[tikka308]

I'm looking to replicate an aluminum box similar to the attached photo. I'll use 6061 aluminum somewhere between 1/16" & 1/8" thick (depending on press capacity) which will be milled to the flat-open-cube shape on my CNC Mill and then pressed into form. The final box will be 1" wide, 0.5" tall and 0.5" deep (so quite small...)

I don't have any experience with the next steps, but would appreciate any comments on the following "next steps":
1) Mill a cavity form that I will lay my aluminum-box work-piece (which is still in a flat cut-out shape)
2) Lay the interior-cavity shape on top of the work-piece
3) Use a desktop press to form the aluminum piece into my mold

4) I don't yet own a press. Any recommendations on a small (desktop) sized, quality press? Grizzly has one, but I don't like their low-quality I've seen in their other products. I have a decent budget and would prefer to buy something quality - but it needs to be small. (http://www.grizzly.com/products/2-Ton-Arbor-Press/H7830)

FYI: For steps 1 - 3 above, in case my explanation isn't clear, an analogy would be making a cupcake, where I mill the cupcake-tray for the form/shape, use the actual cupcake as the opposite-piece (which I've also milled) for the inside form/shape, and the wrapper is my work-piece that I am trying to press-into-shape.

Thanks!

John

[cam1]

Depending on how generous a bend radius you have selected, I'd recommend going with AL5052 H32 or H34. These alloys are way better for brake and press forming. The 6061 T6 has a tendency to crack at the bends, unless you preheat, thus creating 6061 T0, which negates the purpose of having selected that temper.
regards

[tikka308]

Cam1 - Thanks, that's great to know. I'm definitely looking for a tight bend radius, so I'll look for AL5051 H32 or H34. I'm not concerned about the temper / strengeth / etc; this part will not be strssed in any way.

Any rec's on my process or a viable benchtop press?

[cam1]

Hmmm, I'd probably go the route of Box & Pan brake, and treat the boxes like a sheetmetal box, as opposed to the mold & die method. This method would work fine, provided you didn't want to store liquids. The corners could be designed to be locked, using various sheet metal techniques. I'm not aginst the deep drawing method you proposed, but most of the stuff I've seen that was formed that way was round. I think you would have a %^!! of a time dealing with the material "flow" at the corners.

regards

[tikka308]

Gotcha. I'm happy to experiment and definitely don't need to store liquids - so I'll find/buy a small box & pan brake and see how that goes. Thanks!

[cam1]

cheers

[ViperTX]

tikka308....if your dimensions are accurate....I don't believe any of the box/pan brakes in the inexpensive category will work.

I would definitely look at using an 20 ton bearing press....check out bonneydoon engineering.

If you're making a bunch....well, I would get someone with the equipment to build them.

[tikka308]

By dimensions I assume you mean the thickness? I realize 1/8" is pretty thick to bend... but shouldn't I be able to bend a 1/16" thick piece of aluminum that is less than ~1" wide?

[ViperTX]

Tikka308...the problem with the small brakes is that the clamp pressure is not enough to keep the 1/8 inch material from slipping and you end up with a bend radius that is quite large.

Best thing to do is take a piece of your stock that has the 4 corners notched or milled...go to Harbor Freight and use their finger pan/box brake to bend your box and you'll see the problems. Also the fingers are usually in 1, 2 and 4 inch width increments.

[tikka308]

Just wanted to let ya'll know that I've successfully made my first box! It worked perfect; I used the Grizzly 24" box & pan brake. Details, pictures & video are all on my blog - http://www.nyccnc.com/Herbie/HERBIES..._Tutorial.html or http://tinyurl.com/5zsfhb

Thanks for the help!

[ZipSnipe]

Good video Tikka, I like the way you found the limitation of the brake and then figured out a solution. I also like the barefoot work ethic :-)

[tikka308]

Zip - I was hoping no one would notice the barefeet! I saw that when I posted the video and almost re-shot the clip, but figured it wasn't that big of a deal. But to all you youngsters out there: stay safe! proper safety equipment (including shoes!) are important.

[PhoenixMetal]

Do not attempt to make this product via the one-hit cavity punch/die method that you described in your initial post. Due to material springback, the bends will not come out at 90 degrees. It takes some special tricks to get 90 degree bends using a wipe die (a die that "wipes" the flanges up), and I think they may be difficult to pull off if you are wiping all 4 sides at once (as opposed to one or two opposite sides). You will also need to incorporate some sort of spring or urethane stripper system to be able to remove the parts easily from the cavity if you go that way... Otherwise, the parts will likely stay in the cavity and you'll have to pry them out! Yes, this part can be made in this fashion, but unless you are making many thousand pieces it is not worth the effort to build a die which is robust enough to make this work properly.

An easier way to accomplish this part would be to use V press brake dies... You would need a small <1" segment of a male punch, and the female die could be that length or longer. Be sure the punch is a gooseneck type (otherwise a flange may collide with the ram when you make your second bend), and be sure the die is narrow (.375" V opening or so) to allow you to gauge the .5" bend using a manual gauge. You can clamp a little stop block to the back of the die to act as a gauge for the .5" bends. Obviously you are not going to buy a press brake to make this little part, but I have seen little manual benchtop mini brakes sold by harborfreight or grizzly that would fit the bill. You may even be able to modify an arbor press to hold the press brake tooling to do the job.