Possibly the most labour-intensive project I have ever undertaken!
The MDF casing needed priming before paint...
I found a reasonable colour match for the blue, I wasn't going to go all-out and get the colours professionally matched, no point and this, for a cheap shop own-brand paint, does the job quite nicely. While the paint was still drying I loosely fitted the main panel for the first time...
Next day, and after the paint had hardened, I began wiring the Duette controllers into the panel (should call it a Quartette now I suppose)
40 LEDs had to be soldered and glued into position - hours of work involved in this and when I finished, the light was way too powerful as this picture demonstrates...
After a bit of head-scratching, the problem was resolved by adding two more resistors in the 0v return.
The 37 pin breakout PCB was wired, plug-in terminal blocks have been used so that the panel can be removed easily for maintenance.
Everything in position... finally!
There were problems - many of them.
First of all, two of the brand new switches were faulty, thanks to my wiring diagram and schematic diagram I was able to trace and rectify the problem with relative ease. Just annoying that new switches should fail like this.
Then I discovered problems with the Duette controllers. First of all, two of them, when energised, operated at full power on minimum and minimal power on maximum. After more head-scratching the problem was traced and resolved, two wires on the potentiometer reversed!
After resolving that issue, another Duette problem. If controller B was used in forward and controller C in reverse (the two main loops) a short circuit was detected by the ammeters. This one took a fair bit of tracing, taking a whole evening alone to resolve.
Finally the fault was traced to the centre of the potentiometer for controller B. Basically the centre shaft (the bit that the control knob attaches to) is live at +12v dc. On the Duette, this is insulated from the body of the controller by using a cardboard spacer and a large, square cut-out which ensures that the shaft can never come into contact with the controller body. Although I'd re-used the cardboard spacer, I'd drilled a round hole only slightly larger than the diameter of the shaft itself, and this rubbed the centre shaft. After a quick re-drill of all four controllers I refitted & tested. Job done!
Having all of the major components on plug-in terminals made the process of fault-finding much simpler so already this decision has paid off.
A much more sensible brightness level. Just need to secure the main panel and, once varnished, the job is done.
I'm now in the process of testing the PCBs I made for the boards. So far I've tested the eight relay track isolator and the first, two capacitor PCB for board one, just need to test the turntable control - already confirmed that there's power from the panel to the PCB but as it's getting late I'll test tomorrow. The turntable is a tad loud to be testing at this late hour.
Although it's taken many hours just to build a switch panel, I think the end result is stunning - far better than I could ever have hoped. I particularly love the new panel for the four Duette controllers. The printed & lacquered vinyl looks amazing, albeit still with some small air bubbles. It was annoying that I couldn't use the same process successfully on the main panel but this, for now, will do.
Next weekend we'll hopefully commence track laying and wiring.
No comments:
Post a Comment