Cutting rectangular holes in a panel

[moogah]

So, using a drill is easy enough to make frontpanels, so long as everything you want on them is a circle.  Now, I've got some designs that involve both faders and rectangular buttons along with LCD screens, none of which will work with a simple round hole.  Has anybody been down this road before?  is there any type of tool in existance that can make accurate holes of various rectanglular shapes?  I've consideres making small pilot holes in order to use some type of bandsaw with, but I don't know if a bandsaw could handle aluminum.

[illogik]

hi; the easiest way is to drill pilot holes/use a (jig)saw and finish with little files, oh and lock yourself up with plenty of food and water, because this will take a long long time....

man i wanna CNC-machine

cheers, marcel

[Synapsys]

Hi,

Here is a link to the Digikey catalog page that contains a tool called a nibbler.

http://dkc3.digikey.com/PDF/T053/1440.pdf

If you are working with relatively thin panels (up to about the thickness of a PCB) this tool works quite well. I have used it to make many rectangular holes in aluminum panels as well as shape some PCBs. To use the tool you need to drill a hole (usually in the center of the rectangle) large enough for the nibbler bit to fit through. Then you simply insert the bit, grab a piece of the material and squeeze the handle to nibble away at the material. Since the bit is square, the result is a square cut.

Regards,

Synapsys

[Jidis]

I wish they made a more "industrial" version of the nibbler too. :( It's much more affordable and flexible, but has it's obvious limitations.

I grabbed an overpriced square knockout punch for those a while back and still end up resorting to Marcel's file suggestion half the time. It's really only good for it's 13mm (1/2") hole size, unless I'm doing something big enough to knockout the square corners and saw the straight parts. Greenlee's are the popular brand, but you can get generics for less (Digikey or Mouser has those too).

I've been having decent success with rather thick aluminum for the "drill & file" method (1/8th" maybe). It files pretty fast, but gunks things up and requires cleaning with kerosene.

                           - George

PS- Anyone ever seen (or made) a file without those god-awful teeth on the edge? They're not very friendly toward the adjacent side of a square hole.

[Guest analouge]

I can assure you... a bandsaw usually have no problems handeling alu. At least not the thickness we're talking about here - I mean - just for panels... But ther is really no way you can make holes in a panel with this tool without sawing your way into the panel to the place you want to make the hole... But it handles relative thin alu very good... But I wouldn't recomend it... A bandsaw requires a pretty stable hand when doing woodwork to do a precise job. A bandsaw is very eager to "eat" wood, but I guarantee, it's even MORE eager to "eat" alu. So if you want to cut alu with it, you need to be very careful and take it slow, or else you will NEVER get a straight line.

A bandsaw also requires a certain amount of experience to get a presice job done. Before you make the actual stuff you're gonna use, practice on some wood stuff first to learn how to "steer" the bandsaw. I know it took me years to learn how to control it good enough to do a satisfying job with it. I used to make wooden furnitures so I didn't use the bandsaw too much back then... but it's great for old fashioned hand made furnitures though ;)

So conclusion... use some other tools. If you have a steady hand, a normal handheld saw with a blade that goes up and down (sorry - don't know the english word) would be good enough. You have to drill holes first though. And remember to put a blade on that's made for steel - and make sure the blade's tilt setting is off, so that the blade goes ONLY up and down and not back and forward too... But it's rather tricky to make small rectangular holes with - like for faders... And be sure to use protective glasses when you saw in metal (or in anything for that sake). I opened up a wall once with a circular handheld saw without glasses. I spent the next two days in the shower trying to flush out the dust and shit from my eyes! Nothing makes me go nuts more than getting stuff in my eye! I tried like everything, but it wouldn't come out, so I had to pay my doc a visit. He finally got it out, and told me I had scratched my eyeball! No pleasent experience I promise you!

Anyway - this post is long enough as it is...

Cheers!

[Jidis]

synth-o-mania,

I'm the same way with stuff in my eye and I still manage to do dumb crap if I've had too much coffee or don't have goggles nearby. I've done the "scratch the eyeball and think there's still something in your eye" thing too, but it was healed enough overnight where I could let it go on it's own.

The metal thing can't be overemphasized though. When I used to work in a warehouse, on two different occasions I woke up with one eye closed up and stinging. I had to hit the hospital on both. Evidently, if even a small particle of the "wrong" metal hits your eye, and sits long enough, it forms a "rust ring" around itself which will remain even if the metal is gone. They actually have to *drill* the rust out of your eyeball. The drill idea sounds worse than it was. When it gets close enough to your eyeball it sort of disappears and you just feel this mild vibration. The preparation to drill and the aftermath of it sucks though. You wear a bandage over it for a day or two while it heals.

I never did figure out what it was. I think it was something in the forklift exhaust. I used to drive backwards a lot (..don't ask ;)).

I'm glad yours was just wall dust.

-George

[Guest analouge]

Heh! Conclusion - USE protective gear!

My wall opening-up project inluded two major jobs. The first one was to open up the wall made of wood and the second one was to open up another wall made out of a double brick wall. It was those old kinda bricks that is all compact - (and worth a lot if they are nice and whole). You can be SURE I went to buy proper protective gear after my first misstake! :P hehe. So I spent like 1,5 hours with my cutter and a huge diamond blade on it cutting the wall after that. I was so hot because I had an ALL-COVERING working dress on me, cap, gloves and prot.glasses. Hehe. I closed the area with plastic and used two vacuum cleaners for a sort of home made dust sucking thing :P hehe. When I finally got out of there my friends just looked at me all covered up in my protective gear and ALL pink because of the dust from the stones :P Hehe, but at least I didn't get any of it in my eyes!

And I'm sure if I hadn't made that misstake on the wooden wall I would gladly cut the brick wall with just gloves and earplugs - no glasses, no nothing. Hehe... So I'm glad I learned... but the funny thing is that I really should've learned to use proper prot.gear many years ago, but the thing is - it usually turns out great - u don't get ur eye stuffed with dust and shit - and you just become slappy. Then it happens and after that I A L W A Y S use proper prot.gear! :) I also used to weld stuff before with no dark glasses - just small stuff... bigger stuff I always used the glasses... But when I woke up one morning realizing I had overdone the welding without prot.gear I decided - NO more welding without glasses! My eyes felt like a f...ing sandbox! hehe. So....

Be safe!

Ingebret

[Wise]

They actually have to *drill* the rust out of your eyeball. The drill idea sounds worse than it was. When it gets close enough to your eyeball it sort of disappears and you just feel this mild vibration. The preparation to drill and the aftermath of it sucks though. You wear a bandage over it for a day or two while it heals.

Been there, done that... And it realy hurts when the anaesthetic??? goes away from the eye..  :o :o

[Jidis]

Been there, done that... And it realy hurts when the anaesthetic??? goes away from the eye..  :o :o

Yeah it does! I'm just glad (hoping) we don't have any permanent damage from it. It is nice when we can learn our lesson without casualties.

Ingebret, that's funny you did that double vacuum thing. I did that when I was in high school and needed to clean a bunch of fine sawdust off the walls and floor of my home studio. I needed the capacity of the shopvac, but the sucking power of our home (Kirby) vacuum. The Kirby bag outlet was about the same size as the larger size shopvac tubes, so I duct taped them. It was surprisingly effective. You could almost just stand in the center of the room with the Kirby hose and point at things like a sorcerer. ::)

I'm not sure how friendly it was to the motors though. It sounded faster. It could be like running 8 ohm amplifiers with a 2 ohm load.

Back on topic- I cut my eighth inch aluminum iron plate yesterday with a powered jigsaw (if that's the handheld type you were talking about, Ingebret). It cut really quick. With oil on the metal and a new metal blade, it's almost too fast (my magic marker lines didn't like the oil very much though). Running it dry was a lot harder. It should have no trouble doing square holes for people. That and a file should work well. I'm going to see if I can grind the sides of a file flat on a bench grinder before I do any more.

Take Care

-George

PS- I wonder if you could mount one of those saws upside down like a router table and get some type of grooved metal wheel on a rod to brace the back of it, like what the bandsaw blades rides in. That way you could just drill your hole, lay your metal over the blade, and drop the backer rod in place. The side to side wiggle of the blade and the difficulty to view your cut are the only things I don't like about those saws. I may try it with an old one here if I've got time. 

[srmaietta]

you can get a plate to mount your jigsaw to and run it upside down like a router table.  You're at the pont where youre cutting square holes in sluminum sheet, you can probalby make one for yourself!!  youd have to rig somethign up for the power though.. tape the trigger down and get a foot switch for the mains power. 

And for those who just need a hole or two you can get a fine tooth metal jig saw blade and grip it in visegrips and have at it. 

also, if you have a few extra bucks you can send shaeffer your panel and they can do just the square holes/slots and you can do the rest.

just an idea

i love metal.

~Steve

[Jidis]

you can get a plate to mount your jigsaw to and run it upside down

Steve- Yeah, I thought about that after I posted. I've done a circular saw and a couple routers, but they were under thick particle board tops. All the good metal cutting jigsaw blades I've had have always been relatively short. I'd probably have to do like you say and mount to a plate. The remote AC switch is already knocked out here. There's actually three (one with vari-speed). I do a bunch of cabinetry junk.

metal hates me :'(

~George   

[Guest analouge]

Yeah... handheld powered jigsaw was the thing I was talking about. Thanks :)

I have an Idea! Let's all put our money together and get ourselfs a laser cutter :D Haha. Would be nice :P.

I've done quite a bit of metal work over the years. It all started when I was with my dad in his garage when I was a kid. He completely restored an old VW. you know the ones that EVERYBODY used to have :P.

Later on I restored a Golf 83, and when my dad made a wreck out of that I restored a Toyota Carina 2 - wich is the car I have now... I am lucky with that one, coz you can't find any rust under it. It's well taken care of... but cosmetic rust - that's a whole another story! My car is full of glass fibre patches underneeth the surface, but at least it looks nice... It used to leak water into the trunk - So I took out the rear side windows and removed a lot of rust holes that you couldn't see otherwise. And I glued the windows in with waterproof acryl silicone... I shouldn't have done that - coz it looses a lot of it's flex when it dries up! :)

Anyway. A list of tools I use for steel work:

- Heavy duty cutter (the ones with a cutting wheel - diamond/stone/steel)

- Welding machine

- Driller etc...

I really don't like steel work, coz It's so hard to do presice jobs without proper special tools like benders, huge cutters etc... So I use alu where I can.

For alu work I use:

- Jigsaw for cutting inside the panels (with metal blade!!)

- Bandsaw for cutting out the panels from larger alu plates.

- Files

- Handheld manual metal saw

- Sandpapers - a lot of them. From 80-1200 and sometimes even more fine.

- A lot of strong stuff to clean it before spraypainting it.

- And a lot of other tools I can't come up with right now

- A lot of improvising :D

The thing with alu is that when it's new it's almost impossible to spraypaint, coz it's apparently covered with something that makes the paintjob look like it was painted onto an greasy surface... so you gotta clean it well - either with really really fine sand paper, or with other strong liquids...

So here's some tricks for making different finish looks for the alu.

Polished finish:

Use very fine sandpaper from the start - else you will NEVER get rid of the scratches. Unelss you wanna work all night with it  ;D

Then give it a layer of shiny clear coat, coz alu is very sensitive for greasy fingerprints ;).

Brushed finnish:

Sand it with a sandpaper with a relative low number and scratch it - make the patterns you want. I prefer straight up patterns, and no curves and stuff like that... either clean horisontal / vertical / diagonal patterns. But that's up to you!

Then finish it up with very fine sandpapers from 800 to 1200 or so... When you're done, the scratches should still be there giving the brushed look, but the surface will still be very smooth. Guess you gotta experiment with it to see what possibilities there is...

Then apply the clear coat. Make sure it's the shiny type... or that's what I prefer... I use automotive clear coat myself, but I really don't know if there is a difference between an expensive automotive clear coat compared to the cheaper ones... What is obvious to me is the spray nozzles. The expensive ones is WAY much better to work with and gives a finer finish... and you can turn the nozzle the direction you want... compared to the cheap ones with the uni directional nozzles it's better. With a turnable nozzle you get better pressure, less drops etc...

For painting it's some imporant things to remember if you want a pro finish.

- Never spraypaint unless you got proper temperature in the room (or outside). That is around 20'C

- Heat the can in hot water (NOT more than 50'C or you can risk to blow the bottle!!) This way you get optimal pressure.

- Be sure to be in a place where it's not too much dust.

- Some say that you should apply many thin layers... but I disagree a little bit with it. Sure you can get useable surfaces with that method. But I say - to get the best surface - apply the each coat with as much paint as you can before it starts to run.

Metallic coats are a pain in the ass. In my oppinion there is nothing else that looks nicer, but it can be very tricky to get it right. This paint runs much faster than non-metallic, coz the paint is heavier. And it is much more temperature sensitive. Be carefull applying it. To make it look nice you gotta apply to it almost runs... but that's the tricky part. It's really a matter of experience... Coz one minute it looks nice and smooth, after 5 minutes it runs all over the place. So be sure to apply enough but not too much.

OK... A long post, but I hope it was somehow usefull :)

Have fun!

Ingebret

[Jidis]

I hope it was somehow usefull :)

Definitely!

Thanks for the tips on the aluminum sanding and the heating of the paint. I think the spray nozzle you're talking about is similar to the ones I get on Deft lacquer cans. They have a fancy looking nozzle with sort of a "hinged" top section. They do make more of a fine spray mist.

I didn't know about not being able to get the aluminum back to that shiny look either. The times I've played with the texture, I've usually hit it with a finishing (palm) sander with fine grit metal paper, or done swirls by hand with a scrap. I did indeed notice that it usually had more of a gray look to it afterward, but I always figured that it could be brought back to that mirror look with finer paper. The surface of the fresh glossy piece I've been using isn't in perfect condition, so I doubt I'd use any without sanding first, but I'm not sure I like that shine anyway. For the "brushed" look you mention, are you working entirely by hand or do you use power tools for that? I like that look too. I thought about maybe trying some wire wheels or a fine vertical wire brush (cup style) in a drill press.

                                                                      - Thanks!

George 

[Guest analouge]

Hey Jidis!

I guess there's ways to get the shine back in "bad" alu, but I've never managed to do that myself... My knowledge about metal work is pretty much what I've learnt by myself - and from quite a bit experimenting. I guess you could polish the alu to get it shiny and stuff... but I really don't like shiny alu either. I use "polished" alu for small details, not big surfaces... looks so plain... and I've never managed to make it look like a mirror, but I guess alu is too soft to make it look like that in the long term anyway. I've tried it with steel, but I don't got proper polishing tools to make it perfect, so I sort of gave up that idea. I'll post some pics of some of the stuff I did in my car later on.

About painting... I think I forgot about something I wanted to put in here the first time... :) Typical me :P.

I prefer to use more pro tools for spraypainting, but unfortunatly I don't have the right ones yet. With a compressor feeded spraypainter you get a more even surface, and it doesn't run so easily.

But since most of us use spraycans I'm not gonna talk about that too much :). A paintjob can become "bumpy" when it dries up. This is caused by several thing.

1. To cold (room temp, spraycan temp - wich causes loss in pressure, paint object temp etc...)

2. Bad spraycans with poor nozzle

3. Probably more stuff too... :)

Be sure to shake the spraycan for at LEAST two minutes. Many people take the shortcut and shake it like 30 secs, but the results will be uncomparable if you shake it long and well.

BUT! It's still very difficult to avoid those bumps anyway, so I'm gonna lay out some tips on how to get rid of it - if not completely, but enough :)

When you paint you should always apply several layers, right... So the thing you can do is to sand it in between the layers with a fine sanding paper - that way you even most of it out.

But if you still got bumps after doing that, there are still hope. Here's what you do:

Sand the painted surface with a VERY VERY fine sandpaper (I use around 2000-ones).

- It will seem like you have ruined the painting - it will NOT be shiny at all. But we're gonna fix that ;).

Polish it with polishing wax. Maybe you need to do it several times. Then it will become shiny again. And with a lot less bumps.

But there is a chance that this doesn't work out, so there is one more thing you can do. After you sand the surface as described above, you polish it with a rubbing compound instead of the normal wax.

There are several types of rubbing compounds. Liquid and non-liquid. Whatever you do, use the LIQUID ones. A non-liquid compound is hard to work with, and it's easier to ruin the whole thing.

Then there's different "strenghts" in different rubbing compounds. Often there's a scale on the bottle that shows how rough it is on the surface. Often from 1-10 where 10 is most rough. You want a rough compound (especially if its liquid) for this kind of job.

Rub it well, maybe two times... And it's highly recomended you use a polishing machine with rubbing compounds... This polishes very well... but you need to finish up with a layer of normal wax afterwards, or else the paint will be so soft that it will scrach with the touch of a fingertip. When you've done this I'm surprised if the paint isn't shiny... And a LOT less bumps will be there too...

I'm sorry if this post is a bit messy, I'm trying to handle MSN on two different languages at the same time I write this :P

Anyway. Yesterday I was doing some steel work. I'm making a 19" x4 unit rack pc front panel. I'll take some pictures and document how I did it :). May not be in this forum, coz I'm making my own webpage - soon ready, and I'll probably put the "tutorials" there, but I'll give you guys a link if its not posted directly in this forum :)

Anyway - I gotta come back with more later, coz right now I'm running out of time... :)

Have fun,

Ingebret

[Jidis]

Ingebret,

I used to do that buffing thing years ago when I used a lot of brush on lacquer. I got buffing compound and rubbing compound in bottles from the auto paint place here. I think it was 3M brand, but it sounds like what you're referring to. I've since moved to mainly melamine and laminates instead of solid wood, so I haven't done it in a while. My worst problem with it was in the fine (in-between coats) sanding. The painted coat wasn't always consistent, and I didn't always sand the exact same amount, so I usually burned through a spot or two while smoothing it out and always had to touch up things and re-coat. This was mostly with furniture and racks, so it would probably be less of a problem with flat, panel type things. You're right about the sprayer. I finally figured that was the only way I was going to get professional looking results on anything of decent size like furniture. I've come about two inches away from buying a small HVLP system on several occasions and had done many hours of research on it. From what I read it was quieter, easier to clean, and more flexible and portable for smaller stuff than any of the "real" sprayers. They were also supposed to get some really impressive amount of paint onto the surface (like 90%), which is good for my budget and lack of spray booth. I'll probably still get one when I get back to some of these drum shells.

BTW- The highest rated "consumer" model was surprisingly a Wagner. It wasn't the hardware store model, but a couple levels up in the 400 to $500 range. It beat out many of the classier brands up closer to 1000 dollars. I think it was the 3-stage turbine type, which was supposed to be capable of thicker, water based stuff as well as lacquers. This was all last year's research, so it may have changed now. I guess if I was already running a compressor for stuff, an HVLP gun would make more sense money-wise, but I try to make more "neighbor friendly" noise whenever possible.

I did more plate label tests last night and got a nice looking matte finish from hand sanding with fine wet/dry metal sandpaper. The finish sander leaves tiny "swirls" which I don't care for and the hand sanding was fairly easy with the aluminum.

The aluminum toner transfers, however, have gotten me just about ready to jump out a window. With the great results I'm getting  with PCB's nowadays, I'm determined to figure out why the aluminum is so uncooperative. From what I can figure, the transfers are going down the same, but the cooling and drying stage is ruining everything. Right when the iron comes off, the paper begins lifting and bubbling away from the metal. This is a critical time for the bonding and the paper isn't anywhere near ready to be removed yet. I think the metal is still hot enough to where it doesn't hang on to the toner and the paper has a better chance of taking it back. I bought transparency sheets the other night. I'll try them soon. I'm also considering trying a spray coat on the metal before the transfer and trying a spray coat of something on the paper before printing, but each test takes about a half hour in total time. If I can make it work, all that test time will be worthwhile for the convenience of being able to do labels and stuff at home. I'm also thinking of sandwiching the paper between a top sheet of metal to hold it down until everything cools and can be soaked off.

- I'm lost ???

                                                           -George     

[Guest analouge]

Hey. I used to work at a service shop for cars where I used to make old and new cars ready for sale, and some tyre work too. And just about enough oilchanging for a life time :P.

That's where I learnt most about waxing and rubbing. My boss was VERY good at it, and he was a VERY good teacher too. So I learned a great deal of how to rub and wax cars, what types to use in different situations etc... we had an entire arsenal of "good-stuff". I also learned a great deal of how to wash cars totally clean without toutching it with anything but liquids - not to scratch the car's painting. My boss was like - if he acidently dropped a sheet of micro fibre on the floor he threw it away.

So... for a short while we used Turtlewax products, but we didn't find it good enough, so we bought an arsenal of Meguiar's products. And that was like heaven to work with! The best paint / vinyl protection brand if you ask me...

For rubbing we used something called Meguiar's diamond cut compound 2. That was a very rough rubbing, and it cleaned up every scratch possible. Of course people came in the shop with they're cars wanting us to rub it, and was disappointed like hell by the results. Then we had to explain to them that rubbing isnt the same thing as repainting :P. Some people never got satisied!

After the rubbing we used a green liquid wax from megiuar's - made for use with dual pad poilish machines. And the results was GREAT! Sometimes we even had to use sand paper - in example to even out the painting when stickers was removed from the car. For new cars we washed them and just put on a coat of spray wax on it. But that kinda "water" wax is only good for showing off the car in the store, the minute it gets any rain or something it's long gone.

So my conclusion on the rubbing stuff is that you can fix the paintjob to a certain extent, but nothing is as good as plain old good pro paintjobs.

So if we want pro results, we gotta use something other than spraycans ;).

I just wondered it any of you guys has any experience with plastic work. Like "hot-shaping" the plastic either with "hand force" or vacuum forms etc... I've been trying to get hold of information on the net on how to do this, but no luck - at least not enough. I'm not sure what to search for either.

I just finished up my front panel for the rackPC now. So now I'm working on the enclosure and insides. I figured I'd get a 2mm steel plate and bend it back in my garage, but I soon found out that would take a lot of work, and it will never be precise enough! And I found out that I've been living close to a mechanical workshop all my life. Until very recently I thought they just made rails, fences, ladders and stuff. But they do a lot of steel plate work too :). And I also found out that the owner is one of my dad's friends :P. So I got the steel plate for like nothing, he cut it and bent it for me, and I had to force him to take my money :P. I like!

Anyway. Now I just gotta work out the rear panel (wich is a lot more complicated than I imagined - with the PCI slots and I/O slots and all that). Then I just need to make a rack to put it in! I've been waiting for that rack for many years now, and now I'm finally gonna do it! Need it. So I just wondered about something regarding rack building, and I bet there are many of you rack builders in here! It's about the rails in the rack case. Is it good enough (strong enough) with cheap alu rails or do I need to go for steel? I don't want to make it myself, coz I really don't see how I could do it... with the square holes and stuff... The computer I'm building has an enclosure of 2mm steel. The enclosure is 19"wide, about 14" deep and close to 7" high (4 units). It's gonna be heavy as hell  ;D. Course I could make it in alu, but I'm a little bit conserned that it wouldn't handle the abuse by moving around, in and out from cars etc. I want it as strong as possible, so I should probably go for steel rails? Anyone knows where I can buy that? And accessories like rack screws etc.. And the alu framing too - for the edges of the rack... Anyone?

Have fun,

Ingebret

[Wisefire]

i found this website where they explained how to make a vacu form table (its very easy)

and how to work with it.. also some info on how to make a mold for it.. and a lot of

other great stuff.. check it out..

http://www.studiocreations.com/howto/vacuumforming/index.html

http://www.studiocreations.com/howto/vacuumtable/index.html

http://www.studiocreations.com/howto/plastermolds/plastering.html