View Full Version : Curious about CNC!!!!
12-27-2009, 01:50 PM
Hi guys I'm new to CNC. In fact I know very little about CNC at all. I have an ENCO 40 that I would love to convert to CNC if at all possible. I figured that I would need to ask the Pros where to start if even it's possible with an old gear driven mill??. I know a little about " G " code but not a lot. I'm fascinated with the concept of CNC or CADCAM. Just thought I would like to venture into your world. any advice would be most appreciated. Thanks Allan:D
12-27-2009, 08:40 PM
You can convert nearly any manual motion control to CNC given enough time and dedication. I can't comment on your specific mill, as I don't know what it is, but I have seen everything to the little harbor freight x2's to full size knee mills converted from manual to CNC.
IMO, and the road I took, find a old NC or CNC machine with defunct controls and convert it. You start with a better suited machine. For instance, my Bridgepot series 2 has boxed ways and ball screws straight from the factory. The boxed ways are far more rigid than dovetail ways and ball screws are in most cases far superior to ACME lead screws for minimizing lost motion and positional accuracy. You can convert a ACME screw machine to ball screws, but the cost is up there a ways. Z axis drive on a machine that was originally manual can be a bit of a cluster f-ck as well. There is no reason you can not convert to CNC with all the original screws and design, but be aware that it may not be as accurate or precise as you would like.
12-27-2009, 11:12 PM
Fascination is a good start, unfortunately, from experience, I can tell you two things,
1) It is generally short lived, turns into a desire or just dies.
2) That it rarely get's complected projects completed. and CNCing a manual anything is, make no mistake about it, is, a serious and time consuming endevor. If you have a tendency to start projects and not complete them, well, likely you will end up with a mill that is not only non-cnc'd but also unusable. (Ask me how I know :)
Still have a unfinished lathe that is pretty much mechanically complete, however, the electronics just have my brain short circuited in spite of reading reams of information, consequently, I have a lot of money invested in quality parts that just sit there.
If you have the funds, space, Jasons suggestion is a wise one as you will still have a mill that you can use for machining other things or needed items for the conversion.
Not trying to discourage you at all, many have done this and enjoyed their experience and finished product, but it is a daunting project by any means, also, one very daunting project if you have no one to fall back on for help when you need it and you will.
The CNCzone is a great source of this very type of conversion, an almost endless resource of advice, help or information, for me, almost too much.
As far as CNC goes, I can confidently say that you undoubtedly will love it, still, there is a steep learning curve for nearly everyone that uses it beyond simple tasks.
If you enjoy challenges, don't give up easily, have the resources, including time, then yes, go for it.
I have a factory CNC mill that was purchased some years back, when all I knew was what CNC/CAD/CAM were the abbreviations for, so I know what you have in store for you with regard to learning that, not too mention the necessary learning required to build or convert a manual mill to CNC.
It can be done for sure, but it is an awesome task, and I take my hat off to those that have done it.
We need more of those conversions here on HSM, I hope you decide to start it.
12-28-2009, 11:24 PM
Jason didn't mention that a machine already set up for CNC will also have automatic lube, limit switches, and very likely Turcite on the sliding ways to help deal with the higher speeds/greater amount of movement/time that a CNC machine will see. The rest of the machine is likely to be much beefier than a manual machine because the control can keep it running at higher speeds with greater force involved.
An existing CNC machine will also probably have motors, motor mounts and high-power transformers and power supplies already in place. In many cases it is actually more expensive to convert a manual machine to CNC than to resurrect a CNC with a dead control, and the manual machine will still lack features the CNC was designed with.
12-28-2009, 11:50 PM
Yes, I'm sure I left out lots of important stuff.
In my case, I spent $500 on the mill found tarped in a field for the last 5 years. The mill came with a factory optional 4th axis (12" rotab) and when I first got power to it, the controls actually lit up, but I couldn't get it working. It cleaned up beautifully, and all the ways are in good shape with the chrome still in tact, so no serious rust damage.
I went on to spend ~$1500 more fitting it with new drives, a PC and VFD. I built my own power supply for the steppers from parts and pieces from the old controls. I rebuilt the varispeed drive to be fixed speed 1:1 as most of the varispeed stuff was shelled. The VFD takes care of speed changes.
Anyhow, I probably spent less on the whole project than a CNC mini mill costs off the shelf, and I have a much more versatile machine. The S2 has no provision for manual control, so I still have my little Gorton knee mill for manual jobs, but I find myself using the CNC the most.
For what it is worth, the size may be way outside the realm of most home shops, but you can find the old NC and CNC b'ports with dead boss controls for quite cheap if you dig. I have seen a few come up since I did mine for the same money or less. From what I understand, the boss controls were always plagued with problems, and a lot of these machines never saw a lot of use, even in their prime. Mine was built in 1982, and it was in excellent shape with the exception of the controls and the head.
01-02-2010, 01:44 AM
Agree with the fellow that said it is a big job. I have a Servo 3000 CNC mill which works great and decided I would reto my TOS lathe with their lathe conversion kit. Even with the kit its a lot of work and I have basically managed to take a almost new functional lathe and make it non functional. Reason being the time it takes to do the mods etc.... Plus the airplane project is taking priority.
01-04-2010, 11:32 PM
Like most things, it is possible to throw money at the problem to make it easier.
Pick a machine that has had a lot of CNC conversions. The Emco is probably not in that category, at least I don't come across it much. A Sieg X2 is very much in that category.
Figure out your forte. Some are great mechanically, but struggle with the electronics. Some it is the reverse. For a chosen few, both are easy!
If you are not in that last camp, buy the kit that corresponds to you weakness. If you wield a soldering iron like most people would a pen and think nothing of tracking down a problem with a multimeter or even an oscilloscope (heck if you even own and know how to use an o-scope), build the electronics. It's just a matter of wiring up building blocks available off the shelf. Try to avoid the bleeding edge: buy the stuff a lot of others are using.
If you are not naturally e-lec-tron-ic, look for something more finished. For example, a Gecko G540 and a store-bought power supply.
Likewise on the CNC mechanicals. Look for a complete mechanicals-only kit.
In the end of the day, if you buy both finished electronics and a mechanicals kit, it's no harder than putting power feeds on three axes and adding a DRO.
01-09-2010, 04:50 PM
Buying an old CNC machine with the intention of fixing it up is just like buying an old manual machine with the intention of fixing it up, only there's about four times as many ways to lose your shirt. The surest things are the mills where the electronics are completely shot. Assuming the mechanicals are still sound, these can go for short money. You will need a moderate degree of tools, money, and experience, and a lot of persistence, to bring these back to life, but the bang-for-buck can be high.
Conversely, you can now buy turnkey mills for anywhere from $2000 (Taig) to $10000 (Tormach delivered and minimally equipped). Nearly all are serviceable within reasonable limits.
By a similar token, a benchtop mini-mill conversion can run you anywhere from $1000 to $2000 depending on whether you fit ball screws, how many parts you make vs buy, etc. Having done this a couple times, I would feel a lot more confident about, say, gutting the controls on a Bridgeport Boss and replacing it with Gecko drives and Mach 3.
Still, if I was doing it all over again, and I had a few thousand to spend and was primarily interested in CNC, I'd get a Taig and some basic CAD-CAM software and start there. If you find you enjoy making small parts but need to make bigger ones, you'll be able to sell the Taig for most of what you put into it without much trouble. And if you don't enjoy it--and I suspect many people finish their CNC bench mills and discover that the CAD/CAM side is a lot less fun than it looked--you'll still be able to sell it easily.
02-09-2010, 12:24 AM
I recomend you buy a mill that is already CNC and has a bad controller. Often CNC mills have auto lubrication systems so the iron is often good while the controller is dead.
A Bridgeport Series I is a great candidate for a retrofit. Steppers, ballscrews are already there. Mine sits in my garage with her car on one side and my truck on the other.
It took me one week working evenings and weekends to convert this old
BOSS 4 to a PC retrofit. I used Gecko driver boards, a WIN 98 Compaq laptop and Turbocnc. Had it four years now and I just love the thing. $2500 invested
A few people said the laptop would not hold up and neither would the Gecko drivers. I have had no problems with the laptop or the Gecko drivers. Only problem I had was the spindle belt broke. Probably 35 years old.