by AJ Quick
Looking at the picture, is there any plan for heatsinks to be mounted to the Allegro chips? Looking over their spec it seems like they may be a good idea in certain situations but the picture does not appear to show any board mounting points (since a heatsink should not be physically supported by the chip it is on) and there may be a clearance issue with the capacitor on the left.
Yes. There is a full 3/8-1/2" between the chip and the capacitor. It is no problem to install a heatsink directly to the motor control chip. It is supported nicely between the 3 chips. You can see a picture of a (non-conventional) heatsink installed on the chips here: http://sphotos.xx.fbcdn.net/hphotos-ash4/419795_362145290484789_176389105727076_1190142_1465370060_n.jpg
Also. Heat sinks are not required if you are running low current motors and have the power turned down. If you are planning on running 3A they are necessary to avoid overheating.