# Revolving Centre



## BRIAN (Dec 18, 2016)

My store bought centre is in constant use but it often gets in the way, it is simply just to big
I have to have more tool overhang than i want to operate near the end of the work  so a solution had to be found so I looked into the scrap / odds and ends box and came up with a piece of  6082  bar  a length of stainless out of a marine toilet a bearing from a scraped power tool and a sintered bronze bush From god knows where



The first thing was to put a No2 morse taper on the  alloy bar so the old scrap box taper turning attachment was fitted  and the taper duly made.



This was then mounted in the head stock and bored to take the bearing, and drilled and reamed to take the bush.




the centre was then made from the toilet  plunger .




and a cap for the end to take the force of the tailstock ejector and it was done.




Finished 





And a lot smaller




Time will tell if this is an improvement . but at no cost and about  2 hrs work I think I am on a winner,

 Brian.


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## Ed ke6bnl (Dec 18, 2016)

I would like a really long snout, but not going to purchase on, they are too expensive, but would/will make one for my live center that suppose to have interchangeable tips. Don't have them because I bought it used and cheap on ebay and did't even realize it was made for interchangeable tips, picture was poor price was good and run true ans smooth


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## Charles Spencer (Dec 19, 2016)

Great idea.


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## FOMOGO (Dec 19, 2016)

Well done. Mike


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## ndnchf (Dec 19, 2016)

Nice work.  I run into that some issue with the live center sometimes.  I usually resort to a dead center, but this is sweet.


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## Ed ke6bnl (Dec 19, 2016)

Is that one bearing doing the thrust and rotational work? 

Sent from my SM-G930V using Tapatalk


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## RJSakowski (Dec 19, 2016)

Nice, Mike.

Here is one which I made when I was involved with some tiny machining work.  I used bearings from a hard disk drive and the 1/8" shank from a broken printed circuit board drill for the center.  The shank is 1/4" and it fits into the 1/4" Albrecht chuck pictured.  The brass on the right is an adjustable centering mount.  At the time, I was drilling holes as small as .008" in diameter with carbide drills so the chuck had to be centered to sub thousandths both horizontally and vertically.  To pot the holes, I used a 00000 center drill with a .010" tip.  If it started off center, the tip would disintegrate as soon as the body of the center drill touched.


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## barnett (Dec 19, 2016)

I may be confused, what holds the shaft in?


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## BRIAN (Dec 20, 2016)

Hi Tom and  Ed
 Ed  the ball bearing takes all the load It was from a hammer drill of 13 mm capacity so it should be enough the bush keeps the shaft stable by being as far away as possible from the front bearing.
Tom the shaft is retained by its fit in the ball bearing. when under load the shaft is pushed harder onto its seat so it is impossible for it to loosen.
Thank you for your interest. and have a Merry Christmas.    Brian.


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## Ed ke6bnl (Dec 20, 2016)

BRIAN said:


> Hi Tom and  Ed
> Ed  the ball bearing takes all the load It was from a hammer drill of 13 mm capacity so it should be enough the bush keeps the shaft stable by being as far away as possible from the front bearing.
> Tom the shaft is retained by its fit in the ball bearing. when under load the shaft is pushed harder onto its seat so it is impossible for it to loosen.
> Thank you for your interest. and have a Merry Christmas.    Brian.


I always thought that a small indent on the shaft and a ball bearing set in the bottom would serve as a thrust bearing would be good, never got around to making one though.


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## BRIAN (Dec 20, 2016)

Hi Ed
I thought along those lines but I think that if you take any load from the main bearing it will start to float and loose it's accuracy after all it is the angular load that keeps the bearing  running true .
Brian.


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## Big Bore Builder (Dec 22, 2016)

Ed ke6bnl said:


> I would like a really long snout, but not going to purchase on, they are too expensive, but would/will make one for my live center that suppose to have interchangeable tips. Don't have them because I bought it used and cheap on ebay and did't even realize it was made for interchangeable tips, picture was poor price was good and run true ans smooth




I made the one in the upper left of the photo.  Sometimes you need a longer "snout"!

All are no. 3 taper.


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