Mechanical Assembly

Assembling the frame of the Index PNP

What you’ll need


To build your own index you will need to acquire the items listed on the BOM. This includes various mechanical components along with a significant number of 3D printed parts. When printing the 3d parts, be sure to print them with the recommended settings.


The following tools are needed to build the Index.

  • 2mm Allen Key
  • 2.5mm Allen Key
  • 3mm Allen Key
  • 4mm Allen Key
  • Fine Tip Tweezers (for positioning T-Nuts)
  • Pliers / Vice Grips
  • Utility Knife / Precision Blade

Tips & Tricks

When assembling the Index, the following tips will help the process go more smoothly.

  • Clean up your 3D prints well. Make sure that you have removed any support material, and have cleaned up the edges of any holes. Test that you can fit the V-Slot or machine screw for a specific part into the hole.
  • Deburr the aluminum profile at the ends. Then it’s easier to put parts together.
  • Slot Nuts come in two different formats. One form can be inserted into the slot through the slot. The other form must be inserted from the end. Watch for notes in the about when to insert based on which type you’re using.
  • Positioning Slot Nuts can be a bit of a challenge. A simple way to get them into the right place is to use gravity to get them close, and then use either the long end an allen key or a pair of fine tipped tweezers to push or pull them to the exact position.
  • Inserting Belts can be easier if you move the gantry you’re inserting the belt into to the middle of the rail it is on and then as you insert the belt, move it away from the side you want the belt to come out from. The v-slot will catch the belt and once you’ve moved the gantry a little bit, you will be able to catch the belt. Passing a belt through a belt slot from the inner side can be easier if you place an exacto knife blade at the back side of the slot and butt the belt against that while drawing it up through the slot.
  • Press Fit Nuts are used in several places. If your printer tolerances make it so these nuts don’t stay in you can use a piece of tape over the back to hold them in temporarily.

Left Side

The left side provides the rails on which the Y gantry runs. In addition, most of the cables are routed to the front left of the machine as that is where the controller ultimately lives.

Right Side

Assembly instructions for the right side of the frame.

Staging Plate

Assembly of the staging plate.

Frame Assembly

The Left and Right side assemblies that were completed in the previous steps are next connected together by two 600mm v-slot extrusions.

X Idler Mount

Assembly for the X Idler Mount

X Motor Mount

Assembly for the X Motor Mount

Y Gantry

Assembly for the Y Gantry

Y Gantry Motion

Motion Setup for the Y Gantry

X Gantry

X Gantry Assembly

Tool Assembly

In this step you will assemble the tools you desire for your Index build.