Discussion in 'Modding' started by SkiDave, 6 Jun 2015.
This isn't an adhesion problem, there's definitely something up with my extruder here.
Had my 3d printing induction this morning, where I learnt about calibrating the bed, clearing head jams, shrinkage, warping and adhesion (yes, using Prit-stick), rafts, skirts & brims etc. We also had a play with Cura and printed a simple model from Thingyverse.
I'm can now use the college printers for my own projects, which is cool.
Sorry misread you post. Then that's definitely more of an issue.
My replacement board arrived today, fitted it and realised I should have requested two replacement orange connectors rather than just the one for the main power in. I'm still up and running just without the heated bed.
After much mucking about with bed levelling, and one quick strip-down of the extruder, it *seems* to be working OK... https://www.facebook.com/byroncollier/videos/10153764017226652/?pnref=story
Hopefully it'll print a 0.4mm "thin wall" test piece OK now. We'll see I guess...
^ Good luck.
I've just installed Fusion360 and had a quick play. I like it.
Now to get studying how to use it properly so I can start coming up with design ideas for my project.
Exciting stuff, I can't wait to start printing prototypes.
After much tweaking and calibrating, and many... MANY... test prints, the result is...
It's a test piece; specifically, this one - clicky for linky:
Shame that I've only got black filament at the moment, because it really does look much better in person and the black filament doesn't photograph well.
It's not perfect, but it is supposed to be a "benchmark" for 3D printers, so I'm pretty happy with the results that I've got out of my cheap fussy-arse printer.
I assume that means you wouldn't recommend your model to others then?
Nice one Byron.
It handled that well, the overhangy bits (excuse my jargonese ) and curves look smooth.
I would say that it's probably the same as many other cheap Prusa i3 clone kits out there: you get what you pay for. You get a cheap and functional 3D printer, but you're going to spend a lot of time getting things set up properly and then making tweaks afterwards. If you want high quality out of it then be prepared to invest a lot of time in calibrating and tweaking. If you want something that produces high quality prints with less effort on your part then don't buy a cheap kit, spend ~£500 or more (preferably more) on a pre-built machine. Even with a pre-built machine you'll still need to know the ins & outs of how it works so that you can fix things when they go wrong.
To be fair this printer was functional "out of the box" (well... after I built it). It wasn't exactly the most detailed printer out there - forget about printing moving parts with the stock configuration - but it worked. It was only when I re-flashed the stock firmware with standard Marlin that I really had to learn how to properly calibrate and adjust it.
I'm glad I did though, print quality is miles better than it was when I first put it together. Still plenty of things to change though:
Additional support brackets for z-axis guides & lead screws
Power supply cover (yay for exposed 240V mains terminals!)
If I had the choice to make again, I would have gone for a smaller build platform with a more robust/rigid design. I was very tempted by a delta machine for a long time (despite the arduous calibration), because the design looked far superior to the Prusa i3 design; the Prusa i3 won because of it's larger build area, but it turns out that this is nowhere near as important as I thought it would be. I'm considering converting it to a "coreXY" design in order to get better structural rigidity.
It's getting there, that's for sure. Still getting trouble with bed adhesion on very fine parts - this cable chain for example just does not want to print. The finer parts peel up off the bed and eventually the nozzle dislodges the prints from the bed.
Is the bed heating-up OK? Maybe an apron might help?
Edit: noticed this in the instructions for cable chain.
"Uploaded a version with four links arranged in different directions. For an unknown reason, when the links are assembled in a long chain they tend to curve in an arc. Printing with them arranged in different directions so that the error cancels itself out seems to fix the problem."
I think that means when they're printed and you're assembling links together - I don't get that far .
The bed is heating up just fine - I've even validated the temperature with the thermocouple probe for my multimeter (it's a little off but it's good enough). I've only tried the heated bed with blue masking tape as a printing surface - glass and other print surfaces are on my "to do" list with this printer! Right now I can cope with it, because I rarely need parts that small.
I have found that brims/aprons are required for fine parts with small contact areas on the bed. Even on high end printers like the Ulitmaker 2+.
Annoying that it adds post processing to trim them off but makes the world of difference.
Oh, a brim! Wasn't sure what an apron was!
I'll look into it, cheers both .
^ Yes, brim is what I meant, sorry. I don't know where I got apron from.
Note to self: take written notes the next time I'm at the college-of-knowledge.
Apron means the same thing but has been superseded by brim in most of the slicing software options.
I use a brim for all of my prints, and right or wrong I use this to ensure the bed is level making adjustments whilst it's laying the brim down. I'm sure some would say I'm crazy but after getting the initial setup correct and using this method with hairspray for adhesion I've printed 5kgs of filament without a single failed print (with the exception of those that ran out of filament before being finished)
Thanks for clearing that up. Phew, I was getting a bit worried there for a minute.
That's a great idea. Noted.
Byron, I would think that models such as that boat, with a relatively small bed contact area when compared to their height, would definitely benefit from a brim to improve stability while printing.
The boat wasn't a problem. This yarn bowl I'm printing for my other half is coming out just fine, and the bed contact area is tiny compared to the rest of the print:
The only thing I've had trouble with when it comes to bed adhesion is these little pains in the backside:
Those little "spurs" are 2x4mm and they just kept lifting off the bed. (You can clearly see the extrusion problems I was having in the completed links - hopefully that's solved now.) It sounds like a brim is the way to fix that.
The bowl looks to have a contact area many times larger than the boat when compared to the height, and being round it's uniform across all axis. The boat's contact area whilst long, is very narrow.
...But I'm still not getting any stability or adhesion issues with either of those models .
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