Problem with print height

[jimmygjr 0]

Been having a problem with height lately.  I think its something I am missing in the software.    If you see the pic there are 3 levels.  The back, middle, and text.  The back section should be 2mm high.  When I slice I can preview the layers.  I can count 10 layers which should be .2 layer height.  Print turns out nice as always however the back section is only measuring .9mm when done.  I know I will lose some height from the squish into the plate but it seems excessive.  Any ideas

Thanks

[GregValiant 1,145]

If you would attach a 3mf file (File | Save Project) it would be helpful.  There are other things that can cause it (Z-binding is one) but a 3mf file is the best starting point for detective work.

What printer and what firmware would be good to know as well.

[jimmygjr 0]

Using longer lk4

The last update to the printer from the Longer site was 191010_LK4_FW_V2.17

I have had very nice prints all along with tweaking of course.

The z is not binding best that I can tell.  I have checked most of the physical parts of the printer.  However I am up to try anything.

 

Thanks

Longer LK4 tag print.3mf

[GregValiant 1,145]

 

On 1/28/2021 at 9:22 PM, jimmygjr said:

...is only measuring .9mm when done...

I should pay more attention.  You're missing 1.1mm?  And here I was thinking it was a simple layer height fix.

 

I'm going to assume that was a typo.  Using a support blocker as a measuring tool I get 1.9mm as the height of the first step.  At .19 Initial Layer Height and regular Layer Height it slices to 10 layers and 1.9 high.

 

If the .9mm height wasn't a typo then check your Z steps/mm.

Edited January 31, 2021 by GregValiant

[jimmygjr 0]

Yes I have done that.  I put a dial gauge on the beam and moved up by 1 mm at a time and read the gauge.  Kept adjusting till it was correct.  Also homing the z and then moving up the first couple jogs where less than at about the 4th movement.  I am thinking I am goiing to pull it apart some and look at the eccentric bolt for the wheels.  I feel like its adjusted correctly but cant hurt to take a look again.  I really don't like the cantilever stlye with only one z axis motor when using such small layer movements.  I can let you know if I find anything.  Thanks for looking at it

[GregValiant 1,145]

I agree about the cantilevered beam.  When it's adjusted correctly it's OK.  When only moving in one direction it's OK.  If there is any binding on the right side then Z-hops aren't correct as the drop isn't the same as the Hop.

It sounds like you have a handle on it but I'll comment since I'm here.  I adjust it this way:

With the X beam at Z=0 adjust the left and right Z eccentric wheels to provide enough force on the upright beams that the wheel can just be turned by hand.

Then loosen one end of the top crossbar and move the X beam to Z=Max.  Tighten the crossbar.  The Z wheels should have the same amount of friction there as they did at the bottom.  The left and right uprights must be parallel.

 

One thing I altered was to move the X beam to about Z=25 and drill a hole in the left upright so I could access the right X beam mounting bolt from the rear.  With the left bolt tight and the right bolt just a tad loose I can adjust the angle of the X beam (it rotates about the left bolt) and then I can tighten that right bolt.  I generally leave my Z-Hop height at 0.5 and it's even-steven both on the hop and on the drop.

 

I didn't buy a top end printer.  If the Ender would have been delivered with a decent Hot End, ball bearing fans, dual Z motors, and aluminum extruder drive, Capricorn tubing, etc., it would have cost considerably more.  For Creality at least, it was all about price-point.  They sucked me in.

[jimmygjr 0]

So not sure its the whole problem but the beam is having to much deflection on that right side in a direction change so Im gonna try one of the dual z axis kits.  Not the stepper but the second screw on other side attached with belt at the top.  I have read some good things and a few bad but its cheap and I am gonna try it out.  Ill let you know what happens

 

Thanks again

[jimmygjr 0]

So it took a while.  Ordered on amazon and I guess it still shipped from china.

 

Amazon.com: Creativity 3D Printer Aluminium Dual Z Axis Upgrade Kit Lead T8 Screw Single Step Motor Pulley Fit for Ender 3/ CR 10 3D Printer (Ender Version): Industrial & Scientific

Installed it last night so I have not printed alot with it just a few test prints.  BIG BIG difference.  Totally corrected the bottom height problems and there is zero sag of the beam now.  I would highly recommend it.  Small pain putting it on.  Had to redrill one hole on the their plate that goes on the back side of the wheels.  Just took it off the printer and bolted them together with the 2 holes that lined up and drilled the 3rd hole and put it all together.  For what I printed I would say try it out if you like messing around with that stuff.