Enclosure making essentials (metalworking, holepunching, etc.)

[dai h.]

hi all,

I've been doing some websearching reading a bunch of stuff on procedures and tools that would be needed in order to make efx., project, chassis for a couple of days since I want to learn how to do this correctly (and safely). Mainly I think I'll be using aluminum just because it's easier to work with and I'm not looking to do anything very elaboarate. I just want to have the basic capacity to make decent-looking enclosures. I just bought a drill press since it seemed to make the most sense (not too complicated nor expensive for a basic model) compared to something fancy like a mill, plus I'm a total beginner so I reasoned I should stick to something basic. I haven't taken it out of the box yet since I need to buy some other things such as safety goggles and maybe clamps and other things but since I don't have any experience I wanted to ask anyone experienced in metalworking what items, tools, etc. are the most essential and most useful--what do I need for a very basic setup?

right now, I have the drill press, table vise that was included with the drill press, drill bits, center punch, cutting paste, graph paper, scriber, divider, straightedge, files, couple of Greenlee hole punches for tube sockets

my understanding of the basic procedure: mark on graph paper, paste this on enclosure, scribe and center punch accurately before drilling, deburr holes. Use eye protection, make sure the work is held down using clamps, vices, etc. (never use hands to hold the work). Be cautious with power tools.

[Steve Conner]

When you say "making enclosures" do you mean drilling holes in off-the-shelf enclosures or making the whole box from scratch out of sheet metal?

Either way, I'd add a good quality jigsaw with a metal cutting blade. If you have to bend metal, you can do it with a few pieces of angle iron screwed to the edge of your workbench and a mallet, but it always ends up looking awful. I always try to avoid bending large pieces, and do small ones with a bench vice and a mallet.

A pair of vernier calipers and a try square are very useful tools too.

I made most of the Ninja Toaster chassis using the tools you listed plus the jigsaw, but it was really hard work and I wouldn't care to try it again. I got help from a friend who owned a milling machine when it came time to make the front panel.

[dai h.]

yeah, sorry for not being more clear--the plan is just to put holes in ready-made enclosures. Sheet metal benders seem expensive, so it seems easier and less expensive to work with boxes already available.

[defaced]

A box and pan break is fairly easy to rig up, it's the joining of the sheet metal that can be an issue. Using lead cored solder is one way to do it without have to resort to welding, which not everyone has or has access to, a small torch for soldering is easy to get.

A drill press is nice, but you don't need one. You can do everything you need to do with a couple of tools:
steel rule
scribe
center punch
hammer
hand full of drill bits
stepped drill bit used for electrical knockouts
drill
inexpensive dial or digital calipers
and if you have a dremel and some bits for it, you can debur holes with that
layout fluid would be nice too, but not necessary

You will need to ream/grind holes for octal bases to size if you can't find a stepped drill large enough.

Honestly, if you've never drilled metal extensively, grab a piece of scrap out of a scrap bin somewhere (assuming there's sheet metal industry near by) and practice. Laying out and drilling holes is easy, but you still need to know what you're doing. You'll quickly find that drilling large holes in sheet metal takes some practice.

[Rob Mercure]

Hey Dia,

I second the step drill - chassis punches are better for square or "D" shaped holes but really more trouble than they're worth for a circle. I don't know what sort of access you've got to scrap metal but you can often find a suitable box - or most of a box - from a scrap yard and save yourself lotsa trouble. Especially if you're making your own wooden cabinets since you can then dimension the cabinet to match the chassis. About 20 years ago a friend demolished a family owned car wash which left about 50 aluminum "beams" of three sides of a box with a lip on each side of the open fourth side - sort of a "C" squared off - the metal was about 1/8" thick. The dimensions were 8 inches across the widest part (chassis "top"), 4 inches across each of the sides, with about one inch on each side of the open side. These beams were around 12 feet long. He gave me three of them and I've cross cut them to the chassis lengths desired and then cut wooden plugs to cap the open ends - after all this time I still haven't chopped up the first one. Coupled with the others I've reused and I've had all I've needed for year and will for years to come.
What I'm suggesting is look around and you'll probably be able to cobble up great workable chassis with much less work than building the entire boxes from scratch.

Rob

[dai h.]

thanks guys,

inexpensive dial or digital calipers

in general is a bigger one (digital calipers) more useful (than say, buying different sizes)?

(I can sort of picture how one would be useful--checking if things are where you want, matching dimensions, dig. readout easier to read, etc.)

Honestly, if you've never drilled metal extensively, grab a piece of scrap out of a scrap bin somewhere (assuming there's sheet metal industry near by) and practice. Laying out and drilling holes is easy, but you still need to know what you're doing. You'll quickly find that drilling large holes in sheet metal takes some practice.

yeah probably what I need. Lots of actual practice.

Hey Dia,

I second the step drill - chassis punches are better for square or "D" shaped holes but really more trouble than they're worth for a circle. I don't know what sort of access you've got to scrap metal but you can often find a suitable box - or most of a box - from a scrap yard and save yourself lotsa trouble. Especially if you're making your own wooden cabinets since you can then dimension the cabinet to match the chassis. About 20 years ago a friend demolished a family owned car wash which left about 50 aluminum "beams" of three sides of a box with a lip on each side of the open fourth side - sort of a "C" squared off - the metal was about 1/8" thick. The dimensions were 8 inches across the widest part (chassis "top"), 4 inches across each of the sides, with about one inch on each side of the open side. These beams were around 12 feet long. He gave me three of them and I've cross cut them to the chassis lengths desired and then cut wooden plugs to cap the open ends - after all this time I still haven't chopped up the first one. Coupled with the others I've reused and I've had all I've needed for year and will for years to come.
What I'm suggesting is look around and you'll probably be able to cobble up great workable chassis with much less work than building the entire boxes from scratch.

Rob

thanks Rob. I think I'll be buying mostly, but sometimes smaller or bigger alum. boxes show up for cheap surplus. I have two big boxes from surplus already which I want to do something with but I didn't want to hack them up.

another question,

since I already have the drill press, would a set of clamps which included step blocks and machine strap clamps be particularly useful? I found a 20-piece (or thereabouts) set of clamps being sold for a mill. Overkill?

[defaced]

6" caliper is the "standard" size, for this, something larger is overkill. You can get vernier, dial, or digital - I got my digital ones on eBay for 10 bucks plus shipping (less than 20 bucks total). When I drilled my chassis, I used them to measure the diameter of screws, sockets and other fittings, the distance between transformer holes, locations relative to chassis edges, and generally layout the chassis. Most of this you can do with a 6" steel rule, but measuring diameters of threaded parts is a pain without calipers.

For clamping, get one or two cast C-clamps and some scrap 2x4. I'd probably go with a 8" clamp so I would be sure I had sufficient throat to get the clamp around the work table, the wood, and the chassis. You'll find that for drilling large holes, having a wood backing will save you alot of headache and touch-up work. If you get your clamps at a discount place like Harbor Freight (actually pretty good clamps), you're looking at like 10 bucks for a pair.

The reason why I say get cast C-clamps as opposed to those quick clamps used for wood working is because if a bit catches while you're drilling (this is usually an issue with big holes and is part of the reason for the wood backing I mentioned in the other paragraph), the quick clamp won't have enough clamping force or stability to keep your chassis from flying off the drill press and possibly injuring you. You can wrench down on a C-clamp and get the clamping force you need, and a cast clamp is a pretty sturdy tool so once it's locked down, it's not moving.

Oh, add one more thing to your shopping list, cutting oil or machine oil. You don't need much, but it will help your bits live longer.

[dai h.]

thx Mike,

For clamping, get one or two cast C-clamps and some scrap 2x4. I'd probably go with a 8" clamp so I would be sure I had sufficient throat to get the clamp around the work table, the wood, and the chassis. You'll find that for drilling large holes, having a wood backing will save you alot of headache and touch-up work. If you get your clamps at a discount place like Harbor Freight (actually pretty good clamps), you're looking at like 10 bucks for a pair.

I read that clamps should be sized for the work, but in practice would just two of those C-clamps (one for ea. side) be enough?

The reason why I say get cast C-clamps as opposed to those quick clamps used for wood working is because if a bit catches while you're drilling (this is usually an issue with big holes and is part of the reason for the wood backing I mentioned in the other paragraph), the quick clamp won't have enough clamping force or stability to keep your chassis from flying off the drill press and possibly injuring you. You can wrench down on a C-clamp and get the clamping force you need, and a cast clamp is a pretty sturdy tool so once it's locked down, it's not moving.

so I take it a bigger hole means more contact area between the drill and workpiece meaning more leverage and force hence the need for stronger clamping?

Oh, add one more thing to your shopping list, cutting oil or machine oil. You don't need much, but it will help your bits live longer.

thx. I did a bit of reading and one source said it's preferable (if you can) not to use any because the stuff is toxic (says something along those lines--maybe that the vapor is dangerous--on the tube of cutting paste I have alread), but I found some in spray form that was supposedly safer (found a video of a machinist using some stuff like that from a spray can while cutting a workpiece with a lathe), so hopefully that's the best of both (having lubrication and non-? or less toxicity). What do you use after you are finished to help prevent rust? Would say plain 'ol WD40 be adequate?

[Rob Mercure]

Dia,

Around 30 years ago I spent a year as a machinist trainee under the Manpower Program and I can tell you that you just can't have too many clamps! C clamps, pipe clamps, hold down clamps, a machinist vice (a "clamp" of a sorts - let's include vices as "clamps") - "bungee cords", bench "dogs" and wedges, etc. - the more you work with your tools the more you'll need clamps. But with some creativity you can probably make many of the clamping devices you need. I'd acquire as many introductory and student texts on machinery (verb) as I can - as Japan rebuilt itself from WWII your country developed a truly great machinery industry so there should be lots of texts available - don't cheat yourself and depend on the web and electronic media. Machining metal - along with crafting wood and stone and glass - are probably the most physical of arts.

Rob

[dai h.]

thanks Robu-san

I was kind of thinking the same also (i.e. a proper book or textbook). Another item for the list. (I did find a "Fundamentals of Machine Tools" Dept. of the Army on the web which looks good for basics on layout and includes a section on drilling machines.)

oh do you (or anyone else) have any opinions on what to set the drill press on? I kind of realized too late that a purpose-built drill press bench thing (heavy-duty steel, has mounting holes, and is real heavy so probably very solid and helps keep the motion from being wasted as vibration?? or something) is not cheap(!). About double what the drill press cost. (The DP BTW is a Ryobi which weighs about 70lbs--heavy!--but getting a bigger unit seemed to be the general recommendation.) Hack up a piece of furniture maybe or just suck it up and bite the bullet. Lots of small earthquakes here also, so it's probably wouldn't be the greatest idea to leave it freestanding.

[defaced]

so I take it a bigger hole means more contact area between the drill and workpiece meaning more leverage and force hence the need for stronger clamping?

Pretty much. When you?re working with sheet metal, a regular twist drill bit only cuts on one flute at a time (which will give you a triangular hole). If that one flute gets a good hold on the metal, there?s enough torque to because of the surface speed of the bit to throw your work piece, or if it?s clamped down enough, you could stall your drill. What you do to combat this is the backing wood to support the bit as it goes through the work piece and keeps it centered in the hole, and you use slower RPM settings to reduce the surface speed of the bit.



For clamping, Rob' spot on, you can never have enough, but for what you're doing, I'd typically only use one clamp and two clamps on occasion. But if you have the funds, you'll find having an assortment of sizes and quantities to be very valuable.



I'm in the welding trade so to speak, and if you keep your head out of the fumes, you're going to save yourself alot of headache (literally). A good fan will go a long way to protect you from fuming cutting fluid.

[Suburbanite]

I would add :

assorted files
Pop pliers/rivet gun
mole grips (locking pliers...not sure what you call em elsewhere)
some small hole saw's - I prefer using hole saws when more than 12mm diameter, quicker and neater

and some assorted blocks of wood to support inside the box while your drilling - stops you caving in the box when you press to hard trying to get the last out of your screaming blunt drill bit

[dai h.]

Pretty much. When you?re working with sheet metal, a regular twist drill bit only cuts on one flute at a time (which will give you a triangular hole). If that one flute gets a good hold on the metal, there?s enough torque to because of the surface speed of the bit to throw your work piece, or if it?s clamped down enough, you could stall your drill. What you do to combat this is the backing wood to support the bit as it goes through the work piece and keeps it centered in the hole, and you use slower RPM settings to reduce the surface speed of the bit.

trying to picture this mentally as sort of a scraping action by the drill bit flute that the backing wood helps to maintain by compressing up the metal against the flute until the drill bit breaks through. Sort of more consistent force being used that way whereas if it broke through there would be more metal for the flute to contact making it more difficult for the chiseling action to take place. So I suppose this would have to do with the operator's physical technique (feeding rate, choosing correct speed, pressure applied?) making a difference in the outcome? And maybe different techniques such as "pecking"? (IOW not so simple as some guy mindlessly lowering a drill onto a work piece.)

For clamping, Rob' spot on, you can never have enough, but for what you're doing, I'd typically only use one clamp and two clamps on occasion. But if you have the funds, you'll find having an assortment of sizes and quantities to be very valuable.

I'm trying find that sort of Goldilocks zone where I'm not being too cheap by not spending but not overspending either. I guess a price/performance thing.

I'm in the welding trade so to speak, and if you keep your head out of the fumes, you're going to save yourself alot of headache (literally). A good fan will go a long way to protect you from fuming cutting fluid.

thanks I hadn't thought of that. Will definitely keep that in mind.

I would add :

assorted files
Pop pliers/rivet gun
mole grips (locking pliers...not sure what you call em elsewhere)
some small hole saw's - I prefer using hole saws when more than 12mm diameter, quicker and neater

and some assorted blocks of wood to support inside the box while your drilling - stops you caving in the box when you press to hard trying to get the last out of your screaming blunt drill bit

thanks for the additional thoughts. Maybe big files (and a hacksaw) to make square or rectangular apertures. (Have to look up what the other stuff is.)

also, here's a video I found on youtube for anyone else looking into basic metalworking knowledge:

http://www.youtube.com/watch?v=kqxgzpobygM

there are others that deal with metalworking as well plus videos on subjects such as soldering which I think would be useful for someone who wants to see an activity in practice if you search there.

[Rob Mercure]

Dia,

Thanks! So this is a bench drill press? I really don't know about construction materials in Japan (but I used to get some really great hardwoods from motorcycle packaging crates) but in the USA the standard is wood in a "nominal" dimension of 2 inches X 4 inches ("finished" to an actual dimension of 1.5 X 3.5) - the "2 X 4." Over the years I've built several work benchs - seemed to leave on everywhere I've lived - with plywood tops. These have worked well for machining, mechanicing, and wood crafts (have to make sure to remove metal particles) so something like this might work well. I tend to like to fasten the bench to structural members and use lots of triangulation to ensure rigidity ("gussets"). Two by fours are still fairly cheap here in the USA but over the past few years I've tended to recycle shipping pallets/skids as I can usually find harder/denser woods in them than a lumber yard provides and they are free. If you've noticed my comments on the building amp cabinets I've also been able to acquire nice "exotic" woods for combo cabinets. China is shipping products that flood the world and the Chinese seem to buy wood from "all over" - I don't know how much Japan imports from there (we get everything, even babies <grin>) - but if you get "white goods" (appliances like stoves, refrigerators, washing machines) from China you might see if the store will give you the shipping materials for your bench. With a little scrounging the price of materials should be free.

Rob

[dai h.]

thanks Rob,

it's this model:

http://thumbnail.image.rakuten.co.jp...bi/tb-2131.jpg

Looks ordinary, standard-looking. Made in China(says on the box). Apparently MIJ drill presses don't exist for (what I'd guess you'd call) "entry level" DPs. A "pro" DP (which would allow you to accurately drill a hole into a rod) would be from Toshiba from around the equivl. of about 800 bucks on up according to what I've read (mine was on sale for about 220 incl. shipping which was a bit less than I could find elsewhere and seemed to be the best price going).

Thanks for the bench tips. Dunno if I can get packing materials, but the parts about the construction and rigidity I will definitely look into and study.