880? I’m pretty sure I have to take another layer apart but don’t want to take anything apart I don’t have to or shouldn’t have to. I have the service manual and it doesn’t really say how to change the belts. Otherwise, the good news is that the gears look fine so far and everything on the inside looks almost brand new. I see where the capstan belt goes but can’t for the life of me see how to get it out, forget how to replace it once I get a new one. And the belt labelled 69 seems to be completely missing. I have 84 and 85. :-(

Thank you!

 

[amoorey]

Hi, can I ask what the trick is to get the capstan belt out of the RC-880? I’m pretty sure I have to take another layer apart but don’t want to take anything apart I don’t have to or shouldn’t have to. I have the service manual and it doesn’t really say how to change the belts. Otherwise, the good news is that the gears look fine so far and everything on the inside looks almost brand new. I see where the capstan belt goes but can’t for the life of me see how to get it out, forget how to replace it once I get a new one. And the belt labelled 69 seems to be completely missing. I have 84 and 85. :-(

Thank you!

Correction, I have 84 and 69, missing 85.

 

[Superduper]

The plate that holds the motor on needs to be undone enough to slip the belts out.

 

[amoorey]

The plate that holds the motor on needs to be undone enough to slip the belts out.

Thank you!

 

[amoorey]

The plate that holds the motor on needs to be undone enough to slip the belts out.

That worked, thanks! I’ve been staring at the service manual diagram and mechanism for over an hour and can’t figure out where Belt (85) goes as it’s missing. I have scoured the web and can’t find another mechanism showing 3 belts like this one. Any help would be very much appreciated. With everything else being in such great condition including the original belts, am I really missing a belt? Or am I misreading the service manual diagram and parts list? Or did something change? Here’s what I’ve put together and sent to a couple of belt suppliers:

JVC RC-880

Capstan Belt (84)
JVC Part Number: VKB3001-021
Length: 4-15/16" (12.6cm) Flat folded relaxed, measured from original
Width: 5/32" (4mm)
Height: 1/64"? (0.5mm)
Shape: rectangular Belt (85)
Reference Source: None found

Belt (85)
JVC Part Number VKB3000-070
Length: ?
Width: ?
Height: ?
Shape: ? Reference Source: https://www.turntableneedles.com/find20.asp?manfg=JVC-Nivico&modelname=VKB3000070&Select=Model

Counter Belt (69)
JVC Part Number: VKB3000-082
Length: 2-1/4" (5.7cm) flat folded relaxed, measured from original
Width: 1/32" (1mm)
Height: 1/32" (1mm)
Shape: square
Reference Source: None found

 

[Superduper]

Yes, that belt is absolutely necessary. If you look carefully, the flat belt goes from the motor pulley to only one of the 2 capstan/flywheels. You have 2 capstans because this is a reversing deck. That square belt connects and transfers power to the second capstan. Normally when a belt is missing, there will be some evidence of its prior existence either in the form of tar-like goo, or crumbled bits. If it’s completely missing, maybe it broke at one point and someone cleaned out the bits not knowing what it was.

 

[amoorey]

Yes, that belt is absolutely necessary. If you look carefully, the flat belt goes from the motor pulley to only one of the 2 capstan/flywheels. You have 2 capstans because this is a reversing deck. That square belt connects and transfers power to the second capstan. Normally when a belt is missing, there will be some evidence of its prior existence either in the form of tar-like goo, or crumbled bits. If it’s completely missing, maybe it broke at one point and someone cleaned out the bits not knowing what it was.

Thank you for your patience. I’m feeling pretty dumb not being able to sort this out. There is zero evidence of the missing belt so maybe your suggestion that it was removed at some point is correct. Based on how I found the main capstan flat belt when I took the box apart, I think it was routed wrong (looped around both capstans) so maybe someone was messing around with things at some point. Are these photos correct? I’m using the counter belt as a stand in for the missing belt.