RobS
Member
So after having the Rockler Excelsior for 3 weeks, I discovered that the tail stock just had too much play and could be tightened down within 1/8" off center which would not work for drilling, so I took it back and upgraded to the jet 1221vs. I figured go big and just be done with it. The speed control is awesome. The ability to switched pulley locations was painless. I bruised my hand on the excelsior from using it non stop for 3 weeks, not an issue with the 1221. The extra size and stability was great. The push in lock to swap thread on heads was a great touch. The tool holders are ehhh needs better spacing, but they are metal. The wrench to swap out the bolt on face was a nice touch.
However, After one week, I've turned three pens and drilled 4 blanks. I was loving this baby. On the 5th blank the head started wobbling and the longer the machine runs the worse it's getting. I turned another pen but the wobble was continuing to progress and it snapped the very top off my live center. After much searching on line for 1221vs wobble I saw a YouTube video that was exactly what I was seeing. It look like the bearings are failing. I called Rockler they said bring it in to verify the issue is real then it would have to go to a jet service center. No exchange on this $$$$ which is a boat anchor till its fixed. So now it's time to figure how to dead lift the 135lbs.
As a mechanical engineer I can say It's symptomatic of anything using bearings. Four possible issues: 1) bad design, improper support causing large moment arm (not the case here). 2) sizing the bearings with an inadequate safety factor (possibility, but jet is pretty legitimate so not likely). 3) random luck ended up with a bum bearing where a ball had a micro fracture that caused it to crack during the burn in phase which was my one week of mild use(possibility, this is why we did burn in on consoles at work to ensure pumps or electronics did not fail). 4) was not machined square (possibility).
So let's see how tomorrow goes when I call jet. I could not sleep at all. I've got 12 pens on order from friends, and the blanks are already cut and drilled with brass glued in. I also ordered custom tools from Hanau here on the forum. Just bummed my new favorite tool is outta commission.
:frown:
Thanks for listening.
However, After one week, I've turned three pens and drilled 4 blanks. I was loving this baby. On the 5th blank the head started wobbling and the longer the machine runs the worse it's getting. I turned another pen but the wobble was continuing to progress and it snapped the very top off my live center. After much searching on line for 1221vs wobble I saw a YouTube video that was exactly what I was seeing. It look like the bearings are failing. I called Rockler they said bring it in to verify the issue is real then it would have to go to a jet service center. No exchange on this $$$$ which is a boat anchor till its fixed. So now it's time to figure how to dead lift the 135lbs.
As a mechanical engineer I can say It's symptomatic of anything using bearings. Four possible issues: 1) bad design, improper support causing large moment arm (not the case here). 2) sizing the bearings with an inadequate safety factor (possibility, but jet is pretty legitimate so not likely). 3) random luck ended up with a bum bearing where a ball had a micro fracture that caused it to crack during the burn in phase which was my one week of mild use(possibility, this is why we did burn in on consoles at work to ensure pumps or electronics did not fail). 4) was not machined square (possibility).
So let's see how tomorrow goes when I call jet. I could not sleep at all. I've got 12 pens on order from friends, and the blanks are already cut and drilled with brass glued in. I also ordered custom tools from Hanau here on the forum. Just bummed my new favorite tool is outta commission.
:frown:
Thanks for listening.