I’m trying to print the Z-axis support from Thingiverse, sliced it and put it on the SD-card.
Printer starts printing this:
What is going on here ?
Could someone please explain ?
In Repetier it looks normal and is centered.
Made another try. Sliced it again and stored it to the SD
At least this time the perimeter is OK and the print is centered, but then…
Can I check in advance exactly what the printer will make of it whithout actually printing ?
I had something like that, for me it was the belts being too tight, causing the steppers to slip. This will male noise, so you’ll know when it’s that. To be absolutely sure you’re good on the mechanical side you could loosen all pulleys and see if the extruder-head can move with minimal friction manually. When I see the pics and hear you say it shows good in repetier, I’m inclined to think it should be mechanical. One other thing t can be: using repetier on single head while printing dual or the other way around…
Correction, it’s better to loosen the belt from the carriage and leave the pulleys where they are, provided they are in line
Thanks Ivor for your answer but unfortunatly I dont think thats it.
I tried to print another small object and that starts ok.
There is no excessive sound but I did have an issue with the tightness of the bearings earlier. It was solved by separating the bearing holders on the Y-axis by 1 mm.
I am totally convinced this is a SW issue. If it was mechanic it would be a lot more random changes since the tightness would differ from where the print head is. The changes I see are very persistant and exact.
Okay, that’s a good thing in a way… Being a mechanical engineer, this is where I step off lol. I must say that getting the settings right in repetier gave me some study-time. Specially after I fitted the second extruder. Oddest thing remains your printer doesn’t do what repetier says. You tried reinstalling the firmware? Reasonably simple to do:)
This time I tried to print two objects at one time and all went well untill about 4mm height when the printer decided to shift 5 mm sideways.
Here’s another problem illustration.
When I try to print the switchholder as a one off the lines are very thin and it does not even stick together. Picture below.
When printed together with the Z support above it somehow inherits the properties of the support and gets good full lines.
Does Repetier give an indication it went wrong? when reptier itself thinks it’s been ofsetting, this will show in the progress screen. i’ve had it once while there was nothing wrong with the actual print… anyway, not to be an annoying bugger, but are you sure the setscrews of the pulleys are tightened securely? i secured em a few times before i was sure this couldn’t be the problem and used both threaded holes, so doubled the setscrews. i’m actually unhappy with this way of securing a pulley to a shaft but a taperlock of this size simply doesn’t exist. and of course, blah-dee-blah-production costs lol. Like i said, not to annoy you, but from here it really looks a mech. failure. specially if Repetier says there’s nothing wrong.
The shifts have one and only reason : the axis are not correctly tuned. With the belts removed the movement of the axis must be perfectly smooth from end to end. It means that the carriage can be pushed from side to side with the tip of your little finger without the slightest resistance. You can have a look here at the [color=#408040]Wiki[/color].
OK guys, I am also convinced its a mechanic fault.
I removed the belt drives to be able to move the print head freely and gave it some additional oiling and it then was easier to move.
I checked the Wiki but I am a bit allergic to expressions like "there shouldn’t be any friction at all ". If there was no friction at all you should be able to give it a small push and it would glide over and bounce back at the stop. There are tools to measure push and pull forces, why not use them ? Sure everybody does not have them but for those that does it would be a great help.
I suggested in another thread that the axis should only be fixed at one side, the one closest to the homing point. The other should be freefloating in a bearing. Then this problem would not exist.
Anyway, I managed to print the switch bracket with decent quality without any offsetting mid print.
Thanks guys.
[quote=“monza64”]I checked the Wiki but I am a bit allergic to expressions like "there shouldn’t be any friction at all ". If there was no friction at all you should be able to give it a small push and it would glide over and bounce back at the stop. [/quote]Well it’s almost that. When you tilt the printer the head should move freely to the lower side.
Really ?
That should be in the build description and the wiki.
Would that be with everything attached, belts, motors etc ?
[quote=“monza64”]Would that be with everything attached, belts, motors etc ?[/quote]No, when everything is attached there is too much friction.