The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Lucas, Ignition, Charging, Electrical => Topic started by: dynodave on 08.10. 2021 12:17
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How to reinstall new pick-up spring and brush? into PU body? No luck so far with just fingers. I will be making a spring compression tube to hopefully allow it to slide in the compressed large diameter spring. Any advise appreciated.
TIA
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If a spring is a bit wide for a hole, sometimes winding it anti-clockwise while you push it in sometimes works.
Unless the spring is made the other way round- then you’d go clockwise!
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Tweezers were the finger aids but still no match for the stiff steel spring. only by destroying the flared spring at the end would it seem to help.
Search found nothing I could sense was the same problem in replacing brush with NEW pick up parts. Does everyone just buy new pickups?
I'm imagining the flared spring is to give good contact with the metal coming from the plug wire hole.
I didn't want to just cut those 2-3 spring coils off. Old short dirty pick ups showed the pulg wire to brush continuity with the meter
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To get a good contact and secure the pick up in the holder i use a thin shank screwdriver to force the spring down to the bottom of the holder. This obviously stretches the spring as the carbon is not able to enter at the same time. I then spend some time forcing the carbon deep into the holder to try to re-tension the spring. Bit Heath Robinson but has worked well for me many times.
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Solution
I made a restricting guide from 1/4" stainless tube with a .199" #8 drilled bore to accommodate the 5mm brush and spring. It was fairly easy to load the oversize spring end. Offering up the loaded guide tube with spring and brush to the pick up hole, I used a dressed 1/16 wire to drag/push the spring quite easily into the 5mm bore. I took about 5 minutes to finish both brush loading and adjust the spring depth to achieve electrical continuity. The guide tube is relatively short to allow spring stretch enabling the dressed 1/16 wire to catch the large spring coils but not over stretch the whole spring. *smile*
(https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fatlanticgreen.com%2Fimages%2Fbrush-tool.jpg&hash=e55c4d32384c1e559363bdd994cb8c1fb3e1db0e)