Gold

Metalwork by Hand
« on: January 09, 2019, 11:26:46 AM »
The title of this section of the board says CAD/CAM. This is about metalworking by hand.

Shortly after I started building stuff I realized metalworking skills would be required to be able to finish builds. I think that’s a surprise to a lot of new builders.

I’m  a computer idiot so dealing with CAD/CAM is not something that comes easily to me. I had to figure out a way to do what I needed done with non automated tools.

It took a lot of experimentation and mistakes but after a bunch of years I have gained some proficiency. I can drill a straight round hole with a hand drill. I can do a layout by hand and have it come out pretty well.

I think these skills are going to pay off. One downside to all this automated manufacturing is that hand metalworking is rare. Audio techs used to have to be able to do some metalwork because there was not much of a choice. Now not so much.

I’ve been asked to look a a couple of jobs that “no one else will do”. I think the reason is that there is a bunch of metalwork involved. Electrically they are simple.  I think this hand metalwork might end up making me some money.



ruffrecords

Re: Metalwork by Hand
« Reply #1 on: January 09, 2019, 11:55:37 AM »
I am mechanically challenged as anyone who has read my blog will know. But I need lots of mechanics in order to build a tube mixer. Over the years I have slowly come to grips with this by:

1. Simplifying the mechanics
2. Learning and using a 2D CAD tool for drawing
3. Finding cost effective sources of custom mechanical components like front panels, mixer frames and enclosures.

I try not to do any mechanics at all other than assembly. I cannot drill a neat round hole or file or cut in a straight line. Any anyway, at 68 my joints are getting stiff and my muscles are nowhere new as strong as they used to be..

I guess it is just a question of what works for you.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

JohnRoberts

Re: Metalwork by Hand
« Reply #2 on: January 09, 2019, 12:02:04 PM »
When I was a punk kid in HS I held summer jobs two summers in a row working in a machine shop (junior and senior years). Technically I was illegal since by law you needed to be 18YO to work on heavy metal shop machinery, but nobody asked and nobody told. I started out doing bottom of the food chain crap jobs in the machine shop, but worked my way up to lathe and milling machine projects.

For my senior year in HS I signed up for metal shop class, mainly to get access to the school's machine shop to do my own projects. I had a bit of drama with the shop teacher when he wanted us to cut and smooth a small rectangular piece of metal by hand, while we had belt sanders etc sitting idle nearby.

We ultimately had a meeting of the minds after I convinced him of my experience and bonafides using real metal shop machinery.  This experience has served me well over the decades. My older brother actually had his own Bridgeport milling machine in his basement, but ultimately got tired of the expense to move heavy machinery like that around the country. 

JR

PS: Knowing how to do it, doesn't mean doing it yourself every time, especially for production quantities.
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

Gold

Re: Metalwork by Hand
« Reply #3 on: January 09, 2019, 12:04:04 PM »
When building from scratch you can figure out whatever works for you. The jobs I’ve been asked to look at are modifying existing equipment. There is no way to put the equipment in a machining center and press go.

I am a lathe dude and deal with old stuff all the time. Just last night a friend brought over a mounting plate for something that needed two 3mm holes to be 4mm holes.

JohnRoberts

Re: Metalwork by Hand
« Reply #4 on: January 09, 2019, 12:09:00 PM »
When building from scratch you can figure out whatever works for you. The jobs I’ve been asked to look at are modifying existing equipment. There is no way to put the equipment in a machining center and press go.

I am a lathe dude and deal with old stuff all the time. Just last night a friend brought over a mounting plate for something that needed two 3mm holes to be 4mm holes.
If you are a lathe dude, you'd love the machine shop I worked at.. That had a bunch of surplus WWII lathes used to turn naval gun barrels. At least one of these lathes had 15'-20' long bed.

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

Gold

Re: Metalwork by Hand
« Reply #5 on: January 09, 2019, 12:36:56 PM »
I meant a record cutting lathe. I've never used a metal lathe.

12afael

Re: Metalwork by Hand
« Reply #6 on: January 09, 2019, 01:52:32 PM »
Quote
I meant a record cutting lathe. I've never used a metal lathe.

I could send you one of my albums so you can cut some metal in your lathe. ImI



sorry for the bad joke...
heavy metal is the law!!!

JohnRoberts

Re: Metalwork by Hand
« Reply #7 on: January 09, 2019, 02:21:56 PM »
I could send you one of my albums so you can cut some metal in your lathe. ImI



sorry for the bad joke...
I have some old lacquer masters that are actually metal discs... My dad was a recording engineer (RCA) so he would cut one off lacquers of stuff like TV show music for us kids to play at home... they also made killer frisbees long before frisbees were invented.

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

tony hunt

Re: Metalwork by Hand
« Reply #8 on: January 09, 2019, 02:42:32 PM »
I like folding but cutting gives me the willies. One slip and no more Telecaster.

john12ax7

Re: Metalwork by Hand
« Reply #9 on: January 09, 2019, 04:48:02 PM »
There is definitely a market for it.  I've been looking for a guy in LA to pay to do one off prototype jobs.  They are hard to find.


Gold

Re: Metalwork by Hand
« Reply #10 on: January 09, 2019, 05:00:17 PM »
I like folding but cutting gives me the willies. One slip and no more Telecaster.

I just replaced the 14" abrasive cut off wheel in my chop saw with a 12" blade for soft metals. I'm getting really smooth straight cuts now. I feel like I won't kill myself with an angle grinder either. I am going to look for 3" and smaller carbide tipped circular blades for my Foredom rotary tool. I have some small HSS blades but they don't work very well on 20 gauge steel. The Par-Metal cases are 20 gauge steel. I'd like to be able to do clean cutouts in that.

EmRR

Re: Metalwork by Hand
« Reply #11 on: January 09, 2019, 05:41:48 PM »
DaveP really has this down.  I enjoy the metalwork I have to do. 
Best,

Doug Williams
Electromagnetic Radiation Recorders

"I think this can be better. Some kind of control that's intuitive, not complicated like a single knob" - Crusty

"Back when everything sounde

boji

Re: Metalwork by Hand
« Reply #12 on: January 10, 2019, 01:57:01 AM »
For what it's worth, in case anyone has not tried hand-routing 1/6" aluminum sheet metal, let me say it is totally doable.
 
Using some 1/8" HDF (hardboard), I routed out some rather large templates for the sides of my console. When I was happy with the angles, I sandwiched some scrap HDF between the template and plate aluminum, clamped it down good and cut out a 'master template', then repeated the process using the metal template to cut out the sides of the buckets.

All that's needed is a 3-blade (RPM's too slow for 2-blade- I tried) carbide laminate bit with ball-bearing pilot, and a little 1/4hp hand-sized laminate router.  Once you get the feed tempo right, (It will kick back hard at first, and quickly educate you) it will mill out like butter.   Cutting 1/6" soft metal with a bit that was made to cut very thin wood laminate means you'll eat through the bit after about 40 feet. However at $14 a bit, it's well worth the price if you have a single project but want to make clones of large plate geometries without using a computer or milling machine.

Edit: I should mention it's important to pre-trim the metal with an angle grinder or pneumatic cutoff wheel so that when you route, you're shaving down the aluminum near the template edge in 1-3 centimeter passes until it's flush; you don't want so much edge material overhanging that the cut surrounds the laminate bit- that will cause trouble.

Sadly I lost the pictures of the initial cuts, but I may be adding another bucket, in which case I'll be sure to document the routing.

-Cheers,
Boji
« Last Edit: January 10, 2019, 02:59:00 AM by boji »

JohnRoberts

Re: Metalwork by Hand
« Reply #13 on: January 10, 2019, 10:37:27 AM »
For what it's worth, in case anyone has not tried hand-routing 1/6" aluminum sheet metal, let me say it is totally doable.
 
Using some 1/8" HDF (hardboard), I routed out some rather large templates for the sides of my console. When I was happy with the angles, I sandwiched some scrap HDF between the template and plate aluminum, clamped it down good and cut out a 'master template', then repeated the process using the metal template to cut out the sides of the buckets.

All that's needed is a 3-blade (RPM's too slow for 2-blade- I tried) carbide laminate bit with ball-bearing pilot, and a little 1/4hp hand-sized laminate router.  Once you get the feed tempo right, (It will kick back hard at first, and quickly educate you) it will mill out like butter.   Cutting 1/6" soft metal with a bit that was made to cut very thin wood laminate means you'll eat through the bit after about 40 feet. However at $14 a bit, it's well worth the price if you have a single project but want to make clones of large plate geometries without using a computer or milling machine.

Edit: I should mention it's important to pre-trim the metal with an angle grinder or pneumatic cutoff wheel so that when you route, you're shaving down the aluminum near the template edge in 1-3 centimeter passes until it's flush; you don't want so much edge material overhanging that the cut surrounds the laminate bit- that will cause trouble.

Sadly I lost the pictures of the initial cuts, but I may be adding another bucket, in which case I'll be sure to document the routing.

-Cheers,
Boji
Milling soft metal can be challenging if fed too fast. I recall one job back in the 60's when I had to mill a part out of brass... I had to use an ancient milling machine affectionately called the "growler" because of the tired old gears. I was warned before I started about one guy who set the feed speed to fast and sent a broken end mill flying across the room to punch a hole in the cinder block wall.   :o Since the growler was sitting right in front of the bosses lathe, I was on my good behavior and no end mills were sacrificed that day. 

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

Gold

Re: Metalwork by Hand
« Reply #14 on: January 10, 2019, 11:21:01 AM »
Quote from: boji link=topic=70990.msg904762#msg904762 date=1 547103421
For what it's worth, in case anyone has not tried hand-routing 1/6" aluminum sheet metal, let me say it is totally doable.


The next tool I want to tackle is a router. I know I’m going to have to make jigs and templates to make it work. I want to be able to chamfer faceplate edges and do some cutouts. I need a stand to use the chop saw on. I think I’ll make is a router table as well.

Now I can make clean cuts in T slot framing. I was ordering everything pre cut but now I can keep stock on hand and cut as needed.

rackmonkey

Re: Metalwork by Hand
« Reply #15 on: January 10, 2019, 11:49:03 AM »
I built mid-century furniture and metal sculpture in my spare time (where did that go?!) prior to catching the music electronics DIY virus. Mid century furniture building involved a fair amount of metalwork (mostly brass) and I built up a nice shop and machining/fabricating skills, which led to doing some sculpture. Metalwork is one of my favorite parts of pro audio DIY, and I take a lot of pride in it.

A related side skill that I find few people try on their own is powder coating. Unless you want all your metal to be naked, it’s pretty essential. It’s easier and cheaper to get into than you might think. I bought a spraying system on Grizzly.com (awesome for that kind of stuff) for $29. It has been a little workhorse.

I get my coatings from Prismatic Powders (prismaticpowders.com). They have a huge variety and it’s not that expensive ($9 - 13/lb, typically). I’ve gotten vintage looking RCA tan, Collins blue-gray, Gates drab, UA dark olive, Telefunken ivory/blue and Altec green analogues from them.

If you want to do your own mic bodies and faceplates for smaller units like 500-series, you can do it in a toaster oven. I got a large one in good shape on Craigslist for about $25.  It’s so large that I can even put a 19 inch rack faceplate in it diagonally.

If you can’t find a toaster oven big enough for 19” rack faceplates, you need a real oven. In my case, the local Makerspace here in Dallas has one (such an awesome resource). But i’ve looked into getting my own on Craigslist and you could get into one for less than $50 if you keep an eye out.

Sorry if this drives off in the ditch. Seemed related enough to share to me.
« Last Edit: January 10, 2019, 11:57:45 AM by rackmonkey »
Whether you think you can or you think you can't, you're probably right.

Gold

Re: Metalwork by Hand
« Reply #16 on: January 10, 2019, 12:03:37 PM »
I bought a powder coat setup from Eastwood many years ago.  When the powder coat cures it stinks, a lot. I have no place I can cure the powder coat unless I get a spray booth. That’s not in the cards. I have no outdoor space or garage.

I’ve figured out a nice method for brushing aluminum. That’s looking good now.

ruffrecords

Re: Metalwork by Hand
« Reply #17 on: January 10, 2019, 02:42:36 PM »
Milling soft metal can be challenging if fed too fast. I recall one job back in the 60's when I had to mill a part out of brass... I had to use an ancient milling machine affectionately called the "growler" because of the tired old gears. I was warned before I started about one guy who set the feed speed to fast and sent a broken end mill flying across the room to punch a hole in the cinder block wall.   :o Since the growler was sitting right in front of the bosses lathe, I was on my good behavior and no end mills were sacrificed that day. 

JR

The other classic apprentice foul up was to leave the spanner attached to the top of the mill after tightening up a new bit. Boy do they fly.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

EmRR

Re: Metalwork by Hand
« Reply #18 on: January 10, 2019, 04:47:27 PM »
I had fun using a 2 inch hole saw on a drill press to cut UTC LS transformer mounting holes in aluminum boxes.  Some thrills to be had there. 
Best,

Doug Williams
Electromagnetic Radiation Recorders

"I think this can be better. Some kind of control that's intuitive, not complicated like a single knob" - Crusty

"Back when everything sounde

rackmonkey

Re: Metalwork by Hand
« Reply #19 on: January 10, 2019, 06:16:06 PM »
I had fun using a 2 inch hole saw on a drill press to cut UTC LS transformer mounting holes in aluminum boxes.  Some thrills to be had there.

Too funny! The thrill is at maximum when the saw bites into the metal and the whole box starts spinning at 700 RPM.  A Bond villain couldn’t cook something scarier up!
Whether you think you can or you think you can't, you're probably right.


 

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