Z axis problem

[sa...@gropockets.com]

I am still trying to dial in my unit to print.

System specs

Muve DLP Pro

Nano DLP Plate calibration option. 

FTD industrial blend - dyed red. 

Build 1529.

Printer profile is  

Burn in 100 um layer thickness, 15 seconds cure, wait 1 sec before and after

Normal layers 100 um thick, 8 seconds cure, wait 1 sec before and after

Motor 

Z axis max speed 100

Slow Section height 5000

Speed in slow section 200

G code Before each layer

M280 P2 S10

M650 D{([[LayerNumber]]<30)*2+3} S{5-(([[LayerNumber]]<30)*4)}

M651

G1 Z0.1

[[WaitForDoneMessage]]

M280 P2 S110

No G code after

I have managed to get the test pillars to print and the rectangle xy is not precise, but I am at least in the ball park. But although I ask for 10mm of print height. What I get is a total 1.8mm. 

I used the Z calibration tab move buttons to move the Z axis up and down 50 mm. Though its hard to measure, it seemed to be moving around 50mm. 

The motors etc. came predone from Muve.

So any ideas?

[sa...@gropockets.com]

One other clue.

The xy rectangle generated by the plate calibration printing which is supposed to be 10mm, prints at a diagonal slant from the base.

[mUVe 3D Admin]

Sandy,

If you're asking the printer to jog the Z axis by a specific amount and it complies, the problem lies in the print profile settings.

This line:

G1 Z0.1

Should read:

G1 Z[[LayerPosition]]

With the calibration plate generator, the pillars are supposed to be slanted. This helps you measure the cross section to determine the ability to keep accurate while printing an overhang.

[sa...@gropockets.com]

I will update the g code and try again. 

In studying the G code, the doc section that talks about dynamic G codes references this code to go in the after print section

[[PositionChange [[ZLiftDistance]]]] ; Again update position

but none of the muve printer profiles seem to have anything in the after printing G code. Is this needed?

there is also no shutter control code. Is that now taken care of automatically by the code in the machine profile section and is not to be included in the printer profiles?

[mUVe 3D Admin]

Sandy,

Yes the code goes in the after "Print" section, not the after "Layer" with the key difference in that one is part of the print profile and the other is part of the settings area of your nanoDLP printer setup. So yes that code needs to go in, though it doesn't go in the profile. It goes on the setup tab.

The shutter is controlled automatically using the settings provided on the setup tab of nanoDLP. If you have a GCode RAMPS controlled shutter that isn't connected to the RPi, you will need to specify your shutter codes for the print profile. Since GCode shutter isn't really used anymore, at least on any new mUVe 3D machines sold, this isn't part of any print profile. It would be setup using GPIO and those shutter settings in the setup tab of nanoDLP.

mUVe 3D Support

[sa...@gropockets.com]

On Thursday, July 6, 2017 at 11:44:33 AM UTC-5, mUVe 3D Admin wrote:

Sandy,

Yes the code goes in the after "Print" section, not the after "Layer" with the key difference in that one is part of the print profile and the other is part of the settings area of your nanoDLP printer setup. So yes that code needs to go in, though it doesn't go in the profile. It goes on the setup tab.

So this is the code I have

Print Stop G code

M651

G1 Z{[[LayerPosition]]+5}

[[WaitForDoneMessage]]

[[PositionSet{[[LayerPosition]]+5}]]

M84

[[PositionChange [[ZLiftDistance]]]] 

Is this correct?

The shutter is controlled automatically using the settings provided on the setup tab of nanoDLP. If you have a GCode RAMPS controlled shutter that isn't connected to the RPi, you will need to specify your shutter codes for the print profile. Since GCode shutter isn't really used anymore, at least on any new mUVe 3D machines sold, this isn't part of any print profile. It would be setup using GPIO and those shutter settings in the setup tab of nanoDLP.

Thanks for the clarification

 

mUVe 3D Support

[mUVe 3D Admin]

Sandy,

Yes the code looks correct. You can really do anything you'd like at the end of the print. Just be sure you understand what's happening before making any changes. It's good to do a dry run when you change settings like this too, and be at the ready when the print ends just in-case something unintended happens.

What you're seeing here is a peel, a lift of 5mm, and then the position updating so that nanoDLP knows exactly where the Z axis is.

mUVe 3D Support

[sa...@gropockets.com]

I am still having a Z axis problems, 

but also xy. There are 2 places where the xy resolution is set according to focus.

1) in the print profile there is an "Overide XY resolution"

2) in the setup under projector resolution

In the provided printer profiles the overide was always used. Should the setup be set at 100 and then use the override function? 

Now my ongoing frustrating Z axis issues. 

My most recent test....

Leveled vat & plate

Homed Z axis

raised 10mm using Z axis page

Did a dry run, no resin, no projector 

Everything appeared okay

Raised plate

Added resin, turned on projector

Homed Z axis

raised 10mm using Z axis page

Started print

A bit of grinding with the motors during peel, not horrible but quick rattles

Left to let it do its thing

When I came back and it was done the plate was no long level. It was tilted to the right. 

I raised the plate 50mm 

As part of doing that it releveled itself out - no completely but it seemed to compensate for the tilt

and pressed the tilt button to drain 

and reset from tilt and removed the part.

See attached pictures. It seems to be missing several of the test cure pillars as well. The test square is dramatically taller on one corner that the other.

[mUVe 3D Admin]

Sandy,

The X/Y resolution being part of the print profile is something that was brought over as nanoDLP was updated and the feature was added. So the reason you're seeing it in each print profile is because the added a global X/Y setting a few releases ago and didn't want to mess up everyone's print profiles. If you want to correct things in the global sense, set all your profile settings to 0 for the X/Y so that it pulls them from the setup tab instead.

The tilting and sounds from the motor is a combination of a few things.

-First and foremost the noise is the motor not being able to turn, so this motion is lost to never be regained until the tilt is fixed and the printer re-homed to Z0. This causes the tilt you're seeing later on as well and it needs to be corrected before working on other parts of the problem.
-The motor can't turn because of either a. the motor driver needs tuning b. the leadscrew is binding up and needs a mechanical correction c. the cure settings are too high and it's causing the build to get stuck to the FEP d. The speed for the peel is set too high and the motor can't overcome the stress in the time that it is given.

You can correct this through a combination of tuning the motor driver, checking your mechanics are true and smooth, and carefully adjusting your cure time and peel speed to less aggressive rates so that printing can continue successfully.

If you have any other questions let us know!

mUVe 3D Support

[sa...@gropockets.com]

 

With power off the motor axis seems to turn easily. So it does not seem to be the problem. However when I home the printer and raise it, at the very beginning it has problems, and is out of level after raising 10 mm. the problem is mostly in the start of the lift. So I suspect I have a motor tuning problem. I know i need to turn some pots.

I presume this is referring to the pots on the ramps board at the top of the machine, but I don't know which pot to turn. Can you provide a jpg or indicate D8-10 (+)? As I face the machine, the righthand motor is lower, indicating it is the motor too weak.

thanks

[Matthew Caron]

I'd trace the wire to see which connector that motor is plugged in to and then turn that pot.

[sa...@gropockets.com]

Lovely idea except the wires terminate into the Circuit board, and the pots come out of the circuit board on the opposite side.

[Matthew Caron]

You must have a different board then me. All of my connectors are right next to the motor driver chips. Mine is a RAMPS 1.4. But, my machine is from 2 years ago, so I don't know what has changed in the BOM. Sorry for the bad suggestion.

[sa...@gropockets.com]

my bad, i did not get where the pots were and what they looked like. My machine was supposed to be already tuned so I do not have any doc on the board or how to tune it, just some notes about turning pots in a doc. Mine looks like a ramps 1.4, though I can not say since no info was provided. I will now go in hunt for a ceramic screw driver. Frustrating.

[sa...@gropockets.com]

So I got a ceramic screw driver and fixed the driving on the right motor.

Now I notice the left motor screw is not tight. I tighten the coupling but it still can be turned with power on. The right one is locked tight with power. When I raise and lower the plate, the left one is weak and so looses a bit depending.

What can I do to get the screw to be solid to motor, or is it the motor?

[Matthew Caron]

Loosen the coupling, make sure the lead screw is fully inserted into the coupling, then tighten it. I've had ones that weren't fully inserted so they weren't "grabbed" well.

[sa...@gropockets.com]

I loosen the coupling got it very tight. I can not pull it down and off. But with power on, the motor spindle is not locked and freely turns

[Matthew Caron]

I don't think it tries to drive the motor until you issue a movement command.

[sa...@gropockets.com]

Turns out neither motor was tuned properly. I have now tuned and matched the output on the motors. It is no long slipping and grinding when it prints, the print is also level, but it is short. The test plate is supposed be 10mm high. It is only 7+. Where next?

[Matthew Caron]

Do your slicer settings match your printer (say, NanoDLP) settings for layer thickness? If you sliced at 100 micron but the printer was set to 75 micron via NanoDLP, that could do it...

[sa...@gropockets.com]

I am using the plate generator inside nanodlp, so no slicer involved.

[Matthew Caron]

If your slicer settings are not an issue, and your motors aren't slipping.. what's left? 

Maybe your build plate homing? If you have your build plate firmly against the bottom of the vat, if it's pushing down on the vat and compressing, say, the foam on the rails, or causing flex in the plate mounts or something, maybe that could do it? I mean, I had that problem, even with no foam, but that ate up like 0.5mm, not 2.5mm...

[sa...@gropockets.com]

The printer came with the motor software stuff loaded, I did not do that. maybe there is something there? How can I go look and what are the settings supposed to be.

[Matthew Caron]

This isn't a software thing, it's a mechanical thing - adjusting your Z stop height so that the plate is just at the bottom of the resin vat.

[sa...@gropockets.com]

I am back trying to give this one more try. 

I position the plate close to the bottom.

turn the motor off

hand tighten down the lead screws until they don't move easily

back off 1/4 turn

set the Z limit switch to this height

Nothing sticks to the plate

Stuck to the vat I get a few layers very late in the print

I have preliminary cure layers of 10 and 25 seconds of cure time on FTD resin. 1 second,before and after.

9 seconds normal layers

[mUVe 3D Admin]

Sandy,

The build plate should be touching the bottom of the reservoir when the print starts. The nanoDLP software will lift the Z axis for the first layer, so if you are already creating a gap, that gap is just going to be increased with the first layer and potentially cause an issue with attachment to the build plate. Also, don't simply use pressure or resistance on the leadscrews to determine if the build plate is fully lowered. You'll really want to look at the reservoir from below and make sure that you can clearly and evenly see the build plate through the resin. If there's a chunk of resin in the bottom of the reservoir preventing it from being lowered full, you'd never know if you only used the leadscrew resistance as your marker.

One other thing that can be causing detachment is having too much overcure, and/or having too speedy of peel speeds. FTD resin cures very quickly, we're often printing at 2-4 seconds per layer at most, 10 seconds seems way too high and might be part of the problem. For base layers on FTD we usually do 10-14 seconds cure time, for 3-6 layers. Peel speeds we usually start at .1mm/s for the first 30 layers, then 2mm/s thereafter if the part is small, .5mm/s if the part is large. If the peel speeds are fast it will put large negative pressure on the part, potentially causing it to detach. Lowering your cure times and slowing your peel speeds could go a long way into helping troubleshoot the issue.

Try making one change at a time, watch the printer as it is printing, specifically peeling. Listen for sounds of stress in the reservoir, part, build plate, etc. You shouldn't hear any large clunking or popping noises, if so the peel is taking place too quickly.

mUVe 3D Support