09-01-2013, 01:07 PM
Anthony, I've had the same problem and wonder if the side force is just dislodging the taper. We're dealing with machined not ground surfaces to begin with.
I bored a taper in a coupling to match a tapered end crank shaft on an engine from a gen set. I had the armature to measure the taper, chucked it and set the compound to match the angle as you did. Then made a male taper to check the setting. Used bearing blueing to check the contact, perfect, dry the taper would not slip with minimal axial pressure but as soon as you put side load it would un seat and wable a little bit. Figured it was as close as I could get so machined the female taper with the same compound setting. Got the exact same results with the test rod. Perfect smear on the blueing, would carry torque but side pressure would dislodge it and give a little wable. Assuming the boring bar for the bore and cutter for the male taper were both on center height you can't get much closer than machining the two parts with the same compound angle and I still had the same results as you.
By the way the coupling apparently works fine driving a small hydraulic pump for a wood splitter.
I bored a taper in a coupling to match a tapered end crank shaft on an engine from a gen set. I had the armature to measure the taper, chucked it and set the compound to match the angle as you did. Then made a male taper to check the setting. Used bearing blueing to check the contact, perfect, dry the taper would not slip with minimal axial pressure but as soon as you put side load it would un seat and wable a little bit. Figured it was as close as I could get so machined the female taper with the same compound setting. Got the exact same results with the test rod. Perfect smear on the blueing, would carry torque but side pressure would dislodge it and give a little wable. Assuming the boring bar for the bore and cutter for the male taper were both on center height you can't get much closer than machining the two parts with the same compound angle and I still had the same results as you.
By the way the coupling apparently works fine driving a small hydraulic pump for a wood splitter.
Free advice is worth exactly what you payed for it.
Greg
Greg