Ok i have got a wired problem with auto bed leveling,
When i level the bed manually i can easily get a good even first layer, but when i try to use auto bed leveling the sensor senses heights differences that apparently isn't there and start at one side with perfect layer height then prints across the plate while slowly raising and lowering the nozzle giving a really uneven first layer. Any ideas what could cause that?My printer is an Wanhao Duplicator I3 Plus MK2 with inductive sensor.
I need to replace the PTFE tube and hoping someone can give me guidance on the length...
Should the tube be cut long enough so that when the nozzle is being tightened onto the hot end, the PTFE tube "bottoms-out" against the nozzle, and that's what prevents further tightening? Or is there supposed to be a metal-metal seal of the nozzle with the hot end and the PTFE tube is slightly shorter than the space it occupies?
Just upgrade my board to MKS gen 1.4, running Marlin 1.119, and everything seems okay but my estep's for extruder is off by almost 50%. As per various calculators and other posts should be around 100 steps. But it's over extruding to a ridiculous level. With calibration done estep's are down to 56.47. That just seems too far off the mark. Wondering if anyone else has had such a variation and if this may be an indication of other issues.
Pickup up a PowerSpec Duplicator i3 Plus "Powered By Wanhao" from Micro Center as an impulse buy for $188 USD open box. I've had a MakerBot Replicator Dual (the Wooden one) since 2012 that i got for $350. With a bunch of small upgrades i designed myself it's been a workhorse, so I'm definitely not a stranger to 3D printers. With that said, I found a bunch of design flaws in the PowerSpec version of the Duplicator i3 Plus.
Printed a test print after quick out of the box assembly, and it was definitely not all that great but it worked! So it was time to find things i could fix.
First thing i found was the part cooling box, i wouldn't call it a duct. Printed out a really nice design "fan_fun - wanhao duplicator i3 plus" and at 50% speed as more effective and worked surprisingly well behind the part, basically equivalent cooling on the back. Then quickly dropped in an all metal hot end.
Took the machine completely apart at that time. The Y belt idler arm was insanely bad, printed out two little washer to put the bearing on the bolt much closer to the fulcrum point of the little block holding it in place. Screwed down the stepper motor and idler pulley crooked so that when i put tension it was line up which it did perfectly ;-) Printed out some belt locks that slip on to hold by joining the belts teeth together, but made my design with a taper so that i could get the belts in easy but still have a very tight fit. Don't know what i did with that file lol. Fixed the loose belts for the X and Y and squared up the machine properly.
Then lowered the bed as much as possible without fully compressing to allow room for adjustment so there would be minimal bounce, found the Z switch at it's lowest point was too high.. but that makes sense as they don't want the head bending the bed. Took one bolt out so i could lower it further but then realized the bed was flopping around because there was nothing holding the beds screws in place so then designed a minimal shim to raise the bed and put the second bolt back on the z-stop lol. But also hold the springs in place along with the screws.
Found because the bed moves back and forth and basically pumps air over and under the bed, busted out my infrared thermometer and found there was a 1 degree drop every 15mm from the center in a 72 degree room and a about a 5 degree temperature swing while printing on top of that. So if i set the bed to 70, the center would be 70-74 and 20mm from the edge would be 67-70. Then i designed some skirts to prevent pumping air underneath, that made it much better. Center now has a 2 degree swing and the edges are "only" about 3 degrees less. PETG was sticking far too well to the center of the bed while not at all on the edges, then it stuck too well to the whole bed. I'm also certain that's the reason the beds like to develop a nice hump in the middle because the metal expands more there while the edges are cool and hold against expansion so then it just bends up. Found that issue years ago on my Replicator when printing in cold rooms that it would warp the bed because the edges on the bed had a greater delta to the center heat.
THEN, onto the X gantry.. the rod retainers where null for the job. I first tried to tighten them up while squaring up the gantry and after a few prints it got loose again and even worst because i put good tension on the belts so that caused the lead screws to bind because everything was giving way. Busted out my caliper for the 100th time and went to work and made retainers with end stops so you wouldn't have to rely on little screws to hold onto tension and the jerking of the carriage as that's how the X gantry is held together on my old Replicator Dual. Now its amazingly sturdy and no binding what so ever. Which makes me think of why you would even need two larger stepper motors when one "normal" one can do the job, and I'm sure it's to overcome binding when nothing is straight :-/
So that fixed the mechanical issues.. mostly. Somewhere in between i installed Marlin 3.0.2 because the stock firmware had tons of bugs. Hell, i didn't even know it was a color screen lol. Then had to fix the Vref on the board, found there was voltage droop and corrected it while printing a large vase square on it's side lol. Now motion was smoother but still "buzzy". And noticed when doing extrusion and ratio tests that there was a jump or hiccup in the extruder stepper motor. Took a motor off my Replicator and tested that, but it was still there a little bit. Despite also using the Replicators extruder driver, so it wasn't a bump or clump of dirt on the extruder gear and it was at the right distance that a full step would be made. So that's when i learned its a design flaw in the stepper drivers, which can't be replaced and you would just have to get a new board with better drivers or one with modular drivers. I went with option F (fuck it), ordered some tl-smoothers. And the old stepper drivers ran much MUCH warmer, wonder if that made the voltage jump that causes the jump/hiccup/pulse/whatever be harder to effect a motor that had so much waste heat, essentially taking that extra electricity and turning into heat and not that pulse.
Now, i finally really like that machine. And there's definitely a few things i left out like applying tension on the X-rail carriage to remove slop and rerouting cables etc. Which I'm also certain the longer bearing should go on the bottom where the weight of the extruder driver is.
If there's any tips anyone could suggest on these printers i would love it and ill be going though the forums too.
X gantry supports, http://www.thingiverse.com/thing:4254688
Bed skirts, http://www.thingiverse.com/thing:4254456
Spring retainers, http://www.thingiverse.com/thing:4254528