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- Jan 31, 2016
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I have a few that I made years back , couple bearings mounted in a sleeve with the center lightly pressed in . I tapped 1/2"-20 threads in the back of them for different style shanks .
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Homemade live center
- Thread starter Tozguy
- Start date
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- Feb 7, 2013
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Ray C also has a very pro write up on the bull nose he made here a few years back.
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Bull Nose Live Center
I've been meaning to make this live center for a while now. The bull-nose is a special size and length that would make a particular task a little easier. Here's an outline image. This is a background shop project that's going to take a while. The nose is 4140 that I plan to bring up to the...
www.hobby-machinist.com
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- Jan 31, 2016
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Actually I already have a live center so I don't really need another. But it has always been a lot of fun for me to make things that I don't really need at three times the cost and almost as good as a bought one.
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I dreaded the thought of an MT2 taper slipping .............until now.
This is a live center made up from an MT3/MT2 sleeve, a homemade MT2 center, a 3/8ths ball bearing and a couple of screws
The set screw in the MT3 tang and a ball bearing act as a stop to prevent the MT2 taper from binding, but just barely.
The screw in the end of the MT2 center is to provide a hard cupped socket for the ball bearing to ride in.
The tang set screw has a 5/16 NF thread that allows for adjustment of the clearance in the MT2 taper. During preliminary trials I was able to get down to .0005'' clearance and still have the center rotate easily in the sleeve. The MT2 taper was lubed with Rotella 15w40 diesel oil.The MT2 center used for the trials is a low friction ball center but it spun very well so I can only think that the Rotella was a good choice.
These results are much better than those for the live center that came with my lathe which is much more bulky and has over .003'' of slop.
I plan to make up another MT2 center with a 60deg point instead of a ball and provide for some means of lubrication on the run.
This is a live center made up from an MT3/MT2 sleeve, a homemade MT2 center, a 3/8ths ball bearing and a couple of screws
The set screw in the MT3 tang and a ball bearing act as a stop to prevent the MT2 taper from binding, but just barely.
The screw in the end of the MT2 center is to provide a hard cupped socket for the ball bearing to ride in.
The tang set screw has a 5/16 NF thread that allows for adjustment of the clearance in the MT2 taper. During preliminary trials I was able to get down to .0005'' clearance and still have the center rotate easily in the sleeve. The MT2 taper was lubed with Rotella 15w40 diesel oil.The MT2 center used for the trials is a low friction ball center but it spun very well so I can only think that the Rotella was a good choice.
These results are much better than those for the live center that came with my lathe which is much more bulky and has over .003'' of slop.
I plan to make up another MT2 center with a 60deg point instead of a ball and provide for some means of lubrication on the run.
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Here is one that I made some time ago for doing miniature work. The bearings were salvaged from a computer hard drive. It has a 1/4" straight shank for mounting in a 1/4 Albrecht chuck. The chuck is adjustable similar to the Set Tru chucks for centering.
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- Jan 31, 2016
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Emergency live center.........
This is a trial that was just completed with success.
Using a Weldon end mill holder and a broken four flute end mill it was fairly easy to rig an internal stop and allow the end mill to spin in the holder.
With the set screw removed from the holder and the holder installed with the hole facing up, some 0w20 synthetic engine oil was added in the hole.
Hopefully the photos are self explanatory. There is absolutely no precision required in making up the other parts. Clearances between the end mill and holder are minimal as is and once the oil fills the void there is no play. My 3/8 shank end mill was broken off near the root. The shoulder at the root is perfect at 60 deg.
This is a trial that was just completed with success.
Using a Weldon end mill holder and a broken four flute end mill it was fairly easy to rig an internal stop and allow the end mill to spin in the holder.
With the set screw removed from the holder and the holder installed with the hole facing up, some 0w20 synthetic engine oil was added in the hole.
Hopefully the photos are self explanatory. There is absolutely no precision required in making up the other parts. Clearances between the end mill and holder are minimal as is and once the oil fills the void there is no play. My 3/8 shank end mill was broken off near the root. The shoulder at the root is perfect at 60 deg.
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Used the end mill live center again today. The job was to slim down the shoulder on an MT2 center.
This was the set up.
The tip of the MT2 center was driven by friction from a 1/2 steel rod held in a collet and a relatively deep center divot drilled in it.
To ensure that enough friction was available the tailstock hand wheel was preloaded with a weighted lever. This kept some pressure on both centres.
At 330 rpm and a .005'' depth of cut it produced nice long curly chips with a bit of smoking from the cutting fluid. The resultant finish is very acceptable even though feed was manual.
The live center performed flawlessly. After the hole in the end mill holder was filled with oil a plastic sleeve was installed to keep chips out of it.
The center has very low drag and can take significant thrust. After around 20 minutes of turning there was still oil in the hole and there was no heat build up. It seems like this live center could be used all day with no problems.
Another significant discovery was that it is possible to drive work between centres without using a dog. In this case the contact surfaces at the headstock end were completely clean and dry, with a means of providing some constant pressure on the center.
Just wanted to share this with you. I am so tickled by how this live center works that I rate it totally awesome.
This was the set up.
The tip of the MT2 center was driven by friction from a 1/2 steel rod held in a collet and a relatively deep center divot drilled in it.
To ensure that enough friction was available the tailstock hand wheel was preloaded with a weighted lever. This kept some pressure on both centres.
At 330 rpm and a .005'' depth of cut it produced nice long curly chips with a bit of smoking from the cutting fluid. The resultant finish is very acceptable even though feed was manual.
The live center performed flawlessly. After the hole in the end mill holder was filled with oil a plastic sleeve was installed to keep chips out of it.
The center has very low drag and can take significant thrust. After around 20 minutes of turning there was still oil in the hole and there was no heat build up. It seems like this live center could be used all day with no problems.
Another significant discovery was that it is possible to drive work between centres without using a dog. In this case the contact surfaces at the headstock end were completely clean and dry, with a means of providing some constant pressure on the center.
Just wanted to share this with you. I am so tickled by how this live center works that I rate it totally awesome.