Lotem 400 plate edge detection problem

[erwin]

Hey guys we have a Lotem 400, who can help me with this error i get when i want to expose a job :" carriage reached to target without detection.the plate edge detection calibration task failed".

 

[DCurry]

It's been a few years since I used a Lotem 400, but I seem to remember that when I had edge detection issues I had to clean the drum. You know how the drum has grooves that run around the circumference of the drum? Well, on the left side of the drum (when looking at it from the back of the machine) there is a groove that runs perpendicular to the other grooves and it is only a few inches long. Clean that groove out well with a damp dust-free cloth. While you're in there, it's also a good idea to unclog all the pinholes on the drum to ensure you're getting proper suction.

 

[bhennig]

When looking from the back of the machine (where the MCU is or from where you load the plates manually) there's a silver "sticker" on the right side of the drum and a sensor above the drum. Clean these two carefully, maybe that will work.

 

[nemo]

This may have various reasons - dirty drum, lens, wrong focus, weak diode, plate changes, focus motor and so forth.... The plate detection is done by one diode - usually first going on and off the plate - it knows when there is a plate there by reading the reflection from it. if everything is clean, check first if the plate is loaded correctly (no bubbles) and drum vacuum is functional (clean holes).
If the plates changed you may have to adjust the intensity of the laser for edge detection. You can also change the diode used for edge detection from the first to last one. Use the plate edge detection menu and test for various power (lower may help) and focus motor positions.

 

[erwin]

thnx guys i will do that

 

[erwin]

here are some pics of the test i made what do you think is the problemView attachment 3695View attachment 3695View attachment 3696View attachment 3695View attachment 3696View attachment 3696View attachment 3695

 

[PACH]

Are you using different sizes of plates? If so, do you get the problem on all of them? By the way I was unable to open the attachments. Edge detection was always a problematic issue on the L400s.

here are some pics of the test i made what do you think is the problemView attachment 3695View attachment 3695View attachment 3696View attachment 3695View attachment 3696View attachment 3696View attachment 3695

 

[erwin]

we use 2 sizes of plates GTO and 650X550 plates.the plate edge detection error is gone on the 650X550.But when i load Gto plate i get the error again.we don't use the gto plate so much so i leave it like that.i did clean the drum , vacuum holes and the V-block and sprayed some silicone oil on the oiler bracket.

 

[DCurry]

Before you go crazy troubleshooting the machine, it might be a good idea to check to make sure your plates are the right size. I've had plates come in short and cause errors.

 

[erwin]

the sizes are good Dan, i don't get edge detection anymore i got a more bigger problem now there is no image after exposing

 

[erwin]

the whole machine has gone crazy and there is no mechanic here were i'm from.

 

[PACH]

same on both plate sizes?

the sizes are good Dan, i don't get edge detection anymore i got a more bigger problem now there is no image after exposing

 

[erwin]

yess PACH i change the DDB Board and TSP board and reset the TSP Board and after that it i expose and no image.i change does board cause we been getting bad images after exposing.when i did a calibration i saw that from 70% dots to 100% was solit and below 50% is blank