First Prototype Up and Running

A project log for MeArm Raspberry Pi Edition

A robot arm kit that works with the Raspberry Pi

mime-industriesMime Industries 10/20/2016 at 16:250 Comments

After getting my head down and working hard to get the redesigned MeArm mechanicals with the Raspberry Pi base up and running, we were pleased to be able to show a few people the working prototype at last weekend's Maker Faire in Rome. Here are the big things I've been working on:

Simpler mechanical design - after spending some time learning Fusion 360 I was able to fully model the arm mechanicals and use it to simplify some of the mounting mechanisms to eliminate the need for screws.

The side-mounted servos are now held on with some clips, which seem to work really well. The base is held together with a couple of elastic bands, which are a nice, solid way of holding everything together without needing more screws and captive nuts. The grip has been redesigned to make it much simpler, with less parts, so easier to build. The only places there are still screws in this design are where there are joints because they still work well there.

Neater Cable Routing - one of the more radical changes has been to use a PCB as the base of the arm, which means that the cables can be clipped straight on to the base, and then one cable can lead from that base to the Pi HAT.

It makes it much less likely for the servo cables to snag and means the cable from the grip servo no longer needs an extension. If you're making this yourself it's still easy to just switch the base out for a bit of acrylic so you don't need to get PCBs made.

Pi HAT - It wouldn't be a Pi MeArm without a Pi HAT. It's got a couple of joysticks running into a I2C ADC chip that means the Pi can read the state of them directly. I'll do another update on this in the future...