New open source, DIY desktop CNC mill

[lobocnc]

For anyone interested in a new DIY CNC milling machine, check out my recent post in the Commercial Vendor forum:
http://www.chaski.org/homemachinist/vie ... 29&t=95186

You can also find complete details at http://www.lobocnc.com.

-Jeff

[SteveHGraham]

That's pretty neat, but what kind of precision can you expect with a drill press vise and a table that isn't ground? I would think it would be wobbling up and down by a hundred thousandths or more.

[TheBoiler]

Interesting but mainly focussed on wood and plastics so I guess not so much an issue.

[lobocnc]

That's pretty neat, but what kind of precision can you expect with a drill press vise and a table that isn't ground? I would think it would be wobbling up and down by a hundred thousandths or more.

True, you certainly aren't going to have the precision of a machine with ground, hardened ways. However, if your finish cuts are slower and shallow, you can hold a couple of thousandths. (The drill press vice and unground table only actually effect the initial position of your part, not the machining.) The key point is that with a high-speed spindle operating at, say, 20,000 RPM, the cutting forces are very low, and it is much easier to keep your cuts accurate, as long as there is no play in the slides and screws.

-Jeff

[Marty_Escarcega]

That's pretty neat, but what kind of precision can you expect with a drill press vise and a table that isn't ground? I would think it would be wobbling up and down by a hundred thousandths or more.

I think the point of the project is sort of like the low end 3D Printers. Its an inexpensive way for someone interested in venturing into the foray of CNC and being able to produce something tangible with the machine, and with most of us being tinkerers, putting it together makes for a pretty neat project. Interestingly, this machine has encoders on the stepper motors, something you typically don't find. It closes the loop on the control.

I could see someone doing engraving, 3D carvings, light milling with this machine and leaning about CNC. For under $1k
If one becomes more interested in CNC, then you could move up to more sturdy machine. If not, I would imagine you could sell the machine and recoup most of your investment.

I think its a pretty neat concept. No affiliation with the seller, I just thought it a cool idea for the hobbyist.
Marty

[lobocnc]

Marty and TheBoiler have it exactly right - this is not a substitute for a Bridgegport. It's mostly for light-weight tasks in wood and plastic, and a good opportunity to get your feet wet with CNC. Marty also brings up an interesting issue with encoders on the steppers. The encoders not only improve the performance of the steppers with closed loop control, but they also give you a handy DRO capability for manual machining and setup with the motor drivers turned off.

I have another CNC mill I built which is much more conventional, with dovetail ways and ball screws, but when I started playing around with making guitars, I started using this light-weight mill more because the high speed spindle was much better suited for inlays, fret slots, and even carving the neck. It's turned out to be a pretty good compliment to my heftier benchtop machine.
Jeff

[SteveHGraham]

It might be nice to have something that doesn't have you worrying about tiny tolerances all the time.

[TheBoiler]

I am sure there is something, but what would be the price point?

[lobocnc]

I am sure there is something, but what would be the price point?

Curious question - how much is a tool worth? I tend to value a tool by how much I use it. Knowing what I know now, I'd pay $500 for my cordless drill. (Fortunately, I don't have to.) I took one of the Lobo CNC mills to the local high-school for their US First robot building contest. They use it as much as their much more expensive CNC machine. A guess it all depends on if you have enough stuff you'd use it for.
-Jeff

[SteveHGraham]

I may have been misunderstood. I was saying this mill might be a good thing to have. Sometimes you're not interested in holding a tenth; you just want to get something done.

[ng_2-4-2]

A machine like this would be good for someone that wants to teach/learn CNC programming. I would change the spindle to a Kress high speed spindle. About $230 on ebay. I have one I attach to my CNC mill to machine wood gears and parts for clocks.

[Marty_Escarcega]

A machine like this would be good for someone that wants to teach/learn CNC programming. I would change the spindle to a Kress high speed spindle. About $230 on ebay. I have one I attach to my CNC mill to machine wood gears and parts for clocks.

Very nice work!
Marty