i found the problem. The short rod holder. I don't need it. I change it to a normal one and now it works. Why do you make a shorter one? I check the old Bed holder with yours. The carriage are in the same position so you don't need the shorter one.
If you mount the twe-04 as instructed here your endstop/trigger distance (the edge of twe-04 that rams into the rod mount) will be ((38-15)/2)) mm away from the original U-bolt. So that's 11.5mm (right?)
The original LM8UU is 24mm long, and centered under the U-bolt, so its edge (and the endstop trigger) is half of the lm8uu's length (I think the carriage allows a mm or so play in positioning the bearing, so prusa calibration likely allows a bit of slack here) So that's ~12mm vs 11.5mm - close enough to work without having a special rod holder.
Now, maybe if you were to screw in the twe-04 using its other set of holes... that would move the trigger distance 15mm closer to the back of the frame (15mm being the distance between holes rows), and then you'd need to compensate by cutting that off from the rod mount. But it's only practical to cut off 10mm and not more (anything more is meaningless because you'll be hitting the extrusion anyway). You'd still be 5mm from where the original endstop was with lm8uu, but maybe that's within calibration margins?
Anyway, I think there might be a mistake somewhere in the assembly instructions here (?)
You are correct - the picture showing which screw holes to use does contain an error. I have used the bottom set of screw holes on the upper left carriage.
Hi I have problems with the y calibration, it fails every time. The carriage are screw in the right position
i found the problem. The short rod holder. I don't need it. I change it to a normal one and now it works. Why do you make a shorter one? I check the old Bed holder with yours. The carriage are in the same position so you don't need the shorter one.
same here, the firmware can't find the first calibration point if assembled as pictured - seems to be looking for it in the wrong place.
Huh.
twe-04-12 is acc. to specs 38mm long and its 2 rows of screw holes are 15mm apart.
https://www.igus.com/contentData/Products/ProductPictures/p931z15318_1050x700.jpg
If you mount the twe-04 as instructed here your endstop/trigger distance (the edge of twe-04 that rams into the rod mount) will be ((38-15)/2)) mm away from the original U-bolt. So that's 11.5mm (right?)
The original LM8UU is 24mm long, and centered under the U-bolt, so its edge (and the endstop trigger) is half of the lm8uu's length (I think the carriage allows a mm or so play in positioning the bearing, so prusa calibration likely allows a bit of slack here)
So that's ~12mm vs 11.5mm - close enough to work without having a special rod holder.
Now, maybe if you were to screw in the twe-04 using its other set of holes... that would move the trigger distance 15mm closer to the back of the frame (15mm being the distance between holes rows), and then you'd need to compensate by cutting that off from the rod mount. But it's only practical to cut off 10mm and not more (anything more is meaningless because you'll be hitting the extrusion anyway). You'd still be 5mm from where the original endstop was with lm8uu, but maybe that's within calibration margins?
Anyway, I think there might be a mistake somewhere in the assembly instructions here (?)
You are correct - the picture showing which screw holes to use does contain an error. I have used the bottom set of screw holes on the upper left carriage.