Making a bamboo 60% case, looking for any input/suggestions.

[wes1099]

I am working on getting a 60% case cut out of bamboo, and here is my idea. It is going to be made out of 3 layers of bamboo sandwitched together, similar to ergodox cases, or the acrylic cases GON sells. I am going to get the bamboo laser cut from ponoko.com and the layers will be held together by something like this. Each layer will be 6.7mm thick. There is room left on the edges so I can sand off the charred part. Here is a link to download the design I came up with in illustrator - https://www.dropbox.com/s/02wskc6sy4n5f6w/60%20PCB%20mount%20case%20v1.eps?dl=0

I am just going to drill holes manually and put some standoffs in there, but I will need to actually have the PCB I plan to put into it first.

[nubbinator]

Isn't bamboo prone to splitting and splintering when drilled?  It might be better to drill small holes and join them with dowels than to use screw posts.  I've seen screw posts ruin acrylic/plexi, so I'm sure you'd run into the same issues with bamboo.  If you glue the layers and put masking tape where you want to drill holes, then drill small holes and tap dowels it, it may be stronger over time with less chance of causing problems.   

This is just me thinking out loud though.

[wes1099]

Isn't bamboo prone to splitting and splintering when drilled?  It might be better to drill small holes and join them with dowels than to use screw posts.  I've seen screw posts ruin acrylic/plexi, so I'm sure you'd run into the same issues with bamboo.  If you glue the layers and put masking tape where you want to drill holes, then drill small holes and tap dowels it, it may be stronger over time with less chance of causing problems.   

This is just me thinking out loud though.

Good point. Maybe I should get the holes cut with the laser instead of drilling. The dowels will be nice because I can get them ~100% flush with the rest of the case with sandpaper. Do you think 3/16 dowels would work? The portion of the case that the dowels would go into is 15mm wide and 3/16 is about 4.76mm. If I used 3/16 dowels do you think 4.25mm hole would be good? What should I do for the standoffs?

[nubbinator]

I'd get the wood dowels you want to use first and measure them.  Remember, wood swells and shrinks unless dried out and sealed or stabilized.  Additionally, wood is usually smaller than the stated dimensions (2x4s, for example, are usually closer to 1 1/2 x 3 1/2), so you need to confirm the diameter of the dowel.

I'd try to get close to the dowel diameter since you'll want some glue on the dowel peg to make sure it stays in place.

[wes1099]

I'd get the wood dowels you want to use first and measure them.  Remember, wood swells and shrinks unless dried out and sealed or stabilized.  Additionally, wood is usually smaller than the stated dimensions (2x4s, for example, are usually closer to 1 1/2 x 3 1/2), so you need to confirm the diameter of the dowel.

I'd try to get close to the dowel diameter since you'll want some glue on the dowel peg to make sure it stays in place.

Ok. I think I will order some 3/16 dowels and measure them. If the 3/16 is too small, I will go to 1/4. I would guess I should use wood glue right? For the standoffs, should I try and drill some small holes for them and glue them in with epoxy just to make sure they are secure?

[nubbinator]

I'd do wood glue.  Epoxy for the standoffs should work.  Be careful with the bamboo if it's thin.  If it's really thin, you could do a secondary base layer, laser holes large enough for screws that will fit into the bottoms of the stand off, and use a threadlocker on the screws.  I'm not sure if that second part makes sense.

[wes1099]

I'd do wood glue.  Epoxy for the standoffs should work.  Be careful with the bamboo if it's thin.  If it's really thin, you could do a secondary base layer, laser holes large enough for screws that will fit into the bottoms of the stand off, and use a threadlocker on the screws.  I'm not sure if that second part makes sense.

Ok I have two ideas. I can either extend the middle layer out to the standoff locations and laser the holes, or I can glue bits of excess material where the standoffs go, and drill into that. If I wanted to laser the holes, I would have to somehow find out where the holes go.

EDIT: I think I figured out how I can get the mounting holes in the right places.

[wes1099]

I'd do wood glue.  Epoxy for the standoffs should work.  Be careful with the bamboo if it's thin.  If it's really thin, you could do a secondary base layer, laser holes large enough for screws that will fit into the bottoms of the stand off, and use a threadlocker on the screws.  I'm not sure if that second part makes sense.

What size standoffs should I use? I figured you would be the person to ask because I saw your buildlogs for 60% cases.

[wes1099]

My solution for securing standoffs is just to leave the middle layer solid just like the bottom layer, and have holes lasered where standoffs need to be. I will fill the hole with epoxy and put the standoffs in the epoxy filled hole and they should be secure. I just need to get the dowels so I can measure them to get the right hole size before I hey things layered. I also need to figure out what size standoffs I need. I think m2 standoffs might be too small but I'm not sure.

[wes1099]

I just realized that I did not make any cutouts for the USB port. I think I am just going to end up using a dremel to cut out a hole for the USB because I am not exactly sure where the port will end up being.

[tufty]

Use wood glue, preferably a D4 (outdoor use) PVA.  Titebond 3 or similar.  Don't use PU, it foams and makes a ****ing mess of everything. 

You will need to slightly rough the surface, 120 grit sandpaper and then don't touch the gluing surfaces with your hands. Spread a thin (translucent) layer of glue over both surfaces, make contact, and press for twice the recommended time (bamboo isn't wood, it's grass, and it behaves differently to wood).  You'll get best results by vacuum bagging rather than using clamps, but if you have to clamp do so between 2 pieces of flat hardwood, and use as many clamps as you can.  Don't over-press, you only need enough pressure to keep the surfaces in contact.

Remember that Bamboo isn't wood, it's grass.  You absolutely must pre-drill all holes, and if you're considering dowels, make sure they are only "tight" as opposed to an "interference" fit, and glue, again with PVA.

[wes1099]

Use wood glue, preferably a D4 (outdoor use) PVA.  Titebond 3 or similar.  Don't use PU, it foams and makes a ****ing mess of everything. 

You will need to slightly rough the surface, 120 grit sandpaper and then don't touch the gluing surfaces with your hands. Spread a thin (translucent) layer of glue over both surfaces, make contact, and press for twice the recommended time (bamboo isn't wood, it's grass, and it behaves differently to wood).  You'll get best results by vacuum bagging rather than using clamps, but if you have to clamp do so between 2 pieces of flat hardwood, and use as many clamps as you can.  Don't over-press, you only need enough pressure to keep the surfaces in contact.

Remember that Bamboo isn't wood, it's grass.  You absolutely must pre-drill all holes, and if you're considering dowels, make sure they are only "tight" as opposed to an "interference" fit, and glue, again with PVA.

Ok. Thanks for the advice. I am going to go order the glue and I think I am going to get the dowels tomorrow. I can't vacuum bag it, and I only have 1 clamp, so I will pick up some clamps at the hardware store when I get the dowels. If clamps turn out to be expensive, I might just have to sit a bunch of heavy hard-backed textbooks on it. I do not have lots of money, so I will have to work with what I have.

[nubbinator]

Not amazing clamps, but they do the job for dirt cheap.