having issues with sticking(or not), oozing, and other fun stuff

So I have had only one semi successful print which was the initial calibration cube. It seemed to start okay, it got closer to the top though, and broke free of the table (no tape at this point). print otherwise seemed okay, a little shallow around the base, but nothing otherwise in terms of shifting (I was able to lap the print evenly when I tried on its two solid surfaces, VERY good sign so far).

I attempt to print other models though, and the same issue occurs from then on out: it won't stick. It just peels off and sticks to the nozzle (unless I grabbed the tail and then it stuck...and even then it eventually broke loose of the bed very easily).

Using a combination of painter's tape, alcohol, and hair spray it seemed to stick better, though it disliked a transition (and immediately started to break loose).

Things learned thus far: that base layer is everything (which makes sense), and if it's no good, the whole printer turns sour real fast.

fun coding stuff: M302 is the code that overrides cold extrusion. As soon as I locate the codes for extrusion and movement, it's possible to create a script that would allow you to auto feed and press off some excess, and suck in/extrude the wire as a piece of insertable code before a print.

 

Thanks for posting this, very helpful.

Can anyone suggest an extruder height and bed level tolerance? I've folded a number of sheets of paper (0.08mm) to use as a feeler gauge and my heights are as follows in mm, these were taken with painters tape on the bed which is 0.11mm thick:

Left Right
Rear: 1.00 0.88
Front: 0.68 0.68

The first print test did not stick to the bed, the cold extrusion measured 0.38mm so I'm guessing the extruder height should be about 0.20mm to mush it into the bed?

I'm panning on setting this height manually (once I orient the switch correctly). Is anyone doing it within Slic3r? It looks like it could be adjusted via 'First Layer Height' or 'Z Offset'.

Also how are you adjusting the bed along the y axis? The variance between the front and rear of the bed is greater than what I'm guessing the extruder height should be.

Thanks

 

are you using PLA or ABS? the PLA won't stick to the painter's tape very well, from what Tesseract has told me, and I gave up on it. Oddly, Aquanet (specifically, as I've tried about 4 other similar products...you should have seen the looks I was getting in the store, as I'm quite bald lol) seems to be the go to for assisting in getting most things to stick really well to the bed. For adjust variances, Tesseract's bed levelers on thingiverse have worked fantastic in tandem with an indicator (preferably dial, digital's won't show you the inbetweens as well).

in terms of using a feeler gauge for proper height, it's a bit of a trial and error process. What I found worked well for me is using a business card with the y axis set to the middle position, and setting the switch side first to where the card is just barely making contact with the nozzle, then move over and do the other side to the same height. I'll then move back over, and bring the nozzle down to where the card still slides under, but you can feel pressure put on the card (not enough that you have to force it a lot to move), set the switch, then go over and bring the otherside to the same level. check the switch side again to make sure it's not moved. once there I usually either use slicer or the screw to set my height closer (using trial and error as above).

link for the bed levelers: http://www.thingiverse.com/thing:125626

and a list of helpful tools!
http://forums.robo3dprinter.com/index.php?threads/useful-tools.644/#post-1609

 

Thanks Mattchu. The print levelers looks great (as soon as I get my Robo printing that is). I have a micrometer, which I'm using to the measure the paper. I selected a business card that measures 0.28mm and leveled it side to side, the back is still a little lower but the levelers should help with that.

I'm using ABS. I know many say to start with PLA, but I only have a small sample of it and a lot of ABS and it's what I want to work in anyway.

 

Jeff, that is great, thank you. I understand what your saying about it being fluid, I think that's something that a lot of nubies like me might not appreciate at first. I just wanted to make sure I was in the ballpark to begin before getting to the fluid part.

I'll send you a skype request and see how my next print goes.

Cheers.

 

i am getting frustrated... no matter how well i get the layer adjusted... the plastic curls up toward the extruder as it is printing.. can't get beyond the skirt.. as soon as it starts to lay down the layers for the "thing", it curls up and the print is ruined.... sometimes i can get the first two layers down (they look like crap), then it catches and ruins the print... any suggestions. I am using a piece of paper to get the height set.

 

you're still too high. The paper is really just for leveling the z axis, not for calibrating print height. Ditch it and work on feeling now, you're close trust me.

Once you have your paper height calibrated, center (x~110 y~125) your nozzle in your bed, slowly twist both z rods the same amount until your nozzle touches the build platform. Then twist them up slightly until you can see the tiniest amount of light underneath. Still practically touching but not resting on the board.

Once you get this down move your nozzle from side to side along x to make sure it's still level. It's more important for your nozzle tip to look correct in the center than on the edges.

Once you get this you need to adjust your z stop position. Retract the z stop screw until the switch deactivates then slowly turn it back in until the switch reactivates. Raise your z axis +10 and home it. Check your settings and repeat as necessary.

Now that your z stop is set it's time to start a print. Enable 2 skirts if you haven't. While the skirt is printing you can adjust your z screw rods to get the layer looking right. You're aiming for a flat line that merges nicely with it's neighboring line. Too high and it will leave a gap between the skirts, too low and it'll interfere with the other skirt and cause filament to collect on your nozzle, ruining your finish. Getting this right just takes a good eye and practice, but if you're here your print will probably still work. Blobs will smooth out in upper layers, but loose adhesion might pop off on tall prints.

 

Thanks Mike... I will try again tommorow... just tired of it now.