Fitting new 288 diaphagrams

[vyju]

Hi
I tried fitting the new 288 dias.from GPA into my 288 16-G's,but have run into a problem.
The locating pins line up with the new diaphagrams but are just a teeny bit bigger than the holes in the mounting plate,so they do not fit.I do not want to force it through for fear of damaging the diaphagrams.
The pins fit perfectly in the old original Altec diaphagrams.
Please help with suggestions on how to get over this problem.
Regards
Rajiv

[Todd W. White]

GPA's mounting rings are made precisely to the specifications given in the Altec factory drawings, and, therefore, should fit perfectly.

That said, as Altec contractors, we found that the same thing happened on occasion - seemed to me that the makers of the dowel pins (pre-CNC days) weren't always "spot on" in their manufacturing tolerances.

The "fix" is simple - get a drill bit that is just BARELY bigger than the hole in the mounting ring and MANUALLY ream out the hole a TINY BIT.

Careful! Careful!

[vyju]

Hi Todd
Thank you for your reply.
Actually the locating pins fit the openings and go in just a little bit,but after that seem to get stuck.
I will try out your "fix".
Regards
Rajiv

[jnorv]

I am not sure that I would try the drill bit solution without first micing the pin to find it's diameter. Numbered drill bits in the 1/8 inch range are incremented by about 0.004 inch, much too large for delicate work. I think that I would go after it with some rolled up 600 grit sand paper.

Jim N

[Todd W. White]

Good advice Jim!

[vyju]

Hi
Todd,Jim thank you both for your help.I used fine rolled up sandpaper .The locating pins fit perfectly.
I dont think I even enlarged the opening,just removed some burrs,which were preventing the pins from going in fully.
Regards
Rajiv