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Producing new "center gears" for Sony DD ??

christian - 2010-06-03 04:19

Hello!

Some time ago i repaird my WM-D3 by replacing the broken center gear with a good one taken out of a working WM-DD33. Well, now the center gear is broken again. Confused Actually i know that it is possible to repair it in several ways (I have the repaired gear now working in my WM-DD33). But it is not 100% perfect as it gets 1 or 2 "tooth" more or gets a little smaller after grinding job...

So, in fact, the only 100% solution would be replacing it through a new made gear. I am thinking of producing only the black, broken materiel but not the complete assembly. It should be constructed to snap onto the metal part in the center from the side. Wink

Do You have any idea which company can produce some "new" spare parts. Actually as there are so many people needing this part it could be possible to keep the price quite low.
Perhalps CNC production or injection molding ?

Who has a perfest center gear to draw a construction plan and does anybody know a company for "cheap" production ?

Chris

vagabondsteve - 2010-06-24 14:29

If this is the same gear as in a WM-DC2, I'd take one too!

- 2010-08-17 16:28

I´m also interested. Depending on the price I would take 5 gears!

elite1502323 - 2010-08-17 20:58

Hey Christian, did you ever get in touch with harryshawmodel.com?

johnedward - 2010-08-18 06:03

You can count me in for 4 gears if they are ever made.

sajin - 2010-08-18 12:18

Jepp, I'd be in, too...

chrizzy - 2010-08-20 14:27

Hi everybody,

Even being very new to this forum, I would also go for some of those gears...

best regards from Vienna,
Chris

tuna - 2010-08-21 02:21

I would be in sure. That might be difficult though. I don't think any company or simply would settle for less than several thousand pieces.

But heear this, it might be possible to revitalize the existing gears that have not already cracked. I will make an analogy with steel design. For an example, you have a steel beam with "I! cross-section. You want to make something of it to fit the construction so you need to bend it or something. How do you do it? Do you simply bend the beam with heavy machinery or do you do something else? No,k if you would bend the beam just by applying brute force, you would insert additional stress in the area of the flection and that stress would remain there as an imperfection in the material and would in fact waken the material properties. That is why you sink the beam into minearal oil and heating it to the temperature close to it's melting point. The heat ensures the stress is evenly distributed during the bending process and once the steel is cooled under the same conditions, the additional stress will be close to zero.

So in essence, the gear might be heated up in order to reduce the stress that happens in the gear rim. This stress happens due to changes in the material and due to age. Every material, even steel, gets old which means there are changes in the moldecular structure. Some materials are suceptible to changes in the environment - primarily moisture and temperature, and the plastic composites are not iummune to this like many people think. So, if we were to heat the gear, the stress would reduce itself and the gear would not crack. However, as soon as it would get colder, the streess would increase again. So it might be possible to introduce some sort of mechanical stabilizer or mineral oil that once the pastic is heated, would chemaically bond with it and add the so much desired flexibility that the gear lost over time. This might sound like sci-fi but it is really not. The main problem here as I see it is the plastic mold itself - we don't know anything about it! What is it's specific density, what is it's yielding point relative to the ultimate stress and most importantly - the chemicaal coposition and the melting point of th material.

The beahavior of the saystem will depend on this new gear and most likely on the integrity and durability of the gear that is connected to the center gear. If the DD units were produced today, they would last forever I think as in the last 30 years the world has seen some serious advancements in the technology of plastic masses.

I just thought this might be interesting to consider.

rerooted - 2010-08-21 22:19

my black wm-5 finally broke it's geer. it seemed to getting running better and better until it just plain stoped dead. i haven't looked inside yet due to computer problems but a have a bad, bad feeling.

johnedward - 2010-08-22 07:38

Hi George, you mean your WM-F5 broke its gear ? The WM-5 is belt driven. I have 3 WM-F5's one works fine but does have cracked gear, one eats tapes one dead in water no function ( layed in water think one bung missing allowing water in).
Sorry to hear it gave up the ghost. Seems just before most mechanical items break they run their best.

drmr2000 - 2010-08-30 20:20

Here maybe a way to make the outside of that gear.

http://www.youtube.com/watch?v...OUT-real_rn-2r-19-HM

awm - 2010-10-05 14:30

Hi,

I'm still quite new to this (received my first DD Walkman - a DD33 that unfortunately does not 'run well' as advertised by the seller - yesterday and am still waiting for two more - a DC2 and another broken DD33 - to arrive), but I've been reading about the 'cracked gear' issue for a few weeks now.

I've been wondering about the same thing: Why didn't anyone try to produce a replacement part? And, to expand on the original question, why didn't anyone try to do - or at least theorize about - a solid-metal gear? Is there any reason to stick with plastic?

Inspired by this discussion, I'm researching ways to have a small number of either replacements for the plastic 'gear ring' or of solid-metal gears produced, but it's still in the very early stages. And it's probably not going to be cheap. I would be interested if someone else has some success, though. Unfortunately, I'm not an expert, neither in Walkmen or other electronics nor small-scale mechanics of any kind. Or mechanics of any scale, by that matter. But I'm in discussions with some people who might be able to help (no promises, though).

As for the YouTube video: Does anyone know how durable the output of those machines is? The material and processing doesn't look too trustworthy to me.

BTW: Do all those Walkmen from the WM-2 to the WM-DD33 really use the identical part
(notwithstanding the cheaper WM-DD1/2/11/22 series, which AFAIK used a completely different drive mechanism)?
I have conflicting information esp. about the WM-2 itself, its central drive gear may have been a little different. The info from dottor walkman regarding the DC2 was new to me as well.
And, as to my information, the WM-D6C used a different gear, is this correct?

dottor.walkman - 2010-10-06 01:43

AWM Hello, I can tell you how I solved it myself. As well as being an electronic repairman, repairer and it is mainly a manufacturer of micromechanical parts. For my wm-dd (dc2, DD2, DD3, DD100 bood khan, dd-30, d3, etc.) I took the broken gear teeth and I have rebuilt two more. Since this gear has no effect on the transport of the tape but only on the reels of the tape, the addition of teeth is not in any way affect the speed and performance. Doing this will eliminate the pressure of the metal disc and does not break anymore. Must, however, be extremely accurate and have good hand skills otherwise the result is poor and increases the wow and flutter. I have done this many many times for my clients. It has been many years and have never had more problems. It 'a lot better than replacing with new one, because it breaks again. Nod Yes

moses - 2010-10-12 10:02

I would like to see some pics of your repair! Tried it by myself with different materials, but the won´t stay very long. The gear must be plastic because of of the static electricity charge of the part. That´s why Sony used palstic on the outer surface. Not very smart but better to the sound! I heard from some guy who reduced the inside metal of the gear from 28 mm to 27,5 mm and glued the broken part together.... you need the machine to do this but good idea I think!
And look here: http://www.geocities.jp/wm_fun/wm-dd2step6.htm

cheers e.

awm - 2010-10-17 06:24

dottor walkman,
I'd also like to see some photos.

Regards, A.

tuna - 2010-10-22 05:24

Brong on the pics Doc!!

tuna - 2010-10-22 05:31

In reality, this would be difficult. Changing the material properties of one hear automatically menas changing the way the secondary stress along the other gears. To cut the long story short - the other gears would suffer from stress that would exceed what they are designed to carry and thus significantly shortening the lifespan. Also, the friction coefficient (either dynamic and static) are different from one material to other and if the gears were replaced by metal ones, then there would be significant differences and the motor would have a different force to counter. So it is a question whether the motor would be sufficient for this. Cassette decks are complex mechanisms and any deviation out of the ordinary would have an impact on performance and longeivity of the parts.

rerooted - 2010-10-25 22:01

ya,,,i think he just got it right. a patch job is going to be the ultimate fix. sounds very complex but what he said was "simply correct".

moses - 2010-10-26 01:09

In one point Tuna is right - because of the material differences you have still the clackclack sound.....but otherwise it works fine even after month. The "combination" is stabile and will last. And once you´ve pulled out the center gear it´s easy and quick to fix.

cheers

minty - 2010-11-07 08:18

I see one of these center gears for sale on ebay germany guys. Just thought someone might be interested.

minty - 2010-11-07 08:21

Here is the item number: 290497256073

elite1502323 - 2010-11-08 10:09

Derek
Thanks for giving us a heads-up. You are a very helpful member of this forum.
Regards,
Elite

minty - 2010-11-09 05:31

Glad i could be of help. So, did anyone snap it up?

moses - 2010-11-09 06:16

not me! too expensive - will break soon anyway....

soundabout - 2010-11-12 20:40

Wouldn't it have already broken? Sony did make a 2nd generation of the gear that does not crack. I know that a few members on this forum actually own the 2nd generation center gears, and understandably covet them like gold. This one looks to be fine. Do any of those owners want to weigh-in on this topic?

despont - 2011-05-04 09:10

Hi Folks


Should we start a request on Facebook and see if we can get some social networking site to help us convince SONY we need these replacement parts?

 

Just a thought and we pay fair money for the defective part clearly but we need their engineering help here?? There are hundreds of thousands of these Walkmans that need this fix


What do you think?

 

JM

moses - 2011-05-05 04:34

We should figure out who produced this gear for sony theses days. I guess it was not sony itself - they had their suppliers. Hard to find out!

kiritan.flux - 2011-06-21 03:12

i like the MAKERBOT 3D printer idea.

 

there is one of these bots here in berlin at "open design city" and i actually know people who work there and can run it. all that's needed to print is a precise 3D model of the object. the question is now what it should look like! full plastic center gear and then glue the shim for the magnetic gear on top of it? maybe someone can thing of a design of a new center gear. then we just need a 3D model of it (i know people with 3D skills) and print a prototype.

bub - 2011-06-21 08:28

I don't think that a petition will work as the original molds and equipment used to build the parts are long destroyed/sold off as most companies do (costs money to store them) or the machines have been converted to do different tasks.

 

I do think the 3D model is a great idea. I think that the metal insert can be sandwiched between two pieces of plastic to make it easier. While I do 3D work it's not for CAD design (I do cg entertainment).

Another way to do the rough cut is a CNC machine machining the rough gear out from metal. From the rough cut, it can be sanded/machined down to remove any imperfections, and master molds can be made. From there on the 2 halves can be injection molded, which is faster and cheaper for a large amount. Then the metal insert can be glued in.

kiritan.flux - 2011-06-21 08:41

CNC sounds great too.

 

...but can u do a 3D model? it can probably be converted into CAD compatible data the makerbot can read.

bub - 2011-06-21 11:26

Just doing a 3D model won't do unless you have EXACT measurements for everything and diagrams. The best method to start off would be a 3D scanner. Another alternative will be to scan 2 sides of a gear and blow it up to correct dimensions in a CAD program. I use Maya, which is not really suitable for precise CAD work. You'll have to go through a lot of prototypes (you'd need a donor DD for testing) until you can get a perfect master. This will likely take  a lot of time.

despont - 2011-06-22 12:00

How about a Facebook Group to get some support going from Sony? Anyone up for it? We could then email Sony and directly shame them into working with us. Their PR right now is looking pretty low? Its a freebie in terms of what it would cost us Facebook members and we may get them putting these needed parts back into production..

bub - 2011-06-22 12:30

Like I said it will not work: the original molds and equipment used to build the parts are long destroyed/sold off as most companies do (costs money to store them) or the machines have been converted to do different tasks.

 

And even if they do have everything required to make new gears, to start production again for such a small number of spares (Let's face it, the market for these spares is considerably small) is incredibly expensive. Sony is not like Mercedes where they catalog and still make every single original spare part for their products.

 

And the whole hacking thing about PSN and such has NOTHING to do with the Sony audio division (Sony is so large, the branches can be considered nearly completely separate).

t2m253 - 2011-06-23 22:46

I bought a broken wm d-3 for 20 dollars off craigslist. opened it up and found the center gear was cracked. patched it up and it was working perfectly in a day. there is really no need to produce a new gear when the old ones are so easy to fix.

bub - 2011-06-24 01:31

I too fixed mine in less than a day- what method did you use?

t2m253 - 2011-06-24 17:20

I used J B weld. I let it dry for a couple hours so it wasn't so runny. I then rotated the gear so it was in a workable space; I didn't have to remove anything extra or take the actual gear out. I plastered it on, flattened it and then then rolled it against another gear, to make the teeth. It says to let it dry for 24 hrs, I wasn't about to take any chances. pressed play with my AC/DC tape in and it sounded great. there is still a very faint click, though it doesn't affect the sound.

mark - 2011-06-28 18:47

i wish sony were more like mercedes.

 

i have a few tape decks that i'd love some new heads for, just in case. and the side panels for the ta-f444esx and st-s444esx would be so nice to have. plus a new cover for my ps-x600 would be a dream, not to mention an extra headshell. an rm-j701 would be great too since it works on all the 333/555es# decks. oh, and that little headphone jack adaptor for the wm-701c/ex85/many others would be really nice. i'd love to use those walkman. i don't even know what they are like to use because i don't have that stupid stupid little stupid thing that i need to use regular headphones.

 

but yes, very helpful thread. i have a few dd based walkman and they all have the click.

 

 

doublecee - 2015-12-14 14:12

Giving this thread a much needed bump.

Ive been talking to Dr Walkman via e mail a lot recently, as I have a few machines I would like him to look at. The discussion segued towards 3D printing, and like many, I got the impression (at first) that he was not 100% convinced of the approach due to past experience.

My company (Motion Associates Ltd) specialises in Laser scanning and we also do a fair bit of 3D printing with the Form Labs +1 SLA printer.

I have a new batch of their tough resin (http://formlabs.com/products/materials/tough/) which is ideal for such use as a gear.

So, in order to put my theory to the test, I am looking for a centre gear donor piece to laser scan and then 3D model for printing. 

SLA prints in the tough resin are rock solid and not brittle like the prints you get from a maker bot or any other extrusion method.

I think this would not only be a very interesting and viable test, but could be a new source for new reverse engineered parts.

Personally, I have two DDII, a DC2, a DD33 and two TCD3's (WM-D3) all in need of a fix. These are the machines that I hope to get to the Doctor in time, but having this tech at my disposal is just too tempting. 

The reason I am keen to find a donor gear is simply because Im just not confident I can extract one from one of my poor units without some form of mishap (im better with pixels than I am with PCB's). Some specs on the design of the gear would also help, especially if anyone has drafted one as a vector

 

Anyway, hope this was a worthy bump

 

 

 

ball000 - 2015-12-14 23:37

Sure, thank you for the bump! ;-)

IMHO one of the best donor gear is the one you'll find in one of the repaired walkmans by Dr Walkman... so some kind of chicken-and-egg problem there, unless you send him one walkman alone for that purpose?

walkgirl - 2015-12-15 02:41

doublecee posted:

Giving this thread a much needed bump.

Ive been talking to Dr Walkman via e mail a lot recently, as I have a few machines I would like him to look at. The discussion segued towards 3D printing, and like many, I got the impression (at first) that he was not 100% convinced of the approach due to past experience.

My company (Motion Associates Ltd) specialises in Laser scanning and we also do a fair bit of 3D printing with the Form Labs +1 SLA printer.

I have a new batch of their tough resin (http://formlabs.com/products/materials/tough/) which is ideal for such use as a gear.

So, in order to put my theory to the test, I am looking for a centre gear donor piece to laser scan and then 3D model for printing. 

SLA prints in the tough resin are rock solid and not brittle like the prints you get from a maker bot or any other extrusion method.

I think this would not only be a very interesting and viable test, but could be a new source for new reverse engineered parts.

Personally, I have two DDII, a DC2, a DD33 and two TCD3's (WM-D3) all in need of a fix. These are the machines that I hope to get to the Doctor in time, but having this tech at my disposal is just too tempting. 

The reason I am keen to find a donor gear is simply because Im just not confident I can extract one from one of my poor units without some form of mishap (im better with pixels than I am with PCB's). Some specs on the design of the gear would also help, especially if anyone has drafted one as a vector

 

Anyway, hope this was a worthy bump

 

 

 

Mmmm I wil say it will not work!, one of my clients is a former clock repair man and I showed hin such a gear once and he said it will be difficult to replicate!

 

 

boodokhan - 2015-12-15 08:51

It is not difficult to produce the central gear by 3D. We only need the knowledge of 3D. The problem is we want other people who do not have any passion or interest in vintage electronic to make us the parts we need. 

Within few years eBay 3D business will be available for vintage electronics.

I will be starting Auto CAD course in spring 2016 and once i learn, will print the central gear for my Walkman and other members.

christian - 2015-12-15 12:04

Hello,

well, now it loks like there is a "real" solution is coming in sight :-)

But actually i think it is not a good idea to use any repaired gear as reference / donor. The reference object can only be a part in its original condition.  I do not mean that the published repair methods (i.g. with extra tooth or grindig down the metal part) are bad in any way - they are just developed to get the best possible compromise using old material only.  At the end the replica should be as close as possible to the original gear.

So we should try to find a reference of these Gears in good condition, or as an (better?) alternative to draw it completely new with 3D CAD. Perhalps it would be a first step to laser scan an cracked (or repaired) gear to gain important details like the exakt shape of the tooth, but the actual CAD construction should focus more on the original shape...

Also in my opinion there should be minor modifications so that it is possible to attach the finished plastik part to its metal center.

Christian

doublecee - 2015-12-16 09:59

"The problem is we want other people who do not have any passion or interest in vintage electronic to make us the parts we need"

 

Well, thats the thing... I do know 3D. Its what I do 7 days a week for a living. And, if you pop over to www.analogueoctober.com you will see that I am also a tape head. 

Agreed that a repaired part is not ideal in terms of replication. What I need to do is build a new part to the original spec and go from there.