Crimping dial cords
 

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?

Re: Crimping dial cords
 

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

Al

Re: Crimping dial cords
 

Perfect. Thanks.

Re: Crimping dial cords
 

"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

Re: Crimping dial cords
 

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!

Re: Crimping dial cords
 

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...

Re: Crimping dial cords
 

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

poppydog

Re: Crimping dial cords
 

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

Re: Crimping dial cords
 

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

Re: Crimping dial cords
 

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)?

Re: Crimping dial cords
 

This thread about knots may also be useful.

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

Al

Re: Crimping dial cords
 

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

A technique which I've yet to master!

Re: Crimping dial cords
 

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

Re: Crimping dial cords
 

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

Re: Crimping dial cords
 

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

Re: Crimping dial cords
 

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

Mike

Re: Crimping dial cords
 

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.

Re: Crimping dial cords
 

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

Re: Crimping dial cords
 

I can also recommend waxed whipping twine

Mike

Re: Crimping dial cords
 

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.

Re: Crimping dial cords
 

I'd agree the picture looks like a bowline.

A reef knot is designed to be fairly easy to undo. A Fishermans knot might be more secure, though hard to tie under tension. That said, tying half, and then marking as suggested is easier as you only need one hand to hold the cord.

Re: Crimping dial cords
 

The way I always remember the bowline is the rabbit comes out of the hole, round the tree and back down the hole again, I use it when I'm down the woods with braided rope sometimes when winching stuff out, the loop doesn't slip under high strain and it can be undone no problem.

Lawrence.

Re: Crimping dial cords
 

Historically, I've always replaced stretchy fabric-cords with thin-and-flexible stainless-steel "pike lines" freely available from fishing-shops.

These don't 'relax' with age (so throwing the dial-pointer calibration out). The best way to anchor these is to get one of the 'barrel connectors' from a cheap 5A choc-block connector and slice it in half, then use each of the halves to clamp the stainless-steel wire.

[OK, I will confess to having a bit of an anally-retentive thing about dial-calibrations... if the string-provided pointer on a dial is off by a few Kilohertz/Metres I get really annoyed]