2020 aluminum extrusions - Page 1
Forum section: electronics / general

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: July 06, 2021, 02:24:39 pm
content: These extrusions seem popular and cheap.https://www.aliexpress.com/item/4000045797350.html?spm=a2g0o.productlist.0.0.532d6078t1K3HK&algo_pvid=ffa45c1b-106a-45bc-b63f-7cacf8416007&algo_exp_id=ffa45c1b-106a-45bc-b63f-7cacf8416007-2They also come in various lengths so I don't need to cut them myself. Cool.All I want to build is the world's most useless Commodore 64 chassis build. So a frame with some PCB standoffs and some extra bracing to hold other boards, sort of like a PC test bench, but for fun.Can anyone tell me if they ordered this stuff from aliexpress, does it arrive in usable shape? What other hardware should I look for to make a nice big order? I know there's t-nuts, solidifier plates (triangle things), what else?Screws?

author: beanflying
author_rank: Super Contributor
timestamp: July 06, 2021, 02:34:49 pm
content: Last lot of T slot I brought was a lot less than that locally ($7.25/m AUD to $20AUD on AliX via your link).The fittings are/were a different matter Aliexpress or evilbay are typically way cheaper than local. Same thing applies to 4 and 5mm screws etc.Also for drilling and tapping I designed a simple drill jig here if it helps also a link to a step drill to suithttps://www.eevblog.com/forum/3d-printing/3d-printer-yet/msg3571113/#msg3571113

author: thm_w
author_rank: Super Contributor
timestamp: July 06, 2021, 08:31:26 pm
content: Depending on how many you need, may be cheaper to order from Misumi.I ordered the brackets and screws from Ali and the 2020 extrusions from Misumi. They still ended up with a few dents on the ends (same as the ali ones are shown in their reviews, go to reviews and click Photos button).You'll want M5 screws, M5 t-nuts, brackets. Maybe M3 t-nuts, plastic inserts or clips, depending on if you have a 3D printer or not.

author: Skashkash
author_rank: Regular Contributor
timestamp: July 06, 2021, 09:52:24 pm
content: Yeah, I bought 2020 extrusion in bulk from Misumi a while back. Worked out pretty cheap, even with shipping. I like having an inventory available of the stuff for when an idea comes along.But definitely shop around for the nuts, screws, and angle brackets from other sources (china). And buy plenty. They can be pricey, and you wind up using WAY more of them than you realize.You do need a chop saw with the right blade to cut the 2020 to length though. Also helps to have a 5mm tap.

author: themadhippy
author_rank: Super Contributor
timestamp: July 06, 2021, 10:02:14 pm
content: QuoteHacksaw and an engineers square is much cheaper,although it does require a bit more effort than just pressing a button.

author: thm_w
author_rank: Super Contributor
timestamp: July 06, 2021, 10:21:18 pm
content: Misumi cuts to length ordered, so best if you can figure out length you need beforehand. They are insanely accurate and clean cuts.Then add in some spare pieces of reasonable length, 0.5m-1m or so.

author: langwadt
author_rank: Super Contributor
timestamp: July 06, 2021, 10:33:25 pm
content: Quote from: Alex Eisenhut on July 06, 2021, 02:24:39 pmthere's also the smaller 10mm makerbeam, 15mm openbeamhttps://www.technobotsonline.com/makerbeam-starter-kit-in-black-anodised-threaded.htmlhttps://www.technobotsonline.com/openbeam-precut-starter-kit-pc1-in-black-anodised-with-storage-box.html

author: RoGeorge
author_rank: Super Contributor
timestamp: July 06, 2021, 11:58:16 pm
content: Quote from: Alex Eisenhut on July 06, 2021, 02:24:39 pmT2020 Al profile are usually available locally. They are very common especially in the last 10 years or so, since the 3D printers took flight. Those profiles are usually available in any shop for makers or 3D printers. Some have black/green/blue/red finish, but beware the finish can easily scratched by other sharp metals or tools, I prefer the natural Al (oxide) finish, the natural color of Al, but matte.Many times the Al profile seller offers to cut the profiles at specify length, sometimes for free, other times for an extra fee.There are T-slot nuts, corners and other helping elements to build something out of Al profiles. In pieces quantity they can be quite expensive for a complex build, but if you buy in 500/1000 pcs bags they are cheap. I bought two bags of M3 and M4 T-slot nuts for 20x20 profiles from Aliexpress. Not sure if they are made for imperial units, too, here we use mostly Metric screws (M4 means the hole+thread in the nut is made to match with a 4mm in diameter screw).For screws, you need to match them with the T-slot nuts. The most common can be M3, M4, maybe M5, not sure. I bought screws in various lengths and head types from a local shop.Last time I bought T2020 profiles a few years ago. Bought them locally because they were cheaper than the ones from Aliexpress, so search your local shop first. Mine arrived well, no bends no scratches, shipped from another city and they were 2.5meters long, so easy to bend during transportation. Even if locally they might be slightly more expensive, it might worth because Aliexpress deliveries were in average 3 months, sometimes half a year.In my experience 3-6 moths of waiting for delivery is a very de-motivational factor for any project. Most of the things bought from Aliexpress ended unused, in a box, because 3 to 6 months later you'll move away from that project to something else.So yeah, good shopping experience Aliexpress, never been scammed, packages arrived without damage (not Al T slots, but other long packages did well, for example 70 cm long linear rails, or 50 cm long and only 5 mm thick fiber carbon tubes). Aliexpress is OK, but the shipping is too long so I give up using it. For T slot profile 20x20 Al, back then it was more expensive than a local buy.

author: beanflying
author_rank: Super Contributor
timestamp: July 07, 2021, 02:39:42 am
content: Quote from: themadhippy on July 06, 2021, 10:02:14 pmTracksaw and a -1 degree rake high tooth count blade works well for accuracy but a mitre or circular saw will work well with a similar blade providing you get it set up square. That said I am making a sled today for my Bandsaw (14TPI hardened tip blade) for 2020 bits as it is still one of the easiest and safest ways to cut smaller lengths with accuracy as you can clamp both sides and it keeps both parts square for the full cut. Add a stop block for repeat accurate cuts.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: July 08, 2021, 01:26:52 am
content: Thanks, indeed I found a local place and it's half the price of the alix stuff, and it's five minutes from work.