Day: May 3, 2013

Electronics Workbench, Machine Shop

Belkin F6C1500 UPS Battery Wiring Arrangement

Given the length of the battery wires inside a Belkin F6C1500 UPS, you might think any arrangement will work. Not so. The wires from the guts of the UPS must exit to the batteries exactly like this:

F6C1500 Battery wires from UPS
F6C1500 Battery wires from UPS

There’s a black wire tucked under the red wire, both of which must exit though the angled slot and run toward the front of the battery compartment.

Seen from the front, the red wire connects the positive terminal of the lower (left) battery to the negative terminal of the top (right) battery and the black wire connects the negative terminal of the lower battery to the UPS circuitry:

F6C1500 Battery interconnect wires
F6C1500 Battery interconnect wires

Trust me on this: there is no other arrangement of those wires that will simultaneously connect everything properly and fit within the case.

As for disassembly, the small tab on the left end of the case holds the front panel in place. Press that inward with a flat screwdriver, then slide the cover toward the tab. Four locking slots along the sides will disengage and you can then lift the panel off.

With that out of the way, there’s a screw hidden under the BELKIN label in the middle of the removable cover:

Belkin F6C1500 UPS Cover Screw Locations
Belkin F6C1500 UPS Cover Screw Locations
Machine Shop, Science

PLA vs. Methylene Chloride: Joint Peel Strength

The only commonly available PLA adhesive seems to be methylene chloride, which is common only because it’s part of really nasty paint stripper that actually works; I suspect you can’t buy the pure stuff anywhere.

Anyhow, I picked a pair of flat line width test plates from the PLA scrap pile, dabbed paint stripper on each, and clamped them together overnight:

PLA test coupon - clamping
PLA test coupon – clamping

Unlike acetone on ABS, paint stripper doesn’t actually combine the parts into a single fused unit; I could peel the two plates apart with some effort:

PLA test coupon - paint stripper adhesion
PLA test coupon – paint stripper adhesion

That picture shows the results of two glue-and-peel tests, with much the same result along the top and bottom edges. Some solvent damage appears as a thin white line around the edge of the glued joint, but with some care that wouldn’t be too bad.

I think paint stripper makes an acceptable adhesive for PLA, at least for joints that aren’t subject to peeling loads. You must design an interlocking mechanical joint, perhaps filled with epoxy, to withstand peeling loads, which isn’t nearly as good as the ABS option of just fusing the parts together.