How to cut ABS plastic boxes? Or which plastic to use? - Page 1
Forum section: electronics / projects

author: msr
author_rank: Regular Contributor
timestamp: December 05, 2016, 08:58:08 am
content: Hi everyone,I built a prototype for a client and I'm using an Hammond box (ABS plastic). On that prototype I made a few cuts myself with a hot blade (cutter) but the end result is not that nice. Now that I need to assemble 20~50 units, I'm looking for someone that can cut it with a machine in order to get a polished cut.However, NO ONE seems to want to cut ABS. I'm having a hard time finding some one to cut it. But most prototyping plastic boxes I find on web are made of ABS (correct me if I'm wrong). So what's your go to kind of box when you need an enclosure for your electronics and how do you get the cuts on it (for low quantities, eg, 50~100)Thanks!

author: DTJ
author_rank: Super Contributor
timestamp: December 05, 2016, 09:58:09 am
content: I route them on a small CNC router, sometimes you have to drop the spindle speed down to stop melting.Check out local businesses that deal in machining & electronics sheetmetal they may be able to help.orCheck out local maker space or CNC forums near you to find a guy who will do them in his shed for $5 each.

author: Siwastaja
author_rank: Super Contributor
timestamp: December 05, 2016, 10:07:12 am
content: I laser cut ABS panels at the local hacklab. Lasercutting ABS requires good ventilation and limited amount of cutting (i.e., not super thick materials, but these Hammond panels are not too thick) due to nastier gases - and a bit longer waiting time before opening the machine compared to acrylic.I do the cutting and laser marking (text, symbols) in one pass, and I like the result, even though laser engraved text on black ABS is not very visible. The cutting quality is excellent.I made a custom jig that helps me insert the ABS panel so that it's in correct focus and orientation.

author: Dubbie
author_rank: Unknown
timestamp: December 05, 2016, 10:07:34 am
content: A single flute endmill can also help prevent melting.Sent from my phone using Tapatalk

author: george graves
author_rank: Super Contributor
timestamp: December 05, 2016, 10:08:04 am
content: Hammond will cut the cases for you BTW. It's on their site. Be ready to pay through the nose for it.Laser cutting ABS is the worst smell ever. Even with amazing ventilation, it stinks. And the plastic stinks for days. Be ready to "air out" the cases for at least a few days before packaging them or your customer will be greeted with something that smell like you dipped a smurf in crude oil and lit him on fire. Most maker-spaces will refuse to cut it. Or if they do, they won't do it again, especially 50-100 cases.Milling is great - and the set up costs won't be too much.

author: Siwastaja
author_rank: Super Contributor
timestamp: December 05, 2016, 10:22:42 am
content: Quote from: george graves on December 05, 2016, 10:08:04 amI wash the plastic after cutting with dishwasher detergent and a brush. Helps with the smell.Our local hacklab also has ABS on the ban list - probably because they have heard those stories, too - but I discussed with them before doing it, and did careful tests first as instructed. No problem whatsoever. If you are having serious smell problem even "with amazing ventilation", your "amazing ventilation" is possibly broken, or not so amazing - or you are creating far more gases than necessary due to bad focus and too much cutting power, or something similar.50 cases with a lot of cutting at once might be an issue, still. I have done four panels at a time. I think the laser is OKish when you do something like 5-10 prototypes and are experienced with the laser anyway.

author: george graves
author_rank: Super Contributor
timestamp: December 05, 2016, 10:45:07 am
content: Yea, but still. When you open that lid, the fumes come out. No way around it.

author: DTJ
author_rank: Super Contributor
timestamp: December 05, 2016, 01:38:45 pm
content: Quote from: Dubbie on December 05, 2016, 10:07:34 amYep, I use a two flute 2mm routing bit.Standard end mill bits melted really badly!

author: cvanc
author_rank: Frequent Contributor
timestamp: December 05, 2016, 02:39:23 pm
content: Quote from: george graves on December 05, 2016, 10:08:04 amLOL "EEVBlog Quote Of The Day"

author: Jeroen3
author_rank: Super Contributor
timestamp: December 05, 2016, 03:03:43 pm
content: I often punch ABS using a Greenlee punch driver. You drill a pilot hole and punch holes and squares.

author: Bud
author_rank: Super Contributor
timestamp: December 05, 2016, 03:13:20 pm
content: Greenlee punches work very well but they are expensive and only of certain sizes....

author: tggzzz
author_rank: Super Contributor
timestamp: December 05, 2016, 03:30:01 pm
content: Maybehttp://uk.farnell.com/camdenboss-fspt?ICID=I-CT-NP-CAMDENBOSS-HERO-3&CMP=ADV-ELPAG-NPI-000"Farnell element14 offer CamdenBoss’ high quality plastic enclosures, housing, covers and panels manufactured to your precise specifications without upfront tooling charges."FSPT (flat-sheet plastic technology) is uniquely suited to low and medium batch quantities (five to 5000+) and from simple to highly complex enclosure designs. For higher quantities the company offers a comprehensive injection moulding service including 3D moulding tooling design and full volume production capabilities."Also offered are additional customisation services including engraving, digital printing, shielding, finishing, assembly and packaging."

author: SeanB
author_rank: Super Contributor
timestamp: December 05, 2016, 06:54:13 pm
content: If you are doing CNC cutting of plastic use coolant, many soluble oils will not attach ABS immediately, so just take the finished ones out and drop in a large bucket of cool water and dishwashing soap to get the oil off.A nasty plastic to cut is PVC, as it will always make strings, and the material is corrosive when hot.

author: djnz
author_rank: Regular Contributor
timestamp: December 06, 2016, 10:39:12 am
content: You should avoid laser cutting ABS. Apparently it releases highly toxic gases / 'cyanide gas'. Ref:http://atxhackerspace.org/wiki/Laser_Cutter_Materials

author: Siwastaja
author_rank: Super Contributor
timestamp: December 07, 2016, 10:45:23 am
content: Quote from: djnz on December 06, 2016, 10:39:12 amALL plastics release highly toxic gases when laser cut. Laser cutting is extremely nasty! The machine exhaust must really work, and then you have the wait times before opening the lid. With acrylic, I wait at least 5 mins and with ABS, 15 mins. You also need to consider what happens to the exhaust. We had a problem with cutting acrylic at the former location of the hacklab because it was in a residential area. For that reason, we built activated carbon filtration system; in the end, it did work fairly well.Go google it, it's kinda difficult to find proper data or reliable sources on ABS laser cutting, only forum discussions by total amateurs (like me, to be fair!), and random hacklab rules referring to nothing, or at best, to those amateur comments. The fact that they just list all possible dangerous-sounding byproducts for ABS, but totally ignore the similar list for PMMA which they want to cut, shows that they have no freaking clue what they are talking about, and just want to prove their bias using difficult chemistry words they can copy-paste.I quote a good comment regarding forum fearmongering:"There is virtually nothing that you can laser cut that generates fumes that are safe to breathe. That includes materials like paper and wood. The problem with using the MSDS as a criteria is that there is no way that the average person who does not a degree in chemistry, biology, and medicine (maybe even another degree or two) can really make an assessment of the true risk. It always pays to be cautious, but I have looked at plenty of MSDSs and it is pretty difficult to make a judgment as to the safety of laser cutting" (source:http://www.sawmillcreek.org/showthread.php?144771-ABS-laser-safe&s=67e340c9c51708a3e4efbc85dadf940e)If ABS produced such freaking amounts of HCN and other gases that kill you, we would have problems with accidental ABS fires; it happens all the time.I don't have proper data, but it's a ridiculous assumption that the gases from PMMA are just fine and dandy and ABS instantly kills you. AFAIK, they are maybe one order of magnitude apart, at most. Hence, the recommendation to only cut small amounts of ABS, respect the ventilation times before opening the machine, and so on. General extra carefulness, limiting the exposure to the minimum possible.But demonizing ABS and going on with your life laser cutting other materials sounds like a textbook example of the False Sense of Security.I repeat, laser cutting is nasty! You do careful tests and you need to know what you are doing.From the link you posted, I quote: "ABS does not cut well in a laser cutter. It tends to melt rather than vaporize, and has a higher chance of catching on fire and leaving behind melted gooey deposits on the vector cutting grid. It also does not engrave well (again, tends to melt). " In myrealtests, ABS seems to cut just fine, without "melting" too much, without any slightest trace of any goo going anywhere, and the engraving looks OK too. It's not perfect like PMMA. Maybe they are discussing thick sheets of over 2mm or something, but they don't give any sources nor data, just authoritative order, which, of course, is just fine, you go by their rules when you are over there, but it doesn't help when discussing the matter outside their club.For the OP, I'd recommend CNC milling, too, but just giving my $0.02 regarding my very successful prototyping using laser cutting on these same Hammond ABS plastic ends, with absolutely no problems whatsoever, but OTOH, I'm only doing a few of these boxes. Each box has 25 connector holes, 4 LED holes, 28 ventilation slots, and two fans with large cutouts + screw holes, and a lot of text as marking, so they are not that small. If OP has something smaller, the gas problem will be easier on them.

author: Buriedcode
author_rank: Super Contributor
timestamp: December 07, 2016, 12:07:34 pm
content: I can't say I've done 'production runs' if ABS enclosures, but a fair number of projects over the years in the 5-10 quantity range by hand. It is indeed a bit of a sod for odd-shaped cutouts and for <15 units it becomes quite expensive do have someone do it for you - unless you're lucky enough to know someone local with a CNC machine.What kind of cutouts are we talking here? ABS is easy to drill - I've even used a pin vice for holes < 3mm, 4-5 twists and its through 2mm with a very neat hole. Cordless drill run slow is equally as quick.I had to do several handheld enclosures that required a cutout for a graphic LCD, so rounded edged box cutouts, as wlel as 20+ holes. Although its awful to do it 'manually' it was surprisingly quick, knocked out 5 an hour just drilling four holes and using a 'razor saw'. For very 'neat' cuts, I used a craft knife, because ABS is so soft it was pretty much like cutting thick card and didn't require cleaning up afterwards.The above doesn't really look that professional though, so it might be worth taking the hit by getting them manufactured for you if the quantity is 5+. For contracting reputation is important, so I rarely go for ABS enclosures if any sort of odd-cutout is required, instead opting for aluminium. More expensive, but there are plenty of places that will CNC aluminium panels.That isn't always an option though, especially for smaller hand-held enclosures. In those (rare) instances, I'm sorry to say I have spent far too much time doing it all by hand and tidying it up afterwards.

author: LabSpokane
author_rank: Super Contributor
timestamp: December 07, 2016, 05:38:13 pm
content: I've done a ton of production milling on ABS. It works fine.Mill with quality carbide cutters or cut with water jet. Do NOT cut with heat. Be prepared to buy lots of cutters if you do volume because plastic is surprisingly abrasive.I think your local shops are confusing ABS with PVC. No one will touch PVC because it releases chlorine gas when overheated and instantly corrodes all exposed steel. ABS will mill well with proper cutters and cutting speeds. Using cutting fluid is not necessary at all. Just add a vacuum nozzle near the cutting head for chip removal.Keep the cutting speeds down and all will be well.

author: calexanian
author_rank: Super Contributor
timestamp: December 08, 2016, 06:22:15 am
content: +1 for find a milling machine. Its the easiest way. Just thinking about the burning ABS smell gives me the creeps.

author: poorchava
author_rank: Super Contributor
timestamp: December 08, 2016, 10:14:17 am
content: CNC milling machine is the way to go. Use single flute endmill with steep helix angle for improved chip evacuation. For the same reason a mist coolant or compressed air a very good idea. Manual spray of WD40 works too, to some extent. I personally favor cooling mist, this way plastic doesn't melt. Compressed air must have very high stream veloicity to blow out the chips and you need to have a compressor efficient enough to keep up with the usage (on the other hand ABS machines very fast, so cycle time wouldn't exceed a minute or so given reasonable design and machine.Holes in ABS can also be stamped/punched and you can make a die yourself (or in other words, it doesn't have to be made out of crazy expensive crystallized unicorn farts like metal punches do)

author: george graves
author_rank: Super Contributor
timestamp: December 08, 2016, 10:56:22 am
content: Quote from: Siwastaja on December 07, 2016, 10:45:23 amI just can't believe you when you say you wait 5-15 mins to open the lid. I'm sorry, I don't buy that.As far as wood and paper goes, if wood and wood by-products were so dangerous to breath, then all those people that heated their houses with a wood burning stove for 100 years would have children with 6 fingers on each hand, and 2 heads.

author: tggzzz
author_rank: Super Contributor
timestamp: December 08, 2016, 11:23:13 am
content: Quote from: george graves on December 08, 2016, 10:56:22 amBad example. A wood burning stove has to be appropriately sealed and vented to the atmosphere. If not then people canand dodie of carbon monoxide poisioning. The same sealing and venting ensures the other combustion by products aren't released into the room.If there are more subtle failures, then DNA damage isn't a consequence. Typical consequencesareheart and lung problems of various kinds, all unpleasant.Don't go there.

author: sainter
author_rank: Regular Contributor
timestamp: December 08, 2016, 11:37:48 am
content: If the shapes are not too complex, try using nibblers (manual-http://www.dezmo.com/sale/hand-sheet-metal-nibbler-cutter-tool/). They leave clean edges. Easy to work with them. But after larger quantities it may become tiresome.

author: Jeroen3
author_rank: Super Contributor
timestamp: December 08, 2016, 02:49:05 pm
content: ABS box walls are often thicker than the gap the nibbler can eat.

author: calexanian
author_rank: Super Contributor
timestamp: December 08, 2016, 09:44:39 pm
content: A dremmel can be effective, but it makes a mess and you can get the burning plastic if you use the wrong bit and run it too fast.

author: amirm
author_rank: Regular Contributor
timestamp: December 09, 2016, 01:22:29 am
content: Quote from: poorchava on December 08, 2016, 10:14:17 amBack in 1980s I needed to have a hole in a hammond box and that is the method we used. My partner went to a friend who had a machine shop and he made the punch for us. I think it only cost $100 or something like that. He then charged us a buck or so to punch some 1000 boxes as we needed them. Very clean holes.

author: poorchava
author_rank: Super Contributor
timestamp: December 09, 2016, 07:02:26 am
content: Quote from: amirm on December 09, 2016, 01:22:29 amOn top of that stamping allows for true included corners, which milling doesn't because of tool radius.Sent from my HTC One M8s

author: george graves
author_rank: Super Contributor
timestamp: December 09, 2016, 11:18:35 am
content: Quote from: tggzzz on December 08, 2016, 11:23:13 amI'm sure all wood stoves were "appropriately sealed and vented to the atmosphere" for 100 years.I'm not sure why you are so fervent on this subject....I'm just amused - but mostly curious. What's up with that? Why do you feel so strongly about it (not that you're right BTW)

author: tggzzz
author_rank: Super Contributor
timestamp: December 09, 2016, 11:54:57 am
content: Quote from: george graves on December 09, 2016, 11:18:35 amI dislike sloppy analogies, especially when mixed with false "information".I dislike statements that, if followed unthinkingly, can lead to people harming themselves - or worse, innocent bystanders.For the avoidance of doubt, I don't care what adultsknowinglydo to themselves, and am not worried about paying my share of their medical bills.

author: george graves
author_rank: Super Contributor
timestamp: December 10, 2016, 10:32:41 am
content: Whatever tickles your pickle dude.

author: cncjerry
author_rank: Unknown
timestamp: December 10, 2016, 05:09:48 pm
content: I cnc mill ABS and other plastics all the time. If you are cutting thin material then use a single flute cutter as others have said. Also, you have to mill a couple to get the speed/finish correct. There's all kinds of alternatives but if milling works then that would probably be the least expensive for a small run.

author: Teledog
author_rank: Regular Contributor
timestamp: December 10, 2016, 05:47:03 pm
content: If you, or someone you know is good with 3D CAD (Solidworks, etc.), you might design the enclosure (.stl file) and print them out on a 3D printer?I've found a lot of custom enclosures that just happen to fit my projects on the Thingiverse website - do a search!G' Luck!

author: poorchava
author_rank: Super Contributor
timestamp: December 10, 2016, 08:59:10 pm
content: That's a bad solution. Even a high end 3d print doesn't come anywhere near injection melding and machining. On top of that 3d printing is expensive as hell for anything more than a one-off.Sent from my HTC One M8s

author: george graves
author_rank: Super Contributor
timestamp: December 11, 2016, 11:08:34 am
content: Quote from: poorchava on December 10, 2016, 08:59:10 pmNo all projects need the smoothness that injection molding provides. Also, I can 3d print a "hammond" like project box for less then what it would cost to buy. Throw in shipping and the time to wait, and it's a done deal. Not that I ever do that. I use my 3d printer more for making jigs and such. It's really good for stuff like that.