The item number from woodturningz was DEADCENT1.
I did check the manual before ordering the part and the spindle is a MT1.
The dead center is however a bit longer than the taper of the live center. Is it feasible that trimming some metal from the back end of the center would fix the issue?
I was thinking that this part that you got from WTZ was actually a PSI part but it is not.
It is possible that trimming off the back end may allow it to fit. But I would be very wary of doing this .... only as a last resort .... because grinding the steel could be a very laborious process. I have heard it recommended that the tang at the end of some centers can be ground off but I would think it would be a very tedious process.
I believe, from viewing the WTZ picture, that yours does not have a tang (flat piece about 3/4" long at the smaller end of the center).
Have you tried probing into the spindle taper and measuring its depth and comparing that measurement with the tapered porton of the center ?
You can actually calculate the angular taper of the center:
Measure the largest diameter of the center = Dia1
Measure the smallest diameter of the center = Dia2
Measure the distance between the above two measurement points = Lgth
Angular taper in degrees = arctan{(Dia1 - Dia2)/2xLgth}
Most small pocket calculators will handle this without any trouble and should by default give the result in degrees (other units are possible, like radians). The arctan function might be labelled on the calculator key as Tan-1 (where the -1 is elevated about a half-character height above the "n")
Now somewhere recently I posted a link to a table of angles for Morse Tapers. I will find that and repost here by editing in a few minutes.
When you get the calculated answer, you really haven't made much progress because you already know it is a MT1 ... :biggrin:
Back in a minute or two. . Here is the table I found on the website specified:
https://littlemachineshop.com/reference/tapers.php
and I posted it in post #4 of this thread:
http://www.penturners.org/forum/f156/mt0-pen-mandrel-150852/
I would encourage you to try to measure the depth of the taper on your spindle and compare that with the measured length of the taper on your dead center. And then try to deduce whether grinding off the small end of the dead center could help.
You could also try making a MT1 taper out of wood and see how far you can insert it into the spindle. You don't need to be too accurate about the shaping .... of course more accurate is better .... and just use a disc or belt sander to shape the wood.
This is just a shot at trying to figure out what to do next.