lars86

Is this the thread/bug you were referring to? https://ultimaker.com/en/community/view/2734-marlin-bug-the-myth-of-retraction-speed?page=1

Thanks, submitted it.

I haven't used Github much, so not exactly sure of the process.

Here is the Gcode: https://dl.dropboxusercontent.com/u/60958586/Doggy%20Vase.gcode

Repetier shows it, but I can't see the move in Cura layer view.

I'm not sure what is going on here, but with a very clean, fully solid model of a very circular vase, I bring it into Cura, set the shell for one pass, enable spiral outer contour, infill is 0, and uncheck solid top. The layer view looks perfect, but in the same spot on each lap (but not every single lap) Cura makes a little stutter move with the print head. It basically moves backwards 1-2mm then forwards. It is almost hard to see with your eye unless you are looking for it, but the print shows a telltale scar. It seems to migrate diagonally up the print, and doesn't happen on every single layer. Is there a setting that can avoid this bug?

Thanks for the insight! I edited the Gcode and reduced feed to 5000 mm/min on that G0 move, but left the: G1 Z+0.5 E-5 X-20 Y-20 F15000 ;move Z up a bit and retract filament even more line the same. The initial lift seemed fine, then that second fast move skipped steps. I'm wondering if that bug could also be the intermittent extruder step skipping I see during a retracting, Z-hopping, rapid moves. I keep tuning my extruder motion parameters to help mitigate it, but after watching the movement work perfectly a bunch of times, I'll leave the room, then hear skipped steps, and come back to under-extrusion. @Illuminarti and @Daid, help!!!

Agreed. I didn't ever think that was a good idea. I've never found the percentage displayed to be exceedingly accurate though. Especially when a print starts large and narrows at the top.

Well, I went ahead and ordered one. It seems like the forum community here isn't as engaged as it used to be. :/

Hi guys, I don't know if it is related to the newer Marlin firmware, or the newer version of Cura, but I have a strange issue where after a print, as the head moves away, I'm either jumping the belts, or skipping steps. I'm running GT2 belts, and have everything tuned for very nice motion. The print head can be manually moved by hand easily. I can 250mm/sec for travel moves with ease, yet something gets screwed up on the final retract move. Here is the tail end of the code I just ran: G1 F2700 X114.426 Y134.507 E182.46481G1 F2400 E179.46481G1 Z0.900G0 F15000 X114.426 Y134.507 Z5.800;End GCodeM104 S0 ;extruder heater offM140 S0 ;heated bed heater off (if you have it)G91 ;relative positioningG1 E-1 F300 ;retract the filament a bit before lifting the nozzle, to release some of the pressureG1 Z+0.5 E-5 X-20 Y-20 F15000 ;move Z up a bit and retract filament even moreG28 X0 Y0 ;move X/Y to min endstops, so the head is out of the wayM84 ;steppers offG90 ;absolute positioning Could I be skipping steps when trying to move all 3 axes at full speed? G0 F15000 X114.426 Y134.507 Z5.800

Regarding the nozzle hitting the bed: The gcode is trying to print at Z0, so unless you have adjusted your limit switch to trip at least a minimum layer height above contact, that's an issue. It's much better to actually zero your bed for contact, or just shy, then print at a defined positive Z value.

In my opinion, the default acceleration settings for XY are way too high, and for Z and E are too low.

Are you sure about that? To me, it has always seemed like it read out current layer / total layers in percent.

Is it waiting for extruder retract movement?

I'm getting that too :/

Awesome, I love it! I have replaced nearly every single component on my UMO already, and have been scowling at the frame lately I'm also curious about how all the alignment and squaring was, if you could comment.

Has anyone added one of these to their Ultimaker? Having the Ulticontroller is pivotal for sure, but I am finding that using the UC is the main annoyance I have with the printer. Mainly the unpredictability of the knob steps... you never know where it will land. I can't count the number of times I have tried to adjust flow, only to have the UC jump down one step to "change filament" and ruin a print. Plus, the "wheel+click" interface is just outdated and cumbersome to quickly make changes. I'm not sure what functionality this package provides over simply running their ( or other's) free software on a Windows tablet for example. But I really like the idea of a color, touch screen control interface for the printer to bring it into the 21st century! http://www.matterhackers.com/store/printer-accessories/mattercontrol-touch

Nope, (assuming you have an UltiController) just go into the menu -> Control -> Motion -> find X & Y steps / mm. Make the change, back up one level to Control, then chose Store Memory. Doneski!

I was hoping to see them at the RAPID conference in Long Beach. There were definitely a few UM2's in use though.

I believe it. Though, that "creep" you had in the bed was a result of the wood changing with its environment. The new aluminum bed is far more environmentally stable, but a less rigid structure. Even though it sags more, the sag is repeatable and can be tuned out with bed leveling. The bouncing cannot.

I used to use Solidworks for most things, and still do on occasion. At my company, I chose Missler TopSolid for our CAD/CAM/PDM software, and primarily use that now. I have an assembly going based on the original Ultimaker files, that I have updated with most all the customizations I have done (direct drive, custom extruder drive, custom print head, heated bed, etc.). I'll probably do an in-place part design to ensure proper alignments, clearances, etc.

What do you mean by Z at 200? With the heated bed kit and new Z screw, Z steps per mm becomes 200 PS, I just edited my last post and added a bunch of info.

You are right @lars86! my assertion/assumption was just false - it isn't the same diameter and i'm glad you recognized it! at least the effective (pitch) diameter... the calculation goes like this: 200 steps/rev * 16 microsteps/step ≙ pi * effective diameter effective diameter = (teeth pitch * teeth number) / pi that leads to: 1mm ≙ 3200 microsteps / (pi * ((teeth pitch * teeth number) / pi)) 1mm ≙ 3200 microsteps / (teeth pitch * teeth number) 1mm ≙ 3200 microsteps / (2.0mm * 20) 1mm ≙ 80.00 microsteps In the end armstrong and lars86 were right, you have to change the steps/mm to exactly 80! thank you for the comment! Gotta love nice round numbers eh?? XY at 80, Z at 200. I just put my GT2 belts and pulleys on last night. Had to get creative in locking the belts to the XY blocks temporarily since the belts are quite tight already and the Mooncactus XY blocks I am running rely on tensioning to do so. I checked out the Twister blocks you referenced and mostly like the design. The only shortcoming I see from looking at the model, is the way the GT2 clamps are integrated. In order to realize the improved repeatability of these belts, they need to be anchored solidly to the XY blocks. If there is any freedom in that interface, you won't get repeatable XY. The GT2 clamp part is narrow relative to the channel it rides in. As you tighten the cross bolts in the XY block, the channel narrows, tightening on the brass bushing and the GT2 clamp. It seems very unlikely that you will get both very firm clamping on the belt clamp, while achieving a more gentle clamp on the bushing (to avoid distortion and bind). @ataraxis, maybe you can comment on this, since I have not printed and tested. I think I am going to go ahead and design my own with the GT2 clamp a native part of the design. I picked up a couple extra bushings from Robotdigg, both having a 12mm OD and being more resistant to distortion from the clamp. One set is 15mm long and very simple, the other is 30mm long and has a bunch of graphite filled lubricating plugs. I like the idea of a shorter bushing for a few reasons. The main being an increased tolerance of slight out-of-square. The longer the bushing, the more quickly it binds when the 6mm rods are out of square to the 8mm rods. Since we are not relying on the bushings to maintain the squareness (we have belts on either side to achieve that), the shorter bushing seems a better choice. I would actually prefer a spherically outer shape to the bushing, so that it was very strong against distortion and could be equalized for minute out-of-square before clamping. I found a very nice reduction in print head friction last night by going back and loosening each of the 6mm rod clamps last (after belt tension was set and rods squared). If you clamp them down in an out of square position, you are setting the distance from one 8mm rod to the other. When you square the 6mm rods, the length changes, and if you don't release the 6mm clamps, the 8mm rods are forced into bending. Your best bet is to perform this with the 6mm rod you are working on positioned very close to one of the parallel 8mm rods.

That is not my understanding: https://ultimaker.com/en/community/view/3313-changing-from-mxl-to-gt2-belts-and-other-xy-goodness#reply-17275 @armstrom