Multi-function Metal Machines

[Chris In Marshfield]

Hi all,

About to cut out and bend the ribs for my Bearhawk wings in the next week or so, and I know I'll have to, at some point shortly afterward, cut out the rib stiffeners and attach angles (90-degree strips riveted to the side of each rib). Just perusing one of my fellow builders' logs, and he had 370 of those little monsters made up at the time he created them. Since my building partner and I are building two of these aircraft, that'll make 740 of them, and wondered if a tool like this one would pay for itself in time saved for such an event:


http://www.grizzly.com/products/12-Sheet-Metal-Machine/T21320


Of course, it'll be handy for plenty of other metal operations on the plane as well, and maybe its big brother, too:

http://www.grizzly.com/products/Sheet-Metal-Machine-30-/G4011

Any opinions on these devices?

~Chris

[corsair82pilot]

If it is just for two aircraft, it might be less expensive to get it done by a shop. Or if you have a local vocational school, they might do the bending and cutting for you.

[Tom Downey]

Hi all,

About to cut out and bend the ribs for my Bearhawk wings in the next week or so, and I know I'll have to, at some point shortly afterward, cut out the rib stiffeners and attach angles (90-degree strips riveted to the side of each rib). Just perusing one of my fellow builders' logs, and he had 370 of those little monsters made up at the time he created them. Since my building partner and I are building two of these aircraft, that'll make 740 of them, and wondered if a tool like this one would pay for itself in time saved for such an event:

http://www.grizzly.com/products/12-Sheet-Metal-Machine/T21320

Of course, it'll be handy for plenty of other metal operations on the plane as well, and maybe its big brother, too:

http://www.grizzly.com/products/Sheet-Metal-Machine-30-/G4011

Any opinions on these devices?

~Chris

I have one of those Grizzly 3 way machines it is very handy, and will do most all light duty work of building aircraft.
3 things you need to do to one before you press any aluminum. polish the dies both the upper and lower they are pretty rough and scratch the aluminum. set the sheer clearance to cut soft material, it comes too loose and merely bends the sheet. and finally, adjust the rollers to give a true cylinder bend, it will produce a cone other wise.

I use mine a lot and it works well, but the local air-conditioning and ducting company will do the job cheaper than the cost of a 3 way sheet metal machine.

[DaveH]

Try your local EAA chapters, the two I have been to in my area(SE Michigan) have workshops and equipment for members to use.

[Chris In Marshfield]

Try your local EAA chapters, the two I have been to in my area(SE Michigan) have workshops and equipment for members to use.

Unfortunately, there aren't any in my chapter, and the next closest chapter is an hour away (although I haven't checked with anyone there). But being only a couple of hours away from Oshkosh, I'm not too far away from equipment if I need anything specialized.

I do plan to check with the maintenance shop at our FBO, though. They do have a couple of smaller metalworking machines. And there's no shortage of machine shops where I live, either, so I can go that route if I need to.

Appreciate the input :-)

~Chris

[messydeer]

I'm 95% through with scratch building my Sonex. As far as I understand it, the wings are similarly made, aluminum skin with one-piece ribs fore and aft of the main spar. Twice as many ribs as the Sonex, though. I made form blocks out of MDF, cut the blanks with snips, then took 4 or 5 at a time and used a router to cut the edges and lightening holes. Used dies to smash the flanges of the lightening holes. Made the rib flanges by hammering the edges against the form blocks.

I spent about 2 minutes going through several pages of Eric Newton's website, http://mybearhawk.com/ in the wing section and didn't see a slip roll or shear mentioned. What are other builders using? A long brake is definitely needed, but they are way expensive to just use it for a day or two. I'd guess that besides those few long bends for the spar you'd get by with a much smaller brake.

For me, making the ribs with the form blocks, dies, and router was fun. Deburring all the edges was the tedious part.

Dan

[Chris In Marshfield]

That's exactly how I'm planning to build mine: trace ribs, hand-cut with snips, route out the final shape and lightening holes, shape flanges around the forms. The use of the machine would be for cutting/bending straight pieces, such as the stiffening angles that each rib has, as well as any other accessory brackets, etc. that might come along later. I was looking for something that might cut down on the time required to do some of the ultra-repetitive tasks, like those stiffening angles. I get the feeling that I won't gain much.

I agree that a long brake is needed. The spars require an 8-foot brake. But I have access to one of those without having to buy one (pretty dang expensive, anyway).

Appreciate your input, Dan :-)

~Chris

[messydeer]

You're welcome, Chris :-)

That's great you have access to an 8' brake. When you go to use it to bend for the spars, you could also bend whatever thickness those stiffeners and stuff are, then cut them to size later. If each stiffener is 032 1x1x12, then your 8' brake would give you 8 pieces in one bend. You prolly figurd that out, I'm sure. I bought the pre-bent package from Sonex, which was a bunch of mainly 032 and 025 they'd bent to 90 in various widths, roughly 8' long. I cut the thinner stuff with snips and 1/8" angle extrusion with a hacksaw or bandsaw. For longer pieces of flat 025 and 032, like the skins, I used an Olfa P800 razor blade and a straight edge.

Dan

[Eric Witherspoon]

I see a few problems, and would save my money for stuff that will be more obviously needed (Scotchbrite wheel, more drill bits, more Clecoes!!!!). As Dan pointed out (hi Dan!), other builder websites do not show these multi-function machines. What this says to me is if other people aren't showing / talking about using them, it's probably because they don't.

Problems: Shear is too short. You highlighted a 12" model machine. You'll feel silly paying big bucks to make sub-12" cuts. Your snips work fine in that range, and for longer cuts, these Olfa knives seem to be popular, though I haven't used one myself.

Slip roll? Slip roll! Don't talk to me about a slip roll! That's just wasted money right there. May be useful for an airplane part somewhere, but not on my airplane. That's just money collecting dust that you can't use for more Clecoes...

Brake? A 12" brake in a $400 machine? You'll feel a lot more satisfied spending ~$35 on one of these:
http://www.harborfreight.com/18-inch-bending-brake-39103.html

I use a cut-off flange from a piece of .125 angle stock in place of their "hold-it-down" bar to give a nice radius. I tried for quite a while with the "set back determines bend radius" method and figured - just using a radius on the holding-down piece works too. Oh, and if you build up a collection of short, straight-sided cutoffs for clamping things down, you can duplicate the functionality of a "box and pan" brake (I've used these - a nice function, but not worth buying) for building up triangular control surface ribs, etc..

As Dan said, take advantage of the 8-foot brake you have access to, bend up some long pieces of L channel yourself, then cut it to length. That will be the fast way to get through the large quantity of little angle parts you need.

[martymayes]

I agree with Tom, they work just fine provided you're okay with the limited capacity.

[Chris In Marshfield]

I cut the thinner stuff with snips and 1/8" angle extrusion with a hacksaw or bandsaw. For longer pieces of flat 025 and 032, like the skins, I used an Olfa P800 razor blade and a straight edge.

Dan

I've heard of others using the Olfa knife on aluminum, but it's been 6061 (Zenith and Sonex builders). My plane is primarily 2024. Is it tough enough for that material, you think?

[Chris In Marshfield]

Slip roll? Slip roll! Don't talk to me about a slip roll! That's just wasted money right there. May be useful for an airplane part somewhere, but not on my airplane. That's just money collecting dust that you can't use for more Clecoes...

The machine intrigued me more for the combination of sheer and brake more than anything. But I can see where its usefulness is pretty limited, given its capacity (or lack thereof).

The thing that kills me about cutting off pre-bent material (a chunk out of a piece of angle) is the sharp edges at the corner/bend. Granted, that's what a file and scotchbright is for, I reckon. But I imagine it's less time consuming to bend up a dozen or two really long pieces and cut them off versus several hundred short ones!

[Tom Downey]

The machine intrigued me more for the combination of sheer and brake more than anything. But I can see where its usefulness is pretty limited, given its capacity (or lack thereof).

The thing that kills me about cutting off pre-bent material (a chunk out of a piece of angle) is the sharp edges at the corner/bend. Granted, that's what a file and scotchbright is for, I reckon. But I imagine it's less time consuming to bend up a dozen or two really long pieces and cut them off versus several hundred short ones!

The three way machine will do the common angle bracket easily you can do many hundreds of them a hour.

[Max Torque]

I have a 4' brake, shear, and a 3-in-1 in my shop. The 3-in-1 is a 30" unit from Harbor Freight http://www.harborfreight.com/30-inch-shear-press-brake-and-slip-roll-5907.html Grizzly probably has the same unit with a different coat of paint and label.

I do a lot of fabricating for aircraft and I use the 3-in-1 a lot more - mostly the shear & vertical brake - than any of the others for fabricating small parts. Handy unit once it's set up, adjusted, and operating properly.

The vertical brake and removable "teeth" certainly come in handy, but, as stated in an earlier post, you'll need to do a fair amount of deburring/polishing/adjusting to get it to where it needs to be. You'll also want to fabricate aluminum angle strips of various thicknesses to get different radii and to use as protectors.

I'm going to buy a 40" 3-in-1 to supplement the 30" one of these days...

Tom

[Tom Downey]

I have a 4' brake, shear, and a 3-in-1 in my shop. The 3-in-1 is a 30" unit from Harbor Freight http://www.harborfreight.com/30-inch-shear-press-brake-and-slip-roll-5907.html Grizzly probably has the same unit with a different coat of paint and label.

I do a lot of fabricating for aircraft and I use the 3-in-1 a lot more - mostly the shear & vertical brake - than any of the others for fabricating small parts. Handy unit once it's set up, adjusted, and operating properly.

The vertical brake and removable "teeth" certainly come in handy, but, as stated in an earlier post, you'll need to do a fair amount of deburring/polishing/adjusting to get it to where it needs to be. You'll also want to fabricate aluminum angle strips of various thicknesses to get different radii and to use as protectors.

I'm going to buy a 40" 3-in-1 to supplement the 30" one of these days...

Tom
You can also fabricate dies for dimpling, and riveting, punching holes, and cutting internal shapes. and other stuff like a small press.

[Hiperbiper]

http://www.eastwood.com/throatless-shear.html

This is SO much easier than tin snips...
between this, a 30" break and a large hammer I haven't found anything I couldn't tackle in my limited experience...


Chris

[Tom Downey]

When you consider how many times you will buy a full 4X8 foot sheet of metal and try to cut it down into usable pieces you find the 8 foot break and sheer will not be used much. Most will buy material from stores like http://www.airpartsinc.com/ and Aircraft Spruce, and buy usable sizes that will in most cases ship cheaper and fit the 3 in 1 machines. when you are really in a bind to get big piece cut you can always use a good 2X4 Straight edge and a router, with a laminate trimmer bit in it.