I am a laser repair technician working in an art manufacturing shop running 40+ G. Weike engravers (LC1512, LC1490, & LC6090) for approx. 16+ hours per day, five days a week.
A recurring issue has been the x-axis belt running onto the bearing on the left-hand side of the machine, as if it were being pulled towards the front of the machine on the left side.
This issue appears on any size machine, regardless of any variable we can find such as location, type of belt, who tightened/installed it, etc.
Assuming the pictures above come through successfully (using my phone at the moment), thats a general idea of the set up and our issue. I will happily take more if anyone needs them.
As you can see, it is a toothed belt. However, the mounts for the bearings are fixed in place by the manufacturer, they are not adjustable. So I am not sure that they could be out of alignment. Am I incorrect in that? This is a new field of work for me, so I wouldn’t be surpised if I were wrong here.
If this is true, then the assumption has been made by a Manufacturer that this is ‘sufficiently aligned’ and ‘shouldn’t be a problem’. The belt attempting to leave seems to demonstrate otherwise. I can’t imagine the pulley holders having fixed positions with dowel pins. The bolt holes likely allow some bolt clearance and hopefully a minor adjustment can be wrestled out of them.
Find a stiff stick, a bbq skewer, a piece of bar stock, tubing; something rigid that you can fit between the pulleys to use as a gauge. With the belt in place ( or out of place as shown ) begin to cut down the gauge to fit between the raised outer edges or ridges of the pulleys. As you sneak up on the correct size, one side of the pulleys will ‘fit’ before the other. At this point you’ll have a sense of the misalignment. Keep trimming until you’re on size on the closer ridges. Then put the gauge back in the ‘Loose Side’ and measure the small gap. This is how I set the toe-in on my 4x4. I’ll keep that stick for next time. Hopefully this will show .020" or .030" inch and you can attack it from there. A friend recommended a single telescoping tent pole or a monopod leg that extends to the gauge length and can be locked.
Another possibility is that the belt top and bottom runs are not exactly one over the other. I cannot tell from that angle in the image. The carriage where the belts end (bottom belt layer in second image) is another possible place needing correction.
A third possibility is that one side of the belt is stretched slightly more than the other. I would say for sure now that it is running up on the roller edge guides. Even if the pulley has a crown (curved slightly, not flat), it will be very difficult to get that belt to track now. If you cannot find anything slipped or misaligned, I think a new belt is the only solution.
I downloaded Pix #2 and zoomed in. Where the belt attaches to the carriage, I see a hex screw adjustment. I suspect that controls side-to-side belt tension. So it appears you do have some control over belt tracking.
Apologies for returning to an old thread, but I am still having problems with the belts and after re-reading your responses, I think I understand them better. @MikeyH Mikey, you were referring to these bolts here, correct? I have been testing and found that they do allow for quite a lot of vertical movement, which definitely alters the tension on the belt, as you said.
How can I check the alignment of this platform? I tried eyeballing it and haven’t had reliable results, and we are currently burning through belts very quickly.
Does anyone have any thoughts on that? I thought perhaps a jig of some kind could align it and allow me to tighten the bolts while its aligned correctly, but cannot imagine how to go about creating one.
Thank you for all your assistance so far! I know you’ve got me onto the correct path now, and I greatly appreciate it.
I can’t imagine the pulley holders having fixed positions with dowel pins. The bolt holes likely allow some bolt clearance and hopefully a minor adjustment can be wrestled out of them.
I’ll keep that stick for next time. Hopefully this will show .020" or .030" inch and you can attack it from there. A friend recommended a single telescoping tent pole or a monopod leg that extends to the gauge length and can be locked.
