Previously we advised customers to loosen belt tension on the 40w hobby laser
if the laser
head skips during fast X motion during rastering.
We have determined that it is much better to adjust the plastic wheels which allows for tight belt tension but low friction to prevent skipping
We are updating instructions and videos but in the meantime please read the following and email firstname.lastname@example.org
if you have questions.
Theory: The laserhead has 4 plastic wheels. These attach to an eccentric pin through a small Phillips (crosshead) screw. If you rotate these eccentric pins then it will tighten or loosen against the aluminum X axis rail. These eccentric pins are held in position by a set screw with a hex head 90degrees from the top Philips screw. Remove the setscrew before attempting to adjust the eccentric pins. The eccentric pins need to be adjusted by inserting an extremely short FLAT head screwdriver through the BOTTOM. If you adjust the crosshead screw from on top it will have extremely limited motion for adjustment. Tighten the top crosshead screw then do all further adjustments from the bottom. To remove the pins, turn from the bottom to loosen then push from the bottom to remove.
Use a mirror to view under the laserhead so you know what you are trying to achieve. There are 4 FLAT head screws. Use a SHORT eyeglass type flat head screwdriver like this: http://tinyurl.com/3e9htmp
Once you have the right screwdriver it is very easy to turn the eccentric pin (after removing the set screw).
1) Loosen the 4 eccentric pins by using the short screwdriver from the bottom. The laserhead will not be clamped to the X axis gantry anymore.
2) Adjust the top 2 eccentric screws so they that the laserhead is straight with the X axis. Since they are eccentric you want the laserhead platform straight otherwise the belt will be pulled at a angle.
3) Adjust the bottom 2 eccentric screws so that the laserhead is as loose as possible but all 4 wheels are just barely still rolling.
4) Insert the 4x set screws with the hex heads back and tighten. Note that by putting the set screws back in it will tighten the eccentric pins slightly so that is why we say adjust as loose as possible but still rolling in step 3.
5) Test it out and ensure the X axis is not binding during rastering. If you would like you can insert some WEAK thread locking glue on the screws.
6) We sell replacement wheels for low cost so email email@example.com
if your wheels develop flat spots on them.
By adjusting the eccentric pins we have found we can tighten the X axis belt as much as we want (we recommend a bit less tight than a guitar string) but still have no binding.
The eccentric pins will slip over time so adjusting them is the key to optimal engraving performance on the hobby laser
. Threadlocking glue will hold it in longer but may make it harder to adjust.
The professional series lasers have carriages with steel ball bearings and ground precision ways so do not have these types of issues.