3D Printer

[Rehab1]

5 hours ago, esaj said:

Unfortunately, although the "cube" is made from aluminum extrusions, the frame's not entirely made from metal (the motors are attached with plastic parts ) Thoughts?

I also thought about purchasing a 3-D printer. It would be a great hobby for my grandson as well. I might be worried about a printer constructed of excessive plastic parts with all of the inherent activity.

Best to rely on ratings from other purchasers to determine what is the best printer for your money.

[esaj]

Oh yeah, I actually got a 3d-printer... about 20 hours after posting my message on this thread. I pestered my cousin about his experience with his printer, and ended up owning it the next day  It's a typical RepRap Prusa -clone, with some additions made later on (like extra fan at the extruder, motor heatsink, some parts to make it more sturdier and housing for the entire thing to keep temperature more even etc). Or more like, was made the new owner, he first asked me if I'd be interested in buying it, and then before I even had said yes or no, he said "either way, I'm bringing it over now". So, now I have a 3D-printer, although I haven't had much time to play around with it since I got it. Getting good quality prints has so far been a bit of a hit and miss, sometimes they come out ok, sometimes everything goes to hell, usually from the very start... ABS seems a lot harder to get right than PLA, also got a spool of PETT, but haven't even tried with it yet. Already got the nozzle so jammed once that I had to take the extruder apart to clean it.  

[Hunka Hunka Burning Love]

Got any photos?    Of your printer?  And prints?

Geez these things are getting so cheap.  I wish EUCs would drop in price like that!

https://www.gearbest.com/3d-printers-3d-printer-kits/pp_337314.html

[esaj]

6 minutes ago, Hunka Hunka Burning Love said:

Got any photos?    Of your printer? 

Geez these things are getting so cheap.  I wish EUCs would drop in price like that!

https://www.gearbest.com/3d-printers-3d-printer-kits/pp_337314.html

Just took a quick photo, but there's really not much to see:

The whole thing's encased with plexiglass & an Ikea-table sitting on top of a rotating "pedestal", and the spool sits on top of the casing, feeding through a teflon-tube on the "ceiling". I still haven't figured where to place it in the end, right now it's just filling up the guest bedroom along with my wheels and other stuff... hope that no-one's going to come visit anytime soon

Blue painter's tape is used for adhesion for now, I've got a PEI-sheet ( http://reprap.org/wiki/PEI_build_surface ) coming, hopefully that will make working with ABS more easier. There's a heated bed there, but even with that, so far anything I've tried with ABS has failed, usually the base layer doesn't stick and/or the print starts to warp. Not that I've had much time to try things since the first weekend, since I've been pretty swamped with work & school stuff since...

A picture of the few prints I made on the first weekend:

The smaller ones are earrings, the larger part is a servo-arm. All are made with PLA. 

[Hunka Hunka Burning Love]

I wonder if a roll of wide Kapton tape might do the trick for ABS.
 

https://www.amazon.com/gp/product/B007GCCUGM

How are the classes going?

[esaj]

16 minutes ago, Hunka Hunka Burning Love said:

I wonder if a roll of wide Kapton tape might do the trick for ABS.

Kapton might work, also some people apply glue (from a glue-stick, not liquid)... Based on other people's experiences, the PEI-sheet should work pretty well, and be much less of a hassle, as all the maintenance it should require is wipe down with IPA to get rid of fingerprints or other crap on the surface.

 

Quote

How are the classes going?

Fine so far, just the first couple of weeks have been pretty demanding, I wasn't expecting that we have to decide on a project so soon and get the design underway that fast. The actual lectures so far have been mostly about general IoT-stuff, so not that interesting for me, but at least I've gotten to pester the teachers with stupid questions about hardware. And ordered parts on the school's tab worth almost the equivalent of what I'm paying for the course 

The actual project we (hastily) decided upon might be a bit "too much", but we'll see. At least it should be theoretically possible, but there are certain parts that I don't know for sure until I get the components and can make measurements, namely IR-distance measurement between robots for group behavior, while there are lots and lots of IR-distance -sensors, they all work differently than what we had in mind. We're actually measuring the IR-light between one robot lighting an IR-led and the other one measuring the intensity and knowing the direction from where it came (using multiple sensors around the robot chassis perimeter), and which robot was sending it (the sending & receiving of IR-light between robots is synchronized over separate radio-communication, so they take "turns" in lighting up and reading the intensity), they can form a (crude) understanding of their relative placement to each other, and act as a group. Mostly the problems come down to how much power we need to use for the light to carry far enough, as we're using wide-angle lenses (cost & building issues, can't line tens of LED/photodiode or phototransistor -pairs per robot) and the signal might be too weak or get lost in ambient IR-"noise" over further distance. If it's unreadable less than a half a meter away, we might have to come up with a new plan.