Make sure your chuck jaws are not on top of the slit in the collet, or you'll have a large red hand print on your forehead where you slapped it.:thumbup:
I need some collets and other stuff for my lathe
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Make sure your chuck jaws are not on top of the slit in the collet, or you'll have a large red hand print on your forehead where you slapped it.:thumbup:
Hi,
If you don't have a taper bar for your lathe you will have to calculate the angle on the cross slide offset. I have a taper bar and I bore my tapered holes while I run my roller guide on the backside of my taper bar.
Since I disposed of my split collets, my A-Joint and Pins have been indicating about 1/4 thou. total run out. I usually have to shim 1 or two pieces of waxed paper on the high side of the outside of the collet and the chuck. About 1 or 2 minutes of time. If your run out is 1 thou. TRO or less, your cue will roll perfect on the table. With the tapered collets my jobs have been very easy. Before with the other collets, I wasted a lot of time to do the same jobs as shimming and indicating was consuming my time and effort.
Good luck,
Rick Geschrey
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The collets that I have might be too big, because when I chuck up the shaft the slit in the collet completely closes up. Maybe ill try to trim some off and see if that helps. Thanks!
Joe
If anyone watches the video, it's KamuiTips guy doing the tip using some sort of clear material for collet ... was wondering if anyone knew what material he might be using.
looks like nylon rod
Joe,
Friction from a 3" long surface area foot print of the collet ID and holding pressure on the back chuck when doing a pin. On butt work and A joint work, the taper holds the part and gets tighter when you apply drill pressure because of the taper angle.
Side Note:
Just watched the Kamui video. You don't want to work a lathe with long sleeves. Not a good practice. It will bite you with one false move.
Rick Geschrey
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Another option is to make a new spindle for your lathe,or an adapter to fit the existing, easy enough if it is a Taig type lathe. I made mine and it takes ER40 collets, I added a location pin to the collet system.So the collets locate radially ,with the pin about 1/2 way down the collet length.I make blanks and final bore them as needed.
I have 2 types of collets, the disstortion type and the split type.
My ones are made of plastic, I can also use the metal ER collets.I have those in 29-30mm and the 25-26mm.These can also take sleeves of different sizes to suite, so you are not changeing out the collet.
The sleeves are parallel on the outside and suite whatever is needed on the inside. As long as the shaft or whatever is being held, is a close fit to the inside of the sleeve, and the sleeve is concentric, it will be true.
People think that just because they turned the od and the id that the sleeve is concentric. But this is not true. There is stress in the materials and stress introduced into the materials from the machining process itself.
So they need to be rough bored, ruf od, finish od finish bore. If the drill is not sharp enough or it gets too hot, wrong speed etc, stress is put into the material, same for the id and od tools.Place a dti on the id and od to check that the needle is frozen. If not, you have done something wrong somewhere.
I made an adapter to put the 39.6x32 threaded chucks onto the lathe as needed. I have found that running it as a collet lathe to be more usefull than using it as a chucking lathe.
The repeatability is within the limits of accuracy of the spindle bearing assembly and how it is adjusted.
This is not for everyone of course, but just another option.
I too had that problem using the collets. I now use a piece of mylar that is .020 thick and about 3/4 (about as wide as the chuck jaws) and 3-4 inches long. I just wrap it around the shaft to protect it and bring the ends of the strip of mylar out between 2 of the chuck jaws. It runs a lot truer than the collets. Most played shafts are not exactly round and you still might have to loosen it up and spin it a 1/4 turn or use some paper to shim it.
Kim
Hi,
If your chuck is running out and you make your collets on that chuck, the run out can amplify when re chucked. Before making collets it is best to true your chuck to the best tolerance you can achieve and check the chuck on a regular basis for accuracy.
Neil always thinks outside of the box and his statements and methods are great but are not for the average person. Neil achieves some very high accuracy tolerances on his tool room lathe where I am sure he produces his plastic collets. He regularly hits .0002 run out numbers on his set ups.
Rick Geschrey
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Thanks for all the info everyone. I'm taking the advice of Sherm and I'm in the process if trying to make my own collets. As soon as my lathe gets the kinks worked out, I will be back at it. I will post some pics and seek more advice soon.
Joe
Joe