printing problem (ormerod 2) (video)

My ormerod 2 was printing good quality for a few months. Then I had a blockade (melted filament in bowden tube). After I fixed the blockade, it has not been printing right. I made a video to show what's going wrong:
video

I have tried lots of things to fix it, but none of it helped. I don't know what's the problem is and what more I should try to fix it.

Things I have tried:
- Taken apart hot end and put together again.
- Replaced nozzle and tapered nut.
- Replaced Kapton tape
- Changing the calibration of the nozzle height.
- Different filament

The bed seems to be heating fine (65 degrees according to the sensor). The hot end is 200 degrees according to the sensor.

Any ideas?

Hello Sanders.

From watching your video, I can see the issue straight away.

Your z height is way too low. The nozzle hits the bed when it starts to print. I suggest you set the height manually. I actually do this before every print anyway.

2 other things I can see, your nozzle isn't fully perpendicular to the bed, which won't help your print quality and your printing a bit fast for the first layer.

Hope this helps.

Hi Sanders,

Initial thoughts are that the Nozzle is too close to the bed to start with, do you use the "piece of paper" trick to check Z height before printing.
Second it sound as though your extruder is slipping, this may be blocked nozzle or nozzle temp too low (somewhere around 200 -/+ 7) is usually good for PLA.

What type of plastic are you printing with?
What are you bed and head temps?

---

Limited Edition Red RS Ormerod 1 #144 of 200 - RRP 1.09fw
iamburnys Ormerod Upgrades Github
Follow me on ThingiVerse My Designs

Thanks for looking at it. I have now raised the nozzle by manually increasing the height until it no longer bumps into the bed (I'm not sure what the piece of paper trick is). Now the print no longer looks blotchy, but it still peels away from the bed. If it helps I can make a new video.

I'm printing PLA at 200 degrees for the head and 65 degrees for the bed.

The extruder does seem to be making strange noises. I'm not sure why, I don't think the nozzle is blocked (I put in a new one today), and the temperature (200) is the same as I used when it all still worked.

your printhead is tilted. it should be parallel to the bed. you can change the bearing on the backside.

Quote
sanders
..(I'm not sure what the piece of paper trick is)...

The paper trick is using a strip paper of known thickness to manually zeroing the nozzle, 80grams copy paper measure exactly 0,1mm



So if you lower the (clean) nozzle to the point where you can slightly (not) feel the friction of the moving paper you know the nozzle is 0,1mm over the bed, then remove the paper, lower the nozzle 0.1mm and zero the nozzle at that point by sending G92 Z0

Here's a trick that will make it easier, print a star nut with 8 arms and mount it on top of the treaded z-rod, one full turn of the treaded rod lift the x-axis 0,8mm so each arm of the star will move the axis 0.1mm and that amounts to 6 feel able steps with the stepper on

You can also manually adjust the hight on the fly whilst printing, each feel able click will lower/lift the x-axis 0.016mm, right turn up, left turn down

Mount a 5mm in the star wheel, screw it on the treaded rod and secure it with another 5mm nut, eventually mark one of the wings for visual position

Please notice that this might reduce you printing hight a bit if you use a treaded rod of normal length




attached 60mm-8arm-m5.stl (zip)

Also adjusting the first layer settings will help, higher layer will compensate for unevenness of bed, greater width will help in squeezing the filement out against the bed, slower speed will give it time to get a better grip



Erik

I have it working again!

I changed the following:
- z height fixed
- tilt in the printhead fixed (by tightening 2 loose screws)
- changed head temperature from 200 to 230 (I'm not sure why this was needed, because I used to print (the same filament) at 200...)

Thanks all!

Hi Sanders

Glad your up and running again, weird that the temperature has to be so high, that's pretty much ABS temperature.

Have you calibrated the hot-end thermistor? if not i'll dig out the forum thread that describes the process.

The paper trick I mentioned is pretty much as Erik said.

1. ensure the bed is hot and at operating temp (that is 60c for me)
2. obtain a long strip of standard white copier paper.
3. clean the nozzle of all residual plastic, (I heat the nozzle to 100c and use small wire snips to clear the "snot" away)
4. raise nozzle slightly and place the paper strip under the nozzle
5. slide paper back and forth under the nozzle while slowly moving the head down in 0.05mm increments (be careful not to touch or put any pressure on the bed)
6. when you feel the nozzle start to rub on the paper, your at the perfect start Z height. (so do a G92 Z0 e.g. zero Z)

Matt

---

Limited Edition Red RS Ormerod 1 #144 of 200 - RRP 1.09fw
iamburnys Ormerod Upgrades Github
Follow me on ThingiVerse My Designs

I have not calibrated the thermistor. I did all the calibrations that are in the 'official' documentation at repreppro, but calibrating the thermistor was not part of that. If you can link the thread, that would be great

Quote
iamburny
6. when you feel the nozzle start to rub on the paper, your at the perfect start Z height. (so do a G92 Z0 e.g. zero Z)

Depends on how you define the pressure needed to feel the rub of the paper, if needed pressure will cause the nozzle to drop 0,1mm without the paper, then I agree that is the perfect point to zero the nozzle, but I find that the point between feeling the paper or not is inside one feel able click of the step motor (0.016mm), so I would rather zero the nozzle G92 Z0,1 at that point

Erik

Hi Guys
Thanks for the tips in this post, It was most helpful for a newby like myself. As I have been looking all over the web for a method to set the nozzle height correctly.. I have something called a 'feeler' guage used to set the spark plug gap on cars. It is perfect for setting the height as the shims are exact and marked in 0.01mm thickness and you can stack them as needed.
I have been battling for 10 hours straight...
Can you guys maybe do an all in one post that explains in detail how you do a print on the ormerod 2. From scratch, any object, preferably simple..printing from the sd card please, not the web interface
1 The program setup pronter face,
2 Slic3r for now, to generate the g code file, how do you load it on the sd card and then start
*Maybe the best way to set the IR sensor values, what works best and how to then automatically or manually drop the nozzle to the correct height
3 Then the prep before a print, setting home, x, y, z... where must the nozzle be on the glass when you start to print...
4 The feeder speed and print speed .... you get my drift, as much details as possible
PLEASE
Tx Ben