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Hardinge Brake Spring

EHirst

Plastic
Joined
Sep 5, 2020
Hi, I am new to the forum and this is my first post. I purchased a very old HLV-H last week and have started the process of getting it to work reliably and with reasonable accuracy. Thanks for a great fund of information. Using this forum and others I now have relevant manuals for operation and maintenance, some wiring diagrams and a parts list, all of which seem useful. I am currently working on the variable speed drive and the spindle brake. The spring in the spindle brake appears to have broken. The piece I have has one neatly closed end and one broken end. Does anyone know what the correct length and spec are for this spring? Thanks. I look forward to contributing what I learn to this forum.
 
One possibility is that your spring is an improvised replacement. I have many different stock springs on hand, and the compression springs usually have both ends closed. If I need a shorter spring, but have a stock spring of suitable diameter and wire size and pitch, I will just cut through the wire to get the needed length. It is usually not worth the extra effort to close the last coil on the cut end. That leaves a spring like the one you described, if yours is cut rather than broken.

I have never had the need to open up my brake, so I have no idea what sort of spring it has.

Larry
 
Larry, Thanks. The end that I think is broken does appear to have failed rather than have been cut. Having cleaned out a load of muck, I shall try reassembly. Previously, the spring did not appear to be strong enough to push the cork brake pad into contact with the drum; but that could have been due to the muck. If someone does know the spring length, roughly, it would help.
 
Hi, I am new to the forum and this is my first post. I purchased a very old HLV-H last week and have started the process of getting it to work reliably and with reasonable accuracy. Thanks for a great fund of information. Using this forum and others I now have relevant manuals for operation and maintenance, some wiring diagrams and a parts list, all of which seem useful. I am currently working on the variable speed drive and the spindle brake. The spring in the spindle brake appears to have broken. The piece I have has one neatly closed end and one broken end. Does anyone know what the correct length and spec are for this spring? Thanks. I look forward to contributing what I learn to this forum.
Hello

It seems you and I are on similar paths. I have just got my hardinge lathe (a KL1, same as the Hlv-H, made in devon) and am getting it up and running. Im in the UK too, In Bristol.

Where abouts is this spring and how do you access it? I can measure mine for you as a ref.

Alex
 
Alex,

Most definitely we are both on the same path. I live in Birmingham, I shall send you a PM if I can work out how to do it. It may be useful to keep in touch.

I have attempted to attach details of the spring from the Parts List and Maintanace Manuals. Hopefully, they will show up. Getting the brake assembly out was not difficult but it was buried under years of dirt!

Regards

ElliotBrake spring.jpg
 
The very helpful Bill Todd tells me that the spring should not be too strong so that the solenoid is strong enough to disengage the brake. He added that the link from the solenoid to the brake arm often comes loose when the split pins fail in the link pins.
 
Last edited:
From another forum, I understand the size is
overall length: 1.38"
OD: 1.00"
ID: .85"
wire dia: .08"
 
Having messed about for a while with alternatives, I finally decided to buy (at immense expense) the correct spring from Hardinge: Part No HC 0008872 – Spring Compression”
For reference, the dimensions are:
Length 15/16” Ext Dia: 1” Int Dia: 13/16” Wire Dia: 1/16” Closed ends 31/2 open turns



DSC02379.jpg
 

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  • Brake spring.jpg
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