mods for mini

hi anyone done any mods for the mini yet ? care to post pictures ideas ?


Well the first thing I did was put a small C clamp on the fold down arm for the spool, to hold to the frame. I did my first print and was messing with trying to get the filament end secured and oops the arm folded down and the spool hit the floor :neutral_face: . Lucky for me not much un-spooled.

Other than little changes, its been a great machine.

mines been a great machine prints time after time first time switch on load up print magic , had a small initial problem with the nozzle which lulzbot replaced the whole machine , now how many companies would do that

I replaced the horizontal filament arm with center cones, a carriage bolt, and captured nut knob. I had had two prints fail due the filament jamming from the strong tugging required to spin the spool on the stock rod, and haven’t had any such problems since because it takes much less force to spin the spool so the filament doesn’t jam itself into the lower layers. The only part I made was the base to attach the bolt to, the other parts I got from a different project mentioned in the description:

I have not had that issue yet and just wondering about something. The spool is on top, most of the other printers I have seen had the spool on the side and pulled the filament up through a tube. My mini spool on top seems to un-wind a bit and I am wondering if its too loose and it gets tangled on the spool.

Your idea looks great, nice job on the design and the print out!

This is exactly it I think. Both times it happened to me the reel was pretty close to full and the filament being thick, it sort of comes unsprung so to speak. The leading end works its way down into the loose threads and if unlucky, it gets wedged between other strands – kind of like the cutting line in a weedeater tends to do. The extra pulling force required to overcome resistance with the original part makes it more likely for that leading end will get pulled down into the reel and locked in.

this is one of the minor problems i have had with the filament jamming because it has got tangled on the spool from being too loose , i was looking to design something that would position the filament in the centre of the top frame to maybe stop the filament being pulled so harshly

Well on my wire feed welder they have a adjustable tension adjustment on the spool. The same thing could be done for this printer. (But I have not had any jamming… yet.) It would almost take an attachment for the arm that would hold the spool whatever size the hole happens to be. Then a tension adjustment for that spool holder. My welder has a large flat washer held in place by a spring, another washer and a self locking nut.

It could be almost as simple as putting a section of rubber hose over the spool arm.

The tensioner sounds like a cool idea.

Here’s an idea for LED lighting using a $5 Eveready 6v flashlight. It uses the LEDs and switch from the flashlight and a mini-USB cord that is of no use to me anymore.

I have done three so far…

  1. Added case and Pi3 to run OctoPi and control the printer
  2. Added 12v LED light strip on the top and down the left hand side to illuminate the bed
  3. Bracket to mount C270 webcamera for monitoring the print bed using OctoPi

I designed a double cooling duct that fits on the existing original mini print head. Uses a blower so air speeds are near 12m/s max vs 4m/s out of the standard nozzle.

Mods to my Mini so far… added Raspberry Pi running OctoPi, added spool arm bushing , replaced mini squirrel cage fan with 25 mm filament fan and duct , added LEDs to illuminate the bed, added webcam mount, designed heavier duty extruder idler and latch , replaced nozzle wiper with dual wiper , and I’m currently considering installing the BuildTak FlexPlate system removable bed with a PEI sheet .

I did some tweaking as well.

On arrival I had to reprint the filament pully idler, but that was just bad luck.
Then, started with the Y-axis dampener.
Added the USB support.
Added X/Y-axis timing belt tensioner springs.
Created an Octoprint Webcam mount.
Installed the Mini print bed harness clip.

And last but not least, upgraded my linear bearings to lm8uu ball-bearings on hard rods, which is the upgrade I would recommend any Mini owner so far.

Does anyone have some beginner-level instructions and part list for installing Raspberry Pi and OctoPi on a Mini? The 5th/6th grade classroom I’m helping out with is plagued with ancient laptops that have trouble running the Mini (especially on more complex prints). I’d like to set them up with an RPi. I know knothing about these myself, but could probably figure it out with a few pointers. However, I’d really like to get a couple of kids who are interested in this stuff involved in doing the upgrade. The more of it they can do, the better. I’d just be around to monitor and help out if it involved things they were not comfortable with.

That link is to the part for a Taz. Does the same one fit on a Mini?

Did you use a 5 volt fan or a 12V? I think the little fan runs on 5 V, doesn’t it? If 12 V (or something other than the stock voltage) did you install a buck converter, or just run a 12 V fan on 5V?

Did you have to change your print profiles at all to use this fan (e.g. adjustments to fan speed) or is speed not software adjustable for the hot end fan?

Here are a couple good links to get you started:

Thanks, ScottW. A couple of questions for you:

Does the RPi setup require using SD cards to get the STL files to the RPi, or can that be done over the network? The kids are using older laptops or Chromebooks to do their design work. None of these have SD Card readers. Does the Pi have onboard storage for the files, or can we just leave an SD card in it for storage?

I’m trying to get my head around how to control access. Right now, running a print requires physical access to the tethered laptop. This provides some “protection” for a running print: the classroom rule is "if the printer is running, and the print is not yours, hands off the laptop. If we are controlling via a network, what happens if someone tries to send their file to the printer while it’s running a print, or otherwise messes things up while another student’s print is running. I suppose we could restrict the password access to the teacher, but that requires her to personally interact with each print, and makes her the bottleneck. Maybe I’m missing something here, but how does the Pi deal with having potentially multiple people sending it commands?

The raspberry pi option runs a dedicated web server on board the pi board. The SD card becomes the web server hard drive, location the g code file goes, and controling the printer. The USB connection goes from the USB port on the printer to the rambo board.

The Web page shows the print in progress, percentage completed, etc. Anyone accessing that page could hit stop, abort prints, or start new ones. Some software packages will allow sorry stl slicing on board.

Over the network. The web interface provides “drag and drop”, or you can setup SMB file sharing on the pi and then connect virtual drives from the computers.

The pi uses a mini-SD card for both it’s own boot/configuration files, and for storage. Just buy a relatively large mini-SD card for the pi, and you’ll have plenty of storage for sliced gcode files being uploaded.

I haven’t used Octoprint in an environment with a large number of potentially unruly users, so I don’t have a good answer for this. One way would be to setup SMB so all students could upload their files, but give Octoprint login access only to the teacher (which would mean the teacher would need to start all prints). Hopefully someone else here has used Octoprint in a multiuser environment and will chime in with a better answer.