Hello! It’s a long time since I’ve posted here. My printer have experienced a lot of changes and improvements but I’ll make another post about them later (still a lot to do). Improvements you can see from these pics are for example: PEI coated aluminium print bed, cable chain and housing for smoothieboard.
This will be a true stress test for my 3D-printer! So far it have been printing about 60 hours and 1,3kg of PLA -filament. Still 120 hours left, until main parts of the robot are printed.
No sings of wear and belts are in good condition but one problem have occurred with my printer. I found poor connection from heated bed connector(which was pretty hot). After I fixed that, everything is working again. This is another great reason to upgrade to the mains powered heating element and drive it trough SSR (waiting parts to arrive currently). At the moment I’m powering 150w 12V heater through smoothieboards MOSFET.
The parts you see are printed with layer height of 0.2mm to 0.3mm and 30-35% infill. They are sliced with simplify3d. I’m pretty happy how these parts have come out so far. Next print is going to take about 35 hours.
@Step_Cia Thanks! Well since this printer is using direct extruder it is PTFE tubing which is only guiding the filament into right place. But yes, it is going inside cable chain! There is of course increase in resistance but nothing that would really matter. I have also spool holder without any bearings and the spool is still nicely running on it. I guess my extruder is pretty good what comes to the gripping force.
This solution is leading to the easy enclosure build.
o wow I didn’t realize it is direct drive… well that make sense. anyway can’t wait to see the arm final assembly been meaning to print this myself but I think I need to finish my printer first
Great job, this what i can call a great printer. I can see some little artefacts on one of the photo, i think it can be because you have a heavy carriage. Try to reduce a little the aceleration and jerk, pretty sure it will reduce the problem.
@Filipe_Campos Thanks! Yes there is some artifacts. As you said they are caused by heavy carriage but also flimsy bed supporting.
I have tried to tune acceleration, but there is always some artifacts and I don’t want go any lower.(acceleration currently 2500mm/s^2)
I have few improvements in my mind for these problems. If I don’t redesign the whole Z-axis, I’ll make better supporting for the bed.
I’m also planning to do dual extrusion system with mainly printed carriage, so it’ll be much lighter. Now there is a lot of excess aluminium.
2500 is very high acelerarion value, on my printer i use only 500 in printing acelerarion and 15 on jerk. It will print slower and very concervatif way but remove any artefact. Anyway i think you nothing to lose to try a least one print using this type of small acelerarion values. I think print quality is way more important that speed.
By the way, i have similar bed struture. Using 2 16mm rods and only one 8mm threah screw. It is giving my tiny z banding problems but no artefact. I think the artrfacts you have are not related with your bed, but with the carriage height or even the missing belt tension.
@Filipe_Campos I’d say 2500mm/s^2 is pretty low accerelation. I also value print quality more than speed but I don’t like when printer won’t get up to the programmed speed because of low acceleration. I’ve tried as low as 1000mm/s^2 acceleration and there is still some artifacts and in my mind that tells me that there is some mechanical issues that shoul be corrected instead of going down to very low accelerations.
I’m using 12mm rods and 12mm ballscrew that gives me visible z-banding. I’d like to upgrade whole bed structure but first I’m going to put some reinforcing in it and swap to 8mm leadscrew to see if it helps. One thing you can’t see from the pics is that the bed support structure is very flimsy. When printer changes direction the whole bed is shaking up and down.
Whole artifact problem is a sum of many things! Trust me, I’ve been investigating it
Ok. Posting photos of my bed setup and the Z banding problem i have. is pretty hard to solve when using cantilevered like we have. If you find a solution to solve this please tell me.
@Filipe_Campos You have a nice printer! I should have gone with the linear rails from the beginning too…
I’m pretty sure that the main reason causing z-banding is incorrect aligment of those components. Most of the people (including me) are using seperate mounts for rails and leadscrews and it is virtually impossible to get them aligned to each other.
Rails and leadscrew should be perfectly collinear to each other. Maybe a machined parts that holds both rails and a bearing for a leadscrew on both ends of travel would be good solution for z-banding issue.
In my case i already checked the 8m thread screw instalation, from my point of view is correctly installed and is turning very strait. I using a plastic nut, is called the " Anti-backlash Delrin nut" maybe because is made o plastic is causing this problem… any case, any suggestion of what could be the reason of this problem is welcome.
About the big ballscrew, high pitch can be a problem in very low layer and if the ballscrew is not good quality. but if a good one, it should me better that using a thread screw like i have.
