Hi Moisin,
My first thought when I read your comments was that the mounting collar alignment needs to be perfected (either by use of some sort of assembly jig or by keying the two parts to each other).
As I thought about this more (and considered the reality of manufacturing), my thoughts turned toward a universal jig that would accomplish the mounting task elegantly while having the advantage of being compatible with all arms in the field.
This would be a two-part "jig" for setup - one that mirrors the process I lay out above. It would consist of:
(1) the existing jig with only one hole - to ensure that the above method I outline is followed
(2) some sort of trammel affair (think Feickert) that allows you to rotate the arm into position and measure the 233.5 p-s distance - this, after temporarily fitting the arm to the armboard with the single screw.
While a trammel affair has its appeal, it's not inexpensive to manufacture, as you need to account for varying record spindle diameters.
If you bore a spindle hole for a large record spindle diameter (e.g. .287"), then the trammel will tilt when used with the more average record spindle diameters (e.g. .280-.282).
One solution is to produce a wide base plate for the spindle hole. This would prevent the trammel from tilting. Unfortunately, once you add material like this, the costs skyrocket, and frankly, the method I propose above will work fine.
I think a part of this discussion involves working with a competent dealer (hate to blow my horn here, but picking up after the incompetents out there tries my patience). There's still a reason for going to a competent dealer for your setup.
For those doing their own mounting, I think a good interim solution is to remove two of the holes in the existing jig, and to follow the instructions I outline above. Having only one hole in the jig would ensure that someone doesn't blindly mark and drill all three holes at once.
I'll get a version of the above discussion on the Tri-Planar page Doug. Thanks for the kind words.
Cheers,
Thom @ Galibier
However, maybe the setup tool can be improved.I'm thinking out loud here ...
My first thought when I read your comments was that the mounting collar alignment needs to be perfected (either by use of some sort of assembly jig or by keying the two parts to each other).
As I thought about this more (and considered the reality of manufacturing), my thoughts turned toward a universal jig that would accomplish the mounting task elegantly while having the advantage of being compatible with all arms in the field.
This would be a two-part "jig" for setup - one that mirrors the process I lay out above. It would consist of:
(1) the existing jig with only one hole - to ensure that the above method I outline is followed
(2) some sort of trammel affair (think Feickert) that allows you to rotate the arm into position and measure the 233.5 p-s distance - this, after temporarily fitting the arm to the armboard with the single screw.
While a trammel affair has its appeal, it's not inexpensive to manufacture, as you need to account for varying record spindle diameters.
If you bore a spindle hole for a large record spindle diameter (e.g. .287"), then the trammel will tilt when used with the more average record spindle diameters (e.g. .280-.282).
One solution is to produce a wide base plate for the spindle hole. This would prevent the trammel from tilting. Unfortunately, once you add material like this, the costs skyrocket, and frankly, the method I propose above will work fine.
I think a part of this discussion involves working with a competent dealer (hate to blow my horn here, but picking up after the incompetents out there tries my patience). There's still a reason for going to a competent dealer for your setup.
For those doing their own mounting, I think a good interim solution is to remove two of the holes in the existing jig, and to follow the instructions I outline above. Having only one hole in the jig would ensure that someone doesn't blindly mark and drill all three holes at once.
I'll get a version of the above discussion on the Tri-Planar page Doug. Thanks for the kind words.
Cheers,
Thom @ Galibier