How to decouple a plano -reflex arm.
Posted: Fri Apr 05, 2019 7:43 am
Hi,
I started (haven't found the time to finish!) restoring a Columbia 100 portable. As you might know, the tone arm on these shrink and can skate the surface of record. And it appears fatal to disassemble for cleaning and re-greasing. I want to share with you how I successfully decoupled the tone arm, with zero damage. I have some pictures, and am editing a video of the process.
First, I removed the screw on the base.
Then, I whittled down the end of a bamboo skewer (my favorite cleaning tool) so that I had a long, narrow strip.
Next I carefully inserted this into the space between the arm and the base and "fished" for a bearing, and moved it into position above the slit on the base.
Lastly, I inserted the skewer into this and gently played with the bearing until I was able to leverage it though the hole on the top of the arm.
Once I had removed all the bearings in this way, the tone arm easily separated from the base.
After cleaning and re-packing the bearings with moly grease, I punched a 1/32" fiber gasket to fit between the slit on the base, to prevent over-tightening.
Honestly, I don't think this helped the loose fit as much as I had hoped. Maybe a different grease? New bearings one size up? I am still working on cutting a cork gasket that will raise the tone arm high enough without preventing the case from closing. Any suggestions?
I started (haven't found the time to finish!) restoring a Columbia 100 portable. As you might know, the tone arm on these shrink and can skate the surface of record. And it appears fatal to disassemble for cleaning and re-greasing. I want to share with you how I successfully decoupled the tone arm, with zero damage. I have some pictures, and am editing a video of the process.
First, I removed the screw on the base.
Then, I whittled down the end of a bamboo skewer (my favorite cleaning tool) so that I had a long, narrow strip.
Next I carefully inserted this into the space between the arm and the base and "fished" for a bearing, and moved it into position above the slit on the base.
Lastly, I inserted the skewer into this and gently played with the bearing until I was able to leverage it though the hole on the top of the arm.
Once I had removed all the bearings in this way, the tone arm easily separated from the base.
After cleaning and re-packing the bearings with moly grease, I punched a 1/32" fiber gasket to fit between the slit on the base, to prevent over-tightening.
Honestly, I don't think this helped the loose fit as much as I had hoped. Maybe a different grease? New bearings one size up? I am still working on cutting a cork gasket that will raise the tone arm high enough without preventing the case from closing. Any suggestions?