First layer squish increasing with time VC4 500
I'm currently several months into trying to troubleshoot this issue with not much progress. The first layer appears to be creeping closer and closer to the build plate as the print continues. Eventually the nozzle will actually contact the build surface. I don't experience this issue with smaller first layers that print quickly.
First attempt at a fix was to clean the nozzle and redo the beacon calibration, but this didn't appear to help.
Second attempt was to double check all fasteners on tool head to make sure it wasn't loose. Still no improvement.
I thought this may be related to the known thermal bimetallic effects on the gantry, so I attempted to heat soak for approximately two hours before printing. This seemed to help slightly. The nozzle did not migrate towards the bed as fast as it did in the past, but ultimately the behavior was similar.
I'm at a loss for what steps to take next. Aside from this one issue, I've been thrilled with the printer's performance.
9 Replies
Toro Titanium Tube from toro3d . Had the same issue on my VC4 300.
I have a feeling that will be a big part of the solution. Just wanted to query the community and see if there was anything else I should try to eliminate as a potential cause before dropping the money and tearing the printer apart to replace the gantry 😫
I've been doing a deep dive in this thread to see if there's anything I can try before going down that path...
https://discordapp.com/channels/582187371529764864/1360247935496884265
Unfortunately this is caused by the bi-metallic effect between the rail and the aluminum X gantry, because they have different thermal coefficients they "stretch" at different rates thus causing the instability until everything has settled thermally. Lower heat capacity, thinner and lower heat conduction metals help with that.
The only real solutions are:
- ti x gantry
- steel x gantry
- very long heatsoak times before printing (1h30+)
Even with ti and steel gantrys for a 500 machine I would suggest setting a heatsoak time of at least 15 minutes on RatOs for full plate prints
I appreciate the insight. Went ahead and pulled the trigger on a toro tube. Hopefully that alleviates the issue...will report back once it's installed and tested.
For reference, here is the first layer pattern I'm observing.
I see the same pattern with my VC4 500. If I let it soak for a long time it gets better but not good. The same pattern appears on all the flat top layers. Is it the same for you?
I haven't really done any prints with large enough top layers to notice the pattern there, but I'm sure it would be. Layer stacking hasn't been the prettiest either and I'd be willing to bet it's just a continuation of this pattern across layers.
Let me know when you have done some prints with the new gantry! Maybe this will be my solution too☺️
For reference. Yes it is a little bit overextruded, but the same thing happens also with lower flow rate.
And I agree with the not so pretty layer stacking 😖
