Thanks, 24Hacker. Appreciated.
Mike, how do you couple the platters? Is the isolation between the two rigid or pliable for damping? I assume the vibration transfer from the drive idler wheel would have been a concern?
Fran
Hi Fran,
The platters are joined by an interface of brass precision tubing from a K&S Engineering rack, available at hobby and hardware stores.
To describe this, please allow me to use a few loose terms,...
The Lenco platters are a tapered spindle/bushing fit. To make the lower platters spindle fit into the upper platters bushing requires some
shimming - thus, the brass tubing.
The brass tubing is quite precise in its dimensions. Its available in concentric diameters through a range of sizes. Its these concentric sizes that make the fitting possible.
Starting from the top, and working down, then back up,....
Stacked L70 platter, with extended DIY spindle stub in place.
It appears to be a loose fit,... its not, not even close to loose.
When I sink it for permanency, I'll snug it into place with some teflon pipe tape.
The stub is made of the concentric precision brass tubing stock, with a piece of solid rod stock in the center; then its ground to a rounded end.
The stub removed:
The stub fits into the next size larger tubing section, which is inserted into the platter tapered bushing from below, as far into the taper as it will go - an easy snug pressing (will not damage the original bushing).
You can see the ridge inside the OE bushing,... thats the top of the pressed-in tubing.
The pressed-in tubing extended all the way to the bottom of the OE bushing, and can be longer to adapt to a buffer layer between platters, as needed.
The stub interface with the OE spindle is tapered to match the top of the Lenco spindle top.
Looking at the OE spindle top:
The platter bushing bottom, bottom of taper:
There are two layers of concentric tubing in this picture. The inner most piece is the longest, and is the
exact outer diameter of the Lenco OE spindle.
It needed to be supported due to the taper, so another larger outer diameter, though shorter piece of tubing was cut to interface with the OE bushing. It was still just a hair loose, so I deployed the teflon plumbers tape shimming mod, which created the perfect snugging shim, and that piece was lightly snug pressed into place.
Result:
A perfect centering of the stacked platter, without any side to side wobbles, or concern of going off-center.
The spindle extension stub is removable, so it can be adapted to thicker mats, etc.
I've done this to two Lenco platters now, as stackers, and its worked perfectly on both occasions.
AND,.... its all just snugged into place, and is easily removable; no damage to the original gear.
stacked and extended:
To your question of rigid or pliable,...
The top platter is isolated from the bottom platter by a Lenco L75 rubber mat. Its outer diameter is a perfect fit/match to the lower outer diameter of the top platter, for a nice tight fit.
This deck had relatively low use in its former life, a Colorado State Univ A/V portable suitcase system player, with a bad amplifier; like a square dancers player. The motor is like new, and really quiet. So isolation isn't totally necessary, but I feel better about breaking the tie at that point.
