Please talk me into (or out of) CNC machining

matthewsx

matthewsx

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Hi,

I currently have a small home shop with nice older/antique machines, lathe, drill press, sanders, grinders, etc. - no mill at this time although I miss my old Gorton 1-22.

My space is very limited so I'm torn between finding a small manual mill and learning CNC with a small hobby machine. Of course I realize the little china kits will only work with wood or plastic, but I'm assuming the skills you learn there will transfer to larger machines once I get the space/budget for something better.

I've been working around power tools my whole life though my engineer father made sure it wasn't my career. I'm currently a network admin/engineer and consider myself very competent with computers although I have limited experience in 3D cad/cam types of software. Hopefully it's gotten easier since the early days of AutoCad:).

So, I mostly just work in the shop for relaxation but you never know where life will lead you ( I used to have a power equipment business). And, as cool as learning how things were done 100-years-ago with my Seneca Falls lathe I have this feeling that I could do much cooler stuff with CNC or 3D printing. I just don't know if the learning curve will prove too steep and would rather not start out with a $10,000 machine that will end up sitting because I don't want to work that hard at it.

My gut tells me to look for a project that someone else has moved on from for the first try, something small that will fit on my basement work table.

I know some of you have been where I am and probably have good advice, maybe even a lead on a machine that would be suitable.

Cheers,

John
 
It is a common misconception that the mini-machines cannot work metals, they can they just have to take smaller bites than big machines. I am not doing any CNC so can't help you much there, but there do seem to be some machines better suited to conversions than others.


They may be too small for your needs, but Sherline offers CNC ready versions of their mini-mills and lathes. The way they are set up it is also possible to configure them to allow both manual and CNC work as desired.

They also offer complete CNC packages (mill and lathe) ready for use. The entire package would fit on a good size dining room table.

CNC Systems – Sherline Products

www.sherline.com www.sherline.com
 
You should be able to learn the CNC basics on any machine. You will not gain as much knowledge as quickly from an already built and configured Chinese machine compared to building something yourself. I would suggest starting out with parts or a kit from one of the online retailers that sells parts and kits. If you get a small manual mill, along with the lathe you can make many of the parts you need yourself (stepper mounts, bearing mounts etc). The machines themselves aren't that complicated and buying the components and electronics and assembling/wiring things yourself will help tremendously when troubleshooting issues when they occur (and they will). I built a couple CNC routers many years ago, but when I got my first mill I elected to get a small manual mill in a model that others had already converted to CNC (From LMS). It was small but handled steel and aluminum very well for small projects. That allowed me to first learn to operate the mill and make the mounts, bearing blocks etc and manually convert the mill to CNC myself. I later sold it and moved to a larger mill which I also converted to CNC. Since you are already a computer and software guy, that will help a lot because learning the Driver, CAD and Cam software can be one of the hardest obstacles for some. I really enjoy and prefer CNC vs manual and the building is half the fun for me, so it depends on your desires. Learning the CNC side of machining will provide options and results that are hard if not impossible to duplicate with a manual machine. I have the bug and now have a CNC plasma table , CNC router table, CNC mill, CNC laser and a 3d printer which I suppose you could consider a CNC machine. If CNC machines interest you, go for it! If the building side of things really don't interest you get a small mill that is already CNC or a model that is CNC ready and the manufacturer or other source sells an upgrade/kit.
 
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I have a CNC mill and have found it a great way to expand my shop capabilities. I chose to convert a manual machine and would share that it is a large undertaking. If you love building machines like me, then the build is 90% of the fun, but buying a premade one would certainly get you going quicker. I have found that self building the right way doesn't save you a whole ton of money over a comparable machine. Conversion kits are a good middle ground that take a manual machine to a CNC with no more labor than wrenches and screwdrivers.

My machine is a G0704 from grizzly (about 350lbs) and does extremely well in aluminum (works best up to 3/8" cutters) and is very capable in mild steel (up to 1/4" tooling). Any larger tooling or harder materials can be cut with great success, but require a little more patience. As said above a small machine can do most anything a large machine can, just slower and smaller.

Think about what kind of work you want to do. Sheets of soft materials like plastics, wood, and aluminum are best done on a router type machine, but the extra size of the workpiece often equates to poor accuracy and rigidity (there are plenty of exceptions). If you want to do smaller, more accurate work, and harder materials, a bed mill like the G0704 is more the style of machine (at the expense of a small work area).

Feel free to ask any specific questions, I love the hobby.
 
To get the full benifit of a CNC machine, you need to be able to put your ideas into a CAD program and spit them out for the machine with CAM. You can do some by G coding by hand and using conversational, but that's not the meat and potatoes of CNC. I started out my CAD/CAM with Turbocad and switched to Fusion 360. It's quite full featured and relatively easy to use. It's also an integrated CAD/CAM package (with analysis, too). The best thing about it is that it's free for hobbyists and has a huge online learning support. If you just want to dip your toe into the CNC water, you could get one of the cheap Chinese routers or router kits and do some small projects in fusion to get the feel for it. From there, you can decide whether your time/money/interest curve dictates you buy a complete running CNC machine or build one. I started my CNC hobby with a Tormach PCNC1100 and I've made quite a number of parts on it and really love the machine. I picked mine up second hand and saved quite a bit of money that way. Good luck and enjoy.
 
I bought Bridgeport with a 2-axis Anilam Crusader (circa 1983) 18 months ago. I can only program the CNC via conversational, so CAD only gives me tangent/corner points for the manual programming. I'd used a manual mill/drill with hand wheels for around 7 years, then upgraded to a small knee mill, still with hand wheels. Upgraded the knee mill with a 4-axis DRO around 5 years ago; wish I'd have done the upgrade years before.

I can still work with hand wheels only which is the position I get in with my small knee mill in the middle of winter. My DRO stops working if the shop gets below 32 F. The DRO makes the work sooo much faster that I now bungie a heating pad to the DRO for winter use.

Same thing for the CNC on the BP. I've made some parts that could have been done manually, but it would have required rotary table work with multiple set ups. The CNC, even for a one-off, is sooo much faster than manually milling certain things.

Once you get a taste for CNC, you'll appreciate the purchase and won't want to go back.

Bruce
 
I have a small CNC mill (Syil X4+). It will do anything a similar sized manual machine will do and a lot more.

You can use a CNC mill as a manual just by learning a couple of commands, then the mill will act just like a manual mill with power feed. However, just like a manual mill with running power feed you do not get the feed-back to your hand. That feedback is very helpful when learning, not needed so much after you learn your mills capabilities.

In g-code mode the CNC is more capable than a manual mill. Especially in controlling 2 or more axis at the same time. Think arcs and circles and valleys and hills. But then you need to learn CAD and CAM and have access to those programs (Fusion 360 is free & what I usually use).

Right now my mill is down and I am having to make a new control cabinet. NOT what I enjoy or want to do. If I could afford it I would buy a new CNC mill but of necessity I am having to re-build the electronics I have. Just like converting a manual mill to CNC - that is great if you enjoy that sort of thing. I don't. I want to be milling not wiring. I've been dicking with this for 8 or 9 months.

So, in short, if it were me I would obtain a ready made CNC mill. If I wanted the project of building a machine I would convert a manual mill to CNC. If I just wanted to learn the basics of machining I would get a manual mill knowing that eventually I would replace or convert it to CNC.
 
matthewsx said:
I've been working around power tools my whole life though my engineer father made sure it wasn't my career. I'm currently a network admin/engineer and consider myself very competent with computers although I have limited experience in 3D cad/cam types of software.
Click to expand...

My bread&butter is still (after a few decades of it) computer work. The absolute last thing I want to do in machining is use a computer. Good thing purchasing and forum-posting don't count as machining, heh.

The same line of thinking has set me against buying a 3-D printer. If I had some product in mind to build, or was in some way trying to make money off the work I do in the shop, things would be different. Instead, I fix things that are broke, and take on projects that can be accomplished with manual machining.

So I thought I'd throw in a contrarian vote alongside Winegrower's and say don't get the CNC, in fact, buy yourself a good vise and a large collection of files :grin:
 
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