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Nov 17, 2008 4:21 pm
Nov 17, 2008 4:21 pm
Subject: Re: jacks (Jackall system)
some impression from working on one of them. It needs much heat to get the large fine threads moving after 50 years.
To remove the foot from the inner tube, I made an aluminium clamp to hold it: I bored a slightly (0.3mm) to small hole in an aluminium block on my lathe, an then cut the block in two halfs. This clamps around the end of the inner tube to hold it when turning the foot with a big tool after heating it (turbo flame) and while trying to turn, hammering on the foot !
Took me hours to find that procedure. A few scratches in the tube (from some other trials) could be filled by soldering.
Fun is to rebuilt all: first screw the fitting on the top to the screw on the end of the long return spring. Than you can use a lathe to pull the spring out and fix the foot to it. See some impressions on photos.
I will now test if the cleaning made it tight again or if I have to replace the U-seal inside. (now I will be much faster in opening and rebuilding). The U-seal has dimensions 1-1/4 x 1-3/4 x 5/8. Modern U-seals with this diameters are much less high so propbably it would need an insert to fit a modern one.To be continued...
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some impression from working on one of them. It needs much heat to get the large fine threads moving after 50 years.
To remove the foot from the inner tube, I made an aluminium clamp to hold it: I bored a slightly (0.3mm) to small hole in an aluminium block on my lathe, an then cut the block in two halfs. This clamps around the end of the inner tube to hold it when turning the foot with a big tool after heating it (turbo flame) and while trying to turn, hammering on the foot !
Took me hours to find that procedure. A few scratches in the tube (from some other trials) could be filled by soldering.
Fun is to rebuilt all: first screw the fitting on the top to the screw on the end of the long return spring. Than you can use a lathe to pull the spring out and fix the foot to it. See some impressions on photos.
I will now test if the cleaning made it tight again or if I have to replace the U-seal inside. (now I will be much faster in opening and rebuilding). The U-seal has dimensions 1-1/4 x 1-3/4 x 5/8. Modern U-seals with this diameters are much less high so propbably it would need an insert to fit a modern one.To be continued...
Attachments: