Success At Last!

Using the 4 minute JB-Weld Kwick, I re-attached the nylon drive roller pulley once again and let it cure the recommended 4 hours.  Checking the specs on the JB-Weld showed the Kwick version with the same lateral tensil strength as the slow cure stuff so it seems it was a good choice.


I ran my usual back and forth X axis test which drives the rollers over a 12 inch path over and over and returns the bit to the home position.  In the past, this is where skew would normally be observed but this time, the bit returned precisely to home position and the material did not skew at all!


I then ran my usually circle tests and noticed a minute amount of dogleg present.  More cutting and the dogleg got worse.  I realized the X drive stepper set screw was coming loose, so I removed the stepper and installed an allen head hex screw in which I could get a good solid bite on the screw to really clamp down on the stepper shaft.


The next circle test was perfect!  No more dogleg, although in the past, using the original stepper pulley with the same modification, I was unable to eliminate it, so I suspect this occurance was simply due to using the new stepper pulley which had not yet been modified.


I am very pleased with the outcome to say the least!  It confirms all of my past analysis and solves the mystery which has been so elusive.


I think the 3/8" deeper grooved pulleys will work out much better for several reasons, one being that the steps per unit values of the X and Y are now very similar.  This was a problem for the USB CNC software according to Andrej at Planet-CNC.com.  The second reason is that the wear I was seeing on the old stepper pulley was significant and it had very few hours on it.  To compound the issue, when MDF was being cut, the dust would settle in between the grooves of the stepper pulley and harden which reduced an already shallow area for the belt to grab onto.


Depending on the interest from Phlatforum users, I would be willing to put together a video showing exactly how I cut the old pulleys off the drive rollers and how I attached the new ones.


Putting it down in words doesn't convey the topic nearly as well as seeing it done.


Now that I finally have a working machine, I can get back to completing some projects that have been put on hold.


Be sure to check out my blog for updates.  I will be posting some additional articles on how to upgrade the Phlatprinter \\\ with some some different components that should provide some added value to it in the coming days.  This includes swapping out the X axis stepper motor for a larger capacity one, replacing the Easy-CNC controller with a Gecko G540, replacing the spindle drive with a high speed laminate router, more details on replacing the drive roller pulleys with 3/8" pulleys, and a little bit on configuring the USB Planet-CNC software and some caveats to be on the lookout for.