Ordering The Wrong Part: Hardware Woes

If I’d get a penny every time I ordered the wrong part I’d have enough to buy all the wrong parts.

I’m rehousing a Realistic 1987 graphic hi-fi EQ into a rack enclosure. It uses inductors instead of gyrators, has a discrete make-up amplifier, runs on +43 V and sounds really good. Inductors have the vintage vibe factor because they were used in passive equalizers back in the day. With the high operating voltage it has headroom to spare. Not bad for a device which you could buy at your local Radio Shack. More on this EQ and the modifications I’m doing at a later date.

I found a nice industrial rack enclosure by Fisher Elektronik at Reichelt in Germany. Now how do I attach my own faceplate? These enclosures are Eurocard-based and have a rail system in the front which fits an expensive rack-wide insert that has M2.5 threaded holes at distances according to the Eurocard DIN standard. 

Let’s talk about the Eurocard standard because it’s quite interesting. It was created in the ‘70s and ‘80s as a mechanical standard to house and connect PCBs for electronic lab equipment in 19” rack enclosures. German broadcast manufacturers like ANT, Delta and BFE used it for distribution, summing and various utility amplifiers.

These days electrical equipment and the Eurorack modular synth system borrow from the standard. Eurorack synths use the physical standard since the large amount of pins on the rear connectors would be overkill and expensive. 

I think it’s nice how a 1970s lab-mechanics standard is still represented in a modern-day synth format. These Fisher racks would make a great diy Eurorack enclosure.

 

Back to mounting my faceplate. I only need to attach the front with 4 thumbscrews so at €13,40 this rail insert would be less than ideal and expensive. I thought I’ll just order some fitting rectangular M3 nuts to slide in the rails but, after scouring online hardware stores, eBay, and even AliExpress I was only able to find one that might fit, IF… the tolerances were leaning in my favor. Alas, no cigar.

Here comes the kicker: I was about to order the rail insert thinking about whether to use a Dremel or hacksaw to cut it into square nuts when I realized…

I could just take a forkin’ file to knock the square nuts down a millimeter on the face and back and be done. It only took me minutes! Man, was I this close to being that stupid. 

And, the other 196 square nuts? I’ll just use them for general fastening and PCB stand offs. For the time being, I’ll be a square nut guy.