1200reasons
20-04-2017, 06:44
I'm thinking of buying a 750D for my SL-1200 mk2 and might try to 3d print an armboard to save money. The problem is that at the moment I don't have the arm, and I don't have my technics pulled apart, so I'm putting together bits and pieces that I can work out online for now. I'd like to get as much prototyping out of the way asap rather than having to wait until the tonearm is in my hands and the TT is in pieces.
What I THINK I've worked out:
Armboard diameter 119.2mm, with a chunk taken out of it at the diameter of whatever the platter hole is
30mm (or 29.5?) diameter hole in the middle, for the collar to fit into
The centre of this hole is exactly 214mm from the spindle.
There are three 3-4.2mm diameter screw holes 24.1mm from the centre of the hole. These are for mounting the collar to the armboard and appear to be form an equilateral triangle.
The armboard screws into the faceplate with 3 screws of unknown size. These don't Look like they're an equilateral triangle
Questions:
How am my assumptions so far?
Is there any easy way to know how far the platter cutout cuts into the armboard?
The Jelco collar has a notch, which appears to control the movement range of the arm. Is there any way to know which direction this notch should point, or trial and error when mounting?
The The ebay armboard dips down in the middle by what I'm guessing is 3mm. Will the Jelco mount too high without dipping 3mm below the armboard hole? Speedy Steve's dips down by a lot, but then goes up towards the middle
are the mount holes in the faceplate threaded, or will I have to use a nut under the faceplate?
The ebay one is a thin plate that's mounted flat inside the tonearm hole rather than flush with the faceplate (like speedy steve's. How thick would it need to be to get it flush?
Thanks!that's alot of questions, but if I can get an answer for just 1 I'll be happy. I'm new to CAD but I'll post mockups later if I don't lose faith immediately
What I THINK I've worked out:
Armboard diameter 119.2mm, with a chunk taken out of it at the diameter of whatever the platter hole is
30mm (or 29.5?) diameter hole in the middle, for the collar to fit into
The centre of this hole is exactly 214mm from the spindle.
There are three 3-4.2mm diameter screw holes 24.1mm from the centre of the hole. These are for mounting the collar to the armboard and appear to be form an equilateral triangle.
The armboard screws into the faceplate with 3 screws of unknown size. These don't Look like they're an equilateral triangle
Questions:
How am my assumptions so far?
Is there any easy way to know how far the platter cutout cuts into the armboard?
The Jelco collar has a notch, which appears to control the movement range of the arm. Is there any way to know which direction this notch should point, or trial and error when mounting?
The The ebay armboard dips down in the middle by what I'm guessing is 3mm. Will the Jelco mount too high without dipping 3mm below the armboard hole? Speedy Steve's dips down by a lot, but then goes up towards the middle
are the mount holes in the faceplate threaded, or will I have to use a nut under the faceplate?
The ebay one is a thin plate that's mounted flat inside the tonearm hole rather than flush with the faceplate (like speedy steve's. How thick would it need to be to get it flush?
Thanks!that's alot of questions, but if I can get an answer for just 1 I'll be happy. I'm new to CAD but I'll post mockups later if I don't lose faith immediately