DIY Machining center development

The Arduino board, that we know from many multicopter projects, is used to control this 4th axis. This is a video posted by Steve Simpson on YouTube. This is the same 4th axis I have for the BF20 mill, and it’s very nice to see how Steve continue to expand the possibilities.

“here is the long needed custom 4th axis motor controller. Designed specifically to take full advantage of the unique capabilities of the ‘mini machinign center’; which is a normal mill fitted with one of my 4th axis”

High speed spindle for the BF20L

Some pictures from last nights project. I have to mill some carbon fibre parts next week, and the 3000 rpm I got on the BF20 is way to slow for the small endmills I plan to use. The Kress 1050-1 has 5000-25000 rpm and I think it will be a valuable addition to my machine. I’m looking forward to explore engraving and some fine detail 3D aluminium work as well.   

BF20 Machine Enclosure

I have finally started to build the enclosure for my BF20L mill. The BF20 is the same mill as the Grizzly G0704. There are some small differences, but they come from the same factory.

I am going to keep the original Optimum base as is, and modify a lathe stand from an old Boxford for the enclosure. Dimensions will be W:150 x D:80 cm and the top will be open.

4th axis for the BF20 Mill

I have ordered a 4th axis from Steve Simpson. I first became aware of the product when I saw it in a forum post at It’s a versatile unit that can be both 4th axis and lathe. Mine is ready in a couple of weeks, and I can’t wait to test it.

The product have gone through several design changes since I first saw it on YouTube. It has been a fun process to follow, and the result of the evolution is amazing. I went for a heavy duty version with 2 step belt reduction and pneumatic brake. Max RPM in lathe mode will be around 3500 with 1:1 ratio in 2nd gear. I have decided to use a Yaskawa 750W AC servo in the Sigma II range. The servo setup seems easy enough, but I have only tested it with the RS232 interface. As a 4th axis it will be controlled with Mach3 and position control with step and direction signals from a computer.

These machines are hand made in batches, so you have to contact Steve for details. His website is: You can also check out his YouTube channel for more videos.

Expect a follow up when my 4th axis arrives!