Has any member of this forum tried making a chassis using laser cutting to enable the folding process to be made without a press brake or folding machine. As some ventilation is required with most tube amplifier designs it may be possible to design an attractive "flat pack" chassis. I would like to hear from any person that has tried this, it it proves practical we could share DXF laser cutting files on this forum.
Metal Laser Cutting : Fold aluminium and steel sheets easily
Need to Bend Some Metal Parts? Just Do The Wave! - SendCutSend
Rusty Sheet Steel Chair by Max Lamb | Dezeen
Laser cut living hinges for neater designs
Metal Laser Cutting : Fold aluminium and steel sheets easily
Need to Bend Some Metal Parts? Just Do The Wave! - SendCutSend
Rusty Sheet Steel Chair by Max Lamb | Dezeen
Laser cut living hinges for neater designs
No I haven't. I have been wondering about using one of those cheep CNC engravers to mill out some grooves in some sheet aluminium, that would help the bending. Interesting links.
Can't afford a laser so usually use an angle grinder to score a line before folding 2mm ali. I applaud your efforts to make chassis making easier and more pro looking though, it takes me fecking ages to fettle a chassis.
I tried to design a computer chassis with perforations that could be folded without a brake. I think I had it laser cut out of 2mm mild steel. It was foldable by hand but you needed to clamp it in a vice with a couple of stiff bits of wood to act as a guide for the fold and something to push against. I didn't try aluminium but that would naturally be easier to bend. I only did a couple of prototypes and the laser cutting firm really bent me over on the freight cost. I think because I only wanted a couple of pieces, they figured they could make up the difference on the freight (which was never discussed beforehand). Don't forget that the laser cutters will charge per cut so if you do a lot of perforations for your folds, that will bump the price up.
Bit off the subject but I've had a lot of success with flat PC Board panels held together with corner brackets.
2mm thick fiberglass is strong and the finish is excellent from people like PCB-way in China. Shielding wise it would be as good a aluminium if the copper planes are all earthed (E-field shielding but no H-field magnetic shielding). Making the corner brackets is the most tricky part.
2mm thick fiberglass is strong and the finish is excellent from people like PCB-way in China. Shielding wise it would be as good a aluminium if the copper planes are all earthed (E-field shielding but no H-field magnetic shielding). Making the corner brackets is the most tricky part.
hello, attached find some pictures of my ZOOM-H4N adapter for DSLR, made from laser-cut 1.5 mm stainelss steel sheet ("1.4301" also known as "X5CrNi18-10" or "AISI 304" or "V2A").
the bendings were easily made in a vise.
to save some cutting cost the two parts were made as one and cut manually.
the bendings were easily made in a vise.
to save some cutting cost the two parts were made as one and cut manually.
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I do bends all the time this way:
First and foremost I only use3003 alloy for stuff I want to bend, 6061 is tempered too hard and the outer radius will get ugly stretch marks. But 6061 is best for a flat top with no bends.
I have a small woodworkers CNC in the garage that can do aluminum. I groove the backside of the bend with two bits to get full clearance. Depth wise i leave 1/32 inch of material. First I cut a 3/32 slot with a straight bit, stopping 1/32 short of the other side. Then I run out the same groove with a 90 degree V bit where the point just touches the bottom of the previous groove, so the remaining metal is no less. After washing, sanding and final finishing, only then do I bend it, its much easier to leave it flat until its all sanded. Now a perfectly square bend is super easy, with my bare hands I make the bends to whatever angle I want, usually 90 degrees. The bends are strong enough, but if picky you can clamp a 123 block into the side corners and with a MAP torch run a bead of low temperature aluminum brazing down the backside. Grooving is the only way Ive been able to get perfect squareness longitudinally and in the bend, and I have some pretty good bending brakes. Also bending brakes mar the surface, doing it with grooves there is no marring and the piece can be worked flat and bent as the last step.
Interesting thread! I've been meaning to post my experiences of Plåt Precision in Huddinge, nr Stockholm, so this has prompted me to do that!
Plåt Precision
Disclaimer - I had great experiences with this company, but I do not have any experiences of working with other companies!
I had discovered some old Ikea wall cabinets that were 25cm square beech boxes, joined with attractive joints, and since I was building the Baby Huey EL34, I was on the look out for a solution for the case for that. I had looked for suppliers of 3mm aluminium, and went over to the machine shop to see if I could order some.
I had no idea how automation had revolutionised these machine shops! The guy said 'how many do you want?', so I said 5, and then it was ...dunk ... dunk ... dunk ... and I had 5 precision cut plates that fit into the cabinet boxes beautifully. (2 of the sheets were used for the Tubelab TSE)
Then he showed me around the machine shop. They have machines for every job in metal working, and most of them can be left unattended overnight, meaning that unit costs can be very low. I asked about top plates, and he asked me to send in a drawing.
The drawing I provided was below. They convert that into a CAD file, which was a one of fee (£25), and then the plates were produced on a laser cutting machine (£15 quid for the single one I requested).
Unfortunately no picture of what they produced since I work away from home, but suffice to say it was perfect! In hindsight I would do the top plate first, and then use that as a guide for soldering in the bases, since they can be a mm or 2 off.
So, long story short, I think we are missing a trick or two here. We produce these wonderful PCB templates that can be replicated for small sums onto good quality PCBs, but we could also be providing CAD files for the top plates, going to a local matel plate specialist, and having short runs of the top plates, or cases being produced for us. Bending is possible, with the proviso that not all bends in all alloys are clean, cutting is via laser or drill heads, depending on the number and the size of the batch. The possibilities are legion!
Plåt Precision
Disclaimer - I had great experiences with this company, but I do not have any experiences of working with other companies!
I had discovered some old Ikea wall cabinets that were 25cm square beech boxes, joined with attractive joints, and since I was building the Baby Huey EL34, I was on the look out for a solution for the case for that. I had looked for suppliers of 3mm aluminium, and went over to the machine shop to see if I could order some.
I had no idea how automation had revolutionised these machine shops! The guy said 'how many do you want?', so I said 5, and then it was ...dunk ... dunk ... dunk ... and I had 5 precision cut plates that fit into the cabinet boxes beautifully. (2 of the sheets were used for the Tubelab TSE)
Then he showed me around the machine shop. They have machines for every job in metal working, and most of them can be left unattended overnight, meaning that unit costs can be very low. I asked about top plates, and he asked me to send in a drawing.
The drawing I provided was below. They convert that into a CAD file, which was a one of fee (£25), and then the plates were produced on a laser cutting machine (£15 quid for the single one I requested).
Unfortunately no picture of what they produced since I work away from home, but suffice to say it was perfect! In hindsight I would do the top plate first, and then use that as a guide for soldering in the bases, since they can be a mm or 2 off.
So, long story short, I think we are missing a trick or two here. We produce these wonderful PCB templates that can be replicated for small sums onto good quality PCBs, but we could also be providing CAD files for the top plates, going to a local matel plate specialist, and having short runs of the top plates, or cases being produced for us. Bending is possible, with the proviso that not all bends in all alloys are clean, cutting is via laser or drill heads, depending on the number and the size of the batch. The possibilities are legion!
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Just today I drew out a new chassis for the RedRoo amplifier and sent the pdf drawing to freelancer.com to get somebody to convert it to Solid-works CAD files. I got about 30 replies within 30 min quoting from $30 to $150. Its only fairly simple, so I'll select one about $50.
In a couple of days that will be done and I'll send the CAD file off to pcbway.com who will make the chassis and powder coat or anodise it black. I should have the whole thing back in about 2 weeks and it will be a very professional looking job.
So, yes, I agree it's a lot easier than trying to bend things up yourself. Unless you like doing metalwork that is, which I can do but I'm hopeless at it.
Edited - PCBway also do Laser cutting, bending and CNC work.
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Lots of excellent suggestions and ideas in this post, most informative. I have only once in the past made a folded metal enclosure for a customer, I used diptrace to draw up the file for laser cutting as diptrace can export DXF files, I placed the cut outs on one layer and all the dimensions on another, I emailed the DXF file to a local laser cutter, I rang him up and he said the file was good to go, the enclosure was folded and sent for powder coating. Many of you use diptrace so it is an option. Inkscape also exports DXF files so it may also be viable. I no longer have easy access to a press brake, a small 12 inch wide one costs about $500 so hard to justify.
Amp Chassis
I recently designed and made a small 60 watt amplifier using just flat aluminium sheets or bar.
I used 20mm * 20mm extrusions from MKALU, who cut and tapped them, and then had an aluminium supplier cut 3mm aluminium sheet to size. It still involved a day on a milling machine to drill holes and cutouts. Next time (if there is a next time), I'll have them laser cut.
This method makes for a reasonable chassis that is very easy to assemble.
Regards,
Paul Bysouth
I recently designed and made a small 60 watt amplifier using just flat aluminium sheets or bar.
I used 20mm * 20mm extrusions from MKALU, who cut and tapped them, and then had an aluminium supplier cut 3mm aluminium sheet to size. It still involved a day on a milling machine to drill holes and cutouts. Next time (if there is a next time), I'll have them laser cut.
This method makes for a reasonable chassis that is very easy to assemble.
Regards,
Paul Bysouth
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Here are some pics of flat chassis panels made from 2mm thick fiberglass PC Board with black and red solder masks. The front panel was done in 3.2mm but it's quite expensive compared to 2mm. The rear side has a masked-off area to allow continuity through corner brackets. That's me you can see in the shadows.
You can see how the final amp looks at Tube - Valve Stereo Amplifier to Build Yourself | RedRoo Kits
I've just done a one-piece 20g steel design to see how the prices compare.
You can see how the final amp looks at Tube - Valve Stereo Amplifier to Build Yourself | RedRoo Kits
I've just done a one-piece 20g steel design to see how the prices compare.
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Did you use captive nuts inside the extrusion profile? Looks a very good way to go.
