Aries 1 JWM 10 Tonearm replacement or upgrades?

Just a couple of points of clarification to a few of the above posts. The original JMW 10 with the threaded counter weight is shorter than the new JMW 3D tonearm, therefore, it will have a different spindle to pivot mounting distance. Although the original JMW 10 VTA tower does have an adjustable dog leg platform to accommodate and fine tune spindle to pivot distances, the azimuth side weights of the newer 3D tonearms will not clear the older VTA tower.

@brf may be correct; he usually is.

My own experience is a substitution of the 12" 3D arm for an original on a very original 12" base. As I wrote above, I did need to change the original lower bearing for the "spike" now used. At its closest point (which is just after leaving the rest position) the larger azimuth side weight clears the tower by about 1/2 inch. While on the record the distance is far larger.

On the pictures of the arms at the VPI site though, the azimuth side weights of the 10" arms seem quite a bit smaller than those of the 12" arms.

So who knows, but best to figure it out before purchase.

@melm, my comments are in reference to the 10 series of VPI JMW tonearms. 

If you have an original or later production JMW 12 metal arm, you may have to change out the fluid reservoir pivot point for the newer spiked pivot point to be compatible with the JMW 12-3D printed tonearm.  Azimuth side weight and VTA tower clearance is not an issue with JMW 12 tonearms. 

Yes, the original JMW 10 tonearm with the threaded counter weight can accept the new style tear drop counter weight without any modification.  A simple, inexpensive and worthwhile upgrade would be to change out the conical pivot point assembly for the newer spiked pivot assembly.  The end user can perform this replacement without any modification to the tonearm VTA tower.