DaveEstey
DaveEstey PowerDork
3/16/15 4:33 p.m.

I have a large sheet of aluminum coming to make a dash for my hillclimb car. Any tips for forming things up beyond making a template out of cardboard?

Thinking something along these lines:

These are my gauges, so obviously I don't need to go as crazy as the photo above.

Jumper K. Balls
Jumper K. Balls UltraDork
3/16/15 4:46 p.m.

Do you have access to a sheet metal break?

ncjay
ncjay Dork
3/16/15 4:47 p.m.

I use 1/4 turn fasteners to make dash removal easy and build everything for quick access. KISS - keep it simple, stupid.

DaveEstey
DaveEstey PowerDork
3/16/15 4:53 p.m.

In reply to Jumper K. Balls:

No special sheet metal tools beyond a welder.

tr8todd
tr8todd Dork
3/16/15 4:58 p.m.

How do you plan on punching the holes for the gauges? I have some of those two piece hole punches that the electricians use, but I doubt they would be the exact size you would need. They work well for when you need to pass a roll cage tube thru a bulkhead. If you plan on using a hole saw, I have found that when drilling thru thin sheet metal and fiberglass, its best to spin them backwards so they don't grab and rip the metal. I have a 3' sheet metal break if you need to borrow it.

DaveEstey
DaveEstey PowerDork
3/16/15 5:00 p.m.

All my gauges and switch panels have square housings, which will make it far easier than individual holes.

I'll definitely take you up on the metal break!

jimbbski
jimbbski Dork
3/16/15 5:17 p.m.

I have a 30 inch bender from HF that works fine. Just last week I bent up some .060 aluminum and some 22 gauge sheet steel. Also for trimming into corners this tool is handy: http://www.amazon.com/Klein-Tools-76011B-Nibbler-Tool/dp/B0000CBJCT

I also use a scroll/sabre saw to make most of my cuts. "Tin snips" leave a wavy edge that's also very sharp. Their great for small cutting jobs or trimming something to fit but for large cuts use power tools.

Curmudgeon
Curmudgeon MegaDork
3/16/15 5:26 p.m.

This is where you need to practice CAD (Cardboard Assisted Design). The cardboard from beer cartons is perfect for this and it gives you an excuse to buy beer in those cases and empty them fast. Corrugated cardboard doesn't work well for CAD. Make your pattern in cardboard first, that way if you screw something up you are just out the cardboard, not the sheet metal.

I've seen big stuff like dashes made on those metal brakes the siding guys use. I've also done 'homemade' brake stuff by laying the metal on the workbench, then using a pair of C clamps and a 2x4 to hold it in place. Now with thin stuff like 20 gauge you can use another 2x4 to bend the metal, a deadblow hammer is a big help on long pieces. On heavy gauge (.100 or so) clamp it the same way then use the deadblow hammer directly on the metal, you have to keep working back and forth along the bend. That's how I bent the 'lip' on the air dam which graces the rear of the Abomination.

Aircraft snips are a wonderful tool if used properly. The best way to cut the metal is to start with an air or electric shear, like this:

http://www.harborfreight.com/14-gauge-4-Amp-Heavy-Duty-Metal-Shears-68199.html

I own a nibbler which does a good job but spits out an amazing amount of sharp little chips that you find when you walk barefoot. I use it for small jobs where I can hold both the nibbler and the workpiece in a big trash can.

Cut to approximately 3/16" of the true cut line, then use the aircraft snips to cut on the line. The shears will deform the metal at the edge of the cut so you don't want to use them for finish work, the nibbler will leave a scalloped edge. It's possible to sand the scallops off, sometimes that's quicker and neater than using snips. In fact, sanding the edge after snipping makes for a nice finish that won't slice you like a knife.

1/4 turn Dzus type fasteners are a great way to hold the dash in. I've found the best price is in large packages from Day Motorsports, I don't know why everyone else is so pricey. http://www.daymotorsports.com/prodindex.php?g=~Building%20Products~Bodies%20and%20Accessories~Body%20Accessories~Body%20Components~Fasteners~

The dash in the Jensenator is assembled using 10-32 x 5/8 stainless button head screws, available from McMaster Carr. http://www.mcmaster.com/#socket-cap-screws/=wc89a3

I used those 10-32 threaded inserts and the install tool sold by McMaster.

Inserts: http://www.mcmaster.com/#standard-rivet-nuts/=wc88iv

Installation tool: http://www.mcmaster.com/#rivet-nut-installation-tools/=wc87rc

I used stainless to prevent rust, they sell aluminum screws as well but on those I'd want bigger threads so they'd be less likely to get damaged. They are much more likely to round out the heads, too. By the way, you have to drill down on those McMaster links, for some reason I can never link directly to what I want to on their site.

DaveEstey
DaveEstey PowerDork
3/16/15 5:30 p.m.

I do have a set of aircraft snips and my buddy has that HF metal shear, so I guess I have access to more than I thought I did.

My dash won't be full width, just half the width of the cockpit, so I won't need a massive break. When I made sheet metal fan shrouds in the past I used clamps and wood with a deadblow. It worked OK, but I'm looking for a nicer finish on the dash.

DaveEstey
DaveEstey PowerDork
3/16/15 5:51 p.m.

Found this video. Pretty good info (at least for me) https://www.youtube.com/watch?v=9Ca2S59JhvY

Curmudgeon
Curmudgeon MegaDork
3/16/15 6:12 p.m.

Pretty good video. When describing the 'direction' of a pair of snips, most people use them going away. That means the waste will go to your left with the reds and to your right with the greens. So, use the reds on the LEFT side of your work and the greens on the RIGHT. If you only have one pair, say only a red (left) cut you can do one side then flip the workpiece so you can use them on the other side, if you get my drift.

I mark stuff with Sharpie, it comes right off with lacquer thinner.

Oh yeah, when drilling holes for your fastener of choice it's easier to hold the workpiece tight against whatever it's being fastened to then drill both holes at the same time. If you have a long row, mark wher you want them then drill and install the end fasteners first. Then go back and rill/install the middle fasteners, this is a damn sight easier than trying to measure accurately etc.

I also prefer 3/16" rivets. More holding power.

Kenny_McCormic
Kenny_McCormic PowerDork
3/16/15 8:11 p.m.

Gloves, deburring tool.

NOHOME
NOHOME UltraDork
3/17/15 6:12 a.m.

https://www.youtube.com/watch?v=6pFk_CZJvnw

This video will kick things up a notch and show you a different method.

DaveEstey
DaveEstey PowerDork
3/17/15 12:08 p.m.
NOHOME wrote: https://www.youtube.com/watch?v=6pFk_CZJvnw This video will kick things up a notch and show you a different method.

jeebus...

Gary
Gary HalfDork
3/17/15 12:40 p.m.
DaveEstey wrote:
NOHOME wrote: https://www.youtube.com/watch?v=6pFk_CZJvnw This video will kick things up a notch and show you a different method.

jeebus...

Not only was that informative, it was entertaining.

Leafy
Leafy HalfDork
3/17/15 12:47 p.m.

Do not try to bend aluminum in the HF bender, shear, roller combo. I have one. It's bend radius is too tight and it breaks the aluminum on almost all 90° bend and even on lesser bends it still causes cracking.

NOHOME
NOHOME UltraDork
3/17/15 12:57 p.m.
Leafy wrote: Do not try to bend aluminum in the HF bender, shear, roller combo. I have one. It's bend radius is too tight and it breaks the aluminum on almost all 90° bend and even on lesser bends it still causes cracking.

If it is cracking, you are using the wrong alloy. Try some 3003 alloy and it will bend just fine. Wont be as hard to bend either.

stafford1500
stafford1500 Reader
3/17/15 1:37 p.m.

The other option for bending metal that winds up cracking is to bend a thin piece of material and use that as a 'shoe' over the die. That will give a slightly larger bend radius and less cracking...

Leafy
Leafy HalfDork
3/17/15 1:44 p.m.
stafford1500 wrote: The other option for bending metal that winds up cracking is to bend a thin piece of material and use that as a 'shoe' over the die. That will give a slightly larger bend radius and less cracking...

The particular break I have doesnt like have a clamping foot and then a thing you move to bend its just got a V groove and a V point that fit inside each other and the amount of bend varies by the amount you push the point into the groove. Works great for thin steel you can get a super tight radisu bend. But the random 5xxx aluminum sheet I had kicking around was having none of that like 1mm bend radius.

stafford1500
stafford1500 Reader
3/17/15 2:16 p.m.

In reply to Leafy:

Yes, the pointy die can be 'softened' with another piece of sheet that was previously driven to the bottom of the V. This 'shoe' should have a larger bend radius and will produce this larger bend radius on the your final workpiece. You can have several thicknesses/radii to cover many different scenarios. Similar items can be used for box brakes with sharp fingers and adjustable setback.
Since the bend radius for the material you are working varies with thickness, this is a tool to be used to get the 'right' bend.

pirate
pirate Reader
3/17/15 2:41 p.m.

When laying out your shapes or bend lines do not use a metal scriber or sharp pointed object sometimes even a ballpoint pen. Metal especially aluminum tends to crack along the scribe line when it is being bent. It also gives a place for corrosion to start more easily. Instead used a regular sharpened lead pencil. You could used a magic marker but for me the line is always too wide to be accurate.

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