billyd
RRCRat Rig Community [Unofficial]
•Created by Ibot on 1/24/2025 in #fix-my-print
IDEX XY Offset drift (VC4)
Watch your Y belt bodies they are prone to shearing. It is hard to see if you've damaged them also. Look for layer cracks where the bottom of the Y belts exit the printed part. At your loads, there's a good chance for failure. Mine were damaged at lower levels than that and had to be replaced.
657 replies
RRCRat Rig Community [Unofficial]
•Created by Ibot on 1/24/2025 in #fix-my-print
IDEX XY Offset drift (VC4)
Yes, especially for the IDEX where issues can appear at the extremes that were not measurable or visible in smaller prints.
657 replies
RRCRat Rig Community [Unofficial]
•Created by Ibot on 1/24/2025 in #fix-my-print
IDEX XY Offset drift (VC4)
Yes I would say you definitely don't want skew compensation on as that would cloud the mechanical result
657 replies
RRCRat Rig Community [Unofficial]
•Created by Ibot on 1/24/2025 in #fix-my-print
IDEX XY Offset drift (VC4)
Nice thank you! Can you describe how you determined based on the result, which belt was longer?
657 replies
RRCRat Rig Community [Unofficial]
•Created by Ibot on 1/24/2025 in #fix-my-print
IDEX XY Offset drift (VC4)
Specifically what you had to do to make it right would be helpful.
657 replies
RRCRat Rig Community [Unofficial]
•Created by Ibot on 1/24/2025 in #fix-my-print
IDEX XY Offset drift (VC4)
How much should I be able to move my X gantry out of square by hand with no belt tension? e.g. If I gently push on one xy joiner and pull on the other.
657 replies
RRCRat Rig Community [Unofficial]
•Created by Ibot on 1/24/2025 in #fix-my-print
IDEX XY Offset drift (VC4)
Probably not. I was mostly joking. I don't understand the problem so I can't offer a real solution.
657 replies
RRCRat Rig Community [Unofficial]
•Created by Ibot on 1/24/2025 in #fix-my-print
IDEX XY Offset drift (VC4)
Maybe if the stepper motors and drivers were replaced with stuff that's double the stock equipment's holding torque it could brute force the printer into staying square everywhere.
657 replies
RRCRat Rig Community [Unofficial]
•Created by Ibot on 1/24/2025 in #fix-my-print
IDEX XY Offset drift (VC4)
Yes I understand, I should say I have to manually alter what is determined at the camera to align the toolheads in the print area. I have NO idea why it doesn't work.
657 replies
RRCRat Rig Community [Unofficial]
•Created by Ibot on 1/24/2025 in #fix-my-print
IDEX XY Offset drift (VC4)
The interesting thing about my printer is it prints well for the most part. Where it fails are at the extremes of printing, e.g. printing a tall tower with dual color and seeing if they stay perfectly aligned for the full height of the printer. These are not usual cases for 3D printing. 99% of the time we print objects that are much smaller than the build volume. So we don't print at x, y, or z min and max locations except in rare instances. It's possible that many people are fat dumb and happy about their IDEX printers, having no idea at all that the printer fails at the extreme cases because they've never tried them. I can do dual material, color, or copy/mirror and the prints come out fine. The only reason I even found out I have drift is because I stumbled across this thread and tried it. I had no idea my T1 couldn't print straight along Y at the X min areas until I tried it. It prints fine everywhere else. Essentially I have isolated three issues with my printer. I have drift issues in X as is documented in this thread, my VAOC xoffset value is not being calculated correctly (when compared to reality), and the skewed printed line at the front left of my build plate with T1. I can avoid the drift, because I most likely will never have to print a dual color tower side by side, I can correct the x offset manually using an IDEX test print, and I can avoid the front left of my printer. It just bothers me no end that I can't figure out why it's happening, when every measurable metric of my printer says it's otherwise perfect. I can print copy/mirror with a first layer height of .2mm, I have perfect balance in the belts after using GATS, their tension pulley locations match to withing 0.02mm and my skew calibration now prints with literally zero skew in all three axes w/o compensation. The bed high to low even measured with the magnetic bed is less than .2mm. I don't know what else to do other than to disassemble the gantry and toolheads and examine every component.
657 replies
RRCRat Rig Community [Unofficial]
•Created by Ibot on 1/24/2025 in #fix-my-print
IDEX XY Offset drift (VC4)
Very frustrating to be sure. I will avoid the use of expletives to keep the discourse civil and not get banned from discord.
657 replies
RRCRat Rig Community [Unofficial]
•Created by Ibot on 1/24/2025 in #fix-my-print
IDEX XY Offset drift (VC4)
Welcome aboard. I am the captain of that ship and it's not a fun cruise.
657 replies
RRCRat Rig Community [Unofficial]
•Created by billyd on 2/19/2025 in #ratos-support
VOAC calculating offset wrong by the same amount every time
I redid GATS again to 3.3kg and now the error is -0.3mm so it's getting closer. So it's obvious to me this is a problem with my printer, as you stated all along.
64 replies
RRCRat Rig Community [Unofficial]
•Created by Ibot on 1/24/2025 in #fix-my-print
IDEX XY Offset drift (VC4)
Did the the print with toolshift disabled, no drift. I am seeing something odd with tool 1. When the toolhead change occurs from T0 to T1, as T0 leaves the part, T1 shifts slightly (1mm?) towards X min before T0 parks and T1 makes it's full move towards the print. T0 does not do this when changing for T1 to T0. I never noticed this behavior with toolshift enabled.
657 replies
RRCRat Rig Community [Unofficial]
•Created by Ibot on 1/24/2025 in #fix-my-print
IDEX XY Offset drift (VC4)
After doing the GATS method, it's the only way to do it. The other methods are walking around in the dark bumping into stuff.
657 replies
RRCRat Rig Community [Unofficial]
•Created by Ibot on 1/24/2025 in #fix-my-print
IDEX XY Offset drift (VC4)
Just remember the IDEX is limited to how tight you can go on corexy due to the rotational load on the carriages from only having one belt pair. Once the x axis feels rough when you move it by hand, the belts are too tight. I would say anything over 20 newtons (4kg weight on a pulley) is probably too tight for the IDEX, 3.5 kg is probably best.
657 replies
RRCRat Rig Community [Unofficial]
•Created by Ibot on 1/24/2025 in #fix-my-print
IDEX XY Offset drift (VC4)
Started seeing some drift at around 45mm. Greatly improved but still there. Tomorrow I will run one with toolshift disabled and see if that changes the result. A failure but also it demonstrates that equal belt tension is important, as this print is much better than before with toolshift enabled.
657 replies
RRCRat Rig Community [Unofficial]
•Created by Ibot on 1/24/2025 in #fix-my-print
IDEX XY Offset drift (VC4)
The 3.07kg weights resulted in Belter readings of around 5.9 to 6.1 which is pretty light. I was looking for about 6.4 or so. This also demonstrates Belter is pretty inaccurate, as 1/2 of 3.07kg (2 belts/pulley/weight) should be about 15 newtons or 6.35 on Belter.
657 replies
RRCRat Rig Community [Unofficial]
•Created by Ibot on 1/24/2025 in #fix-my-print
IDEX XY Offset drift (VC4)
Edit, unfortunately started seeing some shifting at about 45mm, greatly improved for my printer but still a technical failure. GATS seems to have resolved this issue on my printer. I am halfway into the print and no shift with toolshift enabled. My printer has never printed this far without some shift showing up with this test print. If anything changes I will edit this post, but it looks good. I will probably re-do GATS with more weight. I did 3.07kg weights but I think I can easily do 3.5kg to 4.0kg weights and the belts will still not be too tight. At 3.07 kg on my 300 I can only get 6300hz for X axis which is too low for a 300 and I think more belt weight (tension) will likely increase that.
657 replies
RRCRat Rig Community [Unofficial]
•Created by billyd on 2/19/2025 in #ratos-support
VOAC calculating offset wrong by the same amount every time
Used GATS to tension my printer. Used 3.07KG on each belt pulley. Gantry square front and back. Made belts all the same length. Still -0.5mm out on the VAOC after redoing the commissioning guide.
64 replies