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Thread: Pipecentres
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24th February 2013, 04:38 PM #1.
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Pipecentres
Coming up to do a bit of ally pipe work so I thought I'd have a crack at making some MT2 pipe centres using some bearings and bits and pieces I already had
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The big one is just over 100 mm in diameter and uses two bearings, one fore and one aft.
The cone is made out of a very hard stainless of some kind.
This one runs reasonably true - not that I was after a super precise outcome.
The smaller one is 50 mm in diameter and only uses one bearing - the cone is just made of mild steel and is a tight fit onto the bearing outer backed up by 4 grub screws. Tightening the grub screws too much throws the centre out of alignment so only a light touch is needed there.
After finishing the bigger one I realized I should have recessed the bearings a lot more than the mm amount that I did so that the bearings would be out of the way - I could still go back and do this if required.
The taper on the bigger one is not quite long enough to pop out the MT when the tailstock shaft is brought right back into the tail stock - it should just be a matter of turning down the taper a bit further so that it pokes into the tailstock a bit more. The smaller one is fine in this regard.
All useful learning experiences.
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24th February 2013 04:38 PM # ADSGoogle Adsense Advertisement
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24th February 2013, 04:59 PM #2Dave J Guest
Hi bob,
Just wondering why you never left all the center section in and had the bearing enclosed in it?
For the ejection problem you can drill and tap it to suit a socket head screw.
Dave
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24th February 2013, 08:06 PM #3SENIOR MEMBER
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You should always use a tapered roller bearing in these centres.
I made one up years ago using a single Timkem tapered roller (outer) wheel bearing.
Piece of cake. You have to face off the pipe end regardless of the design, and when you apply tailstock pressure the bearing takes up the slop and self centres.
No runout. Never had a problem with it.
I can also use mine as a normal live centre if required.
Rob
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24th February 2013, 08:47 PM #4.
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The main reason was the steel was very hard and I thought I still have an awful lot of steel to remove so I called it quits. I still want to completely recess the front bearing when I finish the pipe work.
For the ejection problem you can drill and tap it to suit a scket head screw.
Yep, I realize that I just didn't have one to play with. One of the reasons the big centre has so much meat on it is that when I run across one I can probably still resuse it that way.
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24th February 2013, 11:12 PM #5Dave J Guest
If you make up a piece of bar bored at one end to suit the outside of the bearing (with a grub screw or 2 to hold it) then in the other end you could drill and tap for a socket head screw. You could then place a hex bar in the chuck to turn the pipe center and take a cut off the outside to true it up.
Dave
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25th February 2013, 01:48 AM #6Senior Member
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Very nice. I made one a few years ago and it wouldn't pop out of the tailstock either. So i lay my tailstock wrench between it and the tailstock casting and crank the handle back and it pops free...Bob