I got tired of having two of the truss poles on my 16" lighbridge slip out of place every time I used a heavy eyepiece. It's due to a bad design with a notched hole on the clamp block and a small tightening knob. I spent a $1.50 on clamp levers at a local thrift store that has some old stock hardware parts. I re-bored and tapped (3/8 X16) the top ring on the lower tube assembly and filed the clamp blocks to fit the larger clamp levers. Worked great, now the clamps are easy to lock down and they don't shift at all. Equivalent parts are available from McMaster if anyone is interested.
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