Where are you getting your chassis and enclosures/cabinets?

[n4joy]

I've been working on my 813 HF amplifier project and all has been quite well except for one major problem: I cannot find a decent cabinet.  I attempted to build a custom cabinet/chassis with aluminum angle bar and the result was... well... terrible.  Any good sources out there for large enclosures?  Hammond makes a large aluminum chassis, which would be perfect (17x15x4) but finding an enclosure is difficult.

Any thoughts?  I see all these very nice home brew amplifier builds online and there must be a secret source somewhere unless these guys are great metal workers!

Thanks!

Chris, N4JOY

[VE3ELQ]

Chris I had the same issue, I suck at metal work and hate every minute of it.  So I made my last one from wood. Bottom is 1/4 inch 5 ply re-in forced at the transformer location, sides and lid are 1/8 inch plywood with corners re-in forced with 1/2 square spruce stringers.  Front and rear panels are galvlanized sheet steel.  This is a FET amp so no high voltage and low heat to contend with compared to the tube stuff but it may work for you.  You could line the insides with thin aluminum or steel panels.  Just an idea.  Might catch fire.  Couple pics attached.

73s  Nigel

[John K5PRO]

There are some stateside companies that produce aluminum sheetmetal chassis as kits, you specify the front panel size, the depth, height, finish, etc. My info is at work, but we have built hundreds of chassis that look professional this way. We usually have the front panel CNC cut and have recently gone to using plastic sheet overlays (adhesive backed) that can be designed online and ordered and shipped in days, for the logos, labeling, etc.

Looking online, I found one in Arizona that is not bad looking:
https://www.circuitspecialists.com/rackmount-enclosures

You could build your amplifier up on an aluminum sheet or typical bud chassis inside, and bolt that into a rack width enclosure like this.

[Pete, WA2CWA]

Another source:
http://www.budind.com/cabinets.php

[SA2CLC]

I get them from the sheet metal brake at work, but then, I enjoy working with metal. Should maybe convince the boss the need of a pan brake

[n4joy]

Thank you, everyone.  Sheet metal work has been the least favorite part of this project.  I could have had the amplifier completed a week ago if not for this obstacle.  I did contemplate wood as a last resort.  Nigel, you build with wood looks wonderful!

[KJ4OLL]

I found my amp cabinet at http://www.skycraftsurplus.com/



So check your local surplus places - this was an electrical cabinet, DIN rails, relays, etc.
I have seen some server cabinets that would work too, check scrap metal dealers.

Plan "B" is to get a press brake and make whatever you like. (best if there a sheet Aluminum source nearby)







73
Frank
KJ4OLL

[KL7OF]

local sheet metal shop...furnace guys??


good luck...
Steve

[n4joy]

The closest enclosure I can find on the Bud Industries website is their shadow cabinets.  A 17"x9.5"x11" cabinet runs a whopping $145 and I would still need to find a chassis.  Funny how the most complicated part of an amplifier build seems to be the darn enclosure! 

I could spend over a year searching various electronic surplus stores (none near me) for the right part and I never have good luck finding the gems everyone else seems to find.  Purchasing a bender for one project does not make sense to me and I'm simply not skilled at sheet metal work.

The Hammond 17"x15"x4" chassis seems to be the ideal size for my components (variable capacitors, tank, filament transformer, etc.) but it looks I'll have to scrap the project or put it on hold indefinitely.  I think it would have been far easier (and cheaper) to simply purchase a used amplifier on ePay.

[ka1tdq]

A guy heard me on the air talking about my linear amplifier project and offered me an awesome, custom made aluminum chassis that he had. It worked out perfect! I'm no good at metal work either.

This is probably no good to you, but sometimes parts "fall from heaven." If the universe wants it built, they will come.

Jon
KA1TDQ

[W4RFM]

I buy a lot of ham fest junk that is old test equipment, and use the sides, tops and other parts from these items. Using these with Hammond or Bud chassis, will get you there.  Middle Atlantic panels also.
You are correct, it is hard to get good parts without a second mortgage anymore. Old Hewlett tube era test gear has great cabinets, and a lot of good mid high voltage (600-800v) transformers, etc.

[WBear2GCR]

There are a number of construction techniques that can avoid most of the issues of bending metal.

you still need some skills, tools, like a drill press, clamps.

One method is the "flat plate".
In this scheme, you build (drill, make holes mount stuff) on a reasonably thick flat plate, mount on top, put your wiring
on the under side. You'll need an identical plate for the bottom of the chassis assembly.
You connect the bottom and top plates with either standoffs or threaded rod.
This way the height of the "chassis" can be anything you need.
For sides, you don't need anything structural.
Again, flat plates, angle iron (aluminum or iron depending on the other plates)
will do that trick.

Using the drill press, and a jig you can assure that all the holes are the same depth/distance
from edges. (for the angle pieces & the corresponding flat pieces)

Practice on a few small pieces to get the technique right.

That's a chassis. You want a front panel? that requires
some angle pieces along the front edge and to extend the side up higher past the
top deck. Same thing with making taller sides and back for a full enclosure.
although another method is to put the angle pieces on the outside. This is easier still
and requires less precision.

The older ARRL handbooks will show some of these techniques and all of the ARRL projects
were made on chassis built in-house.

PS. there is no need for having no gaps at all between plates, at edges, etc.
In fact for tube gear holes for air flow for cooling is a very good idea.

[WBear2GCR]

With care, a fine tooth carbide blade usually a backing of wood (for the cleanest cuts) aluminum can be
cut on a table saw, as can structural (angles, etc) pieces of aluminum.

In this area there are several metal suppliers that will sell you flat plate and other shapes cut to size, no
charge for the cuts.

[KB2WIG]

There were one or two articles in ER a few years back that dealt with metalwork and aspects of home construction. That being said, have a lot of time, and going slow works. And, like cutting meat, a sharp tool helps.

klc

[W9ZSL]

Don't forget to wear goggles to keep flying fragments out of your eyes.

[WBear2GCR]

Another method/strategy, and one that I intend to use shortly, is to "re-purpose" open frame relay racks. These days they are known as "server racks" , although server racks also include enclosed rack cabinets of the 6-7ft tall variety.

I plan on using this technique to make "stand alone" enclosures for radios like r-390s and SP-600s.

This is known as "Bear's cabinet method".

The idea here is to take one of these racks and chop the rails into appropriately high/tall sections. Now you have 2 or 4 posts (for an enclosure, you want 4) that are very solid, pre-drilled and threaded for standard rack panels. What you need to do is to connect them, and drop a top and bottom plate. They can be held together in the front and back merely by running cross pieces, which can double as cosmetic "dressing". You could pull off a "deco" look or a "modern" look pretty simply with the use of the right metal shapes...

If you flip the rails - usually they are not boxes, but like this:  ] <----19"----> [  the channels facing out, so that they are now [                  ]  there is now outside nice flat surfaces to drill and put side panels on.

For the bottom and top, you can use the front top and bottom for that by a variety of means, including making that out of angle (you'd need to notch the ends) or a flat bar stock for the front, and make a lip out of angle for the back side to hold the top plate.

Since the rails are also tapped on both faces, you can use what is now 2 inner facing rows of tapped holes to do a variety of things, including holding the front and back together, or  adding angle stock to mount the side panels, etc, etc.

Most of these are heavy steel channel, newer ones, including the ones I have up for "1$" in the For Sale section are made of bent sheet metal into a deep rectangular cross section... these are somewhat lighter in weight, but still plenty strong and good.

If you can fall into some aluminum ones, then that's fairly lightweight compared to the steel.

There are a LOT of "don't wanter" racks out there - they get dumpstered when many businesses upgrade or move, close, etc. Many colleges and universities put them in dumpsters from time to time. And of course they are sold.

The other possibility is to just cut down an existing rack, in which case you'd just need to replace the bottom.

Also, "telco" racks are/were 24" width. Less desirable for most. But again the rails are the same, and the width is determined only by some bolts and the cross pieces. So they'll make good raw material.

Both of the methods I suggested require about the absolute minimum of metal skills to get a reasonable result.

Otherwise, you'll need to find the right thing at a hamfest or otherwise nearby, or else pay for it used or new, plus shipping...

Hope this gives some good ideas to work with?

                       _-_-

Perf metal makes good looking side panels...

[W4RFM]

By the way, the company that I work for is a Middle Atlantic and Raxxess dealer, if you guys needs some threaded rack rail, etc, I will talk to you off forum.  We get a BIG discount off their stuff. (If this is inappropriate, please feel free to remove it, I dont mean to run a commercial).

[Opcom]

I seldom buy because I have stacks of old junk gear around and try to use those chassis. I do not mind if the chassis has extra holes. If it is an issue a thin sheet of aluminum will cover it. Do not overlook the too-small chassis  sort of old junk gear at fests as you can gain a front panel and of course several chassis can be bolted together, and possibly you may want some partitions. An otherwise unsuitable front panel can also serve as a strengthening item.

http://www.icamanufacturing.com/store/c/2-AC-Cabinets.aspx

a variety of desktop-type enclosures and various chassis.

[Opcom]

I look at that and keep seeing a horned cattle skull at the roof peak where the lights are.

[WBear2GCR]

<snip>

http://www.icamanufacturing.com/store/c/2-AC-Cabinets.aspx

a variety of desktop-type enclosures and various chassis.

This place was unknown to me. They seem to have some odd and interesting stuff...

Wonder what else they make, that they have these parts hanging around??

[KD6VXI]

ICA came about when Ten Tec stopped making cases.   Up until they stopped,  Ten Tec was THE go to place most CB amp mfg bought from.   Once their chassis went away,  ICA stepped in.  They sell pretty much anything RF parts,  high power.

There is also Matt in NYC.   He sells prepunched chassis for I believe 3cx3000 size to sk300 size holes.  He has two holer 15000 chassis available.   I believe you can order unpunished chassis from him.  I don't remember his exact username on eBay,  but it is similar to matt2knyc.   He's the biggest Bird reseller on eBay,  sells pep kits,  and everything Bird makes.   His logo is his AC powered vehicle.

I know there are others,  but memory escapes me for some.   

Beware of a lot of the "19 inch rack cases' found on eBay.   Most are very flimsy thin steel.   Some have the front panel in quarter inch aluminum,  but the rest is still very narrow gauge steel.   Not going to support 10 pounds,  I found.

--Shane
KD6VXI

[KC4VWU]

Angle grinder fitted with a cut off blade, framing square, and a bench grinder. Oh, and the little 30" bench mounted brake comes in handy for making smaller chassis, brackets, and such.

No hacksaws or jigsaws, hacksaws are for hacking something apart and jigsaws dance a jig all over your work. Totally useless for working metal.

For pre used chassis and rack panels, JB weld and overlays work out very nice.

All it takes is a little patience and some creativity.

...Phil

[KD6VXI]

Jigsaws can be used,  but if not used properly,  they do tend to dance a jig lol.

Sandwich your work between two boards.   Then cut.   No burrs,  etc.

Then,  go back with a grinding  wheel on the Dremel.  Almost as good as my hydraulic chassis punch or the knockout by Greenlee.

Don't use a wood sammich,  it looks like tha CA CA.

--Shane
KD6VXI

[John K5PRO]

AHA! I finally found the source we used at work. It used to be Precision Metal Fabricators, but when I googled that, I got a bunch of auto customizers with that name. Its Proline Metal Fabricators of Fremont, CA. Check this out.

http://www.gotopmf.com/products_chassis.html#assemblies

[N4RMT]

Glad this topic came up.  I've been looking for a while now for something to house an amp project in.