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Steering pin removal from bottom yoke
- Kawboy
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4 years 9 months ago #26166
by Kawboy
Replied by Kawboy on topic Steering pin removal from bottom yoke
Jim's on the mark. I would after interference installing the sleeve on the pin, tack weld the sleeve to the pin for reassurance.
You're math is on the mark however, a little more theory here for you.
After you've interference fitted the sleeve on to the pin, the original machined diameter will grow because the inner diameter will have grown to the new diameter of the pin but not the full .002" so why?
Imagine if you will, taking a 1" id o-ring with a cross section of 1/8" ( so 1" id and 1-1/4" od.) and stretching over a 1-1/2" shaft. (I've exaggerated this to make a point) You would expect that the o-ring would now have an od. of 1-1/2" plus the cross section of the o-ring x 2 so 1-3/4" right? Wrong. In order for the o-ring to fit the new diameter it had to stretch in length making the cross section of the o-ring less than the original 1/8". Makes sense right?
So knowing that, what do we do about it? The easiest way to do your job is to size the sleeve .002" less than the pin and go about fitting the sleeve to the pin in the manner you were going to do (heat sleeve and freeze the pin or just heat the sleeve). Once you have that assembly finished, measure the new diameter of the pin/sleeve and machine the yoke for your interference fit.
You're math is on the mark however, a little more theory here for you.
After you've interference fitted the sleeve on to the pin, the original machined diameter will grow because the inner diameter will have grown to the new diameter of the pin but not the full .002" so why?
Imagine if you will, taking a 1" id o-ring with a cross section of 1/8" ( so 1" id and 1-1/4" od.) and stretching over a 1-1/2" shaft. (I've exaggerated this to make a point) You would expect that the o-ring would now have an od. of 1-1/2" plus the cross section of the o-ring x 2 so 1-3/4" right? Wrong. In order for the o-ring to fit the new diameter it had to stretch in length making the cross section of the o-ring less than the original 1/8". Makes sense right?
So knowing that, what do we do about it? The easiest way to do your job is to size the sleeve .002" less than the pin and go about fitting the sleeve to the pin in the manner you were going to do (heat sleeve and freeze the pin or just heat the sleeve). Once you have that assembly finished, measure the new diameter of the pin/sleeve and machine the yoke for your interference fit.
The following user(s) said Thank You: McBoney
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- McBoney
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4 years 9 months ago - 4 years 9 months ago #26178
by McBoney
Considering that that was the way it was originally done, I was/am considering welding the bottom of the pin to the inside of the sleeve before inserting the sleeve into the yoke, but I was going to see how much room I had to put the welding nozzle in. It may be too deep and narrow, but certainly a good idea (ie; not rubbish, please keep your ideas coming! Far better than silence... )
It would be on the mark Kawboy, as it was your math, haha! Seriously, thank you again, I had not appreciated the sleeve actually growing in dia because of the force-fit - makes sense.
As the sleeve to yoke fit does not need to need to rely on a press-fit as I will have a lip at the bottom that secures it against the yoke the 'new' dia is not that much of a consequence.
Once I have the new sleeve made I shall post pics of the whole process...
Thanks again all!
Six-Pot-Cafe in the making...
Replied by McBoney on topic Steering pin removal from bottom yoke
biltonjim wrote: Maybe I’m talking rubbish, but rather than relying on interference fit between the stem and sleeve, would welding, brazing, or otherwise bonding the two be an option?
Considering that that was the way it was originally done, I was/am considering welding the bottom of the pin to the inside of the sleeve before inserting the sleeve into the yoke, but I was going to see how much room I had to put the welding nozzle in. It may be too deep and narrow, but certainly a good idea (ie; not rubbish, please keep your ideas coming! Far better than silence... )
It would be on the mark Kawboy, as it was your math, haha! Seriously, thank you again, I had not appreciated the sleeve actually growing in dia because of the force-fit - makes sense.
As the sleeve to yoke fit does not need to need to rely on a press-fit as I will have a lip at the bottom that secures it against the yoke the 'new' dia is not that much of a consequence.
Once I have the new sleeve made I shall post pics of the whole process...
Thanks again all!
Six-Pot-Cafe in the making...
Last edit: 4 years 9 months ago by McBoney.
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4 years 7 months ago #26633
by McBoney
Six-Pot-Cafe in the making...
Replied by McBoney on topic Steering pin removal from bottom yoke
Well, that didn't work. Yet!
The sleeve was machined by a machine shop so I have to trust its inner dia is 29.08mm. The pin is 30mm.
I froze the pin to at least minus 15C (my freezer) and heated up the sleeve with a blowtorch, but no way was the pin going into the sleeve (with large hammer). The size difference was still too great and I could not trust myself to hold the pin straight. So after three blows I abandoned the idea.
I'll take it to the mill where I have a press and see how that goes.
Paul
The sleeve was machined by a machine shop so I have to trust its inner dia is 29.08mm. The pin is 30mm.
I froze the pin to at least minus 15C (my freezer) and heated up the sleeve with a blowtorch, but no way was the pin going into the sleeve (with large hammer). The size difference was still too great and I could not trust myself to hold the pin straight. So after three blows I abandoned the idea.
I'll take it to the mill where I have a press and see how that goes.
Paul
Six-Pot-Cafe in the making...
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4 years 7 months ago - 4 years 7 months ago #26636
by Kawboy
The sleeve was machined by a machine shop so I have to trust its inner dia is 29.08mm. The pin is 30mm.
I froze the pin to at least minus 15C (my freezer) and heated up the sleeve with a blowtorch, but no way was the pin going into the sleeve (with large hammer). The size difference was still too great and I could not trust myself to hold the pin straight. So after three blows I abandoned the idea.
Paul
Of course it wouldn't fit. You have .028" of interference. You need .002" of interference or .05 mm of interference. You need to open up the bore of the bushing to 29.95mm to fit that 30 mm yoke pin.
Replied by Kawboy on topic Steering pin removal from bottom yoke
McBoney wrote: Well, that didn't work. Yet!
I'll take it to the mill where I have a press and see how that goes.
Paul
The sleeve was machined by a machine shop so I have to trust its inner dia is 29.08mm. The pin is 30mm.
I froze the pin to at least minus 15C (my freezer) and heated up the sleeve with a blowtorch, but no way was the pin going into the sleeve (with large hammer). The size difference was still too great and I could not trust myself to hold the pin straight. So after three blows I abandoned the idea.
Paul
Of course it wouldn't fit. You have .028" of interference. You need .002" of interference or .05 mm of interference. You need to open up the bore of the bushing to 29.95mm to fit that 30 mm yoke pin.
Last edit: 4 years 7 months ago by Kawboy.
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