Category Archives: 3D Printing

Anything related to extrusion printing. Generally with plastics such as ABS, PLA, PET, and Vinyl.

3D Printing: 3D Printer Build Plate Leveling

3D printers require a level build plate. We’re taking a look at how you can level your Replicator, CTC, Flashforge, or other Makerbot Replicator style printer build plate

Bill of Materials for this Build:

  • Finger Guage (or sheet of paper)
  • (Digital) Dial Gauge
  • 3D Printed Jig
  • Small Magnets (optional)
  • Hot Glue (to adhere magnets)

Some newer extruders such as the Kossel style Deltamaker cleverly level the head instead of the plate, which proves a bit simpler. They’ve got there own weaknesses, of course, but a level plate generally isn’t one. For the rest of us we have to put up with leveling springs in three or four locations needing to be tightened to spec periodically.

As with any procedure you can severely damage yourself or your equipment. By reading this article you acknowledge that the author, this publication, and any other entity have no responsibility for damage or injury. Take all necessary safety precautions and make sure that any procedure will not cause damage or injury before going through with it.

So what’s an easy way to level the build plate? You can fiddle around with a finger gauge and manually level it repeatedly to .102mm or .004 inches (about the thickness of a sheet of paper) on all the points hoping that it’s dragging just right every time and you’re not getting a variance.

Pittsburg branded digital gauge from Harbor Freight
Pittsburgh digital depth gauge from Harbor Freight

Or you can pony up 15$(USD) or so and get a digital depth gauge (ours was from Harbor Freight, pictured right). There are also tire tread depth gauges with the proper resolution for the job available in the 5$ range. We went with the classier dial style digital gauge jig as seen in the pictures. Link to the required jig on Thingiverse: (STL Files at Thingiverse)

You may want magnets as well. Gluing them in place on the print-out provides a bit more staying power to your jig. Less moving about while you’re setting the screws on your plate is definitely a plus but the design will clip on if you have trouble finding magnets.

Digital meter installed in a red PLA jig

Digital depth guage installed in 3D printed jig with magnets

In addition to magnets re-sizing the inner diameter of the print out’s pass-through hole to the gauge might be necessary if there’s a variation to it on your meter. A bit of tape or smudge of dried adhesive on the inside of the opening can achieve the same goal if you’re not keen to pre-measure everything and alter the 3D drawings.

How does it all work? You’re still going to need your finger gauge (or paper) to level a single corner properly. Being careful not to hit the bed with your print head position the print head properly near one of the leveling screws and get it to the correct distance from the print bed. We accomplished this by moving the print head out of the way, manually moving the Z axis all the way to the top, then moving the print head near the screw with the built in jog function.

How to check the depth of clearance on a printhead with a feeler guage

A finger guage balances under the print head to check the depth of clearance

While the build plate is positioned correctly next to the screw go ahead and level the build plate. On most printers this is accomplished by tightening or loosening the screw until your finger gauge (or paper) drags appropriately. Your 3D printer may differ.

Once that screw is tightened to the proper tension go ahead and move your print head(s) off to the side using the jog feature of the printer. With the printhead moved to the side place your jig on the printers carriage rods as pictured.

A 3D printer jig showing zero positioned over a leveling point on a CTC 3D printer
3D printer leveling jig positioned properly on a single level point

Zero the digital depth gauge by pressing “Zero” (or your equivalent) once it is mounted securely in place. With the gauge reading zero move your Y and Z axis around until the meter is roughly next to each one of the tensioning screws. Then add or remove tension with the screw until the gauge reads zero for each of the positions.

You’ll want to repeat your check until all four points read near zero. It generally takes a few passes.

That should be it! If that all worked for your 3D printer you should now have a leveled build plate.

Cleaning your 3D Printer’s Feed Drive Gear

While 3D printing there are few things worse than getting half way through a print and realizing that the filament is getting stuck in the drive gear.  Which happens when you’re running cold filament on a hard metal gear with relatively sharp teeth.

Which leads to the need to clean out the drive gear!  Keeping the drive gear clean can help the filament keep flowing in the right direction and at the right speed leaving you with less errors on your prints and better layer adhesion.

The feed mechanism on the Replicator style 3D printers from Makerbot and the various open-source manufacturers consist of a drive gear applying pressure the the filament and a roller to help press the filament against the gear.  We’re going to take a look at what parts are involved on the CTC printer and how to remove and clean them.

Brass cleaning brush
Brass cleaning brush used on a 3D printers feed drive to clean plastic out.

First I unloaded the filament and waited until the printer was cool.  Not waiting for the printer to cool down before removing the various hot-end and cooling parts can result in being injured; so I’m not going to do that.

Warning: Do not force any parts together or apart.  The process notes here are based on a specific model of 3D printer and may not apply to yours.  Make sure you take all necessary precautions and refer to your manufacturer with any questions.

Once the printer is back at room temperature I needed to remove the fan through-bolts (two in the case of the CTC pictured).  I was then able to unscrew the two screws holding together our filament feed guide components.  Being careful not to loose any of them during the process.

With the feed guide removed the remaining part on this printer is a feed gear.  In the case of the CTC it’s held on by a set screw that needs to be loosened to remove the gear.  When I loosen up the set screw it comes forward and off the motor.

 

And it’s full of ABS gunking up it’s gear!

CTC Replicator Drive gear post cleanup
New clean CTC printer feed drive

What I’m going to do to clear that out is get a set of brushes.  Since the gear in question is a hardened metal I’ll use a soft plastic brush and a harder brass brush.  I’ll then pick out any remaining bits of plastic with a small screwdriver.

Once that’s done the feed assembly gets rebuilt in the reverse order I took it apart and it’s back to extruding 3D prints!

3D Printing: Replicator Windows Hinges

Today’s Makerbot enhancement is a window hinge from Thingiverse complete with custom cut acrylic windows. You’ll have noticed them in the previous post’s CTC Dual Extruder 3D printer.

CTC Replicator clone with hinges and window
Makerbot Replicator 1 clone by CTC with acrylic window and hinges.

These clips seem to work well even with the under-sizing you’ll get on converting from metric to SAE sizes. What you’re seeing there is the combination of these clips and this acrylic window cut-out.

Since we’re going from Metric to the available parts in the United States (SAE) we’ll have to do some quick conversions and allow for overage. Or re-work the models which for some folks might make a fun and quick challenge. In this case it was more work than we were looking for.

On the hinge side there’s a call for 3mm metal rod. So we didn’t have to alter the original models for the hinges we went with the nearest larger size available at Home Depot, a 1/8th rod. To do that you’ll have to drill out the hinge to re-guage it to the larger size.

Close up of CTC Replicator clone acrylic window hinge.
Close up of CTC Replicator clone acrylic window hinge.

Since 3mm acrylic is equally impossible to find we went with 1/16th acrylic for the windows.  What you’re seeing holding the window in is medium strength double sided foam tape.  It’s a bit loose but seems to hold well enough.

The acrylic windows were cut out on an Epilog laser cutter as seen in the picture. You could also cut and snap them if you’re careful or possible route them with a saw. Just mind that a reciprocating saw may bind up making it dangerous.

One other problem we ran into in creating the windows for the case was a slight design difference between the CTC 3D printer and the Makerbot Replicator on which it’s based.  They appear to have cut the wood panels slightly (as in a fraction of a millimeter) too small resulting in some overlap of the acrylic panels.

Window overlap highlighted in black marker.
Image showing window overlap on the CTC Replicator clone.  It’s the area highlighted in black sharpie.

You can prevent that from being an issue with some careful measuring and reworking the laser cutter image (if laser cutting) or simply cutting it to your exact specifications. In our case we took the panels down to the combination belt and wheel sander and took off the extra material on the flat sanding disc.250