troubleshooting a print.

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classicvideogamer
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troubleshooting a print.

Post by classicvideogamer » Sat Jun 11, 2016 8:54 pm

Hi guys just some basic background. My printer was down for a bit, and try as I might I couldn't get it to print out well, so I figured it was time to upgrade to the v4 hotend, hoping that would help solve some issues.

It actually did, and I'm happy to report I am back to successfully printing some things, however it seems like when I try to print bigger items, I have no luck. Here is an example of a robot I'm trying to print. The weird thing is it looks ok for the first several layers, but when I go to check back on it, I end up with this type of typical mess. I'm not sure really where to begin for troubleshooting so any suggestions are welcome. Thanks for looking.
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Tim
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Re: troubleshooting a print.

Post by Tim » Sat Jun 11, 2016 11:26 pm

Hard to tell from the photo what it was that went wrong. Since it's not that big of a print, and seems to have gone bad not too many layers in, it might do you well to babysit it once and try to catch what's happening as it starts to screw up.

What type of filament are you printing with, what are you using for bed adhesion, and what is your bed temperature?

classicvideogamer
Posts: 39
Joined: Thu Aug 06, 2015 12:34 am

Re: troubleshooting a print.

Post by classicvideogamer » Sun Jun 12, 2016 2:12 am

Hi Tim,

I'm using esun black pla
hairspray for bed adhesion
and my bed temp is 65

Thanks.

Jeff

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Tim
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Re: troubleshooting a print.

Post by Tim » Sun Jun 12, 2016 2:47 am

Okay, I see this is the MakerFaire action robot thing, so I dropped it into Simplify3D to see what it was supposed to look like at that point. That makes it more obvious what's going on. The robot is jointed and prints in 10 unconnected parts on the base. Each of those parts does not have much surface area contact with the base. Then, all the edges are beveled, meaning that there is a lot of overhang on the first few critical layers. That's a really bad combination and is often just asking for trouble. In your print, the two upper parts of the leg detached from the glass and got tangled up in the rest of the print. If you have a gcode previewer like Simplify3D, then look at the first layer---some parts of this model are contacting the glass by only a couple of filament widths.

The best thing that you can do here is to print a brim; it only needs to be one layer high, but it needs to be at least 1-2mm wide (more is better) and set at distance zero from the part. That will help hold all those separate pieces together on the first layer. You'll have to cut off the brim after the print finishes, and maybe whittle it smooth with a hobby knife, but that's really the only way you're going to keep it from annihilating itself by the fourth or fifth layer.

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Jules
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Re: troubleshooting a print.

Post by Jules » Sun Jun 12, 2016 3:01 am

I've printed that robot, and it's harder to print than you would think, just from looking at it. (Very small surface area contact on some of the bits.)
All that happened there was that one piece of it warped up from not enough adhesive or from printing too hot, the nozzle started hitting it, and finally broke it off.

For PLA:

More hairspray, especially in the center, where it looks like a piece got unstuck in your print there.
Lower temp on bed, lower temp on extruder. 60°C is fine for bed - too hot is going to cause the PLA to take too long to cool, which means more warping.
Extruder temp - 205°C.
Default print speed - 3600 mm/min
Cooling Tab - Speed overrides - Allow speed reductions down to 5%.
Full fan after first layer (and if you have a separate desk fan that you can point at the back, it always helps to cool things off well with PLA.)

classicvideogamer
Posts: 39
Joined: Thu Aug 06, 2015 12:34 am

Re: troubleshooting a print.

Post by classicvideogamer » Sun Jun 12, 2016 12:32 pm

Thanks guys ! I'm going to try those suggestions. I'm a bit relieved that this is not something wrong so much with my new set up (v4), and more of an 'advanced' print issue.

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