Thursday, April 26, 2018

Box Joints on the Radial Arm Saw

The base of my CNC router was made with box joints on the Radial Arm Saw. I cut one end of all the boards at the same time using a 1/2 inch dado stack with the saw rotated as shown:

After cutting each slot, I cranked up the arm by 1/2 inch. 
 After cutting one end of all the pieces, I flipped them over to repeat on the other end. Assembled, the frame looked like this:

I've been using this frame for about 3 years, rolling around on casters and shaking the Dickens out of it without any issues.

Monday, February 19, 2018

Thursday, February 15, 2018

After a few tweaks, the DIY CNC is back online!

In the past few weeks I've been working on a new CNC instructable, but I was having trouble getting my motor drivers to cooperate. At first I couldn't seem to get them all to even start up. I decided to try out these Texas Instruments DRV8825-based Stepper Motor Driver Module designed as a drop-in replacement of my existing drivers:

I was getting better results but still missing some steps so I checked the 3.3V from my modified phone charger. It was showing the expected voltage on the multimeter, but when I looked with my $20 single-channel oscilloscope, I saw frequent peaks above 9V.
I added an electrolytic capacitor I found and smoothed out the peaks to around 3.6V. That's it, right? Wrong! It took a few more trial runs and a night to sleep on it to realize I also had a mechanical binding issue on the x-axis. After removing 2 screws, it's working great again.

Monday, January 8, 2018

Corner Bench Featured on

Thanks to Woodcraft for featuring winners of the Furniture Contest:
You'll find mine among the second prize winners.

Here's a photo of the table we bought from friends and painted to match...