I’m looking for a way to get high rigidity and low weight links for robots that I am thinking of converting from plywood to a different material. Aluminum seems like the bets bet. I understand that its most likely going to have to be waterjet cut, which means outsourcing. Does anyone have any good links for places for a hobbyist (small orders, money constraints) to get waterjet aluminum pieces?
On another note, is there any other material that would give the same kind of properties as aluminum, but easier to acquire/cut? Lasercutting delrin comes to mind for me, but its not exactly the nicest thing to lasercut on your own machine (formaldahyde fumes, indistinguishable flames = fire risk).
“Big blue saw” does regular sales on aluminum plate waterjet cutting (0.25" 6061 and such.) Sign up for their mailing list to get told about the next one.
There’s also “rapid sheet metal.”
Pololu may be able to laser cut thin sheet stainless steel (22 gauge perhaps?) as they do this themselves for the Zumo blade and other parts. I notice it’s not on their main page, but perhaps you can mail them and ask? If you do, you should plan to bend or roll the edges of your parts for more strength.
I’ve found Delrin to be more expensive than aluminum for comparable applications, although I haven’t looked very hard for a low-cost supplier. Also, here’s a thread with machinists comparing Delrin to Aluminum, and I mainly agree: Aluminum is generally better: practicalmachinist.com/vb/cn … ost1081071
Do you have a maker space nearby? Learning to mill aluminum can be a fun and rewarding hobby. And after the hundredth part you make, you’ll have made back the cost for tooling and learning compared to shipping it out to a third party
As jwatte mentioned, we can cut stainless, spring, and general-purpose steel up to 0.060" in thickness. We also laser cut Delrin, ABS, acrylic, and various other plastics and woods. If you are interested in a quote for having us laser cut your parts please submit a quote request and we’ll get back to you within 1-2 business days.
In case you’re interested, we summarize some of the properties of a few of the materials we cut in this section of our Laser Cutting Guide. McMaster-Carr also has some nice summaries about various materials they sell including their plastics.
I hope this helps!
Thanks for the replies and the links!
I’m particularly an enthusiast of “fast prototyping” in the sense that I want to do quick iterations, so despite having been trained pretty well to do hand-milling/lathing, I am looking for faster approaches. the links you sent are a good basis for understanding materials for lasercutting and such.
I was interested in seeing if theres an option to doing this in-house, which makes waterjet cutting less viable (but when you need it, I guess its there). Plasma cutting is another tool, and heres a link to a promising one: gotorch.com/?gclid=CM3S2tHFm … fgod158Adg
setup cost is about $5K, and countless hours to learn, but it may be a permanent solution.
Regarding the prev. comments about steel, one way to get around the weight of the metal is to sandwich plywood in between thin sheets of stainless steel and fasten it together – it does a good job of being quite rigid and getting a bit of both worlds (metal strength, wood weight – you can hole-out your wood to make it lightweight). its a bit more work, but will get the job done. Also, you can then use a laser-cutter only (given that you have a powerful enough one).
If theres any other tips to achieving aluminum-like performance, i’d appreciate any other tips. Thanks!
Plasma doesn’t give you very good precision, though, and the finish of the cut is very rough. I’d rather get a laser cutter that can do steel if I had the choice