New 12" user and I am LOST!

[Chadd]

Okay, so remind me. Is this in the config.h?

Yes, search for HOMING_FEEDRATE and you will find it.

Happy to say that my homing issues are now solved, I have printed about 4 prints and have not had to mess with homing at all. Normally I would have to screw with it every single print.

[tsteever]

I changed this line of code in the configuration_ad.h file to move the z a bit higher up and the z and y a bit more during the second move step in the homing sequence. This did help a bit. I just thought I would repost.



//homing hits the endstop, then retracts by this distance, before it tries to slowly bump again:
#define X_HOME_RETRACT_MM 10
#define Y_HOME_RETRACT_MM 10
#define Z_HOME_RETRACT_MM 2
//#define QUICK_HOME //if this is defined, if both x and y are to be homed, a diagonal move will be performed initially.

Somewhere in one of the tabs was the move rate/divided by something but I cannot find it. I will keep digging.

[Chadd]

The homing feed rate is in the configuration.h file

Also Colin already has the updated firmware uploaded. Here is the link to download it.

https://drive.google.com/file/d/0B80...ew?usp=sharing

Again this is for the Rumba board.

I changed this line of code in the configuration_ad.h file to move the z a bit higher up and the z and y a bit more during the second move step in the homing sequence. This did help a bit. I just thought I would repost.



//homing hits the endstop, then retracts by this distance, before it tries to slowly bump again:
#define X_HOME_RETRACT_MM 10
#define Y_HOME_RETRACT_MM 10
#define Z_HOME_RETRACT_MM 2
//#define QUICK_HOME //if this is defined, if both x and y are to be homed, a diagonal move will be performed initially.

Somewhere in one of the tabs was the move rate/divided by something but I cannot find it. I will keep digging.

[misquamacus]

Hah, just read through the beginning of this post and noticed how many other people have already given variations of my diatribe. Sorry to belabor the issue, just trying to adjust your expectations.

...can you offer any guidance as to how I can get better, more accurate prints from the printer?

The best advice I can give you is read this book. It's a great resource to fill in much of the background knowledge you need. As for the specific problem you have most recently been posting about (stringy warped ugly prints), that looks related to bed leveling, heat, speed, and extruder settings. Your hot end is too hot, you're over extruding, you're going too fast, and the bed isn't level. Try this, in this order:

1) Use Cura.
2) Re-level your bed. Only clip the glass down on one side to keep the glass level. Stop using paper/etc, and pick up some feeler guages. When using the guages, stay between .03-.2mm of space depending on the material and adhesion supplement.
3) Turn down the heat and the speed. For ABS, go down to about 225°C and set the speed slider to its slowest. If the print doesn't stick to the bed, extruder jams, or print is weak and easily breaks apart then raise the temp in 5° increments until that issue is fixed.
4) Now work on your extruder settings. Start with measuring filament and calculating esteps, then move on to whitemousegary's method.
5) Go back and repeat 2 & 3.

Do all of those steps, print lots of tests playing around with slice settings and then do it all again.

[tsteever]

There is no speed slider per say. Can you give me some target numbers to shoot for?

I did some experimenting with Cura and used these values. The top layer looks better but the bottom layer isn't solid. Before printing I did measure and check that when zero'd the bed is touching the glass. I then commanded the z to move to .5mm and I measured this using my feeler gauges. The distance was .5 at 4 corners and in the middle.

My suspicion is some of the things I did to make a nice top layer have also changed the bottom layer so that it isn't nice and solid.

[Chadd]

I think you would be better off printing some calibration objects instead of actual parts. That way you can follow a guide on what you need to do to improve the parts and calibration of your printer/software. Otherwise you will be chasing your tail.

I use this set of calibration objects and followed the guide in the instructions on thingiverse

http://www.thingiverse.com/thing:5573

There are a lot of other tips out there for getting your machine to print well but until you have your base layer nailed down and your extrusion rate figured out you are just guessing.

When I calibrated my Esteps I tried to follow a the guide listed here on the forum but it wasn't even close when I calculated it based off of that guide. I ended up finding that 1 estep change =.22233 mm in extrusion length change. My esteps ended up at 878 "was 841 originally"

There is no speed slider per say. Can you give me some target numbers to shoot for?

[TopJimmyCooks]

Your best way to adjust how the bottom looks is to play with your Z offset. If you want it squished more, reduce that offset. If those prints ran with 0.5mm offset, I would try 0.47 and play with it until you're happy. You can change the Z offset in Slicer, Can't remember if you have that option in Cura. Once you get the offset exactly where you like it you can change it in firmware. Until then it s easier to experiment doing it in the gcode. First layer height percentage plays into that as well (slicer). I wouldn't play with both variables at the same time, however.

[misquamacus]

There is no speed slider per say. Can you give me some target numbers to shoot for?

Currently, you're set too fast (especially for a small/thin part) considering the build quality of your printer. Getting good prints at higher speeds takes a fair bit of mechanical tuning (tightening everything, adding LOTS of vibration dampening materials, bolting the printer down to something rigid). To get better quality out of what you have built right now, take print speed down to 30mm and you might need to reduce heat when you do as well. Also, I noticed you have Diameter set to 3mm, have you measured your filament? It is unusual for anything but the nicest of filaments to be perfectly spot on 3mm.

Chadd gave an excellent suggestion for some test objects you can use in your tests, and TopJimmyCooks' advice to use extruder offset is sound as well. To add an offset in Cura, click the Start/End-GCode tab, then click Start Code. Just above the end of the code where it says "M117 Printing...", add the line G1 Z--, substituting your offset for --. For example, if you want an offset of 0.05, then the end of your starting GCode should look like this:

;Put printing message on LCD screen
G1 Z0.05
M117 Printing...

[tsteever]

Doesn't the G1 Z0.05 just move the printer to that location? For all 4 of those prints the bed was level and measured to be touching the glass prior to starting the print.

Also, printing too fast, do I just change all values to be 30mm or should the print speed be 30mm and all others be a percentage of that?

I am confused now about the extruder multiplier and the filament size. I thought that by putting in a multiplier it would make the changes for the material?

I am going to spend some time calibrating today it appears!

[misquamacus]

Doesn't the G1 Z0.05 just move the printer to that location? For all 4 of those prints the bed was level and measured to be touching the glass prior to starting the print.

G1 Z0.05 raises your head 0.05mm. For a single extruder printer, all the extruder offset does is change your print height with GCode during the start of a print. "Touching the glass" is not a unit of measurement and does not constitute a level bed; furthermore, large thin beds like the one included with your printer are prone to warping anyway. As I said before, pick up some feeler guages and re-level your bed. Only clip the glass down on one side to keep the glass level. When using the guages, stay between .03-.2mm of space depending on the material and adhesion supplement.

Also, printing too fast, do I just change all values to be 30mm or should the print speed be 30mm and all others be a percentage of that?

Setting print speed will work wonders itself, but it couldn't hurt to scale back everything else the same percentage as well. Nothing needs to be lower than 20 though, leave anything that low alone.

I am confused now about the extruder multiplier and the filament size. I thought that by putting in a multiplier it would make the changes for the material?

The multiplier is just changing around a lot of the extruder settings with one factor; however, it is reliant on the filament diameter. Measure your filament in several places and in several ways. You will likely end up with a few different measurements, average those together and leave that value in the Diameter field. Then adjust the multiplier up or down depending on whether you need to extrude more or less. That is all covered in greater detail in whitemousegary's extruder calibration guide I linked to previously.