Print is not laying down... at all!

Hello,

My printer is:
Mendel Max 1.5+
Trinity Labs Y Axis Upgrade
Trinity Labs X Axis Upgrade
Trinity Labs .4mm Metal Magma Hot end with a speed controlled fan mounted on the heat sink.

Bed is:
G10 bolted to the uni-guide carriage
thing:38288 screwed to the corners.
200W kapton Heater stuck to the bottom of the aluminum heat spreader under borosillicate glass. Blue Painters tape over glass.

Extruder tip is .1mm from the bed.

I have Autotuned both the Extruder and the Bed, all controls function as expected.


So WHY can't I print anything? The PLA does not stick to the bed and the printer doesn't seem to be pushing very much PLA during the first layer of the print, and what it does push out does not stick AT ALL to the blue tape.it just peals up or brushes off. Or worse, it gets picked back up by the print head and makes a mess.

Any help that any of you can offer would be VERY appreciated.

Thank you.

Hello again,

Im new to all this reprapping so bear with me....

You should go over a few things..

Extruder steps per mm in your firmware and extruder ratio in slic3r, make sure they are correct.

Check your mechanics. Make sure tour extruder driver isn't slipping or grabbing too tight and shaving your filament off instead of pushing through the hot end.

In slic3r set your self a nice big skirt, I have mine set to extrude 7mm of filament before starting and the first one always looks terible as the extruder builds up a bit of back pressure.

Play with different temps.Try 185c and then 220c to see if there is a noticable difference.

Make sure your blue tape is clean, if you have handled it alot you'll be leaving body fats and salts on the tape which won't help.

You say you have a heater under the glass, If you are printing PLA onto heated(60 c) glass, you should have no problem with it sticking,,
without the need for any tape.

Myles Wrote:
-------------------------------------------------------
> You say you have a heater under the glass, If you
> are printing PLA onto heated(60 c) glass, you
> should have no problem with it sticking,,
> without the need for any tape.

That's not necessarily true. I know people have reported this, but my experience is that you can still have lifting with a heated bed - especially for large items that already have a tendency to curl. I solve this issue by using diluted PVA cement - 4 or 5 parts water to 1 part PVA (elmers) glue. It works great. Sometimes a little too well and the parts are difficult to remove, but generally cooling is all that is needed in these cases.

I've heard that if you go higher than 60 degrees - perhaps 70 or so - that the sticking will be better, but I've not tried it yet because I've been happy with the PVA solution.

I don't have a problem with 60* bed temps on PLA. In fact on smaller prints I lower it to 55* after the first layer and sometimes print the first layer hotter. I also use a brim for some things. Because of the difference in tolerance between electronics, heater cores and thermistors direct comparisons may not match from machine to machine.

OK, I have checked my bed temp, tried to print on glue stick, checked the hot end to bed offset .2mm, hot end temp... but it seems like the hotend doesn't maintain enough pressure to extrude consistently. On top of that, the PLA does not stick to the bed when it does extrude. It starts out not extruding at all, then you get 3 or 4 laps of GOOD solid extrusion... but then... (in the same, first layer) it starts extruding droplets, less and less, until it is doesn't spit anything else out. OH! and it picks up what it does lay down and it sticks to the hotend and starts making a HUGE mess! I have a fan cooling the top half of the extruder... my temp is only set to 180c and that is the temp that the black PLA seems to like.

*sigh*

Any thoughts?

I think you said your nozzle was 1mm from the bed? Way to high.

Rule of thumb, Nozzle should be one half it's diameter from the surface. So, if you have a .5mm (that's point five) nozzle, you want only .25 clearance to the bed.

You want the nozzle to deposit and very slightly press the filament onto the surface as it moves. Otheriwise, it will just sort of drag along behind.

Now, if you have a heated bed, and it's glass, then there's no need for the tape. As long as your glass surface is clean and heated to at least 60C, upwards of 65C, the PLA will stick like glue. Once a job is done and the bed cools, shrinkage will cause the part to pop itself free from the bed.

Just make sure your glass is clean. Damp a paper towel with some windex and wipe it down, dry it with a fresh paper towel, heat and go.

Kevin.

Inconsistent extrusion could be an electrical or mechanical issue. You extruder motor could be skipping steps. This might be from a config issue or some sort of binding or heat issue related to the stepper drivers. A temp of 180 may be low enough to bind the extrusion by making the material more difficult to extrude or clogging the hot end. One way to test is to extrude filament without printing to observe the flow pattern. Raise the hot end 20-30 mm above the bed and start extruding at small increments 5 mm or so and increase the extruded length to see what is happening with the flow. Based on your observations you should be able to tell if it's the extruders mechanical setup or something in your config or calibration. Another issue could be the quality of your material. Low quality material may have a composition that isn't responding favorablely to being heated.

Reread your other posts, about it starting out ok then reducing to droplets. I had exactly the same symptom recently.

In my case, it was debris in the nozzle, video with pics here:
[www.youtube.com]

I removed the debris from the top with nylon trimmer line while the nozzle was at 170C.

The only other thing I can think, would be that you have an electrical problem and the heat is turning off while you're printing. Loose wire, loose thermistor, etc. In pronterface, you can check the box to "watch" the temp and it will draw a moving graph. If you see spikes in the graph, then you have an electrical issue.. Should be a fairly smooth graph as your printing, only moving up or down an occasional dot.

Thought of something else. If you're using the latest version of Slic3e
r to create G-code. I've seen what I think is a bug in Slic3r. While printing, I noticed that the extruder would suddenly run at half the speed it should be at based on the movement speed of the nozzle. This caused beading since not enough plastic was coming out.

I've seen this happen on different models, so I'm pretty sure it's Slic3r screwing up.

If you are using Slic3r, try a run with cura, or Kisslicer. I presently use Kisslicer, and like it so much that I bought it.

OK' finally a step forward. I raised the bed temp to 65c and the plastic sticks! At least as long as the extruder is extruding... It dose a good chunk of the first layer, and that's all she wrote! I have to back the pla out a bit then run it forward again and sometimes that does it... I am really starting to think there is something special I need to do with this hot end, but not sure what it is and the maker has fallen of the edge of the world, or was abducted by aliens or something. Does anyone have any xp with metal magma hot ends?

Edited 2 time(s). Last edit at 08/13/2013 09:50AM by zanahade.

Should I just switch to a jhead?

I was thinking about using one of these... But I have no feedback to work from... [www.amazon.com]

Bump

I've had problems like you describe a few times. Here are some things I would try:

1) Lower your nozzle even closer to the bed. Really squash that first layer onto the glass.
2) Up the extrusion temperature to about 195C. I've had some PLA that just won't lay down at lower temperatures but when you hit the right temperature all of a sudden it's golden.
3) Check that your idler has good tension against the hobbed bolt. Also, open it up and if necessary clean the bolt (the grooves that are supposed to grab the plastic may have become filled with bits of plastic and slippery). Compressed air in a can is your friend for this purpose. This doesn't actually help with the laying down, but it sounds like you are also having trouble getting consistent extrusion.

Edited 1 time(s). Last edit at 08/17/2013 07:36PM by mjrice.

I am suffering from Hobbed bolt not biting on the filament... even after cleaning the bolt. & tensioning the idler