515-G series magnet types

**magnarc** · February 8th, 2013, 12:17 AM

Following on from the discussion about magnet types on the 515E in this topic http://www.hostboard.com/forums/f700...rice-515e.html

I've noticed that the 515-xG followed the 515E with the rounded back style magnet.
I have seen though, units with just a rounded back, and units with a rounded back and bolts holding the magnet on?

Any thoughts on the differences, if any, and why the design alteration.

**magnarc** · February 8th, 2013, 12:18 AM

Without screws

**magnarc** · February 8th, 2013, 12:19 AM

With screws

**magnarc** · February 13th, 2013, 12:32 AM

Just a bump on this should anyone have any knowledge. If not, I'll add it to my Altec mysteries....

**bowtie427ss** · February 13th, 2013, 09:06 AM

I don't have an explanation. But i would add that this same scenario of bolts vs no bolts also went on in the 421, 422, 423 series of MI drivers.

A WAG(wild assed guess) of mine is that there may have been some sort of issue with the adhesives used to bond the ferrite to the plates. Or, perhaps a combination of adhesive/thermal issues that caused separation and eventual pole shift in the motors. The bolts would certainly ensure that the assembly stayed put thru a variety of conditions.