After it snowed, prints won't stick to heat bed.

Makerfarm, Prusa I3, ABS 3mm, .050 head, 8" heated bed, Ramps 1.4

Today it snowed and my first print of the day kept curling up and was a total failure. I tried again and had the same problem. I thought maybe it was my filament, so I switched and had the same problem. I then cleaned my heat bed which is covered by a layer of glass. It's been about 2 weeks since it's been cleaned and I've applied a few layers of hair spray in that time (I use the Garnier Extreme Control # 5).

After cleaning it, I tried a flat print and it worked (it was just a small ninja star), so I figured it just wasn't holding due to all the hair spray and left over ABS residue. After the star finished I tried a gear that I needed for a project and after about 1/4" of material, it started smearing everywhere. I could also see where the first layer was curling on the edges.

The only thing that has changed from my last 20 successful prints is the weather. It's a lot colder today and the kids were running in and out to play in the snow. I've double checked the distance of the print head from the heat bed and it hasn't changed. The bed is staying at 110c as well. My printer is located in my family room which is half underneath ground level and half above and has 3 heater vents. I would guess it's around 70F for the room temp.

Am I missing something here or is this common?

Edited 1 time(s). Last edit at 11/03/2013 09:03PM by vetteguy112233.

Hopefully tomorrow I can round up a small space heater to see if that helps, but all the extra power being used by the printer and running a space heater all winter is going to raise my power bill through the roof.

I don't think it's room temperature that's doing it.

I tend to get similar issues when I move the printer and the Z axis (bed leveling) goes out of whack. It's fine at the Z end stop, but it's way off at the other end of the bed. Net result is that the first layer isn't anywhere near the right thickness. Second thought would be that your hair spray can is down to just solvents and that all the water soluble plastic in it is long gone.

I'd print a skirt for a part and see how it looks. If it's a mess (rather than smooth and flat) I'd drop the head about a half turn with the Z axis stop. You can always move it back....

I double checked my clearance and it was fine, plus I didn't move the printer. Nothing changed from one print to the next other than a full day of no use and as mentioned the cold weather.

I just turned z axis screw out about 1/8 turn to allow it to get a little closer. I put a piece of paper underneath the print head (which is clean and doesn't have old dried up plastic on it, that is throwing off my calibration) and told the Z to home. I checked 5 different points and the paper can still be pulled out, but it's tight. I'm currently waiting for the bed to warm up and I'll try it again. However the heater in the house has been on for the past hour and I can feel it's a lot warmer in here now.

Nope, still having issues. I'm trying to print a small gear for the "gear heart" project and I can see as the gear starts to flare out, about 1/4" up, it's smearing each gear edge around. It appears that the very tips of the gear are curling up, causing the hot end to make contact with them, thus smearing the plastic. As it prints a new layer I can see it squishing each layer underneath. I'm so confused because NOTHING changed.

Room temperature has a big effect. Try making the bed 10C hotter.

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I've been printing ABS all weekend with an 80C bed in a 70F room. No real issues with stuff sticking. Some of my glass plates are a bit hard to see through from all the coats of hair spray. I've also cleaned them and they work that way as well.

I also having some troubles. Printing a wades for instance. The end curls up.
110 c heatbed and Abs juice.

Then did a run with a 5mm brim... Fantastic flat and sticked like....

I tried turning the heat bed up to 120c, but that didn't help. So I've added a 5mm brim and also kept the bed at 120c, it's currently printing and I'll post the results.

NOPE, this is getting so frustrating! My printer is worthless at this point, it gets about 1/4" up off the bed and just starts smearing everything all over the place. Any other suggestions?

check out this video, fast forward to 5:00. He place couple of lamp at the print area.
[www.youtube.com]

*if* the bed is really at the right temperature, and *if* the glass still contacts the bed, and *if* the plastic hits the bed as it comes out of the nozzle, and *if* the plastic is hot enough...

Then the room temperate should not matter for first layer adhesion. It could matter a lot two inches up into the print. I'm having a hard time seeing how it can impact the first layer. It's straight from the extruder onto the glass. It stays at what ever the bed temperature is for as long as you have the bed heated.

I can see how the room temperature can impact the bed's ability go get to temperature. I can also see how it can impact adhesion on upper layers (just as high temperature impacts slump). It might also affect the corners of a print curling up.

On my last print it's not the first layer that was my problem. It printed the brim and first layer just fine, its the 13th layer or so that it starts smearing everything around. You can see the 8th layer starts to get a little off, then worse on the 9th and by the 13th ish layer it's just an unrecognizable mesh of plastic.

The differential in cooling can lead to what you are experiencing. That is how amibient temperature affects your prints in more than just impacting the heating of the machine elements. Your prints may be failing because the first layer loses adhesion and gives way as the piece cools unevenly and loses the ability to adhere to the surface. Just because the bed is at temp doesn't mean you'll have adhesion for the duration of the print on the base level.

I'd take a day off, come back, recalibrate from scratch, clean bed (perhaps use UHU stick instead of ABS juice), turn the print speeds down, increase the layer height and start printing calibration pieces. You should be able to get it back into the pocket and re tune to what you had before.

Smearing everything around high up can be one of two very different things (to hot or to cold).

If it's too hot then the walls of parts will slump down, you will get filament worms coming in and out of the wall. The part will be very sturdy and you won't be able to tear it apart. It's easy to see with a thin wall part. Dropping the bed (and extruder) temps and maybe a fan are the simple solutions. You need to check that over extrusion / layers to thin is not your real problem.

If it's too cold you loose adhesion between layers. The filament just follows the head around the part. It does not stick anywhere. The part is not very sturdy, you can tear it apart. Increasing temps (extruder temp and bed temp) is one answer. Slowing things down and thinner layers may help. You need to check that under extrusion / layers to thick is not your real problem.

If you print a single wall (spiral vase) open cube, in the too hot case the walls slump down high up on the part. You get ripples in the walls further down. In the too cold case you get a ball of fuzz. The single wall is probably a worst case test for both situations.

If this all comes up on a working printer, I'd check the thermistor wiring and the mounting of the thermistors to the heated bed and hot end.

That's why you go back and check the mechanical integrity and re calibrate. What's happening now is random, educated speculation, not troubleshooting. To solve recurring or consistent issues a methodical approach is best. While it takes longer and perhaps will confirm that most things are correct it's better than just taking stabs at things and hoping it's the right one and not something that masks the real issue that could crop up later on.

Ok, here's where I'm at. I've emailed Colin and sent him pictures of my prints. As you guys suggested we figured out that it was starting way to high (which is weird because nothing changed). I'm convinced that something is moving in my Z axis and not holding calibration, because I checked multiple times while you guys were helping and it was always pinching a piece of paper when I would home Z. I did this in 5-6 different spots, but when I went back and checked again it was no longer pinching the paper in the center. So I adjusted it again and tried another print. It was better, but Colin suggested getting even closer and starting the first layer at 0.20mm instead of 0.35mm which made my first layer look like one shiny piece of plastic and you couldn't even see the lines of the plastic.

I tried to print the hollow cube and it seemed to print just fine, but the corners weren't as perfect as before, but much better. My trouble piece has been a small gear for the rotating gear heart project. It was actually gear # 1, it keeps curling the edges of the gear. From the first layer all the way through the 8th it slightly curls and by the 8th layer it's sticking up so back that it's just smearing plastic around.

Colin wanted me to email him the Gcode so he could try to print it himself. I'm waiting to hear from him.

He also had me make sure the Z axis is moving exactly 10mm, which it was. I've also built a cardboard housing around the entire printer to help trap the heat, as I'm still convinced it's the colder air that's messing with my prints. I don't have a lamp or space heater of any sort to try, but I'm working on it. The guy in the video that's suggested by Augus had to do this with his prints.

I really appreciate all suggestions and help given, hopefully I can get it back to printing properly.

Good to hear you are getting closer to printing ok!

Check the nuts in your X axis motor mount and idler that mate with the Z axis 5mm thread rods. I had a strange issue with one of them working back (down) in the plywood and then hanging up. The net result was that the Z axis cal went bonkers. It was not real easy to see without getting at just the right angle. For what ever reason it was stuck there and would not pop back to it's correct location. Once I pulled things apart and re-seated the nut it has not happened again. The cause could easily been a tiny random bit of laser cut wood that I'd missed when cleaning things up before assembly.

With the massive load of hair spray I put on the glass, I can run the bed at 80C with ABS and not see any lifting of edges on any prints. I have *plenty* of other problems from time to time, but that's not one of them. My room temp swigs from 65F to 80F depending on who's left which door or window open.

aha and i am learning too again.....

I was looking for the secret of that smooth shiny underground.... without feeling the ribs.... just as my printed parts are which i bought.
Tried everything like first layer width, played with multiplier etc etc.... But never tried a first layer of 0.20. because every manual is saying that a thicker first layer is very important. So never changed that rule.

Right now i am printing some spoolholders but i will try it when its ready.

I did find one nut that was a little loose, I don't think that would have caused it, but good info and it helped me to find something that could have been a larger problem later. THANKS Uncle Bob!

Justintime - This is why I try to follow up with my threads, if it helps anyone else in any other way then it's all worth it. I had my z set to slightly pinch the paper when it was told to home. Then when Colin had me change my first layer to 0.20 it wouldn't actually print because it was to close to the glass. I had to adjust my z stop screw a little to get it to print. I suppose I could have just went .25mm, but I chose to go the endstop route.

Colin also helped me understand that running the Z motors at any speed faster than 30 can get them out of sync. When cleaning my head or taking the Z axis up high for whatever reason I would change the speed to 100 so it would raise faster and Colin told me this gets both motors out of sync and not to do it. No I wasn't printing like this, just for cleaning or whatever reason. I guess I won't do that any more.

I just went to print the cube again and noticed that my plastic wasn't sticking to the glass. I checked the Z head and it had moved AGAIN!!! I set it back to the correct height AGAIN and we'll see how long it lasts before it moves itself again. GRRRRRRR!!!!

The desk that my printer is on, is a very solid desk in the corner of the room on a carpeted concrete floor, so it's not like the desk is moving around.

Edited 1 time(s). Last edit at 11/07/2013 04:11PM by vetteguy112233.

Ok, next hints - sorry this is getting a bit like water torture:

I have a pair of #6 nuts on my Z axis bolt. I don't depend on the plywood to hold the bolt in place. I did the same thing (only one nut would fit) on the X axis bolt.

I also have found that the extruder heated up the plywood next to it that the nuts and bolts there were really loose. I noticed that when I saw the carriage rocking back and forth as I moved the filament around .... Once tightened they have not come loose again.

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uncle_bob
Ok, next hints - sorry this is getting a bit like water torture:

I have a pair of #6 nuts on my Z axis bolt. I don't depend on the plywood to hold the bolt in place. I did the same thing (only one nut would fit) on the X axis bolt.

I also have found that the extruder heated up the plywood next to it that the nuts and bolts there were really loose. I noticed that when I saw the carriage rocking back and forth as I moved the filament around .... Once tightened they have not come loose again.

I don't think I understand, sorry!

I've also noticed that the quality of the prints have changed. A few weeks ago I printed a Mayan temple and now my other son needs one for a school project so I'm printing another one. It's currently printing and I have over an hour left, but I've noticed that it's not the same quality as my first one. There are 2 "feet" at the base/entrance of the temple that were pretty much perfect on the first print and on this one they are just 2 balls of plastic. I'll post side by side pix when it's finished and hopefully I can get it dialed back into where it once was. Colin has suggested slowing things down, but I've printed this before without these problems at full speed.

On the "normal" build of the printer, you simply put a #6 bolt through a hole in the plywood for the Z axis end stop adjust. All that holds in in place is the fit to the wood. What I did is to put a #6 nut above and below the plywood on the bolt. That way the plywood is clamped between the two nuts on the bolt. It's *very* secure that way. Not much chance of it drifting as it gets bumped or vibrated.

The same basic issue applies to the X axis end stop adjust bolt. In that case my bolt was not long enough for a nut on both sides of the plywood.