A Small CNC Mill - A Huge Education

P.S. I spent about a year off and on originally developing that mold. I learned a LOT from making it, and it was originally made just for my own use.
 
OK. Set your clocks back to 2003. I was one of those guys who always kept saying "one of these days" I wanted to get a lathe and into metal working. My wife solved that for me and gifted me a Sherline 4400 micro lathe for Christmas. I had never actually touched any machine tools at all at that point, so to say I didn't know jack is an understatement. After playing with that lathe for 6 months, learning how to make some chips, and reading the Yahoo Sherline group regularly, an ad appeared for a CNC Sherline mill surplussed from a school system across the state in Tampa. After a 350 mile round trip drive, and handing the guy $300, I moved a CNC Sherline mill into my garage. The only problem was that nothing about it worked, except that the spindle motor turned. Like my lathe on its first day, this was the first time I had ever touched a milling machine.

The CNC Sherline was a Paxton Patterson CNC Training Center used in the VoTech programs there. It was in a cabinet with the electronics inside the box. From the outside, I could see that Mr. Cutter had been introduced to Mr. Table a few times, and it had a lot of machinable wax residue on it. I quickly found the major problem, though, and maybe why it was sold as surplus. The interface looked like a printer port but it wasn't. It only plugged into a special matching card made by the people who made the controller electronics. When a standard printer port was hooked up to the port, it blew a fuse on the power supply, and that's the way I got it. Once I figured that out, and wired a special connector, I found that two out of three axes didn't work. The Y-axis wasn't moving right and Z didn't move at all. The motor mounts on X were pretty barfed up, too. I had found the old DOS program TurboCNC and used that to issue commands to move the mill around.

The next several months were spent learning how CNC worked. Fixing electronics is my "home field", but I didn't have documentation on that motor controller. The motor mounts were threaded 1/2" aluminum bar, and I could make those. I eventually got it working, but I had to replace the controller with a Xylotex 3-axis board. A new Sherline CNC mill was close to $2000, and I only put another $200 into it to get it working right, so I had a CNC mill for $500. By this time, it was looking like this.

CNC-mill.jpg

As the years went by, I expanded its capability. You can see that I added a fourth axis (rotary) pretty early on (upper left on the angle bracket), and then upgraded the basic machine with the A2ZCNC extended X/Y axes and a longer (15") Sherline Z axis. The stepper motors were upgraded in torque substantially, from 75 in-oz to almost 400. It no longer fit in the little red box, so I built a plywood enclosure for it, to contain chips somewhat. The current mill looks like this:

MillingEnc.JPG

In 2008, I decided to build a CNC lathe. I bought the Sherline CNC-ready lathe, added motors, controllers, made cables; did all that stuff. I had gotten used to using the manual lathe by just walking up to it, chucking up a piece of work and doing what I needed to do. I told my wife that I'd leave both lathes on the bench for a while and whichever got used more would be the one we keep. We ended up keeping both. I wanted to use the CNC lathe to thread and that was a bit difficult, but it eventually did. I hardly used the CNC lathe once I got it to thread. I do virtually everything on the manual lathe. (I've got to admit, though, power feed is a pretty nice thing to have.) I have some pens I want to make, and the CNC lathe power feed will be handy for that.

My mill has always been CNC. I've never used it in a fully manual mode like I have the lathe. CNC is fantastic for never losing count of where it is, although it sure can get lost if the motor drops steps. It never loses concentration and goes too far. CNC has two main uses: first, running many copies of the same part, rather than one part made one time, and second, it's absolutely indispensable for really complex shapes even if it's just one thing. CNC mills have become the standard way the jewelry industry carves waxes to cast in the lost wax casting process and that was my original interest. I carved a lot of waxes with it, but never cast any.

I quickly found that some of the waxes I wanted to carve would take hundreds of thousands of lines of code. They choked TurboCNC and that's when I found Mach3. Been using Mach3 since '07. Today, I have a Warp9 Ethernet Smooth Stepper connected to the G0704, Sherline Mill and Sherline Lathe. I haven't run any Gcode files that long since '08 or '09, though.

I built all the parts for my G0704 conversion on the Sherline, including milling the oil grooves in the cast iron table. I think that 10 pound chunk of metal was too big for it, because right after that it started losing steps and I had to rebuild the X-axis leadscrew mount. I've built a ton of little metal odds and ends on the Sherline and have more accessories for it than the big 0704. Still, though, it's a good little mill when you stay in its envelope.
 
P.S. I spent about a year off and on originally developing that mold. I learned a LOT from making it, and it was originally made just for my own use.

It's a cool looking little shad mold. I could see using that in the saltwater lagoon here for trout or snook.
 
...and expecting validation of my prowess as a machinist. LOL.
isn't that what the internet if for? :applause 2:

I'll also get in on this bandwagon....I also started out with a Taig 2019ER originally just to learn, but ended up manufacturing a dual headlight kit for 2nd generation RX7s ('86-'89) which more than paid for the mill. I had caught the bug. I ended up selling the Taig to a friend (who still has it) and my cnc arsenal now includes a converted PM45 mill, a converted 8X14 lathe, a little shapoko based wood router (18" x 24" work area), and I'm currently building a 4'x4' plasma table. Oh...and a Denford (sherline) learners mill which now runs on mach3

can't stop...won't stop!

But to affirm pretty much everything you said, the Taig was the perfect learners mill. Any mistakes made weren't too bad, and really helped my programming game. Sometimes you have to get a bit creative working with small machines like this. And also, it's a pretty bad-ass little machine. I filled my base and column with epoxy granite and upgraded the spindle to a 2hp treadmill motor. I'm still impressed with the performance I got out of it.
 
Great stories guys. My wife actually gave me the bug when she gave me a Harbor Freight 7x10 for Christmas 2005.
 
Awesome stories. And here I thought that I was just too dumb to figure this stuff out. Turns out I may not be if you guys can do it. LOL. Just kidding. I am just thinking about taking the plunge into CNC with a Precision Matthews mill of some sort.
 
Awesome stories. And here I thought that I was just too dumb to figure this stuff out. Turns out I may not be if you guys can do it. LOL. Just kidding. I am just thinking about taking the plunge into CNC with a Precision Matthews mill of some sort.
I almost pulled the trigger on a PM835, but hesitated. Now I'm in the same boat as you, but leaning toward a Tormach. I like the UI--seems pretty intuitive, and usable without learning CAD/CAM. Definitely a premium over alternative hobby solutions, though. Watching for alternatives.
 
I almost pulled the trigger on a PM835, but hesitated. Now I'm in the same boat as you, but leaning toward a Tormach. I like the UI--seems pretty intuitive, and usable without learning CAD/CAM. Definitely a premium over alternative hobby solutions, though. Watching for alternatives.

Tormach is a pretty stable platform. I've only read one really negative experience, and in the end Tormach bought the machine back from that guy. Currently their PathPilot controller is a customized LinuxCNC based system. In the past Tormach offered a Mach3 configured machine.

I would very much be a player for a Tormach PCNC770 or an 1100 with a high speed spindle upgrade if the acceleration was faster. I do a lot of complex short move 3D machining and even at 25-30iss (my current machine acceleration rates) they often do not make it up to full speed. Tormach machines per Tormach are set at 15iss on all axis'. For regular machining where long linear moves are the norm those machines have a great reputation for being work horses within their power limitations.
 
Great story! Love your attitude and willingness to get to the other side and not give up. Just shows that it is all about attitude and glad to see it has paid off for you. Thanks for posting this!
 
I quickly found that some of the waxes I wanted to carve would take hundreds of thousands of lines of code. They choked TurboCNC and that's when I found Mach3. Been using Mach3 since '07. Today, I have a Warp9 Ethernet Smooth Stepper connected to the G0704, Sherline Mill and Sherline Lathe. I haven't run any Gcode files that long since '08 or '09, though.

I also have a sherline mill and lathe that I have been running with LinuxCNC but have been wanting to change over to Mach3. I have looked at the Warp9 smooth stepper board and it looks very good. Can you tell me what you are using for the motor controllers between the smooth stepper and the stepper motors on your lathe and mill? Do you use one port on the smooth stepper for each machine or do you have to swap cables?
 
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