Routing out a hole for IEC connector

esrevinue · 2024-07-22 12:32 am

Hello again!

I am doing some maintenance (and some upgrades) to my Mosvalve 500 power amp, and one of the things I'd like to address is the captive cable at the rear of the unit, obviously used to power it up. I was thinking of creating space for a standard IEC receptacle, but I don't know the best way of going about it, so I've decided to come here for help. I don't actually have a router, and I want to know how stupid an idea it would be to use HSS drill bits and a drill to get the shape most of the way there and just file out the rest.

Thanks in advance!

rayma · 2024-07-22 12:33 am

That's how people do a one-off.

esrevinue · 2024-07-22 12:40 am

Brilliant, thank you!

What are people's opinions on IEC vs Powercon and the like? Or should I make separate thread for that?

zman01 · 2024-07-22 12:43 am

esrevinue,

Are you set on using an IEC connector, or are you open to using something like a PowerCon connector? With the PowerCon you can do a circular hole in the back panel. You will need to use a power cable with the corresponding connector also - look up these two items from Neutrik:

NEUTRIK NAC3MPXXA
NEUTRIK NAC3FCA

Agree with Rayma, done a few "one-offs" using the drill and file technique for IEC connectors.

P.S. Looks like you are already looking at PowerCon.

rayma · 2024-07-22 12:46 am

Is the chassis steel or aluminum? How thick?

A round hole chassis punch works on 1/16" aluminum or 1/32" steel.

esrevinue · 2024-07-22 12:58 am

rayma said:
Is the chassis steel or aluminum?

Good question! Don't know

rayma said:
How thick?

3-5mm. Can't be sure cos my micrometer is broken atm hahah.

rayma · 2024-07-22 1:02 am

Tap it with a screwdriver. Steel sounds different from aluminum.
From a photo it looks like a steel chassis. Steel is much harder to work than aluminum.

esrevinue · 2024-07-22 1:23 am

rayma said:
Tap it with a screwdriver.

Will do tomorrow when I wake up

.

rayma said:
From a photo it looks like a steel chassis.

That makes sense given the UNbelievable weight of this thing haha. Might have to sacrifice a drill bit to this thing. I need to drill some holes in the chassis anyways for an up-to-code ground, a bridge rectifier I plan to move off the board because the diodes are right next to main resevoir caps atm and small board to improve the ground scheme at the input.

Kris0603 · 2024-07-22 1:23 am

If the cable is in good condition i would keep it, put a new receptacle on if needed. Failing that i'd put in a new nice 3x2.5mm (or 2x3.5mm?) captive terminated mains cable, with a fresh grommet and a knot on the inside.

That said, if you are set on making the cutout i'd use a Dremel, with a cutting wheel first to get the rough shape, and a grinding wheel to get rid of the burrs/sharp edges, and make sure the socket fits. It could be done with a file, I hear folks recommend lubricating oil when filing steel, should prolong the life of your tool.

mhenschel · 2024-07-22 5:45 am

@esrevinue
Aluminum or steel?
Got a magnet?

tomchr · 2024-07-22 6:58 am

esrevinue said:
What are people's opinions on IEC vs Powercon and the like? Or should I make separate thread for that?

PowerCon is awesome. They're easy to make holes for too. Just get a 24 mm carbide tipped hole saw ($10 at Bezos' Bookstore).

Tom

myleftear · 2024-07-22 7:13 am

Filing the square hole is a bit cumbersome but lets you use standard cable. If you go this way, clamp the plate between 2 pieces of wood or something just at the edge of one side of that hole, file along the clamped part. Do this for all for sides. You thus avoid bending the plate and file off too much.

Powercon is great, but be aware that it’s not standard—you’ll need to adapt the cable‘s connector. (Regardless of what wire you’re using.

Or just don‘t use any IEC, connect the cable directly to your PSU/switch/… just make sure the cable is secure (strain relief and a grommet)

Stuey · 2024-07-22 12:19 pm

A tungsten carbide burr in a rotary tool (Dremel) is really good for this once you've cut out the rough shape.

Kris0603 · 2024-07-22 2:12 pm

If you do go the Dremel route, i would recommend doing it outside. It will send a lot of tiny hot metal in a lot of directions, this will damage or at least leave marks on most surfaces.

HalFoster · 2024-07-22 2:16 pm

While a little tedious, one of these works very well - Amazon has them for around 16-17 USD. I use them frequently to upgrade old oval power connector cutouts to IEC.

HalFoster · 2024-07-22 2:19 pm

One of the major benefits of the nibbler above is that there is only a small nibble of material removed at a time - easy to collect so it can all be done while everything else is still mounted to the chassis - no worry about metal shavings/debris in the equipment.

techtool · 2024-07-22 2:54 pm

Yes, these old nibblers do cut fairly well, but the handles can be real finger pinchers. I always wear leather gloves when using them.

techtool · 2024-07-22 3:08 pm

And if you mount the IEC connector from the front, or outside, the flange will cover up the cut lines, so you don't need a perfect cut out.
Check the data sheet below to see the panel cut out is a different size for front or rear mounting,

chrisng · 2024-07-22 3:35 pm

Another method is to drill a large round hole for the IEC socket body and 2 smaller holes for the mounting screws, the other 4 screw holes are optional.
A rectangular PCB, plastic or aluminum plate is then used to accommodate the IEC socket. This is much easier than making a rectangular cutout in the back panel.