Further Adventures in 3D Printer Upgrades (upgrades?)

As previously promised, MegaMax’s Y-axis has been converted to screw drive along with the addition of a larger motor, DSP based driver, and 32V power supply.  The SmoothieBoard arrived and was quickly swapped in to replace the ATMega2560/RAMPS combo.  After studying and configuring the Smoothieboard I attempted a few test prints.  That’s when the problems started.

32V Power supply for Y axis motor.  No regulation necessary!

32V Power supply for Y axis motor. No regulation necessary!

















Smoothieboard is supposed to read the config.txt file from its uSD card (conveniently accessible via USB) every time it boots.  That makes changing configuration very easy and fast – all you do is edit the config.txt file, save it , and reboot the board.  Firmware is updated the same way.  With the ATMega2560 you have to find the configuration variables by searching through multiple configuration files, make the necessary changes, recompile the firmware, then flash the controller.  I said the SmoothieBoard is supposed to read the file every time it boots, but it wasn’t doing it.  I’d make changes and they would not appear in the behavior of the printer.  Hmmmm.

Layers kept shifting in the X-axis- I expected Y-axis problems, but not X!

Layers kept shifting in the X-axis- I expected Y-axis problems, but not X!












I attempted some prints and managed to get two decent ones in about a week of screwing around with it.  I tried dozens of combinations of speed, acceleration, junction deviation (smoothie-speak for jerk) and even tried different slicers.  The machine went completely nuts on two occasions and ignored the Z-axis limit switch and slammed the extruder into the print bed, gouging through the Kapton tape and into the aluminum!  I decided I needed some professional help so I got on the #smoothieware IRC channel and discovered that the developers of the board/firmware hang out there quite a lot.  After a lot of back and forth Q and A and testing someone suggested it might be the uSD card causing the problem.  I picked up a new card at Walmart, put the firmware and config files on it , booted the machine, and attempted a print.  PERFECT!

The new uSD card worked!  The small round post is 4mm diameter.

The new uSD card worked! The small round post is 4mm diameter.











I have made several prints since last night and they have all come out fine.  I still have a little tweaking to do and to test the limits of the machine’s performance, but I think the problems are behind me.

Next up:  X-axis redesign/build.  I’m replacing the two guide rails with a single linear guide.  I have also ordered and received a BullDog XL extruder to replace the hacked up QUBD unit I’ve been using.  I’ll be adding a DSP driver and 32V power supply for the X-axis motor, too.

After that, I have some ideas for a filament respooling machine and ways to fix the retraction problem in the SnakeBite extruder.

It never ends!


The never-ending 3D printer project

MegaMax has been and continues to be my main project for the last 2+ years.  I am currently working on some upgrades that will make him more Mega and even more Max.  The Y axis is being converted from belt drive to screw drive and the round guide rails are being replaced with linear guides and bearing blocks.  The X-axis will also get converted to linear guide and bearing block and change from 5mm pitch belt to 2 mm pitch belt drive.  I feel confident saying that once these modifications are complete the flaws/errors in prints will be due primarily to the nature of liquid plastic squirting through a nozzle, not positioning system errors.

I recently updated my web site with a sort of historical look at the project, including all the mistakes I’ve made along the way and the often failed attempts at correcting them.  Here is the page that shows how it all started, how it has ended up, and where it is going.  http://mark.rehorst.com/MegaMax_3D_Printer/index.html

Don’t ask me why I do this-  I have no choice.

MegaMax beginning

From this…






















MegaMax present state...

To this…

MegaMax 3D printer lives!

After a year’s work designing, building, scrapping, redesigning, building, and working through software and firmware issues, the MegaMax 3D printer is now functional.   It has some common 3D printing issues like printed objects peeling up off the glass printbed.   Tweaked settings in Slic3r, ABS “juice”, and Aquanet hairspray have all been tested with moderate success in attempts to improve adhesion to the printbed.  Finally, have_blue gave me  a block of foam out of the Stratasys printer to try out and it seems to work better than the other methods and doesn’t require heating the bed!  Further experiments to be conducted post-haste.

More info on this project can be found here: http://wiki.milwaukeemakerspace.org/projects/megamax_3d_printer

MegaMax printing on foam from Stratasys printer.

MegaMax printing on foam from Stratasys printer.

March 3D Printing Meetup


Join us on Saturday, March 9th, 2013 from 1pm to 4pm for the Milwaukee 3D Printing Meetup! We’ll be hosting it at the new Milwaukee Makerspace located at 2555 S. Lenox St. in Milwaukee.

The Meetup group is over on meetup.com, but we welcome anyone to come to the meeting and learn about 3D printing. We’ll have a few printers on-hand (as well as many printed objects) and will provide a nice introductory talk to the subject by one of our members. After that we’ll melt some plastic and create some real-world things.

This event is free and open to the public, so come on down at learn about 3D printing!

Frankie’s at it again…

Prusa i3

Looks like our old pal Frankie Flood is at it again! This time he’s building a Prusa i3 RepRap 3D Printer.

If you’re keeping track, he was building Prusa Mendels back in June, a Mendel 90 back in July, and a Rostock in September. I think he holds the record for the most 3D printers built in Milwaukee! (Or at least the most different models of 3D printers.)

(The Prusa i3 is the most recent iteration of a RepRap designed by Josef Prusa. It’s open source, which means you can download the design files, and build your own, and even make changes to it. Josef is also working on a new hotend which looks pretty sweet!)