Category Archives: 3d printing

Rejects and prototypes

Prototypes and rejects from the 3d printer. All part of the design process for my robot:

IMG_4436

Tagged ,

New robot base design and completed prototype arm assembly

I spent all day at hacman¬†Tuesday and Wednesday printing and tweaking robot parts. I put it all together when I got home. This is the front, the lifter arm has holes to allow me to screw in different attachments, I’ve still not designed that part of the robot yet:

IMG_4432

Here is the back view, you can see the lifter arm gear housing (the curved structure) and the motor that drives it, also the battery (underneath the ball hopper)

IMG_4433

The lifter arm gear system looking through where the hopper would be:

IMG_4434

I need to design an attachment for the end of the lifter arm. Here I’ve created a simple one using meccano. It’s too heavy, the bolts catch on the floor and it dumps the ping-pong balls short of the hopper. Other than that it’s perfect. You can see the camera with capped lens that I’ve just wedged into the structure temporarily:

IMG_4435

Next-up: better lifter attachment design, a couple of re-prints with tweaks and some software.

Tagged ,

An assembled hopper

Today I printed out and glued together the first iteration of the ping-pong ball hopper that takes up most of the space of the robot.

The assembled hopper:

IMG_4405

Full of ping-pong balls, I can get 12-14 in without packing them manually. That seems like enough for now, but a larger hopper would be good.

IMG_4406

Mounted on the robot. You can see the completed camera mount and Raspberry Pi mounted on the side in the foreground:

IMG_4407

The reverse angle:

IMG_4408

Tagged ,

Testing new motor mounts

I needed to re-design the motor mounts on the robot base, they didn’t hold the motors securely enough and tended to shift around.

The new mounts are better fitting and include a small wedge that fits between one of the gearbox plates where there are no cogs.

Testing new motor mounts Testing new motor mounts

One of the great things about 3d printing is being able to pull out part of a design and iterate over in isolation, then when you’re done incorporate it back into your main design.

Tagged ,

Prototype robot base #1

The robot base design from my previous post printed OK. Here it is printing:

Robot base printing

The finished print. The two small separate objects are the motor covers:

Completed robot base print

The assembled robot, including Raspberry Pi and MotorPiTX:

Assembled robot base

The underside of the robot:

Assembled robot base base

Tagged ,

OpenSCAD robot base design

I’ve re-designed a prototype robot mount in OpenSCAD as Sketchup wasn’t up to the job. It took a while, you have to program the model in a text editor so there’s lots of trial and error. Will have to wait to print it to see if this design will work.

Prototype robot base designed in OpenSCAD

I’ve made some improvements over the original design, most notably thicker side walls and motor mounts, more accurate measurements and added the cross-pieces with a Raspberry Pi mount.

Here’s the original Sketchup design for comparison:

Robot base designed in Sketchup

Sketchup was great, really easy to use, the only problem was that it seemed to create invalid model files.

Tagged ,

Trying out the prototype caterpillar track mount

It works, but it needs more refinement.

Testing the new motor mount

Tagged ,