Mini 1/4" plywood display shelves


#1

@MiniMouse contacted me a few weeks ago requesting some aid in redoing some shelving for the display of her beautiful miniatures. The shelves she has are fine, but the side brackets are cut so that the shelves aren’t flat but dip down toward the back. The miniatures tend to slide to that back with the existing design.

I thought this would be a nice project to work on. Since the design is pretty simple and uses standard 6mm /.23" 5 ply craft plywood, I could make matching side supports for her. I did a rough design and printed it in cardboard to get a feel for how the design works and @MiniMouse got busy tracing out the existing pieces and modifying it to keep the shelves level.

The cardboard model worked great. Now I have a design I can use to print my own display shelves when I get to San Mateo for Maker Faire using recycled found cardboard!

@MiniMouse’s design worked very well so I could see how deep the notches needed to be. The only thing was to test the plywood (I bought a couple sheets of 12 x 24" Menards). and see how the kerf works to adjust the slots for the .23" thick plywood.

One thing I learned was that in compensating for the kerf, when you are cutting a thicker material, like this plywood, the kerf wider at top and narrower at the bottom does make a difference. I made the settings so that the cut just barely makes it through. That means that if it fits snug at the top, it will be too tight at the bottom. So for the .23" plywood, the slot needed to be .24" wide for a snug fit. This is an interesting point because I just assumed I’d use the normal .014" allowance. I kind of knew this since it is what I had to do for making the bookcase/cd shelves a while back, but I didn’t quite catch the whole issue.

Test notches both for getting the dimensions of the notch correct and for getting the cutting settings correct.

End supports and two of the four shelves needed.

Assembled.

In adjusting the notch dimensions I left a little play since I was only doing the side supports and @MiniMouse would use the existing shelves for these brackets. But it holds together tight.

A couple other points to consider:

The laserbits masking does not stick very well to this unfinished plywood. The surface of the ply is not very smooth. So I have to be very careful to press the masking on firmly and keep an eye on the cut. Loose masking can interfere with the cut and burn. So there is a little sanding to do at the end because of the loose masking.

In regards to using hardware store plywood: another point to consider is that almost every cut had areas where there were skips due to voids or some type of knot or harder substance in the inner layers of the ply.


I used an small razor knife to finish the cuts on a few of these spots. Some of these voids made it difficult to release the form from the matrix.


Here is the design file. I thought of several different ways to do this in laying out for optimum nesting and material usage. One problem is though if you include the shelf in the design and have all the other shelf brackets duplicated, it all overlaps and you can’t position it separately in the Glowforge. So it is easy enough to copy and paste and rotate. Cut two side bracket supports and four shelves.


Weekly Highlights for the Week Ending April 22nd, 2017
In search of: Small shelf for showing off things on conventions
#2

Yeah, it has turned out to be way less adherent than I thought for a purpose built product…


#3

Notice the flashback points on the right side on the one picture, regularly spaced according to the cells of the crumb tray.


#4

Looks great @marmak3261! Thank you so much for your help.

I’ll be trying them out soon and will post pics of them in use next week. :slight_smile:


#5

That was so nice of you! It looks great, and thanks for the kerf advice! I haven’t used much non-proofgrade except for things they don’t sell, and I’m thinking that’s the way it’s going to be going forward. For a low-volume person like myself, I just don’t want to waste time and material trying to get the settings right.


#6

That turned out great! So wonderful of you to make them for her. :smiley:

(And I’ve run into “non-release” problems on many of the non-Proofgrade materials that I’ve cut too, so it does add testing time up front to the workflow for those, to make sure you’ve got a complete cut.)

Awesome!


#7

Looks great! Custom displays will be a ton of fun to make :smile:


#8

Like another level or two would also make good pet stairs.


#9

As always, great job and explanation! Helps me tremendously.
Thanks!


#10

Or make them smaller and display spices! Although I hate to lose cabinet space under the stairs.


#11

Just make them all different colors. Then you can manipulate them in the GFUI individually.


#12

Nice work!
I was just reading about glue in plywood resisting laser cutting and invisible glue spills/smears on the surface causing a skip in the cutting just like in your pics.

http://n-e-r-v-o-u-s.com/blog/?p=6042


#13

#14

Could that be avoided by standing the board on some bits of scrap in the corners to lift it about 1/8" off the crumbtray?


#15

I followed your link to n-e-r-v-o-u-s.com and was interested in their hunt for a perfect laserable plywood.
My own solution, which needs ~1mm or less thickness of wood that I can use with a piercing saw(soon to be replaced by the laser), was to laminate two layers of veneer, steamed pear wood in my case, with the grain at a slight angle between each sheet. Used a pva glue, and a small vacuum press built for the purpose.
Worked perfectly.


#16

How about showing some of the miniatures?


#17

Thanks for sharing this, @marmak3261! I’ve been working on something related for a spice rack. It’s inspiring to find time to print it!

Re: masking, it’s tricky as masking that’s too strong will pull up splinters from the surface of the plywood. Proofgrade material is prefinished which solves this - I’d recommend trying a coat of shellac before applying the masking to help it adhere better & come off easily. Natural shellac is laser compatible (but be careful of other sprays like lacquer and varnish which are sometimes labelled as “shellac”). I believe Zinsser is a natural product.


#18

Is it possible to buy shellac crystals in USA ?
Always used to make my own varnish, but not needed to for years !


#19

RioGrande Jewelry supply carries them
https://www.riogrande.com/Product/Orange-Flake-Shellac/118066

Great and useful stuff, You can warm it with a torch to a goo and embed small parts in it for secure holding.


#20

Thanks Tom.
Bookmarked !