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Author Topic: bukobot 8 v2 duo - prints offset & the starting "glob" is off the bed  (Read 259 times)

jonyo3d

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I got my printer to print, and have printed a few things so far.  But still trying to work out a few issues, not sure if these are "duh" or common issues or I did something weird or what...

At first, had my x-stop set for the 1st extruder to be at 0,0.  Figured out that was wrong, so fixed it so that the 2nd extruder was at 0,0 on the plate, and first extruder is kinda hanging over "space" to the left of the print area.

!.  So now, when I print, the beginning part of the print that spits out a little plastic and would normally just leave a small glob at the starting point, now it makes a string hanging down because it's starting out over nothing... then when it moves into place, I get a spaghetti plastic (the stuff that was extruded over "nothing" at the start) following along after the extruder and ends up just sitting there, so far it's been "out of the way" though.  I'm no expert but seems like that's wrong, it would be purely luck whether that bit of plastic ends up in the way or not...

I started out with the setting imports I found somewhere on the wiki I think...  It's great, has preset starter settings for common stuff like 3mm height, 1.5mm height, etc..  I think it is printing a little slow but I read that they are scaled back so I guess I need to go in and see how fast my printer can handle.  (if anyone has recommendations what to scale the speeds up to, I'd be thankful!)  Anyways I bring this up to ask, are those presets maybe meant specifically for vanilla and not the duo?  Do I need to make a setting change somewhere so the start position isn't hovering in space?

2.  In the "object placement" window, it centers the object.  I go over to slicer tab, click slice, then resulting gcode view it offsets by 30mm (which is the offset for my extruders).  In other words it pushes everything over to the right by 30mm.  And when it prints, the print is pushed over just like the gcode shows.

I'm using the "latest" version v0.95F of repetier host, which looks slightly different in places and has slightly different wording in places than the instructions...

Maybe 1 and 2 are symptoms of same setting mis-configuration or something...

side note:  I think it would be awesome to be able to help out on the wiki but I didn't see a way to sign up or request access.  If we could post changes, we could add "clarifications" where needed, like in my case I have a feeling I either missed something, OR the wiki said to do something and didn't say what to use "instead" for the duo...  Once I do get to bottom of these problems, would be nice to be able to update the wiki if warranted to help future duo users.  :)

edit: realized my title was not helpful at all, so hopefully I'll get a response now with more descriptive title...
« Last Edit: February 05, 2014, 07:03:19 PM by jonyo3d »

jonyo3d

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Re: Need Tips for bukobot 8 v2 duo - weird things happening on prints
« Reply #1 on: February 03, 2014, 12:29:48 AM »
Here is a picture, it's blurry as this is with print in action...  You can sorta see the string of plastic to the left of what it is printing, and can see how it isn't centered...


whosawhatsis

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Re: bukobot 8 v2 duo - prints offset & the starting "glob" is off the bed
« Reply #2 on: February 06, 2014, 12:42:36 AM »
The offset print is probably a result of putting the offset on the wrong extruder, or of configuring repetier host (specifically the "bed left" setting in dimensions) incorrectly for the offsets you used. We've recently switched to recommending the Duos be configured to use the RIGHT extruder (the one that's at 0,0 when homed) as the primary, partially because we found that it makes these types of mistakes easier to avoid.

The bit of plastic extruded before starting the print should be knocked off when the extruder goes over the platform. If it isn't, it likely means that that corner of the platform is a bit too low, and it needs to be re-trammed.

jonyo3d

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Re: bukobot 8 v2 duo - prints offset & the starting "glob" is off the bed
« Reply #3 on: February 06, 2014, 05:13:51 AM »
Thanks!   ;D

I had the extruder 1 set to be offset by -30, and bed left was set to 35.  I'm pretty sure both were set as instructed in the settings section.  And what the simulation "looked like" for the gcode was exactly what it was printing.  That's what baffled me, it wasn't that the computer thought it was going in the center but it was ending up off-center, even the computer realized it was going to end up being off-center.

I had since stumbled on that info about the firmware being updated in newer printers that are shipping now.  So I uploaded the firmware, re-wired the motors / hot end / all that to swap which was which, shorted one of the hot ends in the process  :-[ , fixed the short (thankfully doesn't seem to be any permanent damage, I think board was built to handle that in case hot end goes out or something), and *think* I got the settings all squared away now.  This is as of about 30 minutes ago which is why I hadn't gotten around to posting about it yet.

It is now printing out of the right hand extruder (I do not have 2 spools, yet, so no fun with using the second extruder yet), and stuff starting out in the center on the "object placement" is actually staying in the center.  Having trouble wrapping my head around how the software "thinks" regarding the offset of whichever extruder is off of the print area.  The way it was working, it's like it considered the -30 as "part" of the 200 print area, but it realized it couldn't actually print on the stuff < 0, so it reduced the amount I could print by 30 on the x.  Meaning the way it was, it shifted the 200mm over by 30mm, ohh wait, maybe that's the front left setting that the instructions say to set to 35...  I bet that is the part that was incorrect in the instructions for settings...  Oh well, whatever the case is, since I have it working with 1 extruder, I can worry about that later once I get a second filament roll to play with.  And by then hopefully the docs will be updated for the new firmware so I'll have something to go on :)

Thanks for the info on possibly needing to re-tram the thing...  Glad to know it is "normal" for it to spit the plastic out over nothing like that, it just "seemed" wrong.  That might be another good "mention" on the wiki (unless it already does and I just missed it).

As for speed, I'm trying out 150mm/s for all of the main speeds (all of the ones that start at 100 in the starter config), how high have others been able to push it and still get good prints?  The flyer says 200mm/s but I'm guessing that's top top speed and maybe not a good idea to go that fast for everyday prints?

jonyo3d

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Re: bukobot 8 v2 duo - prints offset & the starting "glob" is off the bed
« Reply #4 on: February 10, 2014, 02:02:23 AM »
Bummer, spoke too soon.  I guess I just was not looking at the position of the printed parts very closely.  I ran some gcode for leveling the print bed and even though on the gcode view, it looks like it is going off print area, the border goes along the correct border.

When I run something large that the slicer makes the gcode, it gets offset and ends up going part way off the print area on the right hand side.  I have not tried running the 2nd extruder (remember I did firmware update, so 2nd extruder is on left, first extruder on right), but it seems like the offsets are wrong or something.

So now I'm totally confused...  I can normally figure out this sort of thing but without knowing how these settings are used, having a hard time.  Logically, "some setting" needs to be subtracted by 35, just not sure which setting that is.  What should the settings be in repetier host / slicer, for a printer with latest firmware such that the first extruder is on right and second extruder on left?  I don't think that part has been updated in the wiki, not sure.  Thanks!

whosawhatsis

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Re: bukobot 8 v2 duo - prints offset & the starting "glob" is off the bed
« Reply #5 on: February 10, 2014, 03:31:15 AM »
The "bed left" setting in Repetier Host should be set to zero. Your primary extruder (the one on the right) should be touching the front left corner of the platform when you are homed, and your extruder offset in Slic3r should be on the second extruder.

jonyo3d

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Re: bukobot 8 v2 duo - prints offset & the starting "glob" is off the bed
« Reply #6 on: February 10, 2014, 03:57:14 AM »
Ok, so I figured... if that gcode from this site to tram the printer shows as off the print bed but it is correct when it actually prints, the trick would be to find the settings that shows that gcode view on the print bed... so that what it showed in gcode preview matches what printed.

Old settings (according to the settings in wiki):

in repetier host, printer settings, printer shape:

xmin: 0 xmax: 235
ymin: 0 ymax: 200
bed left: 35
bed front: 0

New settings (that show the gcode preview correctly):

xmin: -35 xmax: 200
ymin: 0 ymax: 200
bed left: 0
bed front: 0

Printed test:  Success!  Well sort of, print didn't stick but that's a different matter, think I need to turn on the skirt thingy as it's large thin object.  So at least for now, I can print with single extruder, and it doesn't print off the bed, thats an improvement!  Guess I'll get to re-visit once I get some more filament to figure out how dual part of it works :)

edit: we posted at same time - so should I go ahead and put the xmin and xmax back to what it was before, at 0 and 235?  Or does it matter?
« Last Edit: February 10, 2014, 04:45:19 AM by jonyo3d »

danlboon

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Re: bukobot 8 v2 duo - prints offset & the starting "glob" is off the bed
« Reply #7 on: February 12, 2014, 01:28:18 AM »
I am also getting my duo set up. When  I ran the 2 extruder calibration gcode, it was initially assuming that the left extruder was T0. Since this has changed, I edited the code to swap T0 and T1. These each appear twice in the code. I also moved the wait for the platform temperature (I am using ABS) to before turning on the extruder heaters. This reduces the amount of string dangling.

I made one attempt at support material and I didn't get far, but it looked like the printing from the two nozzles was misaligned, so I will have to check my setup. I believe that xminshould be 0 and xmax 235. I believe that bed left should be 0.
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