Chris G0704 Build

Chris,

I find this build and some of the others, very interesting, I see CNC equipment on a daily basis, but have no concept of what it take to make a part. I work with computers, in my business, on a constant basis, We have a locked core of safety procedures and protocols, we can alter some of the operating parameters, the fuels being used and set the combustion fuel/air curves, but the locked core can not be altered. When I first started in this business, I need a VOM, a couple screwdrivers, a few wrenches and sockets and a number of pipe wrenches, now I still have all of them equipment, plus welders, plasma cutters, pipe threaders and now 3 laptops and an iPad.

I basically grew up in my grandfather’s machine shop, where everything was 100% manual, the equipment in my shop ranges in age from 1930s to current, but all of it is still manual. I understand the premise of CNC, but wonder if its a one off, its it quicker/easier to do it manually or spend the time to program it, then wait for the program to run, then if errors, rework. If your doing 150 parts, its another story, so is CNC, based on the scale of the job?? Is it the sense of accomplishment?? Mind over electron??

It looks to me that people buy an inexpensive (relative term) bench mill, then spend 3-4 times what they bought the mill for to convert it to CNC. Maybe my view is somewhat askew to the actual premise or goal of the CNC operator. Spoken by a man who has at least 15 welders (still looking for the perfect one).

All of my questioning aside, the workmanship, design and execution is amazing. The idea of “throwing” a bunch of numbers into a machine, that then carves a part is, truly amazing. Maybe if I understood it better.
 
To me CNC is a game changer even for one-offs. Naturally depends on the one-off. Make a bracket from a piece of angle and drill 6 holes, do it manually. I made a clamp to fit my G0709 lathe's tail stock ram for a DRO. Manually machined it on a mill with a rotary table. It came out nice and works great. But I'd have done the job in a third the time with my Tormach.

CNC doesn't have the "charm" of old-school craftsmanship, no question. Our tool makers at the GM Lansing Grand River Assembly Plant tool room all completed an apprentice program of 8000 hours of various disciplines. They're all over 55, so little to no CNC in that training. Our local community college is spitting out "CNC Machinists" by the dozen with a less than 1 year program. They take one class in manual machining using a lathe and mill.

Strip out an M6 thread and need to fix it? Go to a young "CNC Machinist" and they'll tell you you're screwed (pun intended). Go to one of the old-timers, they'll probably tell you to drill and tap it for a 1/4"-20.

I admit to still being fascinated by watching the stepper motors do exactly what I told them. A couple of weeks ago I cut some helical gears on the Tormach using the 4th axis tipped at a 45. Coordinated moves in the X, Z and A axis that could never be done manually. The CNC just opens up the possibilities to what you can imagine and turn it into a part in minutes.

Bruce
 
Bruce,

Thanks for the reply.

Are you programming from start every time?? Or are you modifying an existing program?? Are there “canned” programs, that allow to insert certain segments?? And you program from segment to segment?? How intuitive is the CNC software??, can you import a drawing and have the machine “read” the drawing and duplicate it?? Or is it line after line of G code, you have to input??

Sorry for all the questions, I find the subject incredibly interesting, personally its not something I’d probably ever do, but every I see it, I have more questions.
 
I model everything in Fusion 360 first, then make the CAM files, and then run them on the machine. There's no way I could do it most of it on a manual mill. I probably put 3-4 hours into the design, and 1-2 hours on the CAM, but then those plates took about 5 minutes each on the mill.

On the CAM side there are routines built into Fusion that will do pockets, follow a contour, etc.
 
On the tap, I only needed another 1/2" of thread. I looked for a tap but nobody has one locally. I decided to chuck the tap in the lathe and grind the shank down with a cut off wheel in my Dremel tool. Afterward I realized that the tap is just HSS and I have some good inserts for hard metals. I cleaned up the ground area by taking light cuts at 190 rpm.
 
On the tap, I only needed another 1/2" of thread. I looked for a tap but nobody has one locally. I decided to chuck the tap in the lathe and grind the shank down with a cut off wheel in my Dremel tool. Afterward I realized that the tap is just HSS and I have some good inserts for hard metals. I cleaned up the ground area by taking light cuts at 190 rpm.

Glad you got it
 
Here's a picture of the entire assembly. I downloaded a step file for the motor from Automation Direct. Everything else I drew from measurements.


AC Motor Mount.jpg
 
Bruce,

Thanks for the reply.

Are you programming from start every time?? Or are you modifying an existing program?? Are there “canned” programs, that allow to insert certain segments?? And you program from segment to segment?? How intuitive is the CNC software??, can you import a drawing and have the machine “read” the drawing and duplicate it?? Or is it line after line of G code, you have to input??

Sorry for all the questions, I find the subject incredibly interesting, personally its not something I’d probably ever do, but every I see it, I have more questions.
I'll shoot you a PM so I don't mess with Chris' thread
 
Good news, good news, bad news...

The first good news is that I machined a bunch of parts yesterday morning and the mill is much more satisfying to run now that I've cranked up the metal removal rates.

The other good news is that the new spindle and gibbs showed up a couple weeks ago. I finally got around to installing the new spindle yesterday. It seems to have a bit better runout. I measured it at .0015" TIR roughly 1.25" from the end of the spindle with a 1/4" carbide shank in an R-8 end mill holder.

The bad news is that the ABEC 5 bearings that I installed in May are shot. The lower has a click and the upper feels like it's full of sand. :^( I ordered two sets of the cheap AC bearings from VXB that I had originally used. They should be here by the middle of the week.
 
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