Thinking about cnc

[stephenc]

Hi guys & gals

I've been gone awhile , had some health issues And then some other issues .
But it's all good now .
I haven't done much out in the shop for the last year or so because of that And I've been thinking about going in a new direction .
I think a small cnc mill is that direction .

I've given this a lot of thought , I know I want to work with steel . So the micro machines like sherline and taig aren't a good choice .
I've given work envelope a whole lot of thought , the work envelope on my little grizzly g0704 more then suits my needs .
So that made me give a lot of thought to converting it to cnc .

I don't know much of anything about converting a machine to cnc , I also know a whole lot of nothing about electronic's in general . So that left me with looking at the ready made kits .
And that brought me to the finance side of thinking about going to cnc .

So I do already have the mill , that's saves cash out of pocket .
But it still has to be considered , if I've added up everything correctly it's going to cost roughly $4500 at a minimum to do the conversion and expect decent results . Costs could also run quite a bit higher to the $6000 range .
And yes I do know that it's possible to convert it for much less . But I have to work within my own ignorance.
So I spend 6 months doing the conversion and say I spend $4500 and everything works .
What do I have ? A converted mill with no support other then myself .
And I no longer have my little manual mill to use .

So I started looking at tormach , Mainly the pncnc 440
The work envelope suits my needs , and the price isn't to horrible .
I can get into a ready to use machine for about $8000
It also gives me a machine ready to use out of the box along with the initial warrenty
And very good customer support , And a whole bunch of user support .

So am I thinking wrongly here that even though it's a lot more money up front , it's still a better way to go ?
Is there some other way I should think about going ?

I know a lot of you are going to say , just get a used vmc for the money , I have a whole plethora of reasons not to , but the main reason is room .
I don't have it , my ceiling is only 7'10" my door is only 7' And floor space is limited .
I'll also get a lot of get a Bridgeport clone cnc . .. I have a long laundry list of why I don't want one of those to . I'll go into it further if you ask .

Any input ?

[RMinMN]

What is the purpose of going to CNC for you? Multiple runs of the same design? Ability to make complicated cuts that are difficult to impossible to achieve by hand? Just curiosity about CNC and how it works?

For me it is more of a curiosity about how it works and lack of hand-eye coordination that limit me to milling in straight lines. Any curve and I make a mess. Since I don't expect production runs and don't anticipate big items, I've been working on making a Harbor Freight mini-mill into CNC. Recognizing that it has severed limitations, I still forge ahead because for me the process of setting it up is one of the goals. For the controller, I use a Raspberry Pi single board computer with no moving parts. This limits how chips can destroy it. Being so small I mounted mine on the wall behind the mill. The Raspberry Pi loads the CNC file in bCNC or Universal Gcode Sender (I've loaded both so I can compare) and sends it to an Arduino Uno with a CNC hat that has the motor controller/drivers. This also, being so small, can be mounted above the mill to keep it out of the chips. Big factors in going this route is the motor current is limited which in turn limits the torque and speed of the motors, the speed limits of the Raspberry Pi, and my ability to put it all together. There will be some serious learning needed and while some of the info is freely available, other parts are completely missing. Try finding the necessary motor size needed. That seems to be just a guess on my part.

[stephenc]

Oh man , there are so many reasons I want to go cnc it's darn near impossible to say why .
The learning something new aspect is there , I like to learn and I enjoy a challenge .
Production isn't a goal , strictly hobby . But I do like the idea that I could duplicate a part simply by running the program again . ( yea I get that it's not quite that simple )

I also see all the possibilities that open up with a cnc machine , it's a whole new world versus manual machining . I dream about all the things I could make ..

Funny thing is , up until I couldn't get out in the shop to use my stuff I never had any interest in cnc , but then you spend a month or three flat on your back with nothing to do but watch you tube videos and blammo. ... you find out there's a whole new world out there you didn't know about .

But it's not something I can jump into foolishly I don't have that kind of cash to throw around . I've committed myself to selling off a fair sized portion of my firearms collection along with a machine or two to make room and pay for my notion .

[RMinMN]

"But I do like the idea that I could duplicate a part simply by running the program again . ( yea I get that it's not quite that simple ) "

Yes it is that simple. You have the part designed, you put that design through the CAM process to generate the gcode and save the gcode with a name you can remember. Next time you want that part, load up the stock on the mill, choose the file and tell it to go. The gcode file has all the information that the machine needs to recreate the part.

[whateg0]

There's a PCNC1100 at the local makerspace that a few people run. There are some shortcomings, but it sounds like most of that can be worked around. One thing somebody mentioned a few days ago when we moved it was that for the current price, a person can get a used Haas that is far more machine. I use my little Sherline mostly for plastic and some aluminum. The biggest issue I have with it is the backlash in the screws. Second is the rapids aren't very rapid. Have you thought about the GUI? IIRC, Tormach uses an iteration of LinuxCNC. Some people won't use anything other than Mach. Others won't use anything that isn't proprietary. Each has their value.

Dave

[stephenc]

I have given some thought to the controller .
The pathpilot tormach uses seems to be rather user friendly and very capeable I believe it is Linux based . And other then some minor quibbles I can't find anyone who has anything bad to say about it .
You can take a virtual tour of it on tormach's site .

I've also read a whole bunch of the used Haas versus new tormach debate .
If I ignore the little detail that even the mini mills and tm1 mills require more head room then I have available I still see a lot of negative aspects for my situation.
But I can boil that down to one aspect that scares me , potential break down costs !
If I have a problem I can't figure out , a tech is going to cost me about $1000 minimum once you figure in travel time .

Tormach on the other hand will bend over backwards to help you get your machine fixed with customer / tech support even after the warranty is over .
And this is where I feel them not being big heavy built for industry machines becomes a plus .. they are simpler machines and easier to fix .

[TRX]

Are you planning to write G-code by hand, or will you use CAD/CAM?

If you haven't used any CAD stuff, be aware that most programs are driven entirely by tiny icons differentiated only by even tinier dots of color. If you don't have perfect color vision you may wind up having to memorize "six icons to the right, one down" to do things, since actually putting any text in the menus seems to be not-a-thing.

[stephenc]

I plan on using fusion 360 , I'd like to think I have good color vision .
But worrying about icon colors is about as low on my consideration list as it can get .
That's just one of things that would have to be dealt with if it comes up .

Tormach sure knows how to put the pressure on , offering quite a economic recovery discount right now , looks to be something like $1000 .
That pays for start up tooling , or maybe a power draw bar .