I mentioned in another thread that I am building a lab power supply. Sorry to keep posting such basic questions, but my searching has brought up no clear results, probably because my question is so incredibly basic, or that I gave up too early when searching.

I'm going to mount a couple analog VU meters on the front panel of this power supply unit. While I know I have the tools to drill holes for the pots, switches, and outputs, I'm unsure what the best way to make nice, neat, and accurate square holes in the aluminum front panel to mount the VU meters in. Routing bits?

I have a nibbler, but I think that would end up not looking very good nor be very accurate.

I do have access to friends with much heavier duty tools than I have in my own shop, too...

Thanks!

 

What I do is drill the four corners with a drill bit and the use a jigsaw to connect the holes and use a file to clean up the hole and square it ... Also use tape on the surface in order not to scratch it and get a cleaner cut

 

How many volume units is the power supply supposed to supply anyway?

Seeing the meter itself would help us offer real world suggestions, but generally one should consider cutting a very straight line to be essentially impossible, even if not combined with cutting three other similar lines joined in perfect right angles. And that assumes the extreem corners of the meter are not rounded, and if the are you have to cut rounded corners.

It looks much better if you can just lay the meter flush against the panel, just relieving a small hole for the movement and or connections. Some hot melt or crazy glue or epoxy can hold it down if there are no mounting screw holes.

 

Awesome. Thanks for the suggestions. I'll see how the parts are when I get them in my little hands, and I think that will help me decide which route to go.

If I do go the jigsaw route, I would imagine I would need a more fine toothed blade for the aluminum, yes?

However, if I can get away with just making holes for connections, hmmm that would be easier for sure. We'll see how it looks.

Obviously this thing has to work, which is the first priority. But I also want it to look really sharp. Methinks it'll inspire me to use it more if it looks awesome. Function AND Form.

 

It isn't as hard as some people pretend it is. You don't have to make perfectly straight lines with perfect corners. You just make a hole for the guts to go through and the front bezel covers the mistakes.

I made a front panel out of aluminum and the guy who bought it asked me who I hired to make the holes.

I didn't. Cover the area with masking tape, pencil in the shape you want, fill the shape with as many round holes as you can fit in it, and file the edges. It's, "work" but it's not magic.

 

Yeah, I was having a conversation with someone here in the studio about that and he mentioned the possibility of a front bezel situation.

Looking at these Velleman volt meters. Unsure if that's got a removable bezel, but worth a try, I suppose.

Ahhh. Yes, ErnieM, you busted me on that one. Not VU. Voltmeter. I work in a music studio, so everything has been VU to me up to this point. Fortunately I put it in the thread title to go down in history. Ha!

 

Those Velleman meters are exactly what I was talking about. They have a round thing protruding from the back, about 2&1/2 inches diameter, and a lot of the face does not have "hole" behind it. One big round hole and 4 holes to put the screws through.

edit: ps, the thinner the metal, the finer the saw teeth. If your saw is going to get hung and bend the metal, you're using too thin of a metal. I really like aluminum! It cuts like cheese and .09" thick is plenty.

 

The standard MU45 sized meters come in a little cardboard carrier, that has the 4 screw stud holes and the main round hole.

Stickytape the carboard carrier to the front panel, then use it as a template to mark out the 4 holes and the large hole. Then centrepunch and drill the 4 small holes, and nibble out the large hole with your nibbler after drilling a 1/2" hole in the centre to insert it.

Soem fine tooth files are very handy for doing front panel work. At the very least you should have a fine tooth flat file, and a fine tooth half-round file. It's worth the expense of buying brand name files singly, not a Pakistan quality set of assorted files made from grey cheese.

 

Right. Good tools don't just work better, they last longer. I still have several tools I bought in the 1970's...and a set of taps and dies from Harbor Freight that can only thread brass.

 

For cutting some holes on a front pannel, it's sometimes uneasy to make good measurements and trace the lines to be cut.
So I print the drawing on an adhesive sticker film and then apply it on the pannel to cut. It protects the pannel, and there's no risk of bad measurement.
After that, I cut with my dremel, and use a file to finish the work.

 

...I print the drawing on an adhesive sticker film and then apply it on the pannel to cut. It protects the pannel, and there's no risk of bad measurement.

+1 One can use many programs to make an entire front panel to print on label paper (comes in 8 1/2 x 11 inch sheets). Non-removable clear contact paper (called "duck" at Staples) covers it and protects.


Many meters look like so:

So a medium hole in the back is hidden by an even larger face plate. I've not held one in my hands to know if there really are mounting screw holes, but if so then use them to your advantage.

 

This is great stuff.

Files I don't have (unless you count the corrupted kind on my hard drive) so I will get some. I've usually been pretty good about buying quality tools. I don't mind paying more under the assumption that I'll only be paying ONCE.

philippe53, you cut with a dremel? I have a dremel, but am unsure if I have attachments that would cut aluminum. What attachment would you use?

I love the idea of printing on the "duck." I've found drawings for the Velleman I was looking at. I'm assuming those aren't to scale. Are there resources online with to scale drawings? Or do you create it yourself?

Best case would be for me to design the entire front panel, then print it out on the "duck," and cut. While this isn't doing it myself, I've used Front Panel Express before for a synth I was building in the past. My experience with that was that I needed to use CAD software for certain custom elements. Do I need a CAD program to design and print? I don't really have a CAD situation here...and I'm running Macs (for the most part.) Could you just do it in Photoshop and have it be accurate? Sketchup?

Now, if I get this project working well, and I'm not entirely happy with my own custom front panel work...or if I want to take it up a notch or two in the looks factor and have the cash to burn, I may still end up using Front Panel Express again. My experience with them was good. That said, I'm first going to just do it myself and see how it goes...

Man, you guys are really helpful. Thanks so much.

 

First it's important to use unbreakable cutting disks and above all always wear protection glasses.
I use these cutting disks, you can cut ferrous and non ferrous metal with them, and they're not expensive, with a very long life :
http://be.farnell.com/proxxon/28808/fibre-cut-disc-22mm-holder-10pc/dp/1075612?Ntt=1075612

For the drawing, I use the program "diptrace", free for what you want to do. What you see will be printed. Very easy to use, and I recommend it also to make the PCBs.
http://www.diptrace.com/downloads/download-diptrace/

 

I love the idea of printing on the "duck." I've found drawings for the Velleman I was looking at. I'm assuming those aren't to scale. Are there resources online with to scale drawings? Or do you create it yourself?

Best case would be for me to design the entire front panel, then print it out on the "duck," and cut. While this isn't doing it myself, I've used Front Panel Express before for a synth I was building in the past. My experience with that was that I needed to use CAD software for certain custom elements. Do I need a CAD program to design and print? I don't really have a CAD situation here...and I'm running Macs (for the most part.) Could you just do it in Photoshop and have it be accurate? Sketchup?

For the "duck" I meant this stuff. It is a clear self-adhesive overlay that keeps things bright clean and shiny. I suppose you could print directly on it (try it and see!) but I would still put another piece over that to protect the printing ink itself.

On my work a white background is fine, that is why I use 8 1/2" x 11" label paper, one lable per sheet, (also at Staples) to print on. Smallet things I can cut out, larger things well... don't look so good I guess.

ANY program (even a simple Paint Program) can be used to do the layout. My first preference is Autocad so I can set the scale to 1:1, but Publisher or Pagemaker are also pretty good at that too. If you use something like photoshop (which I do not use) perhaps you can set the scale somehow to see the real features. If not, hey, print a test sheet, wash, rinse, repeat!

theRB has found you can get places that do engraving (like on sports trophies) to make a very good looking panel overlay and it is not very expensive. You'll probably have to make your own holes thru it for switches and meters but definately something to keep in your bag of tricks.

 

I'm like a kid in a candy store with all this great info. Awesome.

and you dont' actually put the "duck" in your printer...just use it as a protector...

I have some paint programs on my Macs here (and my PC)

I'm also gonna check out diptrace, which could be fun to experiment with.

 

I should also mention you may find lots of "clear covering" that looks inexpensive. Contac paper for one. Some dollar stores carry it.

Pass it by: it is not permanent, similar to post it notes in stickness except it will remove some ink every time it comes off.

(I can give you a good deal on 4 rolls if you want to try it anyway.)