Gantry crane powered by 2 stepper motors. (some assembly required).
Don’t expect to have this thing printed and made in a day.
Extra hardware you will need-
28BYJ-48 Stepper motors (x 2)
37 x 17 x 10 Ball bearing.
The model is quite modular, so you can make it as tall as you like. (Main supports must be in multiples of 2, and crane arm in multiples of 3).
Every part will fit within a 200 x 200 print bed and printed without supports.
It was drawn using Autodesk Inventor, for some reason the parts come into my slicer at 1:10 scale.
To print the main tower, scale everything by 10 (in Slic3r).
Check the orientation of the parts after placement. (The main uprights should be printed on their back), and all of the disks rotated 90 degrees.
Use the same members (as the main support) to print the crane arm, but scale all parts by 5 (half the size of the main upright).
From the base assemble (8x) main uprights, use the angle brace and the horizontal brace or cross brace to secure it together.
For the pin joints I secured the members using plastic rivets. To do this –
- Drill holes to 3mm.
- Cut short lengths of (3mm) filament to suit (20 – 25mm).
- Heat one end of filament with soldering iron so that it mushrooms.
- Fit rivet in place, and trim with 3-4mm exposed.
- Heat exposed end of filament to mushroom other end.
I used the same method as above to secure the crane arm parts, but instead used 1mm styrene rod (from hobby shop). Alternately you could use gravity extruded filament and a 0.6 mm hole.
I used an old bearing from the front wheel of my go-kart for the turntable. The outer bearing retainer is made as an interference fit so it should hold tightly enough. As a worst case it could be secured with adhesive (epoxy or super glue) to secure it in place.
For the crane arm, start with the front wheel braces attached to the (smaller) main uprights and work back, once again using the angle brace the horizontal brace and the cross brace
Eleven parts will have to be glued; Cable drum, half wheel (3*2pcs), and the hook, and the Bearing base ring (with the roller bearing in place).
My adhesive of choice is “Plumbers priming fluid for PVC pipes”. It is quite aggressive, and flashes off quickly, leaving only a neat weld. (Hardware shops stock 250mL bottles relatively cheaply).
The stepper motors were the only parts that I used screws to secure.
The cable drum turns very slowly, so I may look at fitting an external gearbox to that. (Possible future update?)
Feel free to post suggestions and comments.
Most importantly... have fun with it.