GroupDIY

General Discussions => Machine Shop => Topic started by: Gold on January 09, 2019, 11:26:46 AM

Title: Metalwork by Hand
Post by: Gold 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.

Title: Re: Metalwork by Hand
Post by: ruffrecords 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
Title: Re: Metalwork by Hand
Post by: JohnRoberts 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.
Title: Re: Metalwork by Hand
Post by: Gold 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.
Title: Re: Metalwork by Hand
Post by: JohnRoberts 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
Title: Re: Metalwork by Hand
Post by: Gold on January 09, 2019, 12:36:56 PM
I meant a record cutting lathe. I've never used a metal lathe.
Title: Re: Metalwork by Hand
Post by: 12afael 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...
Title: Re: Metalwork by Hand
Post by: JohnRoberts 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
Title: Re: Metalwork by Hand
Post by: tony hunt on January 09, 2019, 02:42:32 PM
I like folding but cutting gives me the willies. One slip and no more Telecaster.
Title: Re: Metalwork by Hand
Post by: john12ax7 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.
Title: Re: Metalwork by Hand
Post by: Gold 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.
Title: Re: Metalwork by Hand
Post by: EmRR on January 09, 2019, 05:41:48 PM
DaveP really has this down.  I enjoy the metalwork I have to do. 
Title: Re: Metalwork by Hand
Post by: boji 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
Title: Re: Metalwork by Hand
Post by: JohnRoberts 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
Title: Re: Metalwork by Hand
Post by: Gold 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.
Title: Re: Metalwork by Hand
Post by: rackmonkey 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.
Title: Re: Metalwork by Hand
Post by: Gold 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.
Title: Re: Metalwork by Hand
Post by: ruffrecords 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
Title: Re: Metalwork by Hand
Post by: EmRR 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. 
Title: Re: Metalwork by Hand
Post by: rackmonkey 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!
Title: Re: Metalwork by Hand
Post by: abbey road d enfer on January 10, 2019, 06:21:21 PM
I've been formally trained for woodwork and metal-work, both hand and machine, but I don't have any heavy machinery, no lathe, no mill. One thing that has made this easier is mastering a CAD package, namely Autocad, but now I use Drafsight, that is just about the same, but free for non-commercial use, instead of about $3K for a basic version.
I print the drawing on paper (indeed you need to calibrate the printer) that I glue to the piece of metal I need to cut/drill/file.
A recent addition to my tool cabinet is an oscillating tool; it takes a little while to get the hang of it, but you can do things you wouldn't think possible.
Title: Re: Metalwork by Hand
Post by: Gold on January 10, 2019, 06:52:57 PM
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!


I don’t like my drill press. I keep trying to make it something it’s not. It hasn’t worked.  It’s a 1/3HP. When I have room I’m getting one that is at least 1.5HP.

I use hand drills for anything 1/4” thick or less. I do hole saw meter cutouts with a hand drill. I did buy two Fein hand drills. They are good for metalwork because they are geared for low RPM and they have a lot of torque. They were expensive but a buy once buy right kind of purchase .

 I have a lot of money into a large assortment of C clamps.  Getting the workpiece hold down right makes all the difference. If there is any movement you’re screwed

Tool skills count for this. You have to keep the drill from bucking but not hold it so tight that if it binds you can’t let go.

Fein invented the hand drill. They also invented the oscillating tool. I’ve never used one but I’d like to try one out.
Title: Re: Metalwork by Hand
Post by: boji on January 10, 2019, 07:18:49 PM
Quote
A related side skill that I find few people try on their own is powder coating

Hope you don't mind the side talk about powder coating, Gold.

I was intimidated by the prospect but turns out it's fun and easy. I learned the hard way that prep of the metal is key to a lasting finish.  Somehow I got brake oil on one piece I was working on and no amount of acetone and scrubbing would allow a good cure adhesion afterwards.   
I did the toaster oven thing until I had larger work, so I bought old kitchen oven off of craigslist and stuck it in the basement. Added an exhaust fan. Works a treat.  And you're right their are so many colors! I took a risk going with a flipflop color for my main project. Green from one angle, brown from another. 

Also anodizing looks to be much easier than I thought, now that we have all the youtube experimentation vlogs.  Not sure If someone here posted this guy before, but I really dig his shop. He expanded his diy interest nicely:
https://www.youtube.com/watch?v=wDA6EEo6dQA (https://www.youtube.com/watch?v=wDA6EEo6dQA)
Title: Re: Metalwork by Hand
Post by: rackmonkey on January 10, 2019, 07:55:01 PM
I bought an anodizing kit about 10 years ago and you’re right, it isn’t that hard once you learn the lesson about very clean, lightly sanded metal. But the chemicals are pretty caustic. If Gold is concerned about odors in his space, he’d definitely need an exhaust fan for that, too.
Title: Re: Metalwork by Hand
Post by: Gold on January 10, 2019, 10:08:38 PM
Hope you don't mind the side talk about powder coating,

Not at all.  The final faceplates for my console will be powder coated. I already have the RAL number picked out. I’m going to get a laser engraver and hand drill all the holes.
Title: Re: Metalwork by Hand
Post by: Gold on January 10, 2019, 10:55:05 PM
The method I use for drilling out faceplates uses aluminum square tubes. I place the faceplate on two 3” square aluminum tubes. One at each end of the faceplate. I have a third one that I move around under the faceplate for support. I use two C clamps to hold everything down.

I use Starrett combination squares and a scribe to mark everything. Then I center punch all the marks. Then I drill everything out. The 3” gap under the workpiece  helps make clean holes. I de burr with a countersink and a scraper. Cleanup is easy with a brush and a vacuum.
Title: Re: Metalwork by Hand
Post by: abbey road d enfer on January 11, 2019, 05:09:13 AM
The 3” gap under the workpiece  helps make clean holes. I de burr with a countersink and a scraper. Cleanup is easy with a brush and a vacuum.
I find it easier doing it the way I learnt at school, i.e. having the plate on a piece of wood (a "martyr") when drilling. The burr is even smaller.
Title: Re: Metalwork by Hand
Post by: JohnRoberts on January 11, 2019, 09:36:38 AM
That last (only) time I drilled a big hole in sheet metal was in the 1960s (something like 6" diameter)... IIRC I cut through several sheets of sheet metal at the same time with a fly cutter tool. The drill press was a serious big dog, as large as a milling machine with an automatic down feed for the drill chuck, and even pumped its own cutting fluid to lubricate/cool the drill or tool. It had a huge heavy bed with grooves to properly attach clamps to secure the metal (you don't want a big pice of sheet metal swinging around if the tool digs in.)

The bed right under the chuck was already chewed up by other workers drilling into it before me... I didn't screw that one up.  I also respected the sheet metal that could really tear you up, after seeing smaller pieces of metal grab and go rogue in normal sized drill presses.  I don't remember exactly, but I probably put a piece of scrap under the sheet metal to protect the machine, when cutting a hole that large.

JR
Title: Re: Metalwork by Hand
Post by: Gold on January 11, 2019, 10:13:09 AM
I find it easier doing it the way I learnt at school, i.e. having the plate on a piece of wood (a "martyr") when drilling. The burr is even smaller.

I don’t like that method for a few reasons. First you always need a sheet of wood. In a small room it’s one more thing to keep around. Second it generates more debris which needs to be cleaned up. Third it basically doesn’t work if you are using a step bit. You would need a 2” thick piece  wood and the step bit would go almost all the way through for an XLR sized hole. Lastly I think wood dulls  the bits faster than metal. I’m not sure that’s correct but I get that impression.
Title: Re: Metalwork by Hand
Post by: JohnRoberts on January 11, 2019, 10:28:55 AM
I don’t like that method for a few reasons. First you always need a sheet of wood. In a small room it’s one more thing to keep around. Second it generates more debris which needs to be cleaned up. Third it basically doesn’t work if you are using a step bit. You would need a 2” thick piece  wood and the step bit would go almost all the way through for an XLR sized hole. Lastly I think wood dulls  the bits faster than metal. I’m not sure that’s correct but I get that impression.
All but the last one sounds valid...

JR
Title: Re: Metalwork by Hand
Post by: abbey road d enfer on January 11, 2019, 01:52:58 PM
Third it basically doesn’t work if you are using a step bit. You would need a 2” thick piece  wood and the step bit would go almost all the way through for an XLR sized hole.
You only need a moderately thick piece of wood if you drill over a hollow. That's what happens when I use my column drill; the table has a hole about 1" in diameter. I typically use a piece of 3/4" plank. 

Quote
Lastly I think wood dulls  the bits faster than metal. I’m not sure that’s correct but I get that impression.
It's never been a serious issue so far. The piece of wood is drilled once and used many times.
Title: Re: Metalwork by Hand
Post by: Gold on January 11, 2019, 03:10:00 PM
That's what happens when I use my column drill; the table has a hole about 1" in diameter. I typically use a piece of 3/4" plank. 
 It's never been a serious issue so far. The piece of wood is drilled once and used many times.

I only use a drill press for material thicker than 1/4".  I am talking about using a hand held drill.  If you are using a hand drill on a workbench you would need either a thick piece of wood or to elevate the whole thing like I do with aluminum square tubes. After you've raised the workpiece There isn't much advantage to backing it with wood. It takes longer to clean up the saw dust than it does to de burr.

I find using a drill press to drill out panels an exercise  in frustration. Without center punching all the marks, your average inexpensive drill press will have the bit wander when lowered. No advantage in that regard, you still have to center punch everything. Since there is play in most inexpensive drill press columns you have to line the bit up to the center punch mark, then clamp the workpiece down. Then drill. Then unclamp, line the next hole up, clamp it down, then drill. It takes forever.

With the piece setup on a bench and using a hand drill, once you have made all the marks you just move the drill where it needs to go. It takes me about a quarter of the time it would take on a drill press with no loss of accuracy.
Title: Re: Metalwork by Hand
Post by: abbey road d enfer on January 11, 2019, 05:01:50 PM
I find using a drill press to drill out panels an exercise  in frustration. Without center punching all the marks, your average inexpensive drill press will have the bit wander when lowered. No advantage in that regard, you still have to center punch everything. Since there is play in most inexpensive drill press columns you have to line the bit up to the center punch mark, then clamp the workpiece down. Then drill. Then unclamp, line the next hole up, clamp it down, then drill. It takes forever.
That's because you don't use a drill vice.
Title: Re: Metalwork by Hand
Post by: Gold on January 11, 2019, 06:37:59 PM
That's because you don't use a drill vice.


I don’t understand how you would use a drill vice with a 19” faceplate. I’d assume you would want to keep the vice centered under the column with the hole you are drilling also centered under the column for stability. I guess you would have the faceplate sitting on a wood block. If you have it set up that way and drill a through hole you would hit the bottom plate of the vice with the bit if you went through the wood.  I know some drill vices are more like a frame. That would work but it seems like a awful lot to keep track of and arrange. You still have to clamp, unclamp, clamp,unclamp, unless you have a cross slide. Maybe I’m missing something.
Title: Re: Metalwork by Hand
Post by: pvision on January 11, 2019, 07:29:13 PM
DaveP really has this down.  I enjoy the metalwork I have to do.

I tried to emulate one of his chassis - not an embarrassing failure but not up to my standards

A sheet metal brake is the key, I think

Nick Froome
Title: Re: Metalwork by Hand
Post by: abbey road d enfer on January 12, 2019, 01:28:34 AM
I know some drill vices are more like a frame.
  That's how mine is.

[/quote] That would work but it seems like a awful lot to keep track of and arrange. You still have to clamp, unclamp, clamp,unclamp, unless you have a cross slide. Maybe I’m missing something.
[/quote] You don't need to clamp. The vice is not fixed to the table, it's free. Due to the added inertia, it never goes spinning. You just need a moderately firm hand.
Title: Re: Metalwork by Hand
Post by: madswitcher on January 12, 2019, 06:39:37 PM
  That's how mine is.

 That would work but it seems like a awful lot to keep track of and arrange. You still have to clamp, unclamp, clamp,unclamp, unless you have a cross slide. Maybe I’m missing something.
 You don't need to clamp. The vice is not fixed to the table, it's free. Due to the added inertia, it never goes spinning. You just need a moderately firm hand.

I agree with Abbey on this in that a good quality drill press is probably the most useful tool you can get if you are doing a lot of metalwork.
 
I have also been formally trained in metalwork and wood work and there is a technique called 'touch centring' whereby having centre punched the centre of an intended hole, on the drill press you bring the drill tip down gently and slowly to just touch the centre dot: the drill will then self-centre and you can then apply pressure to drill through.  It takes some practice so experiment, but it avoids having to clamp the metal sheet down.

I was also trained to use a sacrificial block of wood under the metal when drilling sheet metal as it absorbs vibrations and stops you drilling into the drill plate.

Don't forget that when you have your sheet centre-punched up, write the intended size of the hole near it with a marker - it save tears later when you drill the wrong size hole.

Another tip is to use small drills to start you hole and then work up in increments of 3 to 4 mm ending on a size that is 1 to 2 mm below the final size, then use the end size.  This will give you a clean  edge if the drill is sharp and prolong the life of your larger drill bits as it is the drill point that takes the most wear and smaller drills are cheaper.

When using a step drill, you can 'step-drill' out a block of wood first and then use that under the work piece.  Your next best friend is a de-buring tool to clean up the edges of you holes and a small grinding wheel to keep your drills sharp, although bulk buys of twist drill are so cheap nowadays that they are almost throw-aways.

One of my fonder memories of metal work is using Engineers Blue, which is a kind of blue dye mixed with alcohol.  The smell was intoxicating.  The idea is that you paint it on the metal and then use a scriber to mark out you work so that it gives a contrasting colour to work with.  You can also use it for showing the degree of fit of two fitting metal pieces.

Cheers

Mike
Title: Re: Metalwork by Hand
Post by: Gold on January 12, 2019, 07:35:50 PM
I have also been formally trained in metalwork and wood work and there is a technique called 'touch centring' whereby having centre punched the centre of an intended hole, on the drill press you bring the drill tip down gently and slowly to just touch the centre dot: the drill will then self-centre .

You have to do that even if you want to clamp the workpiece.  Lower the bit until it self centers in the centerpunch mark. Then clamp. When I don’t clamp the work down the holes aren’t as clean or as round. That may just be my radial arm drill press. It’s loosey goosey.  But without a radial arm drill press you can forget trying  to fit a bottom plate of a chassis.  I’ve given a lot of things a go.


Quote
Another tip is to use small drills to start you hole and then work up in increments of 3 to 4 mm ending on a size that is 1 to 2 mm below the final size, then use the end size. 

I decided when tooling up to go with imperial because the selection is greater here. I have #1-#50, A-Z and  1/32”-1/2” in 1/32” increments. I also have larger bits which the drill press I have doesn’t have enough torque to use.

Quote
One of my fonder memories of metal work is using Engineers Blue, which is a kind of blue dye mixed with alcohol.  The smell was intoxicating.  The idea is that you paint it on the metal and then use a scriber to mark out you work so that it gives a contrasting colour to work with.  You can also use it for showing the degree of fit of two fitting metal pieces.

I use engineers blue for panel layout. I’ve also used it to hand file parts to fit.
Title: Re: Metalwork by Hand
Post by: Brian Roth on January 12, 2019, 08:07:40 PM

I decided when tooling up to go with imperial because the selection is greater here. I have #1-#50, A-Z and  1/32”-1/2” in 1/32” increments. I also have larger bits which the drill press I have doesn’t have enough torque to use.


I REALLY need to buy  new drill bit sets for my occasional projects.  Curious about brands besides the "Super-Duper Master China Crap" stuff sold at the big box stores.  I've seen Bosch and Mitsubishi (IIRC) as more expensive options at Blowes, etc, but I'm curious what everyone else prefers these days.  Looking for a brand new number/alphabet set as well as fractionals.

Bri
Title: Re: Metalwork by Hand
Post by: Gold on January 12, 2019, 08:19:56 PM
I REALLY need to buy  new drill bit sets for my occasional projects.

I buy everything from McMaster-Carr. They have never sold me crap. When I know what brand I want and have loooked around for price McMaster was never more or much more.

MSC Industrial has a large selection with brand names listed.

I have no doubt that in a machine shop with a quality drill press using  it is better and faster than a hand drill. If you want to do a complete chassis in a drill press it needs to be radial arm drill press  to fit the dimensions. A radial arm drill press that is under say $1000 is not up to the task. I speak from experience. It is my experience that in a small multiuse space a hand drill is the better option.
Title: Re: Metalwork by Hand
Post by: Brian Roth on January 12, 2019, 08:45:33 PM
Price is not my criteria at this point in life....a quality brand is.  Just looking for what brand is good these days before I buy.

Thanks!

Bri
Title: Re: Metalwork by Hand
Post by: Gold on January 12, 2019, 09:30:15 PM
McMaster doesn’t usually list brand. You just pick type. Carbide, HSS coated or noncoated.  I never recognize the stamp or brand name of bits. They are always long lasting. I buy uncoated HSS short length bits mostly.

MSC lists brands. It’s machinist supply. You can’t buy Harbor Freight stuff there. It’s all good quality. Usually a small American manufacturer.
Title: Re: Metalwork by Hand
Post by: john12ax7 on January 12, 2019, 10:19:25 PM
Do you guys not use punches? Worth the expense imo.
Title: Re: Metalwork by Hand
Post by: Brian Roth on January 12, 2019, 10:44:54 PM
I have a life-long collection of Greenlees, ranging from 1/2" to well over 1", as well as some oddball rectangles.

You still have to drill the pilot hole....sometimes 1/4", more often 3/8".

Hence my question of best brand choices in 2019 for aging twist bits.  <g>

Bri

Title: Re: Metalwork by Hand
Post by: john12ax7 on January 12, 2019, 11:22:56 PM
You can also get punches for the smaller holes, then switch to greenlee for the bigger ones.
Title: Re: Metalwork by Hand
Post by: JohnRoberts on January 13, 2019, 12:00:38 AM
You can also get punches for the smaller holes, then switch to greenlee for the bigger ones.
+1   Roper Whitney old school...

JR

(https://encrypted-tbn3.gstatic.com/shopping?q=tbn:ANd9GcRtJjkdImyens0uS66x6JoB7cX8Y3qNzRiGZMvq-rxSjr3853_pTA&usqp=CAc)
Title: Re: Metalwork by Hand
Post by: Gold on January 13, 2019, 01:49:30 AM
I have both Hertel and Interstate jobber length bit sets I got from MSC. Both are good. I prefer screw machine bits.
Title: Re: Metalwork by Hand
Post by: Brian Roth on January 13, 2019, 07:14:46 PM
I have both Hertel and Interstate jobber length bit sets I got from MSC. Both are good. I prefer screw machine bits.

Thanks, Paul!  I'll check those out.

Bri
Title: Re: Metalwork by Hand
Post by: Brian Roth on January 13, 2019, 07:18:49 PM
+1   Roper Whitney old school...

JR

(https://encrypted-tbn3.gstatic.com/shopping?q=tbn:ANd9GcRtJjkdImyens0uS66x6JoB7cX8Y3qNzRiGZMvq-rxSjr3853_pTA&usqp=CAc)

I had forgotten about those Roper Whitneys, but perhaps of limited use due to the limited depth of the "jaw" (think of a 2RU rack panel), or knocking holes into a prefabbed metal box with flanges.

Bri

Title: Re: Metalwork by Hand
Post by: Marik on January 13, 2019, 09:32:40 PM
I never had any formal training working with machinery. Started with mini lathe and mini mill. Grew out of those within a couple months. Now have in the shop heavy duty Matsuura CNC mill, Hardinge Omniturn CNC lathe, and two Mori Seiki heavy duty CNC lathes. Without experience of working with manual machines I don't believe could actually learn to work on CNC with different metals and feeling them. I don't use any CAM programs. Our mill is Centroid retrofitted, so it is completely conversational, which is a luxury--the part of any difficulty can be programmed in a couple hours max if there are lots of linear, and/or arc moves. Usually, I don't spend more than half an hour for any microphone/electronics related part.

Lathes are easy--I program them with G-code. It took a few days to learn and get a grip, but not hard, though more time consuming. Now retrofitting all our lathes with Centroid, so the programming and setting up time is going to be minimal...

All of that is not hard as long as you know concept of speeds and feeds and have good understanding of manual machining and feeling of the tools and metals. Once you are on the other side of the fence you can see that all of that is actually pretty easy... by far easier than to learn any instrument to play:)))

Best, M
Title: Re: Metalwork by Hand
Post by: Gold on January 13, 2019, 09:49:46 PM
I just got a 12” saw blade to go in my 14” abrasive wheel chop saw.  The blade is for soft metals and is rated for 6000RPM. The saw spins at 4500 RPM. The blade also has a 5 degree negative rake angle so it doesn’t pull the piece into the blade. I’m getting super clean straight cuts in aluminum.  It took a long time to figure that out. It makes me happy.

I think next I’ll try some sheet steel. A small brake is cheap and a hand shear also isn’t expensive. For not much more than $100 I could have both. That’s a good start towards custom enclosures.
Title: Re: Metalwork by Hand
Post by: Gold on March 08, 2019, 12:56:46 PM
Here are some shots of me making the faceplate for the T-Filter EQ I just made.

(http://www.saltmastering.com/Console/TFEQ/TFEQA-12.JPG)

(http://www.saltmastering.com/Console/TFEQ/TFEQA-13.JPG)

(http://www.saltmastering.com/Console/TFEQ/TFEQA-14.JPG)

(http://www.saltmastering.com/Console/TFEQ/TFEQA-15.JPG)

(http://www.saltmastering.com/Console/TFEQ/TFEQA-16.JPG)

(http://www.saltmastering.com/Console/TFEQ/TFEQA-17.JPG)

(http://www.saltmastering.com/Console/TFEQ/TFEQA-18.JPG)

(http://www.saltmastering.com/Console/TFEQ/TFEQA-19.JPG)

(http://www.saltmastering.com/Console/TFEQ/TFEQA-10.JPG)
Title: Re: Metalwork by Hand
Post by: warpie on March 08, 2019, 03:09:18 PM
Nice :)