What is the most difficult part of 'scratch' building for you?

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KMossman said:
I DO appreciate the "blue-print" but saying "how easy" makes me balk. For me Math is easy...............yet others recoil at the mere mention.

To do a 'proper' job, one [I would think] would need an excellent cutting tool [certainly not a hack-saw!], bending tool[I shudder at the thought of doing it by hand], files for removing blurs and rough edges, and the right material !

Not forgetting that getting all the parts to fit 'exactly' can be frustrating.

Then drilling the holes [aligned!!] to keep the thing together.

Then de-grease, and finish.

Excuseme please. I apologise for my expression if they hurt you.
In my country you can buy the metal sheets already cut to size for a small amount of money... and it's cheaper if you are lucky enough to find your metal sheets among scrap pieces :usd: . The bending is a little more expensive, but you pay for each kilogram of metal, so it isn't "so" expensive. Even you can fold your sheets by hand using a hammer, a vice and a couple of pieces of wood.. and this is why I said "how easy", because you don't need special machinery to do that simple bends (just 90º).

You can take for sure that the drilling task is a complicated one, mainly because aligment, but I usually draw by hand a template for drilling on a sheet of paper and then apply it using masking tape in order to pin point the holes. An electric drill is necesary, but not a very sofisticated one and a drill press is better :D but not at all necesary if you have enough patience. You also need some tools not at all expensive, but they are the same you can use to do repair tasks at home, so the investment is no so hard...

I'm talking from my own experience, but I'm sure you can find your own method if you have the time to look for it. Otherwise, you can always buy a chassis and apply DIY in another areas of your project. ;)
 
I find working around DIP or SMD parts the hardest thing. I can't do PCB's, all the software is for computers more modern than mine, using an operating system that requires biannual updates at $300 a pop, and I can't keep a printer cartridge from drying up, anyway. So I make CB's on CE laminate that I drill myself. I prefer the 1/8" laminate but a lot of components don't have leads long enough for that. 1/16" CE laminate is not strong enough, and glass laminate is too hard to drill and a breathing hazard. DIP components, the solder tends to bridge across two pins on CE laminate or lexan. I bought some DIP project boards from mcmelectronics, but the leaded part area around the edge doesn't have enough room for the discrete parts I prefer, so many projects end up with a dip project board screwed to a homemade board. Ends up with weird arrangements like 20 V logic spread between two boards, and 120 vAC on both boards too, with the triac and transformer on one and the optoisolator 120 VAC trigger on the other with the other DIPS.
The case is no problem, I have a large collection of old factory motor drives and control panels, surplus. They don't look good, but hey, NEMA 12 is drip resistant! Drilling large round or square holes, I use the many small holes method, then connect the dots with a carbide hacksaw. Then smooth with a hand grinder- tree head or cylindrical burr. Having a dirty shop in the garage with a vise is nice. I did break down and spend the $40 for a .875" greenlee chassis punch for tube sockets, only it turned out to be actually .895" !@#$#$%#%^
I have plenty of heat sinks on the motor drives, but drilling 4 holes for TO3 packages on the flat inside without hitting the fin outside is also difficult. Almost worth ordering TO3-p output transistors, even though the ones I already bought turned out to be Vceo rejects. They were honest, Vceo=40 and they mean it, too.
Screen for tube covers is a bit iffy, it has to be bent. I used to have a 56 Ford truck frame on tires I could clamp metal to and bend sheet with two hammers, but the city made me scrap it. I've got a 4' 8"x8" square steel section, but the corners are too round to make good bends and I havene't bothered to put it up on legs, so depth is limited also. I had access to a Jet press brake at work, it was useless. Specified strong enough for 16 ga brass, you know how expensive brass sheet is? The scrap aluminum I could find would break up in bends, the wrong alloy probably. Anyway, don't buy Jet anything sheet metal tools; the company had a Jet lathe that wouldn't turn plastic without stalling and a Jet shear that was good only for plastic sheet like ceiling tiles.
 
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Excuse me please. I apologise ......

1) In my country ............


2) Even you can fold your sheets by hand using a hammer, a vice and a couple of pieces of wood..

3) You can take for sure that the drilling task is a complicated one, mainly because alignment, but I usually draw by hand a template for drilling on a sheet of paper and then apply it using masking tape in order to pin point the holes

NO NEED to apologize whatsoever! I am a big boy!

We ALL have different views and different experiences and different resources available. That is one reason I started this thread - to see what and how and why the challenges we experience.

1) I am in China now. It's just easier and faster and cheaper to buy a cabinet. There is a very good selection available. One used to be able to do that [have a machine shop cut & fold] in my hometown in Canada, but many of those shops are now closed or remote.

2) pleeeeeeeeeeeeeeeeease! no, no!, No!, NO! unless the metal is thin and pliable it looks like heck, and it is nearly impossible to get the dimensions right - in my experience

3) yep! Though I have found that using masking tape over the pending hole, helps to keep the drill bit from skipping AND if it does skip, then reduces the marring.
 
1) I find working around DIP or SMD parts the hardest thing.

2) I can't do PCB's,

3) glass laminate is too hard to drill and a breathing hazard.

4) Ends up with weird arrangements like 20 V logic spread between two boards, and 120 vAC on both boards too, with the triac and transformer on one and the optoisolator 120 VAC trigger on the other with the other DIPS.


5) The scrap aluminum I could find would break up in bends, the wrong alloy probably.

1) I have not done any SMD!

2) why?

3) I worry about soldering! the fumes from the soldering and charring plastic.

4) ECKS!

5) wrong alloy perhaps. You could try heating it first - tricky to do, though!
 
FWIW I started making amps a LONG time ago (1969) , still living from that (44 years later, non stop).
Started with Tubes, of course.
After the first couple small amps built on bought iron chassis, I got to *hate* that material.
My first Fender Bassman clone was built on a U shaped piece of 1.5mm aluminum, with ends filled and reinforced with "hard wood" rectangles, which also allowed mounting inside the typical Tolex covered MI type cabinet.
All round holes drilled, tube sockets and fuse holder punched with Greenlee type bolt-in punches.

But .... how did I cut and bend the chassis?
Only one practical way: I located *somebody* who had the necessary machines for their own use, and begged .
There's tons of such people: those who make tin stuff such as air conditioning ducts or *some* car/truck body shops or those who make "white appliances" (washing machines, stoves) or those who make , say, pizza ovens, etc.
I grew in an agricultural town in the middle of the Argentine Pampas (imagine a small town in the middle of the Corn Belt).
As far as possible from Industry you say?
Well, there was this guy who custom made galvanized sheet metal "food holders" for chicken farms, drinking vats for pigs and cows, repaired windmills, etc. who had shears and folders.
Not heavy duty by any means, but "aluminum is easy".
Usually they even didn't charge me but the "16 y.o. nerd kid" was always welcome, because I always left on a workbench a grocery bag with a couple "long necks" (fine wine bottles) or a sixpack or something.
Then I upgraded (when living in Buenos Aires which is a 14 Million people city, surrounded by Industry towns) finding proper metallurgical shops.
I was already into small scale production.
I usually bought 1 x 2 meters x 2mm thick Aluminum sheet, best quality (Kaiser or Alcoa brand) , and had it cut into proper size strips with edges bent, paying between 20% to 30% of the raw sheet cost, a bargain.
1 such sheet gave me 10 "U" shaped chassis, 50 cm wide, 10 cm high and 20 cm deep, for peanuts.
Here's one 1972 example, a then very advanced 200W RMS PA amplifier (standard in that era was a bulky, heavy and expensive 100W 4x6L6 amp):
729090782_cf3fb0f620_z.jpg

Notice all holes are round drill made, except the fuse holder ;) , and well within the DIY builder capabilities.
I later made *tons* of amplifiers, standardizing on only 2 (two) hole sizes: 10 mm for 3/8" jacks/pots/neon pilot lamps/switches and 4 mm for everything else, from 1/8" screws or #6 Parker type ones, 4 mm nylon bushes for the TO3 transistors, etc.
So even a quite good looking small batch product can be DIY made, if you simplify design.
The cherry on the cake was learning how to silkscreen, of course.
 
Well, considering I make my own PCBs, transformers, chassis, cabinets, speakers, voice coils, silkscreening, and even own corner caps, strip handles, rubber feet, aluminum horns, reverb tanks, and have half finished die sets for injecting chickenhead knobs and horn drivers, I'd say, no. :)
But it took 44 years to get to that .
Rather than "DIY" I'd label it "in house made".
Conceptually the same as Behringer ! :p:p:p
Although in a "slightly" smaller scale :(
 
Not exactly, but almost :eek:
In my home town in the 70's and 80's there was this Nisei (second generation Japanese) guy who after the usual couple years visiting Japan in his 20's and working there in some Factory (it's a sort of modern "coming of age" Ritual for them), he brought back the license, machinery and stuff for making Panasonic caps ... under his own brand, of course:
CONELSA (Condensadores Electrolíticos Sociedad Anónima = Electrolytic Capacitors Inc.)
Being a Nerd I visited his factory, which was not a NASA type thing by any means.
Basically they had huge man sized cardboard drums with the treated alumimum foil, graded by insulation and "uF per square meter", 200 liter tanks of electrolyte, all sizes of empty cans, even the light blue heat shrink sleeve preprinted "Conelsa", plus rolling machines, what was needed to seal the end caps, etc.
Basic process was to set the machines to cut and roll the strips of treated aluminum with some kind of very porous paper between them, attach terminals, stuff it in the proper can with some drops of electrolyte and seal it.
And yes, he could make small batches of custom, weird value capacitors for me, which was great for Tube amps.
Not because I was any kind of Industry heavyweight, of course, but because my Father was a very respected Country Doctor, who had delivered all of his kids and probably earlier had delivered himself.
Talk about being in the right place at the right moment ;)
The light blue electrolytic is a CONELSA.
All other stuff was made in Argentina before "Globalization", such as Philips tubes and transistors, Mallory capacitors, Texas Instruments transistors and ICs, etc.
http://www.dtforum.net/index.php?action=dlattach;topic=11040.0;attach=268583944;image
 
2) pleeeeeeeeeeeeeeeeease! no, no!, No!, NO! unless the metal is thin and pliable it looks like heck, and it is nearly impossible to get the dimensions right - in my experience
Even though I always try to use a bending machine, I've made a couple of cabinets folding them in a very primitive way :)smash: ) and if you are a bit careful, it doesn't look that bad after you have filed and painted the surfaces.

A lot of years ago, there was a couple of factories devoted to make and sell cabinets in Argentina, but in the late 90's they get closed or changed their product line. Now, it's almost impossible to buy a ready made cabinet or they are VERY expensive. Perhaps it would be possible for us to buy them abroad, but our money exchange and taxes aren't "good at all", so....welcome DIY!! ;)
 
This one bends up to 18Ga steel, which means it's usable with 1.5mm aluminum , for all of U$99.99 .
Compare that to chassis prices and you'll see you can recover cost in a couple chassis.
You'll still need to buy aluminum cut to size, but that's much easier to source:
18 GA, 30" Metal Brake

Thos is my Car Body workshop V-notch type bender:
Original width: 40cm (16")
Not bad, but then I had a custom set of tools made 60 cm wide (24") for 2x12" "Twin type" Guitar combo amps.
731065720_2f391dcb1d_z.jpg


This is the aluminum and PCB copperclad shear, straight from a failed Tin Shop:
730961732_166e010198_z.jpg


These are the front panels being bent in the first picture, already painted, silkscreened, perforated and populated:
730546838_5368176040_z.jpg
 
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