Baltic birch plywood users - impact strength?

[454Casull]

How hard would you have to pound a 3/16" thick 10"x16" sheet of plywood in the middle so that it would suffer permanent damage? (i.e. cracking)

[pinkmouse]

That's very thin. Assuming it is only supported at the edges, a fist or boot should easily do it. A point load like a hammer blow will punch a nice neat hole.

[RHosch]

Well, as pinkmouse hinted at, it depends in large part on the manner of loading. Evenly distributed normal force, like a pressure? Point loaded somewhere? A load spread over a defined footprint?

The boundary conditions also contribute significantly to the result. Are the edges constrained only by orthogonal 3/16" panels? Glued to a solid structure, like a workbench? Somewhere in between, like glued using wedge blocks to 3/4" orthogonal sides?

Lots of variables there to be able to begin formulating even a ballpark figure.

[454Casull]

The top will be fixed atop the 4 sides of a rectangular box (plus the bottom panel, but that doesn't really matter much). The side panel thickness isn't restricted to any range, so the material can be 1/2", 3/4", 1", etc. This is actually for a arcade-style control panel (joystick + buttons).

Something like this:

http://www.arcadereview.com/images/finaltop.jpg
http://www.arcadereview.com/images/finalbottom.jpg
http://www.arcadereview.com/images/finalbottomhole.jpg

You can consider the recessed areas to be the actual thickness of the entire top.

Obviously I won't intentionally hit the top hard, but I may lose my self-control on occasion and slap the top (probably near the center).

[Illusus]

If you can live with something closer to 1/4"(actually 7mm), I can send to you a panel of some 'super baltic birch' made for Mercedes transport trucks. It is made of thinner plys glued to each other with a hard epoxy, and comes finished with a black cherry coloured resin. It is extremely stiff and tough. I just got a truckload of this stuff.

I (just now) grabbed a piece, 10"x12", clamped the narrow end in my woodworking vise, grabbed onto the top of it and pulled, I put both my feet on my work bench so I was literally hanging from it and pulled, it bent a bit. It finally broke when I gave it a strong sharp tug...and I fell on my butt, hard. I took another piece of similiar size, placed it accross a couple saw horses and punched the middle hard, it punched back harder. I hit it harder and it creaked a bit. I focused, and palm struck it as hard as I could and it broke...I doubt you'd ever get that angry with any game. I tried another piece and hit it with a hammer...it took a few really hard knocks before breaking. Keep in mind I weigh ~200lbs and am physically fit...used to fight a bit too.

I'll do a full post about this material in a new thread in a day or two...I just got it. I'll send out some some samples to interested forum members. I think it has a lot of validity for use in small speaker enclosure construction, large sections have some flex...but all that will be talked about in the new thread.

[Illusus]

Ahh, I just took a look at the pics you linked to. I assume you want to use 3/16" so you don't have to machine the recesses for the buttons. You may be able to use the slightly thicker material if you trim a bit of length off those retaining clips. They're plastic so you could just file them down.

[454Casull]

Ah... I didn't think of shortening the clips so that they allow a thicker material to be squeezed. Only problem is, I'm worried about not shortening to the right depth, and making sure all the modifications are uniform.

Regardless, the material you are talking about seems almost purpose-built for me.

By the way, you didn't have to injure yourself on my behalf (not to mention destroying good wood.)

[Illusus]

>By the way, you didn't have to injure yourself on my behalf (not to mention destroying good wood.)

It was all in the name of curiosity. I would have done it anyway.

[planet10]

Originally posted by Illusus
I'll do a full post about this material in a new thread in a day or two...I just got it. I'll send out some some samples to interested forum members. I think it has a lot of validity for use in small speaker enclosure construction, large sections have some flex...but all that will be talked about in the new thread.

Very cool... i'm in for a sample

dave

[454Casull]

Originally posted by planet10


Very cool... i'm in for a sample

dave

Me too, if shipping won't cost you much.

Are at least one of the faces natural wood? If so, can it be stained?