▼This page was part of an MTU course MSE4777 OA and MSE4777 OB/MSE5777/EE4777/EE5777: Open-source 3-D printing

Please leave comments using the talk page. The course runs in the Fall semester. It is not open edit.

This is a shovel handle to either replace broken ones, or add one in where the shovel/hoe/whatever tool has only the wooden handle. Grips such as these can offer not only greater leverage but also comfort and wrist relief preventing long term injuries such as carpal tunnel. Due to tools having different diameters and users wanting different sized grips, everything about this has been mapped to easily changed variables which require only the easily measured constants inputted; all the trigonometry for the supports with be automatically adjusted. The number and placement of screw holes and also thickness and length of the section that overlaps the shovel can also be easily altered to user preference for strength.

Bill of Materials

1. 2-6 screws to connect grip to shaft
2. screwdriver
3. File for removing support residue

Scad and STL files available here http://www.thingiverse.com/thing:555240

Tools needed

1. MOST Delta RepRap or similar RepRap 3-D printer

Skills and knowledge needed

Nothing more than basic 3D printing and altering well commented variables to get desired size required

Technical Specifications and Assembly Instructions

I used Openscad for the model, Cura for the slicer, and Pronterface for the controller

1. Open the.SCAD file in Openscad, and adjust the given parameters to fit your needs. All units are in millimeters
2. Compile and render the file into a new.STL file
3. Open the.STL file in Cura
4. It will likely be vertical, so rotate the model 90 degrees so that it is on its "back"

   

5. In the support section of the left toolbar, select "support type" to "touching buildplate"

   

6. In the Expert Configurations, I suggest increasing the "Distance Z" to.20-.30 to allow the supports to be disconnected easier and leave less residue on the printed model

   

7. Choose speeds and layer thickness as ideal for your printer and desired strength
8. Save the Gcode and then load it into Pronterface and print away
9. When it is done printing, carefully snap off supprt structure
10. Use a metal or wood file to remove excess plastic from support residue
11. Fit handle over the end of your tool, and screw into place

Print Time Estimates

1. With.06mm thickness, ~16 hours depending on size
   
2. With.25mm thickness, ~4 hours depending on size
   

Assembly time Estimate

1. 10 minutes

((Note that a handle like this would be better suited for an implement with a shorter shaft, this was just the only shovel like that we had around the house I could put a handle on))

Cost savings

1. My design used $3.30 in plastic at $30/Kg
2. Commercial Shovel Handle like this will cost around 10 dollars
3. The benefit is not so much in cost savings, although they are there, but the fact that this can be made to easily fit any and all shovel/hoe/tools with long wooden shafts where this would be desired on the end and the ability for a village to make them themselves instead of needing them delivered from some large manufacturing facility

References