I am looking to purchase a hot knife for cutting holes in ABS plastic project boxes - for square switches etc. a lot of the reviews on Amazon report them dying after a short time. I have a Hakko FX888D-23BY Digital Soldering Station and then a small Weller 40w soldering iron. So buying a tip for one of those is an option maybe. Any recommendations?
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You can grind an iron tip like this http://www.instructables.com/id/How-to-cut-squaretriangle-holes-in-ABS-project-bo/
My recommendation is to laser cut the holes precisely out of the ABS with our laser cutters.
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If you have a nice iron that they sell a hot knife tip for I would just go that route. The cheap irons are the part that break not the tip, so why not use a good iron.
ABS is forbidden on our laser cutters.
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To better inform,
We shouldn’t cut ABS plastic on the laser because it out gases Cyanide when burned, another issue is that ABS tends to melt rather than cut. This leaves often a sloppy result.
If you are interested in more info on cutting different materials, the ATX hackerspace has a cool write up.
http://atxhackerspace.org/wiki/Laser_Cutter_Materials
EDIT:
I’ve added the atx materials list to our wiki as well. I made a new page called Laser_Cutter_Materials. If anyone would like to add items to the page just try and follow the formatting as it is nice. Also, not sure how to link the page on the laser committee wiki so if someone would do that for me it would be appreciated.
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dremel tooool ftw
IMHO
Can we cut HDPE om the laser? I’m currently cutting it with my dremel with very melty sloppy results.
Abs doesn’t harm the laser. Just stinks to high hell and creates black smoke. It shouldn’t be cut in mass quantities though.
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Cyanide may not harm the laser, but it isn’t good for you. That stinky smoke contains cyanide.
Hi Clayton,
If you look at the link for the materials page it does mention HDPE:
HDPE/milk bottle plastic Catches fire and melts It melts. It gets gooey. Don’t use it.
So, it doesn’t strait up destroy you or the laser, but it seems to be a troublesome material to use. I’m not saying that you can’t or shouldn’t use it, just be cautious as it can when handled incorrectly mess up things / burn the laser down. But, to be honest it seems like anything the laser can cut could burn the laser down when not handled well. 
I would not trust that table. ABS does NOT emit Cyanide in large enough quantities to be concerned with. PVC can and will emit Cyanide and Chlorine Gas.
When in doubt find the MSDS of the material that you are looking for.
http://www.plasticsmadesimple.com/DataSheets/ABS_MSDS_GP.pdf
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Where does the MSDS talk about the levels of cyanide from burning? I looked over the form you posted and it stated when burned (closest I could find to laser cut) produces thick toxic smoke. When melted the fumes are an eye, skin and respiratory irritant.
Not saying your statement is incorrect, but the source you cited didn’t give a suggestion to me that burning ABS was a good thing.
well, that’s because it isn’t.
how toxic and why is really the question at hand…
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In further looking found a nice white paper talking about toxicity of ABS plastic when burned.
Page 104 has a cool graph showing amount needed to be burned and how toxic different plastics are compared to each other. I highlighted the ABS in green.
Also just below this graph they explain that the principle gasses which make ABS toxic are HCN (Hydrogen Cyanide) and CO (Carbon Monoxide).
Thanks for poking me @william_petefish and @jast it was cool learning this and moving beyond an MSDS sheet. I’m still not sure at what levels we consider ok? Another side not to the paper is that ABS mixtures are not standard and curtain formulation are more or less toxic. So there may not be a cut and true answer.
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I also found data that suggested that combustion conditions could make at least a 100x difference in HCN formation. But it appears that laser cutting with air assist would be at the low end of the scale.
Almost always the case.
Good work on digging this up!
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I have a restaurant grade plastic lid I was hoping to cut a hole out of tightly for my Sous Vide machine.
You could always use a drill bit. I also have a plastic hole reamer I use to cut holes in my plastic RC bodies.