Tag Archives: fdm 3d printer

Upgrading your 3D Printer – x-axis improvements

Upgrading your 3d printer

After my initial excitement of having a fully operational 3d printer waned, I used the printer to produce parts to upgrade itself. Making itself better, stronger, faster than it was before. (How cool is it that the printer can make parts to upgrade itself??) Mass of the moving components limits the speed at which they travel and increase printing time. Inertia has to be compensated for in acceleration parameters as well. In short, less mass equals faster printing. The primary goal of printing replacement parts was to reduce weight of the moving components, the x and y axis sleds.  The Z axis moves very little and the mass is much less significant.  This post focuses on the x axis upgrades. The above photo shows the x axis sled with side by side comparison of the original (on the left) and the upgraded (on the right) components.  The left side is the original proof of concept machined aluminum bearing mounts and cross brace. The right side shows the upgraded 3d printed LME8UU linear bearing mount with a skeletonized machined aluminum cross brace that also lowers the print head slightly.

3d printed LME8UU bearing mount

 As you can see more clearly in the above photo, the 3d printed ABS plastic bearing mounts are considerably smaller then the original CNC machined aluminum design.  My plastic bearing mount raps around the bearing 20 degrees beyond 180 on each side for positive retention and due to the flexibility of the ABS snap over the bearing with a perfect fit.  The plastic mounts remove 18g of mass from each bearing.  The skeletonized cross braces come in at 8 grams in aluminum vs 36g of the original aluminum parts.  I did print them in ABS at 2g part weight, but they were a bit too flexible and I was concerned with heat from the making them softer still.

3d printed LMe12uu linear bearing mounts  skelotonized x axis sled

The upgrade of the linear bearing mount and cross brace resulted in 128g of mass removed from the x axis moving components. Also the bearing mounts applied a more uniform clamping pressure on the bearings then the CNC machined design, that when over tightened resulted in bearing drag.  As is often the case when building something, you design and build using the tools you had on hand. I always planned to replace the machined bearing mounts.  My original CNC machined aluminum bearing design was accurate but bulky, ugly, and heavy.

LME8UU bearing mount    

Above is a rendered image of my LME8UU bearing mount design.  The mounting holes are tapped M3 after printing and 10mm between centers. Here is a pdf technical drawing showing the dimensions : LME8UU bearing mount technical drawing.   I have added the linear bearing mount to Thingiverse.com as an STL and IGES file for others to use. Here is a link if you want to print your own 8mm linear bearing mount for a project:  http://www.thingiverse.com/thing:142243

x axis limit switch plate

All was not 100% perfect with the bearing mount upgrade, I did not consider the limit switch contact points when designing them.  I added a small aluminum plate using 2 of the 3mm tapped holes to solve this minor oversight.  Eventually I’ll add a physical feature to the 3d model and print  new bearing mounts for the two limit switches.  My original purpose in designing these LM8UU linear bearing mounts was as a universal part so that I can use them in the future for other projects.

wire mounting on 3d printer

Along with the weight reduction I moved the wire support to a more centralized location on the back side of the sled.  I felt this would help reduce strain on the wires during the repetitive movement along the x axis.  I orient my parts when printing such that the bulk of the printing travel is done by the x axis.   All in all,  these improvements along with other upgrades (to be shared in future posts)  have gone a long way to increase my printers speed, reliability, and aesthetics.


First parts printed on my 3D Printer

3d printed test parts

The very first parts printed on the 3d printer I have designed and built.  Nothing glorious. Frankly I was expecting nothing to happen when I clicked print.  I had not finished all of the final alignment adjustments needed to the build platform and frame. This print happened while I was testing the build platform heater for the first time. To see how the software worked,  I loaded a small stl part file (the two pieces are a hub for a whirlyprop kids toy) mostly to see how the software processed the file. After playing with the code and making adjustments to some settings,  I said to myself, “Let’s see what happens.”, clicked print and voila parts were made.

Zac 3d printer- First printed parts-2413   FDM 3d printer test print

 The above pictures show I still have  a lot of work to do on optimizing parameters in the software code for my unique printer design.  It did surprisingly well spanning the overhang with only a few loose rows of filament being out of place due to droop.    The acrylic adhesive on the blue masking tape smelled something terrible after heating. This is due to some thermal degradation of the adhesive.  I was happy it peeled off the build platform cleanly.  The blue tape is used to help the abs stick to the build surface as it is extruded in the first layer.  I had ordered some 2″ wide polyimide tape but was waiting for it to arrive when I printed these very first parts on the printer.

parts in hand from 3d printer

These parts are the very first things the 3d printer I designed and built ever printed.   I was pretty excited when I saw my design in action printing.  The printer is not “done” by any means. There has been a heated bed V2.0 built and installed already.  The #1 issue I have found with designing and building a 3d printer that is much larger than the majority of cupecake, makerbot, reprap style printers people typically build is flatness of the build platform.  More on this in my next post.