Aiwa tpr 990 tuning string broke

[stereomann]

The tuning string broke
I took some pictures I'm trying to use fishing string but it is hard to get the sting the way it was every time you almost get it it keeps losing slack I'm not sure how the spring goes back on the big tuning wheel I believe its supposed to keep tension on the string

Let me know what you think thanks

 

[Superduper]

I don't think standard fishing line will work, it's probably too slippery and if you do use fishing line, you should probably use the braided variety, not the monofilament ones. Monofilament will have a lot of stretch. There are universal "tuning string" available that should be a far better choice.

As for the stringing, I suggest you get the service manual. Typically speaking, the exact routing will be shown along with how many turns around each pulley and the direction of the turns, and also very specific length of cord required down to mm fractions. Yes, the spring should have some tension. You won't be able to just measure it like you would a capstan belt.

 

[Tinman]

I agree, the fishing line is probably too slippery and stretchy.
Those cords don't stretch at all, that's what the spring is for.
It keeps tension on the cord but also gives just enough slack to slip it on when installing it.

 

[floyd]

You can buy this tuner cord on ebay
It's called FM tuner string/cord .
You can buy it in rolls or smaller lengths.

 

[Tinman]

You can buy this tuner cord on ebay
It's called FM tuner string/cord .
You can but it in rolls or smaller leI was just looking and saw they also sell different sizes of springs too.

I was just on there looking and also noticed they sell different sized springs too.
I never checked that out, good to know.

 

[stereomann]

I got it working again here are some pics of it and of what string I used

 

[Superduper]

You only have 2 turns around that brass stanchion, the specs call for 3. But if it's working, it's working, and if you're happy, then be happy -- life is good.

 

[stereomann]

Yeah I noticed that after I took the picture I'm not going to mess with it anymore if it breaks again then I'll worry about it maybe I didn't make the string long enough but I thought I did unless I did something wrong. I was working on this for about 6 hours the other night and today I only took about 40 mins to do it.

 

[BoomboxLover48]

Spec says 3 turns and that gives enough friction area on that brass stanchion. Chances of it slipping or lowering the COF is higher, if these turns are lower. I've done this by mistake once and paid the price later. One or two more turns won't hurt will increase the friction (grab more on the shaft) but lowering the turns is not good on the flywheel shaft.

I've done lots of stringing on tube radios and much less on boomboxes. The last time I did this stringing was on a Sharp GF777 which needs some skill level. It was a royal pain!

Note: The main plastic drum pulley is missing 2 more posts for adjusting spring tension. The is a design flaw. Normally there will be 3 holes or posts for spring tension fine adjustments.

 

[Tinman]

The knot behind the spring looks to be sitting against the post.
Usually the cords come into the drum and onto the spring without being routed behind anything.
It looks to be showing that in the diagram too.
If you took the cord out from behind the post, adding another turn on the stanchion looks to be fairly easy in that setup.
The spring should be stretched out for some decent tension on the cord.

Damn, I haven't fished in years, that looks like nice line (65 lb test ).
I've only ever used monofilament, 8 lb test.

 

[Superduper]

If you research braided line, one drawback is that they are known to cut grooves in fishing gear guides. Given that the pulleys in a tuner stringing system is made of fairly soft nylon, I would be concerned with wear in the system over time.

 

[stereomann]

I was messing with this for awhile before I downloaded the service manual I tried a few different ways at first and none of them really worked the manual made it little easier. I tried putting the spring around the other post but it kept popping off of the main tuning pulley so I just put the string around the other tab I know it's probably not right but for now it works. If I mess with it again I might be there for another few hours.

Spec says 3 turns and that gives enough friction area on that brass stanchion. Chances of it slipping or lowering the COF is higher, if these turns are lower. I've done this by mistake once and paid the price later. One or two more turns won't hurt will increase the friction (grab more on the shaft) but lowering the turns is not good on the flywheel shaft.

I've done lots of stringing on tube radios and much less on boomboxes. The last time I did this stringing was on a Sharp GF777 which needs some skill level. It was a royal pain!

Note: The main plastic drum pulley is missing 2 more posts for adjusting spring tension. The is a design flaw. Normally there will be 3 holes or posts for spring tension fine adjustments.

 

[stereomann]

The reason I did that is because the spring kept popping off of the post I could probably try taking it out from behind the post but I'm not sure if that will give me enough slack to wrap it around the tuning shaft and there would be a chance of me having to do the whole thing over again I'm not sure if I want to do that or not.

The knot behind the spring looks to be sitting against the post.
Usually the cords come into the drum and onto the spring without being routed behind anything.
It looks to be showing that in the diagram too.
If you took the cord out from behind the post, adding another turn on the stanchion looks to be fairly easy in that setup.
The spring should be stretched out for some decent tension on the cord.

Damn, I haven't fished in years, that looks like nice line (65 lb test ).
I've only ever used monofilament, 8 lb test.

 

[stereomann]

the fishing line was my Grandfather's i got it after he passed. He was big into fishing and crabbing we live in Maryland. He would always catch rock fish and crabs and have us over

 

[BoomboxLover48]

If you research braided line, one drawback is that they are known to cut grooves in fishing gear guides. Given that the pulleys in a tuner stringing system is made of fairly soft nylon, I would be concerned with wear in the system over time.

Like Superduper mentioned these strings are made of nylon material.

Fishing line is not for this purpose and application.

Moreover, many fishing lines are coated with Teflon (PTFE) Polytetrafluoroethylene and I suspect the braided one you put there is that type. PTFE is to give excellent slip or reduce the COF (coefficient of friction) that makes it so slippery. This defeats the purpose.

Sorry to say once it starts to slip, it will get stuck at one position and on the flywheel, axle won't move the cord anymore.

 

[floyd]

the fishing line was my Grandfather's i got it after he passed. He was big into fishing and crabbing we live in Maryland. He would always catch rock fish and crabs and have us over

I also live in maryland. I have caught rock fish 36 inches long in deale maryland and they are ****ing delicious when cooked on the bbq grill.