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Happijac leg
Posted: July 10th, 2015, 4:05 pm
by TonyS
Wanted - HAPPIJAC 4150. damaged, bent, seized, rusted with/without motor, condition unimportant as I am looking to totally refurb and keep as a spare.. Tony
Re: Happijac leg
Posted: July 10th, 2015, 6:48 pm
by zildjian
Out of interest Tony, what typically needs attention on these?
Re: Happijac leg
Posted: July 10th, 2015, 7:53 pm
by TonyS
I honestly don't know, Zildjian, its all a bit of a learning curve to me at the moment. I just thought that it may be a good idea to have a spare ready to bolt on in the case of failure, rather than be temporarily out of business. I also love dragging things back to my lair and pulling them to bits
It will be interesting to see if any of the internal parts are available off the shelf in the uk..
Re: Happijac leg
Posted: July 10th, 2015, 8:14 pm
by zildjian
I did read a strip down on these some years back, I think it was on
Woodalls
might be some clues, I'll re-read through myself as well
Re: Happijac leg
Posted: July 10th, 2015, 8:16 pm
by zildjian
Re: Happijac leg
Posted: July 10th, 2015, 8:54 pm
by TonyS
Ah.. Thats very interesting. . . plenty of info there. Thanks
Re: Happijac leg
Posted: July 16th, 2015, 9:35 am
by derestrictor
On these though, from an engineering perspective at least, they probably all get made the same way with that huge threaded bar through the middle
somebody could make those I would imagine, but how best to attach a gog to the top end to mesh with with another at right angles, would a weld be good enough or would you need to put a pin right through it?
Re: Happijac leg
Posted: July 16th, 2015, 4:36 pm
by TonyS
At a casual glance, the threaded rod down the middle looks very similar to the Lead Screw on a lathe, if it is, it would be available as a stock item somewhere. . . I would imagine that the bevel drives are either, as you say, pinned to the shaft with a roll pin or taper pin, or they may be keyed and grub screwed. . . . I can't wait to conduct a post mortem
. . . one of my four electric legs is slightly faster than the other three, maybe its been fitted with a racing screw or a high performance motor. . .or both. .
Re: Happijac leg
Posted: July 18th, 2015, 8:01 pm
by derestrictor
this might be the moving core inside a happijac leg or at least something like it
http://www.ebay.co.uk/itm/3-8-12-ACME-D ... 20fe88f106
Re: Happijac leg
Posted: July 19th, 2015, 10:48 pm
by TonyS
It does look very similar. . . the thread in the jack must be fairly close pitch in order to take the strain off the electric motors and to give a more controlled lift.