03/20/2023
9 years ago
After I graduated, I wanted to build my own machine shop, because back in 2011 the economy was still suffering from the great financial crisis and even with 5 years of cnc experience and 3 different degrees in manufacturing. (I did two associates at the same time) the best offer I got was part time at 15 dollars an hr.
So, I found an old Bridgeport knee mill and my uncle let me set it up in his pole barn.
I gutted the whole entire thing and retrofitted it into a cnc machine. New spindle, ball screws, controller; I made my new machine held .001”, every time all day long.
My 1st project was a no-brainer, I was going to bring back and clone the Philadelphia Ordnance U*I 80% receiver. Because my senior year, I reserved engineered my sample into a 3d model and already wrote a program.
Attempt #1: I started out with a piece of wood and a standard vise and a right-angle block. What a complete nightmare. Taking a 20mm drill down 10”, was not possible.
Attempt #2: bought a very expensive right-angle attachment off of eBay and did the ends with the 6” vise. But I needed to swap out each tool and reset the offset everytime.
Attempt #3: Bought a 4th axis and 14 tool holders and wrote 2 programs to do the whole thing.
After 7 hours, of standing in front of the machine because I needed to make manual tool changes. I was mentally drained.
Attempt #4: I bought an robotic arms from a tech school and try to program in automatic tool changes. Python is completely different than G code and learned very quickly, it was not worth the energy to make it happen.
Not willing to give up and called up Philadelphia Ordnance and bought out all Bobs old fixturing and took a tour of his shop. The critical key was not having a 100,000-dollar horizontal CNC.
Finally, I realized without professional grade equipment I reached my max potential with having a DYI CNC retrofit.
Attempt #5: Went to a local machine shop with my ATF letter of compliance and a 3 ring binder of information and got an agreement for a production run. 2 weeks later, I received a phone call. I got good news and bad news. Bad news under quoted the job and cannot delivery for the agreed upon price. Good news, After listening to your story about this project and looking over all your information that you provided. If you ever need a job, you’re hired.
I ended up writing a small program for the robot arm and made myself an at home bartender. I should have kept it, but when I was offered 1000 dollars for it, I took the money.
Morale of the story: Before I commit to any project over 1000 dollars, I make myself write a cost analysis report to identify everything that could or would happen.
