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Need to make my own CNC machines, where to start?

Scruffy887

Titanium
Joined
Dec 17, 2012
Location
Se Ma USA
I have a need to start building my own CNC machines of maybe several types. Is there some resource where all the CNC bits get explained and hooked together as one and spelled out? No problem with the metalworking side as I have Mazak 30x65 VTCs and multiaxix lathes, and more.
Not looking for advice as to if/why. I can sort that stuff out myself. It may end up with me buying very cheap ebay/amazon components to start and possibly Siemens complete hardware packages for the final machine. Or others.
 
I have never really seen a 'one stop' resource unfortunately, because there are a *lot* of different approaches for all the different parts and which one is right really depends on what sort of tolerances you need to hold and what sort of feeds/accelerations you need to achieve... Many, many decisions to make depending on what the application is.

If you're able to prove out the idea with low cost hardware that is definitely a good thing to do! The price of all this can be pretty staggering even for 'inexpensive' gear. I have had good experiences with Geckodrive stepper drivers with LinuxCNC (w/ Mesa FPGA cards for driving stepper drivers) as the control, this was on smallish 3 axis CNC routers.

The crew over at C N C Zone . com will be pretty helpful if you're looking to homebrew something, but building machines for continuous industrial use or for sale is a bit outside of the wheelhouse of most of the crew there unfortunately. 'Motion Guru' here on PM might be a great resource for the more serious side, maybe contact him/his company?
 
What niche will these machines fill that existing ones won't?
Im not a critic, just a guy with a case of the wonders.

I'm not really criticizing either but it's nice to have more info when you're being asked for advice. Lots of
different ways of approaching something like this.

Sadly, most of these "I'm gonna build my own" stories don't end well...
 
The first thing I'd do is figure out how many interactive axis you need, depending on that answer you may be talking to Siemens a little quicker than you thought.

The second thing I'd do is try to get Motion Guru's attention, and pick his brain as much as he has time for (as Aaron mentioned).

And the might even be some local interest, like from me. I have some similar ambitions, perhaps there's a help you/help me aspect that could be mutually beneficial...
 
Perhaps look at buying a new or used CNC machine (Cheaper probably )
And then use as many as the components you can for your own machine
Perhaps changing a existing machine might do the trick

Peter
 
as I have Mazak 30x65 VTCs and multiaxix lathes, and more.

Huh? If you already have 'some' cnc machines, why do you need to build some? I mean seriously, wtf? As a learning project or...? Do you mean cnc as in computer numerically controlled, or cnc as in something to automate a process? I mean, I have built special purpose machines that did step 1-2-3-4 with the push of a button and some proc switches, but by no means cnc, just a button with some electronics (dumbed down, obviously more to it...), linear guides, air cylinders and drills...
 
Perhaps look at buying a new or used CNC machine (Cheaper probably )
And then use as many as the components you can for your own machine
Perhaps changing a existing machine might do the trick

Peter
There are "aftermarket" tool changers, turrets, etc.
For example:
Productos | Sidepalsa

better to use those than pick one off a Mazak xyz, that will not have any warranty, nor support (especially if they obsolete it shortly)
 
I have a need to start building my own CNC machines of maybe several types. Is there some resource where all the CNC bits get explained and hooked together as one and spelled out? .

I would suggest taking a look at the mycnc.com uk-based forum. There are CNC builds there of every description, from bench top size machines to multi-ton affairs. There's a lot of info to wade through...
 
There is a shop out west that adds ball screws, stepping motors and cnc control to Warner Swasey lathes and ending up with a great machine. It seems this is a good approach of improvement to existing machines.
 
Gonna need to be a little more specific than "CNC Machine" If you are trying to automate a bandsaw then amazon and Arduino are your friend, but for a machining center or turning center.....not so much. Start simple with something like a saw. I have found most of it you are better learning on your own as there is too much BS info out there cause most people doing stuff like that.....shouldn't.

Once completing a simple project like a bandsaw you will understand the system enough to know you are way better off adapting a complicated proper machine like a machining or turning center than building one.

I once made an offer on a turning center I thought had a 3T control. When the offer was refused and the seller responded that the machine was worth more because it had been retrofit with some GSK controller I then replied with a $10 offer and RAN!
 
If you give a man a fish he will eat for one day. Teach him how to fish..... I am a manufacturer, not a job shop. Some operations could be sped up quite a bit with a small CNC. I cut mostly HDPE. To the point of generating 2 gaylords of HDPE swarf per week.
There are some small CNC machines, like the one that comes with a pallet jack, that are almost big enough to work, but almost does not work.
CNC Zone may be of some use but most there are into tinker toys, but that may be where I start. My goal is a basic 3 axis router type machine with the ability to do thread milling too. Some type of tool changer will be needed, rack or umbrella.


I have equipment and experience with epoxy concrete, milling and turning, CNC press brake, 5'x 10' laser, TIG and MIG.
 
If you give a man a fish he will eat for one day. Teach him how to fish..... I am a manufacturer, not a job shop. Some operations could be sped up quite a bit with a small CNC. I cut mostly HDPE. To the point of generating 2 gaylords of HDPE swarf per week.
There are some small CNC machines, like the one that comes with a pallet jack, that are almost big enough to work, but almost does not work.
CNC Zone may be of some use but most there are into tinker toys, but that may be where I start. My goal is a basic 3 axis router type machine with the ability to do thread milling too. Some type of tool changer will be needed, rack or umbrella.


I have equipment and experience with epoxy concrete, milling and turning, CNC press brake, 5'x 10' laser, TIG and MIG.

Best advise I can give skip the whole stepper part other than for learning and playing around, and stay away from mach 3 or just about anything windows based (way to unstable). The absolute bare minimum I would consider implementing is clearpath servos. Pretty much any controller will be able to run 3 axis simultaneous to threadmill. What size work envelope are you looking for?
 
Not sure of group consensus on Centriod equipped machinery but they do seem to have quality ac or dc servo driver boards that use encoder feed back. The motor control is separate from the Windows interface. The Oak board is the AC Servo board and the All in one DC board takes care of DC servos. The Acorn board is a step/ direction board that can use servos without encoder feed back. The Acorn does however have one encoder port that would work for spindle location.


CENTROID CNC controls,CNC Controller, CNC Retrofits,CNC Milling Machines,CNC Lathes,CNC Routers,5 Axis CNC Cylinder Head Porting Machines,CNC Rotary Tables,Fanuc Retrofits,Digitizing Probes,Conversational Programming

They also have a support forum discussing all things CNC retrofitting or ground up new builds.


Centroid Community CNC Support Forum - Index page


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First, a CNC forum may be a better place to ask.

Or one of the amateur machining forums because the pros will be buying the needed machines, not making them.

Either of these places should find more people who have built their own CNC machines.

One approach to this task is to buy a machine that has the work envelop and power and other manual features that your CNC machine will need and then converting it to CNC. This conversion would probably start with replacing the Acme screws with ball screws. There are many sources of ball screws and where you look may depend on your needs and pocketbook.

After the ball screws are installed, the motors come next. The first and most basic decision here is stepper motors vs. servo motors. Steppers are probably the least expensive and most often chosen by those who make their own machine. The big drawback to steppers is the old "lost step" problem. If anything causes the stepper motor to miss a step, there is no way for the software to know this and all subsequent movements will be offset by that one, lost step. So, in effect you start a part using one zero point for your coordinates and finish it with another. The other big decision in the motors is that they need to be properly sized to your machine and the requirements of making the parts you intend to make. There is a great amount of "seat of the pants" engineering going on at this point. Actual, engineering calculations are not all that easy to make because a number of factors are involved, including but not limited to the torque needed to turn the ball screws in the heaviest cut that you will ever make. This is a very important factor in avoiding that "lost step" problem.

Servo motors are designed with feedback so that a command to go to a certain position is not complete until that axis actually reaches that position. This feedback can come from a number of sources like DROs, rotary scales on the motors/ball screws, etc. This method is not susceptible to the "lost step" problem as each move is to a specified location as determined by the feedback. The motor size is also important here as they must keep up with the software commands.

Motors require motor drivers. These are circuit boards that convert the logic level signals from the software into the Voltages needed to operate the motors. Most of the time these driver boards are a separate item, but some motors will include them.

Finally, in the logical progression, there is the CNC software that you use and the computer that is needed to run it. Although I list this as the final step in my logical progression, it is probably the first thing to think about and to decide upon. Some CNC software would not be able to drive servo motors if you choose that option. And, of course, you will want a program that is easy to use with your machine, drafting software, and the parts that you will be making.

So, as to exactly where to start, that would be getting a rough idea for all of the above. Try to choose a software program early on in the process or at least, narrow it down to two or three. And think about your budget for this. Then start looking at the prices for the various components. Perhaps spend an hour or two on the web looking at each one and their prices.
 
Why not just buy something that is already working and then design custom fixturing to increase production in the specific envelope instead of building 10 smaller, unsupported homegrown machines?
 








 
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