yeah, I saw in another post somewhere about the temperture difference due to the thermistor placement. Thanks for verifying the info.

I have started running a temperture calibration tube now when I change filaments to find what works best for a given color/type - heat it up slowly to when the filament is oozing steadily, then step down by 5 degrees every 15 layers or so - so far the PLA filaments have been running about 163 or so, and ABS has been in the 185 range (give or take a couple degrees...)

There has been a lot of trial and error with this thing, but it has been an interesting journey so far.

Note that the stock solidoodle hot end measures temperature a little differently to many other hot ends. Many people say it's "inaccurate", but I feel this is jumping to conclusions: SD has chosen to attach the thermistor to the nozzle itself, whereas it's more common practice to attach the thermistor to the heat block. You can go back and forth a lot on the possible pros and cons but they're all much a muchness really. The result is, for what we believe to be the same plastic temperature, a thermistor on the nozzle will read about 20C or so lower than one on the heatblock. So when you see recommendations to print ABS at 230-240C, you should probably adjust that to 210-220C on the solidoodle hotend: it should print/adhere quite ok at this slightly lower temp setting, and won't set off your over-temp alarm.

the stock Y idler blocks were cracking, one of them pretty badly it turns out - I printed up some new ones (made a little beefier), got them installed, and now everything lines up perfectly! no more issue with the first line being out of alignment. Yay!

I am really surprised at how easily the one piece split open when I was trying to get the little brass screw inserts out...it cracked open like an egg on the edge of a pan. I can see they have excellent quality control at Solidoodle... LOL

an added note: the new idler blocks have pretty much eliminated the flat spots i was still getting with my circles, too - added bonus!

I did try spinning the cube 45 degrees on the bed, and it comes in closer to dimension, but still just a bit off - maybe I am just expecting too much out of this machine?

having cleaned and regreased the rods several times, I can say there are no noticable burrs on the Y axis - however, the rear X rod has some sloppy epoxy goop on it (the one for the rear plastic guide bushings), but it is on the right side, not a lot of it, only extends maybe an inch or so, and doesnt really affect the center area at all...

on the carriage - it is really ugly - that pic isnt the greatest - that one section is delaminating pretty badly and the longer I use it, the worse it seems to be getting...maybe it is just my imagination, but it seems worse now than when I first got the printer...

Both of the Y idlers are showing cracks between layers so want to replace those as well... anyone have a file for the non-adjustable version they would be willing to share?

to be perfectly honest, I want to replace all the printed parts on this thing - none of them look very good - like the filament just wasnt hot enough to stick the layers together well?

I know the printhead carriage really needs to be ABS because of the heat involved, but what about the other parts? Can I do them in PLA? or is it too brittle to hold up? I printed out a fan shroud for the X motor in PLA and it seems to be doing great (best mod I have done to this thing so far! I re-purposed the fan from the back of the case to cooling this motor. LOL) and it fit fine - snugly without being difficult to get on...

the reason I ask this is I am having a hard time getting this thing hot enough to print with the ABS (Octave brand).

I understand the limitations of the stock hotend, and 230C being the max temp it can handle, but I cant even get it that high before it hits the "max temp" thing - about as high as I can get is 225C according to the readout on RH, if I bump it up to 226 it shuts down with the "max temp" error.

Is it possible for this thing to be reading the temps that far out of whack? where 225 in RH is really 230?

Unfortunately you've got me stumped now. I don't think skipping steps is the issue here, but on the off-chance there's a burr or something on the y shafts that lead it to skip and stop at exactly the same point every time it comes forward, you could try winding the y motor current up 10% or so, or printing the cube in a slightly different spot on the bed... I do trust you've dealt with motor current and that's all good now, I'm not advocating going around in too many circles, but I'm running out of ideas!

Awesome - thanks.

So the manual moves come out accurate... I'd be looking for extruder wobble back and forth now: does the carriage wobble back and forth during a print?

Not that I can see when watching - edit: printhead carriage does have a very slight side to side wobble, seems to be a bit of play in the bushings - no detectable wobble front to back.

Does the hot-end wobble back and forth if you try pushing on it (best try this cold, be wary of the hot surfaces!!)?

Will have to check that one - edit: hotend seems to be mounted solidly, I dont feel any looseness there.

Is there any looseness in the y-drive hardware?

The only hardware issue (aside from carriages) that I have right now is a stuck screw in the Y axis motor that now has a stripped head...any suggestions for getting that out? I have some longer replacements already, just need to get that one out of there...

Are the idler pulley brackets at the front firmly attached?

Yes, altho they both show signs of fatigue cracking....and mine do not have the adjustment screws that I see in so many others - including the replacement versions? all belt adjustments are done at the carriage

Is there any sign of cracking or damage in the y carriages?

Actually yes (see pic), this carriage is why I am so durned determined to get this thing printing as accurately as possible so I can print up some Lawsy carriages (bearings are on thier way already) and replace it.

So the manual moves come out accurate... I'd be looking for extruder wobble back and forth now: does the carriage wobble back and forth during a print? Does the hot-end wobble back and forth if you try pushing on it (best try this cold, be wary of the hot surfaces!!)?

Is there any looseness in the y-drive hardware? Are the idler pulley brackets at the front firmly attached?

Is there any sign of cracking or damage in the y carriages?

printed in PLA, extruder temp of 160, bed temp of 59, layer size at .2, multiplier at .81 to get wall thickness down to .44 - any lower there and I dont get complete fill on the bottom.

thoughts? ideas? suggestions welcome.

edit: marking the glass bed & moving the printhead manually 100mm in either X or Y does measure out to 100mms on both... so terribly confused by all this...
if both X and Y are actually moving the correct distances, then why are the dimensions so far off on a print? I am not looking for perfection, but would like it to be a bit more accurate than it is.

I let the full cube print run last night - got some issues with bridging, too, but one step at a time here...

still has that little lip on the front - the very first line laid down is different than the rest...

20 x 20 single wall cube is measuring out at X = 21.84 mm & Y = 16.76 mm on the walls,
but if I measure the bottom layer I get X = 23.11 and Y = 21.082

Belts have been re-aligned and re-tensioned just this morning...

I have found the X/Y dimensions to be off on other items I have printed as well that are supposed to be symmetrical... help!

Solidoodle states that X, Y & Z should be at 1v ea, and E should be at 0.250v...
My initial readings of what they were as is are below...

X = 1.219
Y = 1.249
Z = 1.210
E = 0.834 (!) no wonder i was getting diagonal pulsing!

so after much fiddling about, power up, test, note readings, power down, unplug, adjust, plug back in, and repeat (don't have a ceramic screwdriver - yet), I now have:

X = 1.003
Y = 1.006
Z = 0.993 (was super touchy - or would it be better to have it slightly over - around 1.05 +/-?)
E = 0.251

test cube coming up...

found my glass cutter, cut a piece of the mirror to fit (sort of - a little crooked on one edge, but so what), found a couple of binder clips to hold it on (other half is going to pick up some more on the way home instead of a glass cutter, lol), re-leveled everything with bed at full temp and extruder halfway warm - was just shy of oozing... and snugged the short belt just a teensy bit more, trying not to bend the rod...

and viola! the odd line is odd no longer!

the 20 x 20 cube is still a little small on the Y axis, but MUCH closer than it was.

edit: on closer inspection, that first line is still just a smidgen off, but no where near what it was, and the fill layer was actually meeting it on the first layer....could possibly be due to that first layer squish?

now to try some circles....

It helps if you have bearings there, I am not convinced the bushing SD used actually made things better.

In fact they make no difference. The only difference is you will experience binding sooner if you tighten down the motor too much.

Bearings are better.