So having looked at a lot of failures on my project I began looking for places where I could extract some value. First success, the buttons!
YAY! Buttons fit!
Then checking out the engraved converted to outline fonts turned out quite well.
The engraved areas looked pretty good.
Then I tried filling it in with paint…
Infilling the text
More infilling
Finally a look at what the panel looks like with the cover paper removed and the LEDs installed.
Infilled panel with LEDs installed
As mentioned previously my Ponoko order arrived.
So people tend not to show off their screw ups. The purpose of my building this site was to share with friends, family, and the internet at large what exactly it takes to create a coffee roaster controller. The money, the heartaches, and well…. the good… the bad… and the ugly.
Unfortunately, today I give you… the ugly.
The Ugly
You don’t usually get to see what goes wrong with laser cutting jobs but considering how many times the curves overlapped each other I’m surprised it isn’t worse.
Surprised it isn't worse!
Most of what’s wrong with the job is obviously what happened on the bottom where the acrylic came in contact with whatever Ponoko cuts on top of. It seems that some sections obviously burned and melted/cratered portions of the acrylic.
Some areas are brittle.
In a few places the plastic is brittle but only from the bottom side but that last one looked ok on top but there wasn’t enough to count on it not breaking later. In some areas pieces burned back into one another!
Some areas burned back into one another
Many of the bad spots would not be an issue for a small one off project that gets covered with some sort of screw or bolt. Others that appear on the surface would be a huge deal. A few places I apparently removed too much line near a curve and didn’t fill in the straight line so I need to dremel off some stray plastic.
Oops! Apparently I deleted too many straight lines!
Outside of the too many circles and that stray plastic I did not make the spacing correct on the hole that keeps the fan and heat potentiometers from spinning even though I measured it with a micrometer. It was VERY close but still off by a small bit.
Close... no cigar
I could totally fix it with the dremel for now but will fix it properly for the next run. Also it appears that I calculated a reduction in the length of the inner bottom plate wrong.
Sometimes you forget you already subtracted the length off the total.
I had taken the outside measurements and subtracted the thickness of the acrylic twice when I had subtracted the rear once already and then subtracted the front and rear later. Finally I calculated it into a measurement adding it back twice instead of the one extra time. As a result it is too short front to back.
For these parts I will be testing the process of infilling the engravings for the test to see how they come out for very narrow and wider text. I will also (when the tools arrive) test the drilling and countersinking with a few various plastic bits before trying them out on the final plastic pieces.
So I’ll be the first to admit I have no idea what I’m doing. Assuming I benefit from a miracle I will eventually be in possession of a laser cut case and it will actually look acceptable.
Ponoko had a spend at least $50 and get a $50 voucher promotion. I’ve spent days moving lines around and changing colors and thickness and deleting stray bits out of it until I couldnt see straight. Tonight I finished a 31 x 15 sized panel. For giggles I put two cases on one panel since it seemed to be the most efficient way of dealing with this. On one panel I used vector engraving for the labels. On the other I used vector engraving with a raster fill for fancier looking fonts. I’m curious how both look and intend to try to fill them with paint to see if they look ok with the various sizes represented.
I’ve thrown together paper models trying to confirm spacing and suitable sizes/dimension and had wanted to try to create a model using some paper coated foam board but I ran out of time. The promotion ended tonight and I was running out of hours and decided to just give up and hope all my calculations and re-calculations and CAD drawings and everything else I’ve tried were correct. The order only covers part of the case and I still need to generate a left side panel in addition to the right side one. The front, bottom, top, and rear are all covered already. I have a second project I was going to include in the excess space but I figure I should wait for the first order to come in and see how it turned out. If anything is horribly wrong I’ll try to get it made again using the voucher but otherwise I’ll just continue on if it came out ok.
First laser cut job sent to Ponoko
The top left is the raster filled engraved layout. The next one to the right is the non filled one. Next, the bottom piece. The two items on the bottom right are “inserts” for the LCD area. I sized them out for the 7 inch touch screen with the two panels able to be “popped in” to the opening to hold a 4×20 New Haven Display mounted into the piece.
Supposedly if you make a rectangle at say 50mm and then make a second rectangle somewhere else at 50.2mm this .2mm is referred to as “kerf” or something. This sizing allows you to friction hold a plastic piece in an opening…. I figured I’d try it out to see how well that works/doesnt.
Continuing to the left on the bottom there is a cut rear piece on the bottom with a slotted front plate above it to allow air to be pulled through to the fan opening cut into the rear. Next are two right side pieces. One has a position cut out for a termocouple connection and then the other does not have one. Finally on the far left bottom is a second rear with no cut outs and a front panel with the slots cut into it.
Once I decide if I totally botched this I will either redo the job or continue with the right side plate and any adjustments for other sides that I think I need. Then I will find some acrylic square “rod” to glue into the corners. Some of the positions will be drilled for mounting the top/bottom/rear and the others will just be glued. I intend to be able to unscrew the bottom, rear, and/or top while the other edges will be glued in place. I just went this route since I wasn’t sure on the screws I’d end up using and wanted to see how well things turned out before I would go back and laser cut any of the pieces with more holes in them or whatever else I want to do to it.
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