Filament curling on hot end + Z axis issues  

Re: Filament curling on hot end + Z axis issues

Hi Sascha

Welcome to the forum.

When loading filament, in order to ensure it is properly loaded and the nozzle is cleaned of the previous filament, it does extrude several inches. This is quite normal, but depending on where the nozzle is located, the filament will come out from the nozzle straight down, or sometimes it will curl up. You just have to ensure that the excess is removed before printing.

The default Z axis home position is indeed 0.23mm. This is the standard alignment thickness and you would normally need your first layer to be at least this thick.

If your first layer is extruding apparently too much material, then it could be a sign of bad calibration or you could be extruding too much material. For best results, set the extrusion width in the slicer to the same as the nozzle width (0.4mm), make sure you have a 0.23mm gap (the thickness of the supplied card) on hot calibration and ensure your first layer is 0.25mm thick.

You can set the extrusion width to slightly greater than the nozzle size, but I have found that for most models, using the nozzle width works very well.

Also ensure that the slicer is generating relative E gcode commands. I just tried the Craftware slicer which generates absolute E commands; the result was quite a mess!

Peter

Re: Filament curling on hot end + Z axis issues

Thanks for the reply.

I'm not able to work on my 3d-printer for the coming two days, but I'll check those parameters in slic3r. Though I haven't changed anything after my first prints which both turned out great.

So the curling is normal? When I just started working on the printer, every time I loaded filaments it produced a near-perfect straight string of plastic whereas now I need to be ready with a pair of tweezers and remove the filament so it doesn't bunch up too much.

What's your preference for making the prints stick? Glue stick or blue masking tape? And what's the bed temperature you prefer to use?

Re: Filament curling on hot end + Z axis issues

Hi Sascha

You could try cleaning the nozzle - use this method (from point 3): https://ultimaker.com/en/support/149-atomic-method

Personally, I use blue tape, but I think most on here use Josef's recommendations: http://shop.prusa3d.com/forum/print-tips-slic3r-settings-kisslicer-model-repair--f12/-material-settings-a-print-surface-preparation-1-7-t96.html

I printed almost continuously for 2 months before I needed to change a nozzle and that was because I ran out of filament when printing and didn't notice. I think the nozzle was still useable, but I changed it anyway.

What material and temperatures are you using?

Peter

Re: Filament curling on hot end + Z axis issues

I'll try those methods. I had ran into them while googling for these issues. I'll get back here with results as soon as I tried them. I'm guessing the two spring-loaded screws for the filament idler needs to be removed so I can push the filament through?

I've only printed with PLA so far, using 210/50 and experimenting with 210/60 since one of my prints started lifting a bit on a couple of corners.

Re: Filament curling on hot end + Z axis issues

Hi Sascha

Your temperatures are good. If you use blue tape, you will need to lower the bed temp as if it is too hot, the tape will lose its stick.

To do that nozzle clean, you do have to remove the screws and springs. Have to say that I was quite amazed at how the filament comes out. With the screws/springs removed, you can also heat up the extruder and try pushing the filament through manually - a nice steady pressure - to see how it extrudes.

Peter

Re: Filament curling on hot end + Z axis issues

Hi, I thought I should come back here with an update on the issue.

First of all, I tried blue masking tape. But what I did additionally was to take some acetone on some tissue and lightly rub it on the surface.
After that I checked my Z calibration and noticed one thing: The glass surface was resting on the washers on two of the corners. This made it bend just a small bit, but enough that the nozzle was just slightly farther away in the middle part of the surface.

All my Slic3r settings looks good, so I didn't change anything so I decided to give it a try.

It all came out good now and the acetone treatment made the part stick so hard that the tape came off from the glass when I tried to remove it and it prints perfectly now.

Oh, and I tried that 260C > 90C > pull-out method and it fixed the issue of the filament curling (though a bit later it began doing it again, but it doesn't affect the print). I'm guessing that the new print surface treatment was what fixed it all.

Thanks for all your help!

Re: Filament curling on hot end + Z axis issues

Sascha

I always clean blue tape with isopropyl alcohol before printing - it just rakes any fingerprints and oils off the surface and with big prints, it does pull away from the glass when removing the print.

The only downside with blue tape is that when the bed is heated, the glue is not as effective, so you do have to get the temp right, otherwise you will get lifting during print.

Peter

Re: Filament curling on hot end + Z axis issues

I don't know if this is still current, but Joseph produced this short video a couple years ago for cleaning the nozzle at room temperature.

I tried the atomic method, but if I allowed the nozzle to reach 90'c after initially letting the nozzle temperature max out I was never able to pull out the filament as it was described. I therefore looked for other suggestions for cleaning the nozzle and found Joseph's.

I did find some other sources that suggested unscrewing the nozzle and then letting it soak in some acetone, but that doesn't work for PLA - which I use - so I'm still looking for an effective way.

If Joseph is looking at this it would be nice if he could do a newer version of this unblocking video 🙂

Re: Filament curling on hot end + Z axis issues

Hi Robert

Yes, I had seen Josef's video before, but I am not sure how that would work with the E3D extruders.

I think it best to remove when the filament is above the "glass" temp; 90 degrees works well for me.

Peter

Re: Filament curling on hot end + Z axis issues

I use acetone (as isopropyl alcohol is hard to get a hold of here, and it costs a lot). So far it has worked well and I have printed a whole lot ot things during the last two days. I mean, check out my upgraded spool holder I found some designs for! https://www.dropbox.com/sh/q2edhs0rqahdc0g/AAAd4ATDBHi6LvGCqMUr0VqJa?dl=0

I noticed that the acetone roughens up the blue painter tape a bit, making the item stick really well. Any differences between isopropyl and acetone?

Re: Filament curling on hot end + Z axis issues

Hi Sascha

I would think that the acetone has the same effect as IPA, so no problems.

As long as it works for you, that's great.

Peter