SNAM1500 WOOD 4dof robot arm sg90
This was bought via Amazon at what I thought was a fair price for 4 laser cut pieces of wood and four servo motors. The kit does sell for twice what I paid in the same format and for four times as much just replacing the wood with acrylic. Buyer beware, shop around. I got four servos, which I could of bought for around 2/3 the cost of the whole kit so I wasn't disappointed. It doesn't come with anything else and needs a servo driver board to interface it to an MCU. As it turned out, I also bought a robot car which came with one included, result.
My primary objective with this arm is to modify it but I always like to start with something which works an change it, rather than try to mess around with it from the start, so this is just my take on building it in a vanilla format.
The picture shows what came in the box, which is the bare robot arm. I'll be pairing this up with a PCB I got from another kit, a Sensor Shield v5.0 which is made for use with an Arduino and is fairly cheap, being mostly breakout pins and no active components.
There not being any instructions in the box, a weblink on the kit's box lid led to a site with instruction for a similar arm and while I could repeat them here, it wouldn't tell anyone just what it's like to build.
Straight off I scanned and printed copies of the four laser cut boards so that I could easily make replacements of plastic in the future, and of course add my own modifications. This was best done while the boards were complete to give the best sharp edges. With this I also took measurements for future reference. I did find very similar plans for a robot arm on Thingiverse and I'm not sure just where the design originates.
Instructions were found here.
In the pictures above I've tried to 'improve' the construction by adding extra nuts to the tops of the supporting bolts, which is a mistake because the platform dips forward and snares on them when rotating, so they had to be removed and the bolts adjusted level with the platform as in the following picture.