SOB Son of Brute is now Vamp, uses 3/4" Trim Channel found at your local home center. My design uses the Trim Channel for the Frame Linear Rail and Motor Mount. Blocks of Delrin with a V cut in them run on the Lips of the Trim Channel. What you see on this page is weeks of work and testing. It took a month to get to the Acid Test! Below is some pictures of that project as it was built. I always build the Z-Axis first! Once you get the design to function with the Z-Axis the X and Y are cake!
The "Build" starts out with my Trusty $9 Harbor Freight miter box mounted to the bench. Each piece of aluminum Trim Channel is cut to length and then touched up using a cheap HF belt sander.
The parts for the frame are drilled using a cheap HF drill press. The Frame is bolted together with 10-32 X 1/2" bolts, Nuts and Star Washers. Corner Brackets to prevent Skewing are also made from the Trim Channel. This forms a super simple CNC Axis Platform that is Frame, Motor Mount and Linear Rail.
Here you see the Z-Axis assembly. I incorperated my Captive Bearing system as an End Bearing. The leadscrew is allowed to float in the Delrin Drive Nut.
Here we have Gas Pipe used to hold the Z-Axis. This idea comes from my Brute model introduced 15 years ago! Notice the 1/2" PVC transition block mounted to the upper Pipe Flange.
Here is the Acid Test! With a Dremel in it's mount sporting a 1/8" drill bit, I flex the tip of the bit with increasing pressure. It is at that point I can determine what the machine is capable of doing. The goal was a PCB Milling machine. It is worthy!!! Think about it! I spent over a month on this idea. Others have used Trim Channel but not like this! There are $600 to $800 Kits out there that are not as tight and stiff as this crazy design. How come? They are out to make money! I am out to find out what if? A big difference!
We now assemble the X and Y axis. All final holes are drilled and de-burred.
The four mounting holes are located and drilled in the oak board. All hardware is located and mounted. The final possible problem was mounting the stepping motor using four nuts as spacers. That caused no problem. On the Z-Axis the motor is mounted using joiner nuts. NEMA 23 Steppers have a plateform near the shaft. I had to find a way so it would sit straight on the frame. The nuts took the problem out of the picture. I could have used more joiner nuts. Saving money here using a plain nuts!
The Y-Bed is added allowing the X-Axis to be mounted to see if all the holes line up! Do I have enough bolts? Will the weight of the motor pull down enough to cause the V-Slides to wear out prematurely? Lots of questions get answered by building things! Right!
Now we reassemble the machine and calibrate as we go! The Z-Axis is now finished. I am using a stepper with a dual shaft. Using a light weight knob on the motor will allow me to accuratelly set the cutting tool above the PCB.
The Y-Axis is now assembled and calibrated. Note to self!!! Don't work on an axis when it is bolted to a board. Talk about a hop in the ass! I made a Delrin drive nut. Very well made but there was no place to make an adjustment. I had to use my Delrin mounted on a piece of aluminum angle. The Z-Axis uses a floating Leadscrew. You need to have places to dial in the alignment!!!
The X-Axis is now assembled and calibrated. Can you make a CNC machine out of Trim Channel? The answer is Yes! I would do this only if you need a different size than the Brute or you can not locate the storefront window channel. This design went from drawing board to reality smoothly. There was only one big problem! Me! My old eyes and shaky hands!
Email: John a quick question
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