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No excuse not to make an er32 chuck for the lathe
- Thread starter mickri
- Start date
- Joined
- Oct 31, 2016
- Messages
- 2,721
The spindle end is done. It screws on easily and mates up square to the spindle. Before I took it out of the 4 jaw I used the jaws on the 4 jaw to scribe 4 lines to give me a reference to drill 4 holes around the chuck to help remove the chuck.
- Joined
- Oct 31, 2016
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Next task is to drill some holes through or in the chuck so I can insert something in the chuck to be able to remove it from the spindle. Or I could use a strap wrench. Or I could mill two flats 180 degrees apart for a wrench. A hole for a bar seems to be the simplest solution. Would a 1/4" bar be big enough? I think the largest bar would be 3/8." Should the hole go all the way through? The chuck is 2 1/2" long. The spindle threads go in 1" and the collet goes in 1". This only leaves 1/2" in the middle for a bar to fit all the way through.
More decisions. Help me out.
More decisions. Help me out.
I think that you will need a wrench on the chuck to tighten the collet as well as to remove it from the spindle. If there is work extending through the chuck then a bar will not work. Might as well buy or make a pin wrench. I would hesitate to mill flats on the chuck for a spanner but that is just me.
- Joined
- Aug 7, 2018
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- 668
Hi Guys, Mick,
My personal preference would be spanner flats ! I don't think a 1/4" bar would be enough, and 3/8" would need a deeper hole than 1/4" to prevent pull over and hole damage.
Apart from removing the chuck from the spindle, tightening the collet, unless you have a ball bearing one, takes quite a fair amount of force.
My personal preference would be spanner flats ! I don't think a 1/4" bar would be enough, and 3/8" would need a deeper hole than 1/4" to prevent pull over and hole damage.
Apart from removing the chuck from the spindle, tightening the collet, unless you have a ball bearing one, takes quite a fair amount of force.
- Joined
- Oct 31, 2016
- Messages
- 2,721
I decided against milling flats because I don't have a wrench big enough. So I drilled four 7/32 holes equally spaced around the chuck and have ordered another ER32 nut wrench that with just a bit of file work on the corners will fit in the holes. And I have faced off the collet end of the chuck.
Next task is to bore a tapered hole for the collets to fit into. I set my compound at 8 degrees as a starting point. I put an ER32 / mt2 chuck into the spindle which I am using to more precisely set the taper. Here is my setup.
I have to read the TDI with a mirror. I set the height of the probe on the TDI at center height. My TDI has .0001 printed on the face and the range goes from 0 to 15 then back to 0. My current range of movement is from 0 to 5 on the dial which I believe is .0005 if I am reading the TDI correctly. I have tried gently tapping the compound to try to obtain a smaller range with no success. Is this close enough? Suggestions please.
Next task is to bore a tapered hole for the collets to fit into. I set my compound at 8 degrees as a starting point. I put an ER32 / mt2 chuck into the spindle which I am using to more precisely set the taper. Here is my setup.
I have to read the TDI with a mirror. I set the height of the probe on the TDI at center height. My TDI has .0001 printed on the face and the range goes from 0 to 15 then back to 0. My current range of movement is from 0 to 5 on the dial which I believe is .0005 if I am reading the TDI correctly. I have tried gently tapping the compound to try to obtain a smaller range with no success. Is this close enough? Suggestions please.
- Joined
- Oct 31, 2016
- Messages
- 2,721
Well I tried again this morning with the same result. No matter what I try I always get a range of movement of .0005. At this point my conclusion is that .0005 is the tolerance in the chuck. And I was able to turn the TDI 180 degrees. Same result. Have to go to town today. Will cut the taper tomorrow.
- Joined
- Aug 7, 2018
- Messages
- 668
Hi Mick,
Half a thou isn't to be sniffed at. However there are lots of places that can move to show that tiny amount. If you think that its the spindle, then use a long wooden batten to lever the spindle up or to the side with the DTI in the bore. It will soon show how much the spindle will affect your readings.
Though I would want to greatly reduce the distance between the mag stand and the DTI, since a half thou indicator on a long arm like you show would influence the readings you are getting. I try and make my setup as rigid as I can.
This is the setup that I use to make measurements similar to the one that you are making.
This replaces the lathe tool in the holder. I can replace the gauge with any of the ones that I have.
Half a thou isn't to be sniffed at. However there are lots of places that can move to show that tiny amount. If you think that its the spindle, then use a long wooden batten to lever the spindle up or to the side with the DTI in the bore. It will soon show how much the spindle will affect your readings.
Though I would want to greatly reduce the distance between the mag stand and the DTI, since a half thou indicator on a long arm like you show would influence the readings you are getting. I try and make my setup as rigid as I can.
This is the setup that I use to make measurements similar to the one that you are making.
This replaces the lathe tool in the holder. I can replace the gauge with any of the ones that I have.
Not able to indicate a constant taper? Maybe the chuck is not to blame. If you are off center, but parallel to the axis, the indicator tip traces a hyperbola, which does not have a constant slope. The needle will always be moving. This makes a good interview question. A perfect taper is just a truncated cone, whose equation is very simple in rectangular-cylindircal coordinates. Solve the equation of the intersection of this shape and any z-plane. You only get a straight line at the origin. All the rest are hyperbolas.