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Post by Deleted on Nov 28, 2014 15:45:38 GMT
Hi all, I have to wind some springs in brass for the vac valves which fit in the bottom of the vac cylinders on Don Youngs Barnet drawings.
I have no idea how to do this but have come up with an idea. The info I have from the drawing is that the spring is 1/8 bore x 24SWG and 7/16 free length with 7 coils.
My initial thought was to set the leadscrew on the lathe to 16 TPI and somehow pull the wire around an 1/8th dia. piece of steel rod for 7/16 (thus making 7 coils) I'm going to drill a small hole across the dia. of the 1/8th rod to initially poke the brass wire through and then soft solder it in to give me a start but how do I hold it in the toolpost giving it enough tension to keep the wire tight without it breaking??
Any ideas welcome!!
Cheers Ben
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Post by Deleted on Nov 28, 2014 15:53:19 GMT
Hi Ben I did a little digging as i remember winding my own springs for Great Northern's regulator from bronze wire which has worked perfectly...I did it by hand on the lathe...few details here... modeleng.proboards.com/thread/6510/project-2-lbsc-heilan-lassie?page=8regards Pete edit: forgot to add...iirc I held one end of the wire in the 3 jaw with the bar for the bore required and the other end via plies... I kept the wire tight at 90 degrees while turning the chuck by hand letting the coils follow each other in turn and then just cut to length.
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Post by AndrewP on Nov 28, 2014 16:29:51 GMT
There used to be an excellent website with spring making instructions and whilst it seems to have bit the dust I found a shadow of it here in the internet archive, I have used the instructions with great success. Andy
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Post by ejparrott on Nov 28, 2014 16:51:28 GMT
Seen it done with the wire clamped between 2 bits of hardwood in the toolpost to keep the tension on.
I've not wound springs, I prefer to spec and buy mine from Lee or Entex!
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Post by Deleted on Nov 28, 2014 17:20:56 GMT
Thanks for the replies! It seems I might be on the right track. I'll do some serious digesting of all options and go from there ta! It would be nice to make my own but the Lee or Entex solution is always worth investigating, do you have a website for either Eddie?
Cheers Ben
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Post by Roger on Nov 28, 2014 19:41:59 GMT
There are some YouTube videos of methods. Personally, I made a hollow square bar to go in the toolpost at centre height and used the nearest screwcutting pitch to move it along a mandrel turned a little under the inside diameter I wanted. The easiest way to hold the wire to the mandrel is to drill a hole across the diameter. If the mandrel is long and slender, add a centre to the end to support it. It's dead easy to wind, but not so easy to get the right diameter.
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jma1009
Elder Statesman
Posts: 5,896
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Post by jma1009 on Nov 28, 2014 20:17:11 GMT
hi ben, i wouldnt use brass wire. far better to use phos bronze wire or better still stainless. ive lots of both so if you need any let me know. i dont like winding my own springs as it can be a bit alarming especially with stainless or the larger gauges, but i have done it every 5 years or so without any injury! cheers, julian
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Post by Jim on Nov 28, 2014 21:29:02 GMT
Ben, I used the method you describe. The wire, stainless in my case clamped between two hardwood blocks as you describe to keep the wire taut ie. plays around middle C when plucked. I pulled the head stock round by hand to keep everything under control. It took a couple of goes to get the set up right and to produce a pair of very acceptable springs to the specs recommended by Gordon Smith in his articles on making safety valves. I must say I would have bought them but there was nothing available commercially here, unlike in the UK I forgot to take a photo of the set up but this is one of the pair of springs made. Jim
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Post by ejparrott on Nov 29, 2014 8:18:40 GMT
Thanks for the replies! It seems I might be on the right track. I'll do some serious digesting of all options and go from there ta! It would be nice to make my own but the Lee or Entex solution is always worth investigating, do you have a website for either Eddie? Cheers Ben I just google Lee Spring or Entex when I need to look them up!
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Post by Roger on Nov 29, 2014 9:23:53 GMT
Also look as SPEC (Associated Springs), but I find all of these standard manufacturers expensive.
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