3DR issues.

Hi all,
Some time ago now we got a 3D printer at work and when I started using it i realised I needed to have one of my own. So I decided on the 3DR, pritned all the parts at work and built it all up checked but it has never really worked and I am now wanting to do something about that. The problem it has is that the printing movements are extremely jerky, the reprap coin test print eneded up looking more like a badly printed gear than a round coin. Well that was the first time I managed to get it to print now I cannot even get it to stay level when printing, it homes fine and moves down to its central position fine and everything is smooth when doing those movements and it all stays level when manually moving it in the x/y directions but when I give it a print it goes all steppy/jerky/stuterry and then the head rises off the bed near the front left tower and sometimes crashes into the spectra line.

My setup is:
Reprap discount RUMBA with xxl screen
A4988 x 4 drivers
4 x Nema 17 1.8Deg stepper motors, I cannot find the listing for the ones I bought now but I think they were 2A ones
The head is a clone Jhead but that works so I'm not concerned there

I have read that disabling the screen can help with the limited resources the RUMBA has but It didnt help in the slightes in my case. I checked all the diagonal rods when making them up and they were all exactly the same length. I followed every step in richraps tutorial as far as software goes but beyond that I'm not sure what else to change.

I expect somebody out there has been plagued by this problem too so any help is much appreciated.

Thanks in advance
Smithy

okay so I found out what motors im using and they are casun 42shd0440-22 units. these are 1.8deg step 1.2A models

The Marlin version on Richards blog is quite old now. You may be better off starting with a newer version. The full graphics display will definitely cause issues with an Arduino running a delta. Did you disable it in firmware or just unplug it? You need to comment it out in config.h

the screen isnt a full graphic one just the xxl, [www.reprapdiscount.com]#

And yeah I commented it out and disconected it physically but it had no effect. the thing i dont get it I'm running pretty much rich's setup so I dont understand when people say the RUMBA cant handle a delta and a screen while others get it working flawlessly.

Last time I tried it and actually got it to print a gooey mess I was using repetier firmware.

Try to reduce the DELTA_SEGMENTS_PER_SECOND to 80 or lower in your firmware. See if there's any improvement in stuttering or hiccups. If so, you can hook up your display again.

Okay new issue, rebuilt the printer at a larger size with gt2 belts instead of spectra line, Followed jay coutures delta setup guide and got it so that when z=0 the hot end just catches a sheet of paper on the bed at 3 points, one in front of each tower and one in the centre.
Well I did a dry run print and it jsut doesnt work out, it's high at the edges and crashes the bed in the middle despite being level when you input manual commands to move to xyz locations.

Not sure what I have done wrong but I really hope one of you do. I'm running repetier 0.92 now.

Thanks,
Smithy

Quote
j.smith1995
Okay new issue, rebuilt the printer at a larger size with gt2 belts instead of spectra line, Followed jay coutures delta setup guide and got it so that when z=0 the hot end just catches a sheet of paper on the bed at 3 points, one in front of each tower and one in the centre.
Well I did a dry run print and it jsut doesnt work out, it's high at the edges and crashes the bed in the middle despite being level when you input manual commands to move to xyz locations.

Not sure what I have done wrong but I really hope one of you do. I'm running repetier 0.92 now.

Thanks,
Smithy

Hi I;m just in the process of setting up my first delta printer and thought id share what i think ( having spent the past 2 weeks reading the net whenever im not building) its sounds a lot like you have a "concave" print surface or at least the printer thinks you do. ( its either concave or convex)
I found this very useful in understanding the issues and relationships
[builda3dprinter.eu]

It refers and is based around Marlin firmware but i believe the core elements are similar if not the same
Hope it helps you too
Cheers
Phil

cheers for the reply, I discovered my error, for some reason I didnt set slic3r centre to 0,0, not sure how that causes what happened but after changing that setting it seems okay.

I had already calibrated the build surface to within a paper thickness, that link looks pretty useful,definitely bookmarking that for later use.

Movement still seems steppy but it is a lot better than it used to be.

Quote
j.smith1995
cheers for the reply, I discovered my error, for some reason I didnt set slic3r centre to 0,0, not sure how that causes what happened but after changing that setting it seems okay.

I had already calibrated the build surface to within a paper thickness, that link looks pretty useful,definitely bookmarking that for later use.

Movement still seems steppy but it is a lot better than it used to be.

Define "steppy" Just kidding :-) Im sure i have got loads of fun ahead as well so i'm following all the "delta problems" threads

well, just incase, I mean the movement isnt smooth when i say steppy, almost like the caridges are taking turns to move so it goes a little left then a little forward etc creating like a jagged finish.

To be honest this time it hasnt been too hard to setup but the tuning is yet to come I guess. just the first time I kinda lost heart after I couldnt get the thing to stop hitting itself and since I have works Ormerod to play with I didnt need to finish my 3DR but now I want it finishing and useable

If you have an Ormerod and you like the firmware and web interface, then you might be interested in converting it to Duet electronics. See the link in my signature for how I did a similar conversion on my Mini Kossel.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I'd rather not spend any more money on it for now, Just want to get it working as it is. I think I'm close now anyway, as for the duet web interface I never use it I just control it via usb from pronterface and always print from the sd card.

If you never use the Duet web interface (especially the new one by zombiepantslol), you are missing a lot! It does so much more than Pronterface does.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

to be honest the only other thing i'd like pronterface to do is be able to list more sd card files and/or manage the sd card gcode files so i can delete them. bt to be honest that isnt worth the hassle of adding in a mini switch or running another line from the server.

If you have wifi then you can buy a wifi to Ethernet bridge for just a few pounds on eBay or Amazon.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

ok new issues, Got the thing printing but the head randomly crashed into the model at like 3mm up but before then it was fine, I think the Z tower is messing up but I have no idea why since I can run the cariage up and down by hand and there are no discernible rough spots in the movement.
I tried to print a 1cmx1cmx1cm cube and the here are the results, fine until a point then it ruins it.





Also it wobbles uncontrollably, like the base stays flat but the top of it is all over the place with fast movements which sounds like bad thing looking at the way it warps the entire structure as it goes.

Edited 1 time(s). Last edit at 03/10/2015 03:56PM by j.smith1995.

just my 2 cents worth
from what you are reporting you have a serious issue with the rigidity of your frame which in turn causes all manner of issues with stability which in turn sounds like the belt tension and general calibration is being affected.
The good news is it has to be fairly easy to identify ....If i were you id really go back and double check the build of the frame . Forget printing for a while and focus on the basics of the frame and the machines motion.
Good luck

Edited 1 time(s). Last edit at 03/12/2015 01:27AM by bigfilsing.