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truing a crankand welding pin advice.
Posted: Thu Feb 02, 2012 9:34 pm
by tavspeed
hi all,i have just re-assembled my indian crank with a vespa ape conrod,i have pressed it together and have .3mm clearance between the big end eye and the inside of the web,giving .15 both sides,is this sufficient.
i scribed a line across both cheeks as a reference for re- assembling,now the width of the crank at the pin is 40.53mm,exactly opposite it is 41.06mm,i'm thinking of squeezing it in a vice to get the cheeks parallel,when i have the cheeks correct do i then check and adjust the run out,i have some vee blocks and dial guage to check it with.
also i am going to tig the pin,anybody any advice,i'm thinking of welding oneside,then getting run out correct,then welding other side,thanks all.
Re: truing a crankand welding pin advice.
Posted: Fri Feb 03, 2012 4:30 pm
by Darrell Taylor
id not be happy at .3
.5mm to .7mm be better especially if the rod has plain sides with no lubrication cut outs
grind slots around the pin on opposite sides and fill with weld otherwise you grind clean therefore removing the weld
clamp the crank securely during welding and check after all is still well
Re: truing a crankand welding pin advice.
Posted: Fri Feb 03, 2012 9:07 pm
by tavspeed
thanks darrell,your a gent.
Re: truing a crankand welding pin advice.
Posted: Fri Feb 03, 2012 9:14 pm
by tarmac tickler
get some suitable sized tubing to slip over the crank that will protect the oil seal faces, otherwise spatter will ruin the seal between the two,,
Re: truing a crankand welding pin advice.
Posted: Fri Feb 03, 2012 10:46 pm
by Darrell Taylor
as tt says
or a couple of cunky wide jubilee clips will do to protect the shaft seal areas, also good when cutting the crank pin/cleaning up weld/cutting off seized bearings,grinding slots in seized bearings prior to using a nut splitter to release
Re: truing a crankand welding pin advice.
Posted: Fri Feb 03, 2012 11:26 pm
by shocky
why would you use a welding process that produces spatter on such a delicate item as a crank surely you would use a tig welder with a dissimilar type filler wire ?
Re: truing a crankand welding pin advice.
Posted: Sat Feb 04, 2012 1:01 am
by tarmac tickler
why would you use a welding process that produces spatter on such a delicate item as a crank surely you would use a tig welder with a dissimilar type filler wire ?
i am shite at welding but good at grinding!! i do use a tig, but dont even know what dissimilar filler wire is?? the filler wire i use chucks itself all over the place hence the advice,,
Re: truing a crankand welding pin advice.
Posted: Sat Feb 04, 2012 5:31 am
by Robi D
There is no spatter with T.I.G.! That's part of the reason why it's T.I.G. Welded!!
Re: truing a crankand welding pin advice.
Posted: Sat Feb 04, 2012 9:09 am
by tavspeed
hi all,i will be using a tig welder to weld the pin,and we have some dissimilar wire somewhere,i have plenty of insulation tape round the seal faces,i will not be fully welding the pin,just some thing like a 10mm run at 3 anf 9 0clock,and as darrell suggested i will put a good fitting packer between the weds and clamp them together with a carver or g clamp,first job is to get it running true,i will let you know how i get on.