Cutting a small taper on the metal lathe

Measuring the angle will give you a clue as to what angle you have to set the compound.
Chuck up the shaft and dial in the compund perfectly with a dial indicator in the tool holder.

jviss said:

That's a good idea. But, I'd have to hold the shaft between centers, no?

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Let the shaft stick out a little more than the length of the collets your trying to make. Check that the shaft is spinning true in the chuck and swipe along the side of the shaft, adjusting the compound until you get a perfect reading.
Then just replace the shaft with your delrin stock, drill a hole close to the smallest diameter, and use your boring bar and compund from there.

Kim's method is good.

Another method, since you actually know the offset, is to stick a very straight round bar (say drill rod, for this app would be good enough.:smile in a good collet in the spindle and indicate it. Roll it and bump it until you get 0-0 everywhere. Alternately, roll it and mark the high and low spots at each end, then roll it to the mid-point on one side to split the difference.

Next, set a plunger style indicator in the tool post with sufficient travel for the desired offset. Be sure the tip is on the centerline of the 1" drillrod/round. If it is above or below center, the offset path will not quite be a correct reading.

Now, figure out your taper in 2", and divide that number in half since you are going to indicate one side, not both.

(Note, if you read this below earlier, yeah, i posted it backwards for boring ID, as opposed to turning OD
Edited, should be correct now. )

Run your carriage down to where the indicator tip just clears the spindle nose (does not run into it). Set the carriage stop on the front way. Back the carriage away 2" using, say, a 1-2-3 block for gaging from the lathe stop, and use the 2" block to bump against for dead length.. Decide which end of the (soon to be bored) hole you want big. To keep it simple, lets say the end facing out/toward the TS should be bigger. With the 2" block in place, set the indicator to 0 or whatever reference # you find convenient. Remove the block & run the carriage back towards the spindle, against the lathe stop. Now adjust the taper bar or compound to read the offset. This will be very close, if you have a taper attachment on your metal lathe. If using the compound, it will change where -0- is at the other end, so you will have to reset the indicator, & iterate back and forth a few tries to nail it. Either way you want the indicator to read an offset over exactly 2" travel, that is exactly what you predicted by calculation.

This all sounds complicated, but it is easy after a few set-ups, and allows setting tapers for all kinds of things you might not have the actual part on hand.

You know they make nylon 5c E-collets, too, right? (E-collet" = "Emergency" collet, IOW, "bore it yourself to suit")

smt

Your calculations is way off.
Measure the first 3 inches at the joint end to calculate the angle of the joint . Not the whole shaft.
.050" taper in the first 3 inches is pretty common .

No taper on the ferrule end is needed unless you are working on conical tapered shafts .


There's really a much easier way to set the angle.
Chuck up a drill rod sticking out about 1.5".

Have a boring bar on the tool holder.

Offset the tip around .008" per inch. You can use feeler gauge.
Lock the compound.

Try boring with that . Add or subtract as needed.

Good luck in eyeballing less than half a degree of offset on the markers.
Not happening there.

Joey~Likes it caveman style~

One thing that I use when making tapered collets is this. I'm able to use my drill on the compound as a power feed so that I get a good surface finish on the id.

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handy way to taper with a boring head and bearing: https://youtu.be/MzJ6wR59AkY?t=214

jviss said:

Thank you. Cool video and technique. I think I have a boring head around somewhere.

However, not applicable to cutting an internal taper, which is my challenge with making collet liners for cue shafts.

Click to expand...

Set up a palm router on the tool post.

Use a 2" long 1/4 router bit.

Problem solved.

However, not applicable to cutting an internal taper,

Click to expand...

Just to be contentious :smile: you said short taper. Tree boring head will do it.

Didn't have any pix with ID, but it should be obvious it will do either, from either side, so long as the tools are ground for the direction of rotation.





Center up a 5c spindex or chuck on the table for convenience instead of a vise.

smt