Metal work

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Jerry

Active member
Joined
Jun 10, 2004
Messages
27
Location
Paoli, PA, USA
Hello everyone,
I've built several projects over the last few years before discovering the GroupDIY community (about two or three days before the recording.org meltdown). I like building the projects, and to a lesser extent, sourcing the parts.

I don't really like preparing the enclosure -- particularly the metal work. No matter how careful I am with my drill, a row of knobs always comes out with some higher and others lower (no drill press at my disposal). It takes forever to cut a square hole for a meter or an IEC plug with a Dremel tool. Furthermore, I wind up doing labeling with a sheet of generic radio/television dry transfers from Antique Electronics that rarely have the exact wording that I want to use. Aesthically, my projects look a little shabby.

Is it possible to contract out the part that gives me the least joy? I recently bought some PCBs from the "Black Market" forum (Thank you, Gustav - they are beautiful), so the level of precision is an even greater issue than it has been in previous projects. What do you guys think?
 
Hi Jerry,
I haven't really got anything helpful to say other than that I sympathise and that you shouldn't worry too much about it. I gave up a long time ago trying to get things too perfect cosmetically. I'd rather work quickly and get the thing hooked up and passing audio so I can experiment with the circuit.

I do all my labelling with a sharpie pen or a silver marker on black paint, or tippex. My holes are rarely straight or circular. But hey! I like the way it sounds and that's the important thing. I think a strong, solid construction beats anything pretty. If it sounds good it is good etc etc..
And there's nothing wrong with sub-contracting out the bits you don't want to do. So long as you're having fun and the final product meets your needs.
:thumb:
Stewart
 
I'm going to try to build some rack cases soon with the eventual goal of possibly making them available in the black market. I think I will be able to make some fairly high quality stuff, but am currently collecting the tooling. Another possible goal would be to drill holes for knobs and connectors at the request of whoever's buying (maybe even powder coat cases.......). I wouldn't mention it if you hadn't brought it up (because I'm still not sure it's going to work out). You post did make me curious though, so I guess I'll ask here, is there anyone else besides Jerry that would be interested in a service like that. My racks should have aluminum front and back plates and the rest steel (still playing around with the final design), hopefully cheaper than is currently being offered commercially. This would really be more of a service to the members of the Lab, since I don't know the most about electronics I'd like to be able to give something back. If you guys think this is a bad idea, let me know before I spend anymore of my wifes grocery money on tools. :grin: Nathan
 
thats usually the hardest part but with practice it goes a lot quicker. I mask up my projects lay them out with a ruler. tools you should definatly have are an automatic centerpunch to set holes. a taper reamer(if you holes are offset you can drill them undersized and use the reamer to line them up a little closer) a cut off wheel set for your dremel tool (be carfull with them if you don't have the flexible handset cause it can get away from you) and a good set of files large and small

Wilebee
 
increasingly i'm doing more and more metal work for my clients who want things "racked up". This is my experience. Get a drill press! I bought a cheap chinese one for $120 (australian )....it is not the worlds best drill press but it is more than useable and so much better than a hand drill. Getting holes in a straight line.....I use Corel draw, setting up guidelines at the exact points I need to centre holes, then using snap to guidelines i can draw in crosses to indicate the exact hole centre. I then print this out and tape it in place on the panel and punch through the paper onto the panel with a centre punch. Pull the paper off and you have points marked very accurately on the panel to locate the drill bit on. I've recently made a panel with 52 XLR sockets on it and they are so straight and square it is as professinal as you could wish for.
Labelling...I use corel draw again, once more setting up guidelines ( or often just using the ones set for the drilling sheet ) put my text, including colour or anything else. I then have two options, print this out, laminate the front side and place double sided sticky tape on the back, cut out with a sharp box cutter and steel rule...or... I have friendly printer who can print stickers from the corel file and so I get a sticker made with a choice of background colour and full colour text and images.
The results are pretty reasonable for such a low effort :cool:
 
Here's my experience....

After i get my chassis from par-metal.com, I cover the front, back plate with blue painter's tape.

Why? So I wouldn't scratch them while working on it.

Then I layout my knobs and switches and LED on top of the panel trying to visualise how it will look. Then I get a ruler, and square and mark hole locations with a sharpie pen, or ball pen.

Then I take out a punch, and try to center punch these future holes as accurate as I can. The center punch will create a small indentation on the metal work, which hopefully the drill bit will "fall in" and start the hole where you want it to be.

A drill press is a definite must if you want great control... a hand drill won't be ideal for this work.... hard to control. You can get a $60-$80 drill press at Sears. That's where I got mine. :)

For drilling big holes, for XLR jacks, I use a step drill bit.... also at Sears. They're kinda expensive but that's the only way you can make big holes... or get a punch.

For square/rectangular holes, I load a 1/4" drill bit on my press, and try to outline the square holes using multiple holes.... don't worry if the holes dont overlap each other.... at least make them close to each other... 1/16, or 1/8". Make sure to leave enough clearance from the edge of the square you want to make. ... say 1/8" or smaller.

Then I get a jigsaw, and cut through the holes... i.e. cutting the metal connecting each hole... until the square metal gets knock out. Then I get the file and smoothen the square hole... this is the hard part... make sure to always fit the device in the square hole. You don't want your hole to be too big and loose.
 
Well first, I do warmup scales, starting with C Ionian, and moving through Dorian, Phrygian, Lydian, Moxolydian, Aeoliaan, Locrian.

Then onto hammer on pull off excercises. And after that..... ummmm.....

sorry, wrong metal work :green:

pretty box owel :thumb:
 
You can file a round hole into a slot which will give you the opportunity to adjust the up and down position of your controls. The knob will cover up any gaps.

Center punch, then an 1/8 pilot hole using oil.
Then 3/8 or if you need a bigger hole, use an intermediate pilot drill bit, like 1/4 inch.
Keep the chassis and the drill motor in the same position when drilling. This keeps the wander more consistent.
You can true up a bad hole by slanting the drill motor towards the direction the hole should be.
You can use autobody products to get a really nice finish and cover any mistakes.
A drill press won't help wander unless you clamp the piece in a vice that is bolted down.
Mechanical is 90 percent of a DIY project so I symphathise.


:guinness:
 
Metalwork is also my least favorite part of a project.

That blue painter's tape Owel mentioned is great stuff!

Here's a tip I don't believe has been mentioned yet: after drilling a hole, you can deburr it using the tip of another drill bit a few sizes larger. This must be done carefully and slowly so as not to oversize the hole... You can do it by hand, but use a rag or thick gloves to hold the bit so it doesn't cut into your hand.
 
Count me in as yet another who dreads the metalwork. Small drill presses really are stinkin' cheap these days & worth the relatively small investment if you've got room for one.

Nibblers are nice for chewing holes into non-round shapes.

If you can print out your layout full size, using glue stick (eg UHU) to attach the paper to the metal as a drilling guide works well--it sticks just well enough to survive the drilling, but it cleans up pretty easily.

Use big washers to cover up your drilling botches.


Tom
 
Oh, and my method of cutting square holes for meters differs from the above listed.

I too cover the panel in blue or tan masking tape, draw out the square, and here's the departure:

I just drill a hole in opposite corners big enough to get a variable speed jigsaw with a metal cutting blade through it. the holes don't have to be perfect in the corner, just relatively close enough. Then just cut in two directions from each hole, and out drops the squarish metal. use the jigsaw to clean it up so that it's square, and if your a perfectionist, file to taste.

Regards

ju
 
OWEL....

Very nice job on your rack metal work! What series are you using from Par-Metal Products? Think I will order some to try out.

Thanks for the tip!
 
Owel,

Your method makes a lot of sense.

But for the "figuring out where to put what" - stage, I put the different knobs, switches and meters in my scanner, crop and size the images, and move them around in CorelDraw untill I have a nice layout.

For cutting square holes in (up to 4.5mm aluminum-) frontplates, I use a wood hand router mounted with a 6mm standard wood-cutting carbide tool - and lots of oil. Make a template to guide the router, and it's more or less fire-and-forget..

Jakob E.
 
Thank you everyone for your suggestions. I'm happy to see that I'm not alone. Nathan, if you are considering putting out a shingle on the "Black Market" forum, how soon do you think that that might happen?
 
It'll probably be a month or so, hard to say for sure, I'm starting a second job tuesday :sad: I'll probably try a couple tests and then try to make a run of ten or twenty. Hopefully I'll know for sure if it's something I'm gonna do within the next week or two. It really depends on how my tests cases turn out. I'm not gonna do it if I end up with bad face panels and loose cases (but I'm pretty confident they'll turn out good). One good thing is it shouldn't be any harder to make 2u and 3u cases than it would be to make 1u cases. I'll keep you guys posted and maybe have some picks of my first ones in a week or two. Nathan
 
Apparently, I'm the only one here, who looks forward to building the racks! (Not only the fun of building them, but it means it's almost time for the smoke test!) :twisted: You know, a good way to save on drill bits is a plasma cutter; oxy-acetylene is a little too much, unless you're using armor plate! :grin: Of course, I guess you could just weld the hole back up to the proper dimensions! heh-heh! :sam:
 
I cant express how much my life changed with the purchase of a drill press and a good set of calipers, two things which make panels SOOOO much easier! Another thing is the material you are working with- the par metal panels are really easy to file, so filing out the meter boxes and stuff is a breeze after youve drilled out the perimeter. Bud enclosures are even thinner aluminum... Ive tried to work on some stuff where putting an IEC connector on the back was like going to war. I was able to get these deburring tools at home depot, sort of like a miniature sickel that you carve around the hole with and they work great but the idea of drilling with a bigger size bit is pretty genius, Ive never thought of that.

If you plan to make two boxes in your lifetime, think hard about getting a drill press, the press I got at the depot for $90 is single speed, but fully awesome.

dave
 
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