Scroll Saw Bowl Re-Reborn (Re-incarnated?)

acrylic
scrollsaw
cardboard
bowl

#1

Continuing the discussion from Scroll saw bowl reborn:

Been working with @jordanloshinsky to assist him in making his squiggle bowl design a reality on the Glowforge. Here is what I have come up with so far.

In cardboard and hot glued. The biggest challenge is figuring out how to accurately position each successive ring. I’m not that precise of a guy.

This next is the 1/4" acrylic that I found. It didn’t cut all the way through on some of the inner rings so I had to force them apart and broke a few. Reminds me to do a test of wavy circles and not just straight lines to make sure that settings work for different designs. Should have done 85/15 with two passes.

This is stacked and not glued.

I have a feeling that I’m going to use this 1/4" acrylic up pretty quickly. It’s nice stuff. This design would work better with thinner acrylic though since I can only cut a bowl of 10.25". It appears a bit thick.

Going to practice the design on a few other materials and have some ideas in the hopper for cool effects.


Weekly Highlights for the Week Ending March 25th, 2017
#2

THAT IS SOOOOO AWESOME!! I can’t wait to make this out of wood!


#3

It’s lovely in acrylic. What do you intend to use for glue?

Next step: edge light it!


#4

I have no idea at the moment. I know there have been lots of discussions for acrylic gluing. I won’t be gluing this one since it didn’t cut correctly. Bottom edge is shattered and lots of sharp edges. Look closely and you can see some red from a cut! Four rings are broken in one place and one ring is broken in four places. Proof of concept though.


#5

Owie! (I’ve only had to deal with one splinter so far, and that was from the box-store ply when we cut it down to fit.)

Looks awesome though, even if it isn’t comfortable to handle! :grin:


#6

You shouldn’t have to bleed for us. I call that true dedication. I love your design and all of the cool stuff you are making. :smiley:


#7

Very nice. Could you etch each layer with line up markings of the layer above to help with location when gluing up the bowl?


#8

I’ve thought about registration marks. Right now it is a 27 minute print since it goes through each cut twice. Add an engrave on and who knows how long it would take. Definitely worth thinking this through though because it does need to be precise.


#9

I wonder if a quick once over with acetone could smooth out the edges and get enough layer stick to be worthwhile. Though the precautions and cleanup may not be worth finding out.


#10

You don’t know how happy I am to see this in reality, after 1.5 years of wait. This is one of the projects I bought my GF for!

I will be making a few wood blanks with different strips of wood per blank to send to @marmak3261 . Hopefully this weekend.

As for registration marks and such, I never did with mine. I started from the smallest and worked bigger. Using a diluted wood glue in a syringe, I worked outward. Every one to two layers I would flip over and place a few books on top to pressure for a few mins. Once you have a very busy apprence with multiple woods, minor misalignment becomes indistinguishable.

Thought a series of small brass pins periodically would add some pleasant funk.


#11

I don’t know if it would work, but what if we inverted the bowl made from layers of different colored acrylics and slowly rotated it while an appropriate solvent was dripped on it from the top? Could we get a blending of acrylic colors in a stalactite/stalagmite form?


#12

Another great project @marmak3261, thanks!

This concerns me. I was under the impression that the GF specs at least allow up to 1/4" cuts in acrylic? @dan why is it struggling here? Should it cut slower? Also, is 2 passes on acrylic a good idea? Does it not melt the first pass edge faces during the second round?


#13

No concern. This was the first time I cut acrylic 1/4" thick. I just needed to boost power and slow down. It was two passes but I was trying least power as possible at a higher speed. It wasn’t Proofgrade so I was guessing. I cut some other pieces fine but they were smaller squares. It’s standard to do thicker acrylic in two passes. After I did this I found my 1/4" Proofgrade and checked it out and the Default is two passes.


#14

I prefer 2 passes on thicker acrylic. It gives it an amazing finish.


#15

What an awesome collaboration!

I wonder if you could create a jig to align the pieces that would be a cross-sectional profile of the bowl opening. Something like this.


#16

I was thinking the same thing as I was scrolling through the posts. My idea was to use the same wavy pattern to “lock” in the pieces and build it upside-down. Yours uses much leas material and can work with multiple wavy variations of bowl designs.


#17

Ah ok. I did not see your original settings, only your conclusion that you should have done 85/15 setting with two passes. I assumed you had cut at 100% first time and it didn’t work. What were your settings the first time around if you can remember - sorry if I missed it(?)


#18

Still, I was under the impression that the original spec was that 6mm acrylic could be cut with one pass…

I guess up to 25mm or more could be cut with multiple passes if the edges give an amazing finish (?)
Are there any guidelines about multiple passes on acrylic / timber etc - maximum number? Or can we cut stuff as thick as fits into the machine? What happens with the laser focus in this case?


#19

One if the fundamental problems with deep cuts on a laser is that the beam is cone shaped. So as you try to focus deeper and deeper the side walls of the cut above impinge on the cone. If there is enough power to ablate at the fringes of the cone it will cut a V but if not the walls reduce the power at the focus point below.

The GF can only focus over a 0.5" range so I don’t think cutting 25mm deep from one side is realistic.


#20

Cool! It looks really bloody great :grin:

With wood of different colors it will look even cooler.