From RepRap
Jump to: navigation, search

This page is a development stub. Please enhance this page by adding information, cad files, nice big images, and well structured data!

Crystal Clear action run.png

Release status: unknown

No image available.png
A robotic arm based reprap.
CAD Models
External Link

IKBot is intended to be a robotic arm reprap that can print its entire plastic parts list in a single print. Additionally, it should be able to print parts larger than any of its individual parts. In essence, this means you could incrementally build a larger arm to increase the build area.


So far I've nailed down all the firmware and IK concerns, I do think there may be some resolution concerns at the max extent of the build area, though those should be minor. Another concern is speed, though the use of variable stepping division should make it a little faster when needed.


Base will have attachment points to secure it to the surface that will be printed on.

Main Rotation Gear Train

The main rotation gear train will have a reduction of 14.4:1, which will change the step distance to 0.125 degrees (2880 per 360 degree revolution). Speed will be maintained due to the fact that it only ever has to make a 180 rotation while building (worst case travel). This is so that the resolution at 230mm from the base (edge of the build area for generation 1) is an acceptable 0.5mm. This can be improved by either using partial stepping, or adding an additional reduction gear to the train.

Arm Gear Trains

The arm gear trains will have a reduction of 10:1 to maintain a small enough step to get good resolution on the line heading away from the base (this is constant WRT distance from base, unlike the rotational gear). For 150mm length arms this is sufficient to maintain good resolution, for each doubling, partial stepping will enable good resolution.


  • Motor Torque/Arm Torque vs. Plastic strength/Arm Weight
    • Need for reinforcement on the arm segments?
    • Use bowden extruder to reduce arm weight
  • Resolution difference as a function of distance from base
    • Make worst case resolution acceptable and all other area should have >= acceptable resolution.

Interesting Thoughts

  • Arm could technically add parts to its own base while the base was still attached. Self-decoration for the holidays perhaps?

Bill of Materials/Assembly

The following is auto-generated by ThingDoc[1]. It is also incomplete and wrong in a lot of places. It will continue to be so until I finalize the documentation. But as sections of the design get finished, so will the assembly instructions, thanks to ThingDoc :).

Bill of Materials


Quantity Description Type Comments Diagram
1 Base Bracket RP
3 Motor Gear RP
2 2 to 1 Reduction Gear RP
1 4 to 1 Reduction Gear RP
1 Base Rotation Gear RP
2 Arm Gear RP
1 Lower Arm RP Lower arm.jpg
1 Upper Arm RP

Fasteners & Rods

Quantity Description Type Comments Diagram
18 5/16 Inch Nut Fastener
18 1/4 Inch Washer Fastener
8 608 Bearing Bearing


Quantity Description Type Comments Diagram
3 Nema 17 Stepper Motor Motor


Assemble 1x Base

  1. Attach all Base Gear Train parts to a Base Bracket.

Assemble 1x IKBot

  1. Attach the Upper Arm to the Lower Arm by inserting a 50mm Long 5/16 Inch Threaded Rod through the attachment holes.
  2. TODO: Do stuff with nuts/washers
  3. Attach the Upper Arm to the Base by inserting a 50mm Long 5/16 Inch Threaded Rod through the attachment holes.