Location of parts

I was away on a personal matter. You’re doing just fine. At a glance it still appears to be a lost motion problem but I’ll review all the current information here before weighing in.

When LightBurn begins communicating with the C3D board, does it offer a Smoothieware Firmware version number?

I’m going to dig in to see if I can


I took your file and burned it with my laser machine. Everything looks in the file.
So it is not the file. It is either in the transfer from Lightburn, which JohnJohn is looking into, or, it is a mechanical issue. If you need anything from me, just ask. I think JohnJohn will figure it out for you.

Is the vertical line supposed to line up with the center of the notch at the bottom?


Jack If u are talking about this pic…
Yes the horizontal guide line is should run thru the centre of the slot .
The outside cut as shown, should be shifted down ie

When i start the k40 in the console i see no reference to Smoothieware Firmware version number see below.

Is this what u mean?
firmware ver downloaded 2022sep13

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Actually the one in post 22… the one @MrMag did on his machine.

Doesn’t really look centered to me… :thinking:

Screenshot from 2022-10-05 03-38-29


Jack You are right, the guide line should be in the centre of the slot…
To me that’s not the problem, I can easily handle an edit to fix that. The big problem is the gross miss alignments, like this:-
Where the out side cut is is displaced upwards.
Other cuts have much bigger layers displacements, can send u a pic tomorrow, if u want.

I just put a piece of cardboard in the machine and cut it. I did not focus the lens. That might be why the line isn’t centered.

It’s getting closer and closer - It still looks like Lost Motion.
This can be caused by acceleration that is too rapid for the machinery.
The errors are getting smaller and smaller.

As a diagnostic criteria, are the inside shapes and the outside shape sized and shaped correctly? - This will confirm that motion is still being lost on traverse moves instead of engrave moves.

A second diagnostic question: Regarding the two short vertical lines to the Left of the Number 5; are they engraved consecutively and are they the correct distance apart? This may show us that the traverse is showing the symptom.

I found the config file on C3D’s site:

I’d like to compare these settings to the ones you’re using.

Please share the backup of your config.txt file in a thread here.
It should drag and drop into a reply with no issues.
It appears that final tuning is in order.

“Get Position” gives all zero’s
i now think in doing a cut like this:-

forces axis Y to top and produces Y motor/belt chatter
So i’m thinking the only problem i really have is the displacement of the cut layers.
What do u think ?

diagnostic criteria 1
the inside shapes and the outside shape are correct, size correct, but layers are displaced like this:-

I think this is the cause of Y over run ??

Do you think enabling soft limits will detect if it goes out of the work area?

I think it’s losing it’s position, but not seeing it operate makes it more illusive.


second diagnostic question
short vertical lines in this

should look like this:-

Where is the config.txt file ?

I think he’s asking for you to enter $$ in the ‘console’ and it should print the configuration settings to the console.

You can scroll the console and ‘copy’ the text, mark the text and use ^c (hold the control key and press ‘c’) to copy the marked area.

Use any text editor and open a new file called config.txt and ‘paste’ (^v) the information there. Save and close the editor and drop the config.txt file on the reply window.


No meaningful response Jack

Waiting for connection…
Waiting for connection…
Project loaded in 1 milliseconds

what am i doing wrong ??

I have made a Lib. item for low power etc to print onto paper…
Now by shifting the start position i was able to print the following:-

The Frame position does not match the actual lines position, that’s why the above pic shows the lines off the work area, if i shift the start position to home ie Top LH goes straight into belt slippage…

I can not measure the distances between the short lines. It is possible that the y-axis acceleration is set too high for the mass of the machine causing the lost motion. If the vertical lines are engraved consecutively and are generated at the wrong distance apart then we have a piece of evidence to point toward an acceleration based symptom.

On smoothie, it’s different - there’s a config.txt file on the SD card that ships with the device. FluidNC and some of the newer G-code (but non GRBL controllers) use a file and the ‘$$’ command doesn’t work. I poured over the smoothie docs and didn’t see a console command to pull all the settings. There is a ‘config dump to console’ command in Fluid NC.

I Just noticed your optical laser for framing in the corner of the picture you posted.
laser cross-hairs

On occasion, I have seen this type of accessory reduce the available Y-axis travel. If the work area is not reduced in the settings (to match) it will crash into the rail closest to you and furthest from the limit switch causing the controller to lose position.

With the K40 powered down and the computer disconnected (wait a few minutes) then slowly move the engrave head the full distance of the Y-axis to confirm the physical travel distance available. Please measure this - a tape measure should be adequate.

We can then confirm that the axis length matches the Machine Settings.
In LightBurn, click Edit then click Machine Settings - then click the small > to reach the Output Settings. Please screen capture everything in this window.

Adding mass (weight / heft) to the engrave head can require lower acceleration values to prevent belt slip - So, I’m still not certain what’s happening.

After we get this sorted, the Pointer Offset setting appears in the Device Settings window. We may have to adjust this if there are inaccuracies between framing and work location.

The measured Y travel is 230mm
The Device Settings are Width=250 and Height=200mm
I have disconnected the cable tray and measured Y travel is 235mm

From home pos, on f2 iget:-

Looks like the cable tray was restricting travel, need to test other former’s, but looking good.
If this is the solution, have to work out how to get Air and Volts to the diodes.

Another test on f8, still producing layer displacement,
Start from current pos. ie Home. no chatter…

John You say:-
In LightBurn, click Edit then click Machine Settings - then click the small > to reach the Output Settings. Please screen capture everything in this window.

Have 2 choices Settings and Device Settings, Which one?
Can’t see “then click the small > to reach the Output Settings” in either window… Trevor

If the option to access the Machine Settings isn’t shown, it’s entirely likely that it’s only available and accessible in the Config File on the SD card. Smoothie is a new process for me and I’ll be ordering a C3D board right away.

I hope Lightburn is buying that for you… :face_with_spiral_eyes:

I just got a Makerbase MKS DLC32 … looked at it, but haven’t powered it up.