[Amps] chassis maker?

Sun May 5 14:40:01 EDT 2013

I'm using sheet aluminium and angle stock. Ripping straight took some learning, but also good, high-end power tools. I'm using a Festool circular saw with rail guide for long rips and a Festool jigsaw for shorter rips and cross cuts. With practice, exact measurements, patience and of course the rail guide, I have learned to cut within 0.5 mm. Dewalt or Bosch Blue might do it as we'll, but the cheap, €100 jigsaw from the supermarket is not good enough. The blade is wobbling too much.
I guess a high-end table saw is just as good. But the cheap ones don't cut straight enough. The guide fence is not rigid. Fine for wood working but not for exact rips on aluminium.

With proper paint and laser printed labels on Safmat, the result can become close to factory manufactured. 

73 de Ulf / SM0NOR

Sent from a wireless device of an unrevealed brand.

On 5 maj 2013, at 04:40, Vic K2VCO <k2vco.vic at gmail.com> wrote:

> I am doing it what might be the hard way, but is a learning experience. I inherited some 1/8" aluminum sheet that I am using for chassis plates and inner and outer panels. I can cut it with a saber saw (I am getting better at this) and clean it up with a file. The trick is not to go so fast that the blade loads up. I use an orbital sander to create a clean matte finish on the surface.
> 
> I use 16-gauge 6061-T6 sheets from Metal Supermarket for sides and 18 gauge material for bottom and top plates. I hold the pieces together with 1/2" square aluminum sections and in some cases 3/4" x 3/4" x 1/8" aluminum angle. Both of these seem to hold very well when tapped for 6-32 screws. The square sections make a very strong assembly.
> 
> I've also used a 7x7x2 aluminum Bud chassis for the enclosure for a 4Cx1000A socket. Yes, the material is very thin, and soft, too.
> 
> I am making plenty of mistakes along the way, but so far I've overcome them. I don't think I have enough planning ability to order a commercial assembly -- I admire the guys who can plan everything in advance and have it all fit, but I am always getting surprised.
> 
> On 5/4/2013 5:28 PM, Carl wrote:
>> One of my last jobs before retiring had a nice prototyping shop complete with a 48" brake with many dies for various compound bends, band saw, 5hp 2 stage compressor, plasma cutter and Miller TIG setup. When they went belly up in 2000 I bought the above plus many smaller items (including a Henrob 2000 torch) for very little. Couldnt afford the big stuff (-;
>> 
>> When I retired in 2002 I brought the part time rod and custom shop in my garage to full time and moved into a real building with employees and took all the goodies out of storage from a friends barn. Sold that biz to the shop manager 10 years later but still get to use the goodies and have built many chassis.
>> 
>> Even the heavy duty larger Hammond aluminum chassis are only 16 gauge so if you need support strength either add them underneath or go to steel. Their small ones are 18 gauge.
>> Hammond steel chassis are 18 and 20 gauge.
>> 
>> Steel sheetmetal for a vintage vehicle is 16-21  gauge and the thinner gauges can be handled with a homeowners size shear and brake. Heavier gauge for aluminum
>> For amps it is a heck of a lot easier to build clamshell cases with the lower half used to mount components as the manufacturers have been doing for decades. Use a Hammond or LMB chassis for something small such as just mounting a tube(s) on. You can also roll your own small chassis or build using 2 sided copper PC board. Then dress all the soldered edges and paint, and it looks factory made.
>> 
>> Carl
>> KM1H
>> 
>> ----- Original Message ----- From: "Roger (K8RI)" <k8ri at rogerhalstead.com>
>> Cc: <amps at contesting.com>
>> Sent: Saturday, May 04, 2013 8:39 PM
>> Subject: Re: [Amps] chassis maker?
>> 
>> 
>>> On 5/4/2013 12:59 PM, Colin Lamb wrote:
>>>> "I consider a shear essential unless you are not considering looks. Only
>>>> a few have the skill to saw and file with a professional look."
>>>> 
>>>> Although I have a shear, that may not be the perfect solution.  In order to cut thicker
>>> aluminum or steel, you need a 2,000 pound shear, which involves space. And, often they are
>>> not able to do more than cut a flat edge the full length of the material. If you are going to
>>> fold it, the shear may not be able to cut all the shapes you need. However, both a table saw
>>> and a radial arm saw, with a non-ferrous blade can make clean cuts (warning - secure things
>>> before you cut).  And, if you build edge guides, even a saber saw with a metal cutting blade
>>> can make clean cuts.
>>> 
>>> 
>>> Agreed.
>>> 
>>> The shear has one strong negative when it comes to thicker pieces. The rolled edge.
>>> 
>>> The table saw can throw an unsecured piece across the shop and stick it far enough into the wall that it can be difficult to pull out. Voice from long in the past.  Basically I don't like table saws, do to a slip with one I have a thumb the Doc tells me will never be the same.
>>> 
>>> 
>>> I much prefer the milling machine with saw for the thicker pieces. A horizontal/vertical combination mill is ideal but pricey and I've not seen any at regular machine shop brokers. Grizzly has imported ones. I don't know how good/durable they are.
>>> 
>>> I've seen break/shear combinations that would (were reputed to) cut out corners, for making chassis, but again I think the thickest material they could handle was either 12 or 16ga.
>>> 
>>> There are also specific punch presses for cutting out these corners ranging from hand units for a standard thickness Aluminum to hydraulic for serious work.  Thing is, I see the newer versatile shops using laser cutters which put a new meaning on the word pricey, but they will cut virtually any metal.  Programed they can do an entire panel in a few minutes. I think one of the companies that have been mentioned offer that service. They send you the software to lay out the panel, you send the layout back and you have the new panel back in about a week.  I think they will even do powder coating.
>>> 
>>> Now that would be quite a toy.<:-))
>>> 
>>> Surprisingly, a plasma torch with a moveable/roller power feed can cut Aluminum or steel with a pretty good edge.  I've cut painted barn metal using a guide without scorching the paint. Course that's thin and you are moving fast.  That and it's not an edge you'd present to a customer.
>>> 
>>> I've never gotten a good edge from a sabre saw.
>>> 
>>> 73
>>> 
>>> Roger (K8RI)
>>>> 
>>>> 73,  Colin  K7FM
>>> 
>>> 
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>> 
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> 
> -- 
> Vic, K2VCO
> Fresno CA
> http://www.qsl.net/k2vco/
> 
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