Crimping dial cords

[skodajag]

Restringing dial cords is rarely easy, and one of the most difficult tasks is making the knots to connect the cord to to the tension spring. Sometimes though instead of a knot the cord is crimped, which would be much easier if one had access to the right crimps and possibly the correct crimping tool. Any suggestions?

[Alistair D]

Search Ebay for jewellery making crimps. The tools are also available on Ebay.

Al

[skodajag]

Perfect. Thanks.

[Boulevardier]

"one of the most difficult tasks is making the knots to connect the cord to to the tension spring."

I find the easiest way is form a loop through the "eye" of the spring, put in a few twists, and seal the twist with a blob of superglue.

Mike

My way is to do a single overhand knot, pull 'till it is the right tension and mark with a felt pen (held in teeth). Slip the cord off something so it goes slack, then you can make a proper reef knot with no tension in the right place. Put cord back on and viola!

[Graham G3ZVT]

I find it "helpful" to imagine how many sets the ladies in the factory could have strung, in the time I am struggling to position a single knot...

[poppydog]

I get my misses to tie the knots for me, its surprising how delicate the "iron fist in the velvet glove" can be..

poppydog

[Julesomega]

I love the professional feel of anything crimped and I recently bought a circular crimping tool to crimp ferrules. The crimper probably came from Banggood in China, the plain ferrules from eBay. (If you buy from Banggood set up an account first so that you get the full guarantee service)
Use the smallest practical ferrule diameter, they will crimp down literally to zero diameter

[Nuvistor]

Originally Posted by rambo1152

I find it "helpful" to imagine how many sets the ladies in the factory could have strung, in the time I am struggling to position a single knot...

Probably find the string was made up to the correct length and knotted using a jig before it got anywhere near the radio.

[ionburn]

I have never used them for other than the stainless steel wire intended for (not in the original application) but I have some crimps that are used for stainless steel wire used in fishing. It might be worth a look to see if they are suitable (possibly too small but I have not checked)?

[Alistair D]

This thread about knots may also be useful.

https://www.vintage-radio.net/forum/...d.php?t=142721

Al

[David G4EBT]

I believe that dial cords were originally tied with a knot called the 'perfection loop'.

A technique which I've yet to master!

[crackle]

That looks exactly like a Bowline knot, designed to tighten with more pressure applied.
You can also try a Blood knot, which can also be used to tie onto a ring.

Mike

[Boulevardier]

On this topic, is anyone able to direct me to a source of "traditional" tuning cord? I have tried fishing line (to avoid stretchability), and it doesn't grip properly on plastic pulleys. Haven't yet tried abrading the surfaces, but better to get the proper stuff.

Mike

[DonaldStott]

Originally Posted by Boulevardier

On this topic, is anyone able to direct me to a source of "traditional" tuning cord? I have tried fishing line (to avoid stretchability), and it doesn't grip properly on plastic pulleys. Haven't yet tried abrading the surfaces, but better to get the proper stuff.

Try here: -

https://www.bendijkman.nl/index.php?...oduct&ipath=16

Ben also provides this advice: -

https://www.bendijkman.nl/how-to-kno...ord-2?ipath=16

[Boulevardier]

Thanks for that Donald. Looks perfect, but I can't see any way of actually placing an order on their website!

Mike

[emeritus]

You could try whipping twine, which you should find in a yacht chandlers. It is inextensible and available in waxed polyester in a variety of diameters and colours, usually on 3" spools.

[DonaldStott]

Originally Posted by Boulevardier

Thanks for that Donald. Looks perfect, but I can't see any way of actually placing an order on their website!

Hi Mike - just send Ben an email and he will explain how to place an Order - it's not a commercial operation.

Info@bendijkman.nl

[crackle]

Originally Posted by emeritus

You could try whipping twine, which you should find in a yacht chandlers. It is inextensible and available in waxed polyester in a variety of diameters and colours, usually on 3" spools.

I can also recommend waxed whipping twine

Mike

[Test Desk]

Originally Posted by Julesomega

I love the professional feel of anything crimped and I recently bought a circular crimping tool to crimp ferrules. The crimper probably came from Banggood in China, the plain ferrules from eBay. (If you buy from Banggood set up an account first so that you get the full guarantee service)
Use the smallest practical ferrule diameter, they will crimp down literally to zero diameter

In a previous existence, I used a similar tool to crimp the centre connector of a thin coax called RG179 which was widely used by Cable TV companies to interconnect 2mbs to multiplexer mountains up to 140mbs. The pins were very easy to bend if you weren't careful.