so I have this Lorch LLN lathe that I'm trying to tool up, and I wanted to make a new drill chuck arbour for it for a keyless chuck I recently bought. problem is, the tailstock taper is non-standard (non morse, and also like a half length) and there's no spec I can find for it (this lathe doesn't even have an entry on lathes.co.uk) so I had to measure it myself.
I guess the smart thing to do would be to measure the tailstock bore directly - with two balls of appropriate size and a depth mic one can determine the taper. unfortunately I don't have the right size balls, so I opted to measure the male taper angle off of some dead centers instead.
1. optical comparator
first method was to try using the protractor screen on the optical comparator. at first I tried to align the dead center/vee block to the crosshairs and measure the half angle with the protractor; but really the better option way was to measure one side and move the stage over to measure the other side and add the angles. with this method I got something like 2°, but I didn't feel super confident that this (not better than +/- 3-4')
2. dogmeat cmm using the mill
I guess this was kind of an excuse to use the optical rotary table since I have one and never use it. sweep back and forth on the X axis of the mill and fiddle with the rotary table until the indicator stays still. here the half angle seems to be 1°3'. again the setup is pretty cheesy (rotab is not clamped to table lol, vee block is held to the rotab using a magnet) so again I'm not super confident in the results - though measuring both dead centers and checking zero with a dowel pin implies that this method is at least consistent.
I'm sure there's even more ways to skin this cat (I also have a surface plate and a set of inspection room angle blocks... and then there's the cmm at work) but this is probably good enough for me to go off of (probably gonna try to make it on the cnc lathe at work).
so? my guess is it's 2° included angle since it's a round number - and also schaublin uses a 2° tailstock taper on some of their smaller lathes so it seems reasonable...
I guess the smart thing to do would be to measure the tailstock bore directly - with two balls of appropriate size and a depth mic one can determine the taper. unfortunately I don't have the right size balls, so I opted to measure the male taper angle off of some dead centers instead.
1. optical comparator
first method was to try using the protractor screen on the optical comparator. at first I tried to align the dead center/vee block to the crosshairs and measure the half angle with the protractor; but really the better option way was to measure one side and move the stage over to measure the other side and add the angles. with this method I got something like 2°, but I didn't feel super confident that this (not better than +/- 3-4')
2. dogmeat cmm using the mill
I guess this was kind of an excuse to use the optical rotary table since I have one and never use it. sweep back and forth on the X axis of the mill and fiddle with the rotary table until the indicator stays still. here the half angle seems to be 1°3'. again the setup is pretty cheesy (rotab is not clamped to table lol, vee block is held to the rotab using a magnet) so again I'm not super confident in the results - though measuring both dead centers and checking zero with a dowel pin implies that this method is at least consistent.
I'm sure there's even more ways to skin this cat (I also have a surface plate and a set of inspection room angle blocks... and then there's the cmm at work) but this is probably good enough for me to go off of (probably gonna try to make it on the cnc lathe at work).
so? my guess is it's 2° included angle since it's a round number - and also schaublin uses a 2° tailstock taper on some of their smaller lathes so it seems reasonable...
