Dual 701 turntable assembly problems

[Jan Dupont]

Hi All
Servicing a Dual 701 turntable and detached the Cam wheel the wrong way.
Now I got these two small parts (#146 Pawl and #145 Tension spring)

And have no idea how to fit these. Service manual doesn't give any help, so do we have a Dual expert here?
I think it must be close to this, but where to attach the spring?

Any help appriciated

 

[Logon]

See if the following page fit your issue just as it does seem

https://www.vinylengine.com/turntable_forum/viewtopic.php?f=37&t=109844

 

[Jan Dupont]

Thanks ulogon however not showing or mentioning the parts in question.
I should have been more precise and mentioned that the two pieces in question is placed UNDER the Cam wheel in connection with the start/stop selection lever......

 

[Logon]

Can the following image help you in any way?


Edit to add: may be you can't see the spring, but it looks like that small part needs to be inserted upside down compared to your pic.

 

[Jan Dupont]

Thanks ulogon 👍 That places the Pawl #146. Any idea where the Spring #145 may fit?

 

[Logon]

Thanks ulogon 👍 That places the Pawl #146.

No problem.

Any idea where the Spring #145 may fit?

Not yet.
Aren't you able to guess it by looking at the assembled piece?
Are you sure some (plastic) pieces haven't fallen off?

 

[Logon]

Any idea where the Spring #145 may fit?

Look at this.

"d. move 145, brings one finger of 146 into the path of the deflection lever 132
(that's the one which decides the path on the cam).
(162 > 145 > 132 (on cam) > selects Start track on cam.".

 

[Jan Dupont]

Thanks a lot ulogon 👍 you have been a great help

 

[Logon]

My pleasure.

Hopefully there is some useful further information here too. 😉

 

[Hearinspace]

See page 14 of the service manual Here or Here

 

[Jan Dupont]

Thanks to all sofare 👍
Found out that the small roller "Ball 4.0" #165 where missing. Maybe the first reason for the problems with the automatic.
Haven't yet found the position of the "Tension spring" #145, but awaiting the arrival of a new ball......

 

[Hearinspace]

And it's not the spring shown at lower right in the first pic of this post?

 

[Jan Dupont]

And it's not the spring shown at lower right in the first pic of this post?

Sadly no. That is the antiskating spring, and it's in place and is much longer....

 

[Logon]

I believe this image is the one! 😉

 

[Logon]

In this other image (too tired the other night to save the source too) you can see the spring from another angle and also the position of the metal ball that you lost.

 

[Jan Dupont]

ulogon 😉 You nailed it! Thank you so very much 👍

 

[Logon]

My pleasure. 🙂

 

[Stuey]

What I always think of with this kind of mechanical device is some poor fellow has designed it by drawings and then hand made a prototype and fiddled with it with a pair of pliers and some files, tweaking and filing those pressed steel bits and fiddling with springs, to make it work every time. - before setting them up for production.

 

[Kay Pirinha]

With due respect, I don't think so. By 1972, when the 701 emerged into the market, Dual was one of the biggest TT manufacturers in the whole wide world, if not the biggest at all, and had some huge amount of experience with automatic TT's and record changers. The definitively didn't need to »fiddle« around with something.

Best regards!

 

[Stuey]

Of course, I was being semi-facetious, although I'd imagine there would indeed be some tweaking to the first production parts that may not always work as intended; say, an automatic tonearm stopping half way. I guess should have added a smiley face, but if you have to do the joke has failed.

I'm sure most people on diyaudio know about Dual. I've almost bought a couple of their tables, but resisted as we don't have many in this country so there are few to choose from. I am always amazed at mass production of things and how they get them to work reliably. I was imagining a little balding German guy with glasses and a leather apron...

I took apart the whole dashboard of my son's car a few weeks ago and made the comment to him to imagine...somebody had to design all this to fit together...as I found out when putting it back together. Everything worked first time and the airbags didn't go off.