I'm thinking I might still try open loop steppers. The TC211 is quite a small machine I might get away with it. Cost is a factor. I don't want to spend $1000 on it. This machine cost $50, I don't think it is worth investing in it as I already spent $1000 on another CNC machine which is almost working. This Brother came as a chassis with motors and seemed a better project than converting a manual mill or buying a desktop engraver. I previously bought another bigger mill, also BT30, with drivers, tools, spares, manuals, controller and a full Bosch Rexroth control system which seemed a more cost effective and viable way to get started in CNC than investing 1000s in the Brother.
Someone on youtube has a Grisly Mill converted to CNC using open loop stepper motors, and ball screws, which gave me the idea to restart this project with a low end $250 refit. It would be very useful to have this nice small Brother mill with hand controls on it as a manual mill and ideally DRO type functionality, as I don't have any mill at all, and really need something for small projects that don't require CNC. I was wondering if I could add some digital scales to the axes and use that to provide a closed loop output.
As the machine has no drives or any electronics, it does seem appealing to design and build a motor driver, resolver, etc, rather than spend say $5K on a nice easy life solution, off the shelf controllers, cards, etc. Especially as I will probably blow up a few, and will want multiple machines. Perhaps this is how projects lose track, never get finished, and end up being sold for $50?
