1 Topic by driggers

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Topic: unexplained Z-lift

Printing was going fine until I went away for about 10 minutes and came back to find that Z had lifted quite a bit higher than it should.

I was running heaters at 230 hot end, 97 bed, printing at a normal speed.  Had Z lift at 1mm which seemed to be behaving fine.

This is not an extrusion problem.

http://i.imgur.com/cFFnITA.jpg

SD2 Sanguinololu 1.3a atmega1284p, wood platform, lawsy's carriages, braided fishing line, pallet wood overhead spool mount, carboard/magnet enclosure, glass bed, E3D v6, bed levelling knobs, extended z-stop, 25A DC-DC SSR for bed heater, everything fixed to the SD2 frame, marlin firmware with some adjustments and extra failsafes enabled.  I'll never give up on you, little printer that could(n't)!

2 Reply by IronMan

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Re: unexplained Z-lift

Are you running a cooling fan on your Sang board?  Z-lift could be overtaxing the system a bit...

Q. - Why are you using Z-Lift?

SD2 - Stock - Enclosure - Heated Bed - Glass Plate - Auto Fire Extinguisher
Ord Bot Hadron - RAMPS 1.4 - Bulldog XL - E3D v6 - 10" x 10" PCB Heated Build w/SSR - Glass Plate
Thanks for All of Your Help!

3 Reply by wardjr

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Re: unexplained Z-lift

I would ask the same question and add that your Z isn't moving freely.  Probably time for some cleaning and lube.  Perhaps even a slight VREF tweak.

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

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4 Reply by driggers (edited by driggers 2016-02-10 17:32:11)

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Re: unexplained Z-lift

I'm blowing air on it now, as the stepper drivers seemed very hot.    I haven't run prints at 97 degrees before, so do you suppose this higher temperature and current draw (bed heater direct from board) could have a motor skipping effect?  So the Z-axis was lifting and then not being able to come back down (recall that coming back down = bed go up, which is more work than simply gradually lowering bed!).

Maybe this is why I seemed to be getting all my layers squished together on this print too (sometimes but not every time).  I'll be making electronics enclosure with fans soon.

Betwen the PSU fan, extruder fan, hot end fan, and electronics fan (a fan space heater that is not heating) my printer sounds like a wind storm.

Also, there is a very high pitched whine sometimes -_-

SD2 Sanguinololu 1.3a atmega1284p, wood platform, lawsy's carriages, braided fishing line, pallet wood overhead spool mount, carboard/magnet enclosure, glass bed, E3D v6, bed levelling knobs, extended z-stop, 25A DC-DC SSR for bed heater, everything fixed to the SD2 frame, marlin firmware with some adjustments and extra failsafes enabled.  I'll never give up on you, little printer that could(n't)!

5 Reply by wardjr

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Re: unexplained Z-lift

Many of us avoid z-lift at all costs.  I'm guessing mechanical binding on the guide rods and threaded rod.

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

wardjr's Website