MadModder

I got the X axis leadnut block printed along with the new Z carriage, and the heatset inserts have been installed.  I thought that I had assembled the Z carriage for the final time, but I was mistaken.  I haven't greased the linear bearings yet, so I'll have to partially take it apart to grease it.  One of the things I did during the design for my upgrades, was to make sure Future Don wasn't going to curse my name when it's time to service this thing.  I'll need to remove the rails to grease the bearings, but it's possible to do that and not lose the alignment.  By removing the stepper motor and the two screws retaining the upper end of the rails, it's possible to pull the rails out the top of the carriage.  The spindle, spindle clamp, and the bearing block can then be removed as one unit.  Since none of the bolts holding the critical alignments in place need to be loosened, the alignment shouldn't change.

I've got the carriage roughly aligned to the bed, meaning that it's as square to the bed as my square and my Mk1 eyeballs can make it.  The final alignment won't happen until I've got this thing moving under it's own power.  Then I can use a DTI and a 123 block to really dial things in.  This is the current condition of the Z carriage.


The X axis leadnut is currently bolted to the bottom of the bed, I kind of got ahead of myself when I did that.  I guess it's a good thing that I made it easy to remove the bed to work on the bottom of it.  Just remove the four bolts holding the endplate on and the bed can be slid off the rails - bed alignment is not affected.

I need to get a measurement of the distance between the top of the leadnut block and the bottom of the bed, with the leadnut block assembled on the leadscrew.  If I did the "Plottin-N-Conivin" right, that distance should measure around 3mm.  BUT,...  I can't measure the distance until the leadnut block is assembled on the leadscrew.  That can't happen until the anti-backlash nut is assembled and adjusted.  And THAT can't happen until the leadnut plate is fabricated.  And since the X axis and Z axis leadnut plates are very similar, I might as well do them at the same time.  That'll be happening next.

OK, time to Fess up, I make-da-nuther-boo-boo. For some reason I designed the mounting bolts for the Z axis NEMA17 stepper motor to use heat set M3 inserts. Normally that shouldn't be a problem. HOWEVER, the NEMA17 motor mounting locations are M3 threaded blind holes. Something tells me that four M3 threaded blind holes facing four M3 threaded blind holes just ain't gonna work to hold the motor in place.

The Z carriage was printed with 80% infill so you would think that if I could just drill the blind holes through with no problem. That actually would work for the two holes closest to the rails. The other two holes however would still be buried in the upright section of the carriage. That's probably what caused the brain-fart of thinking I could get away with using the M3 threaded inserts in a blind hole. Nope, I need to redesign the Z carriage. It's nothing serious, I just need to move the rails, leadscrew, and everything associated with them about 10-12mm farther away from the upright section.

The X axis leadnut block is printing now, by the time it gets done I SHOULD have the changes ready to go. The plan is to get the carriage reprinting by the time I go to bed.

Hi Folks!
A mish mash of phone and camera this week, which never works well as my editing software  does not like phone ! Will it start? of course it bloody will! A great relief to all involvedfootage! Commando gardening, bramble eradication, dead tree removal, and starting the Fordson after two years in't hedge bottom!
Phil, in pleasantly warm East Yorkshire

Yipes, a string of bad luck! I'm sure you'll get it working soon.

This is what I hate about trying to program absolutely everything in advance, as opposed to measuring and cutting during fabrication. Not that fabrication isn't also subject to errors, but with work in hand, often times you can try pieces against each other, or mark from each other, or quickly measure a fastener and the drill bit you are planning to drill it with, etc.

Some people work better one way, others vary from that. I find I make fewer errors in manual work than I do in additive machining, because the latter demands advance perfect location of all features or a part is often ruined. One frequent problem in an imperfect initial rendering: since infill is usually partial to save material and time, relocating or even resizing a hole or other feature is often not feasible.

Nevertheless, I admire anybody who makes the effort by this or any other means and manages to create something in our hobby. I'm sure this mill project will provide rewards when it starts machining other parts! 

I had a couple of 3D printing milestones recently, I started printing with something other than PLA and the P1S glitched on me.  Although in all honesty I probably made it worse than it should have been. 

I decided to try PETG, and I wanted to get the scaling dialed in to correct for shrinkage.  I decided that I might as well be printing something useful to do this testing.  My new spindle uses an ER11 collet, so I found an STL for a chip fan that presses onto the collet nut.  The friendly Google AI said the scaling factor should be 100.3-100.8%, so I scaled the fan to 100.5% and gave it a shot, way too tight.  I scaled it to 100.8% and printed it again. It takes less than 1/2 hour to print the fan - including the 7+ minutes the P1S uses for setup on every print.  It was still too tight, but I could force it on the nut.  I printed it again, this time scaled to 101.5%.  It presses onto the nut, not all the way, but since I didn't design the fan I can only guess the designers intentions.  I WAS going to print a fan scaled to 102%, but that's when the glitch occurred.  I started the print and left to do something else.  When I came back about 15 minutes later I had a bird's nest on the print bed.  It happens, so I did what I do when the D6 screws up late at night - I shut off the power and went to bed.

When I got up the next day and fired up the printer it was not happy with me, the AMS was making very unhappy noises.  I realized that I SHOULD have aborted the print, then shut off the power and gone to bed.  Ain't 20/20 hindsight just wondermus though?  I realized that the filament had frozen in the extruder and that I needed to get it out of the hot end so the AMS could retract it and be happy again.  But, I needed to do that before the AMS was powered up.  I decided to try unplugging the AMS, heat up the hot end, and see if I could pull the filament back by hand - to see if that would work.  I did, and it did - so I decided to try printing again.  All seemed to go well, until it tried starting to print about 50mm above the print bed.  All I could do was abort the print and hang my head in shame wondering "What the Hell did I do to this poor machine?"  Before I contacted Bambu Labs and confessed my sins, I wanted to run the initial calibration cycle again.  I wanted to see if that would let the printer find its' lost marbles. 

I'm proud to report that it worked and the plastic pooping robot is now about 7 hours into an 8 hour print.  That print will give me the Z axis rail holder, and the bearing block that will slide on those rails.

Don