RepRap Snappy V1.1 Chassis Assembly

Introduction

If you’d like to see the journal of my personal progress building the RepRap Snappy v1.1, click here. Most of the language and all of the non-photo images for the chassis assembly were adopted from the RepRap Github. It has been modified to assist those unfamiliar with 3D printer building, use, and vocabulary and to better fit the one-stop-shop goal of this guide.

Part two will feature the wiring guide.

Printing Notes

Many of the parts were printed using a FlashForge Finder while I was attending a workshop on 3D printing for educators with the Digital Harbor Foundation in Baltimore, MD. Several pieces were too large to easily print on this print. So, I cut superfluous design elements and shaved millimeters off of corners before printing. Those special cut gCode files can be found here. The additional pieces were printed using the University of Oklahoma’s EDGE. They were either printed on a lulzbot Mini or a lulzbot Taz.Thanks so much. Print Settings Everything was printed using PLA with the following settings:

• 3 Perimeter layers
• 3 top and bottom layers
• 0.3 or smaller layer height
• 20% or better infill
  • The exception to this will be extremely long prints on the Finder. Since it only has three tension pins, it has a real problem with warping. Reducing the infill helped get through some of these.
• Grid/Rectangular/Linear infill
• No support
• No raft
• No brim

The link below has a complete list of all necessary tools, materials, and prints to complete this printer.

You will need to download and print all of the .stl files before proceeding. Note: The link may say it is "160+ hours of printing," but I found that to be a pretty massive underestimation for my printer resources. I have estimated a little over 300 hours of printing was necessary, but I had several failed prints on the FlashForge Finder.

Click here for the list of Materials.

Press-fit a drive gear onto the shaft of a stepper motor, making sure to align the flat of the shaft with the flat of the shaft hole. Repeat this with the other drive gear and another stepper. Both the male end of the motor and the female end of the drive gear will have flat sides, but they can be quite difficult to see. The hole corresponds to the flat side inside of the shaft hole.

Attach a limit micro-switch (with wiring) to one of the side clips, with the lever end towards the center. Do this again for a second switch and mount plate. Click here for a quick tutorial on wiring leads to your limit switches.

Seat the stepper motor with drive gear in the X/Y motor rail segment. Clamp it into place with a motor mount plate with micro-switch. Route the wiring out a side wiring access hole opposite the limit switch.

Join a rail segment (pink) to each end of another motor rail assembly (green).

Join opposing platform supports to either side of the sled endcap. Point the tabs toward the side with the joiners.

Join two XY sled parts together. Make sure the bottom racks line up.

Join a Y sled endcap assembly (blue) to one end of the Y sled central assembly (purple).

Slide the Y sled partial assembly (Purple/blue) onto the Y axis rails assembly (pink/green), so that it is centered. If there is too much friction when sliding the slide onto the Y axis rails assembly, then sand the rails on the Y axis.

Join the other Y sled endcap assembly to the end of the Y sled partial assembly.

Join a rail endcap to each end of the Y axis with completed sled assembly.

Seat the stepper motor with drive gear in the X/Y motor rail segment (lighter green). Clamp it into place with a motor mount plate (dark green) with micro-switch. Route the wiring out one end.

Join a rail segment to each end of a motor rail assembly, to make the X axis slider. Route the wiring to one end of the slider assembly.

Join two XY sled parts together. Make sure the bottom racks line up.

Join the X sled cable-chain mount (White) to the front/left side of the X sled endstop (Burnt orange).

Join an X sled endcap assembly (white/burnt orange) to one end of the X sled central assembly (Purple).

Slide the X sled partial assembly (purple) onto the X axis rails assembly (pink/green), so that it is centered.

Connect the Y axis assembly to the XY joiner on the X axis partial assembly. Route the Y axis wiring through the front hole in the XY joiner.

Join the other X sled endcap assembly (burnt orange) to the end of the X sled assembly (rainbow), fixing the Y sled assembly in place.

Attach the cable chain joiner mount (white) to the X motor segment, on the same side as the X sled cable chain joiner and Y axis wiring.

Attach the cable-chain assembly (green with 13 or 14 links) to the cable chain mounts on the X axis assembly, making sure to feed the Y-axis wiring through the cable chain. Route the wiring in through the wiring access hole beside the cable chain mount, then out through the end of the X axis assembly.

Seat the stepper motor in the Z motor rail segment (lighter green). Clamp it into place with a motor mount plate (darker green) without micro-switch. Route the motor wiring out the bottom of the rail.

Screw the lock nut onto the threaded rod.

Screw the rod into the coupler fully, then tighten the lock nut up against the coupler. There will need to be room for the male end of the z motors to enter the coupler. This can be adjusted in a later step.

Press-fit the lifter rod assembly to the mounted motor shaft. Make sure the flatted side of the shaft is aligned with the flat of the shaft hole. This can be tedious and take quite a bit of effort. Take your time and aim for slow, steady progress. Damage to a print or motor caused by using too much force will set you back much farther than taking the time to carefully seat this.

Attach two rail segments (pink) to the top of the motor Z lifter assembly (greens).

Attach support legs (copper) to each side of the yz_joiner part (blue).

Repeat Z Tower Assembly steps 1 - 5.

Attach the Z rail assembly to the top of a YZ joiner assembly. Route the wires through the back of the YZ joiner.

Attach a cable chain joiner mount to the front-size of the left Z tower, above the top hole of the bottom rail segment.

Attach the Z rail assembly to the top of the YZ joiner assembly. Route the wires through the front of the YZ joiner.

Insert a 686 bearing into the extruder idler arm.

Insert the idler axle through the 686 bearing. Lock it into the extruder idler arm with the axle cap.

Attach the extruder drive gear onto the stepper motor shaft. This is the machined metal drive gear that would have been purchased, not printed.

Slide the JHead extruder hot end into the slot in the bottom of the JHead platform. Route the wiring up through the wiring access slot, and along the back of the extruder platform. The hot end will fit snuggly into the slot that matches the groove on the hot end.

Clip the extruder motor with drive gear to the jhead platform using the extruder motor clip (teal).

Insert the idler arm into the idler hinge hole on the JHead platform.

Insert the idler latch arm into the latch hinge hole on the JHead platform.

Insert the extruder fan shroud into the JHead platform, latching the JHead hot end, and idler and latch arms into place.

Clip a cooling fan to the top of the extruder fan shroud using the extruder fan clip part. Route the wiring along the back side of the extruder platform. If you need to extend the fan wiring, click here for a video tutorial.

Attach a cooling fan to the cooling fan shroud.

Attach the cooling fan shroud assembly to the bottom of the extruder fan shroud. Route the wiring up through the wiring access slot, and along the back side of the extruder platform.

Attach rail segments to either end of the extruder platform assembly. Route the wiring through the left side rail segment, and out the front-left wiring access hole.

Attach a vertical cable-chain mount to the front left side of the extruder bridge.

Attach Z sled segments to either end of the extruder bridge assembly.

Attach the right Z tower assembly to the right end of the XY axes assembly. Route the right tower wiring through the rear X axis wiring access holes.

Attach the left Z tower assembly to the left end of the XY axes assembly. Route all wiring out the back of the left Z tower base.

Lower the extruder bridge down into the Z tower grooves. Once the threaded rods meet the threading in the z-sleds, you will need to begin turning the stepper motor coupling evenly on both sides to move the extruder assembly low enough to attach the z end cap and spool holder.

Attach a limit microswitch, with wiring, to the Z rail endcap.

Attach the Z tower endcap to the left Z tower. Route the limit switch wiring down through the wiring access holes in the left Z tower, and out the back of the base with the other wiring.

Attach a cable chain (17 links) from the extruder bridge cable chain mount to the left Z tower cable chain mount. Route the extruder bridge wiring up through the cable chain, back into the left Z tower through the wiring access hole below the cable chain mount, down the left Z tower, and back out the motor rail segment to where the controller board will be mounted. Be patient. Once the chain is assembled the links make for great cable management, but frustration and rushing can lead to broken links. Take your time.

Attach the spool holder to the top of the other Z tower.

Attach the RAMPS motherboard mount to the end of the printer base.

Clip the glass build platform to the build platform supports using four binder clips.

Cradle the spool axle in the spool holder top.