Holding a threaded bolt in a lathe?

[Morrisman]

Buy a collet chuck?

And find the bolt head isn't swaged true to the shaft, so it's impossibly to tap true......

 

[bricol]

It is actually the correct bolt for a Triumph GT6 rear shock as the originals did not have a sleeve in the bush

Same for Spitfires and if memory serves the Herald and Vitesse as well

I'm guessing that whatever shock is being installed already has the sleeve bonded into the bush

I thought I reckonised it from over 30 yrs ago of playing with Spit bits. If there's a sleeve bonded in, its not the right shock - but in the spirit of making do, use the correct bolt for the sleeve and make a simple short sleeve/spacer to sit in the bigger hole in the chassis and avoid the issue?

Drill the sleeve out? Fit the original style bushes?

Being a bodge artist, to answer the original question, I'd probably grip the threads and take shallow cuts. Or wind a nut and lock nut on and grip the nut.

On bottoming out my Spit based kit car with a rather "robust" mate in the passenger seat, the upper shock eye bust off the top of the shock - one of my earliest welding jobs with my dads arc welder was to reattach it . . .

 

[Agroshield]

….the hex head doesn’t need to be concentric with the thread does it...

No, but if you grip the head, then anything you subsequently do to the rest of the bolt will become concentric to it. The original post says that some of the plain shaft is to remain "up to 3mm from the head". The plain shaft is likely to be the best-made part of the original so it seems to me that it should be used as the reference surface and new stuff done relative to it.

You are quite right that in this case absolute accuracy will not matter, but the risk is that future people will read this, think that the methods suggested are 'good' ones and will try similar when such things are more important.

 

[merryman]

grip the head, but in a 4-jaw and dial the plain shank in until it is running true.

Be interesting to see someone trying that suggestion.

 

[mtt.tr]

Be interesting to see someone trying that suggestion.

I see no issues 6/4= 4 right

 

[dobbslc]

Be interesting to see someone trying that suggestion.

Tried that and it doesn't work
I'll have a go with the 3 jaw and put the head in and see how true I can get it.

 

[Kram]

Id chuck up a bar and tap it blind, to hold the threaded section. It should get the shank concentric to the thread. It is a massive pain when bolts bind up if not concentric and needing a bigger clearance hole.

 

[dobbslc]

I've done them!

I was overthinking it possibly as I didn't think I could get them to run true in a 3 jaw chuck.
I got them to within 0.05mm so I'm sure that's good enough.
Thanks for the advice chaps

 

[not done it yet]

Hells bells, too much talk and not enough go. I could have set it running true and centre drilled both ends, and then turned it ‘between centres’ while it’s been discussed on here - not that some options (with care) would not have sufficed.

 

[brightspark]

if i need to true stuff up and carnt be arsed to change the 3 jaw chuck to the 4 the 3 jaws only a few thou out so i just pack shim the one jaw with a bit of a tin can or a bit of cardboard

 

[dobbslc]

Hells bells, too much talk and not enough go. I could have set it running true and centre drilled both ends, and then turned it ‘between centres’ while it’s been discussed on here - not that some options (with care) would not have sufficed.

Sorry it taken so long boss but I'm not a professional machinist! I haven't been standing here scratching my balls for days looking at it though.
If the post wasn't so sxxx I'd have sent it to you to do instead

 

[not done it yet]

Sorry it taken so long boss but I'm not a professional machinist! I haven't been standing here scratching my balls for days looking at it though.
If the post wasn't so sxxx I'd have sent it to you to do instead

Neither am I. I’m only a hobbyist. You can scratch your balls as much as you like. I don’t. Better to use a couple of brains cells than rubbing a couple of balls together - unless there is a connection?

All you need to do is mount that bolt so that it will run concentrically - and remain so, while machining away the unwanted metal.

 

[dobbslc]

I thought all mens balls and brains were connected directly

 

[not done it yet]

I thought all mens balls and brains were connected directly

Yes, connected - but not both in the same place.

 

[brightspark]

I thought all mens balls and brains were connected directly

unless its women then the balls take over

 

[Greeves246]

I thought all mens balls and brains were connected directly

They are, but the body has only enough blood to operate one or the other, not both at the same time.

 

[ukracer]

Be interesting to see someone trying that suggestion.

@doubleboost will run with this and turn it into a Sunday night nitecap.

 

[Chippie]

@doubleboost will run with this and turn it into a Sunday night nitecap.

Yeah, I’m watching out for that one….lol…Hope he includes my split bush gag..

 

[dobbslc]

I seemed to have missed half the posts in this thread on page 1
Sorry I didn't reply or comment!
I'm not normally that rude

@roofman there was some chundering from the lathe but the roof is still in place