MadModder

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

What a Klutz  !

I meant to add that anyone who wants the drawings can also send me a note here using messages or use my direct address - grnbaystmr  "AT"  gbonline.com - the AT used here is to divert web searches and spam . use the ast...  and    no dashes

Send theirr home email and I will send them by email in 5 packages .. It's like 29 Meg donload in one shot
and that would get me in trouble with my provider. 
IMPORTANT , The Subject line must say MONITOR  in Caps
Rich

Up Date 2026 - April 13

Yes, The drawings were withdrawn during a web site revision two years ago, sorry about that .
I have been advised they will  be re-posted, and will return to the same web site
It may take a few more weeks for that to occur, so keep trying .

I have spent the past 5 years writing a book (technical) on the engine and all of it's components to help those who downloaded the drawings and those
who wish to know more about the engines' operations and design  and other data from my research
That book is very close to completion and I hope to have it published before years end so I can go back to modeling.
Thank You for your patience , This is a not for profit undertaking

Rich

Thanks greatly for pics! 

I had my old Blueberry flip-phone for so long, I keep forgetting that my new flip-phone has a camera.  It doesn't have the anti-blur capability of my camera so sometimes it takes several attempts to get a decent shot.

Today was spent putting the Y axis leadnut assembly together. I started with your standard 3D printer anti-backlash leadnut, looks like this when assembled on the leadscrew.


This is just 2 modified leadnuts assembled back to back with a spring between them.. The spring keeps the 2 halves of the nut separated, removing the backlash, and a tab/slot arrangement keeps them in sync. This works fine for the minimal tool pressure of a 3D printer. BUT, and there's always a big butt, any tool pressure that opposes the travel will overpower that wimpy little spring and your backlash is back - don't think that'll do the surface finish any favors.

I remembered that Awesome CNC Freak had modified his 1310 machine to deal with backlash, so I did some digging - and then quite happily swiped his idea. This was the test rig I built.


It proved the concept. By using the nut to squeeze the 2 halves together you eliminate the thread backlash, and it's much more rigid. It does take careful adjustment though, you go from free falling to totally locked up in 1/4 turn of the nut. The bolts I used on the test rig weren't long enough though, the nylocks wouldn't lock - going from M3x35mm to M3x40mm bolts solved that problem. The bolts also keep the 2 halves in cync. This is what the business end of the Y axis anti-backlash leadnut assembly looks like.

That part will be buried between the Y axis bearing blocks though. This is all you'll see.


OK, OK, if you ignore the bit in the lower LH corner - THAT's what you'll see. Really shoulda cropped that picture.