[searcue]

Hi, I've been reading, and lurking within the forum for a few month's, and I'm impressed with many people in this forum with their knowledge, and willingness to share. Thank you. Because of this I feel the smartest thing I can do is ask for advice here.
I currently own, and used a home built mill style machine with an ah-ha 4 axis controller. The travel I have, and need is Y - 30" X - 10" Z - 5," and a rotary 4th axis. I'm interested in building, or buying a high resolution controller.
I have very little knowledge of controllers, software, and motors. I'm willing to, and want to learn, what ever it takes. I also do have a friend who can help with putting the components together. He's put a few together.
Finally my question, if you wanted to build your own, have built, or buy a plug a play controller, motors, and software, I would greatly appreciate learning what products you would go with. There are so many different company's, products, as well as types, that it's very confusing to a newbe to make these choices.
I'm wanting this machine to hold tolerances within .0002/3" The controller and software needs to be able to perform 4th axis (rotary/degrees) wrap type parts, as well as engraving. I guess it might need to be capable of four axis simultaneous movement to do this. Most of the machining I do is very small in size, and holding tolerance is most important, more than speed. Most machining I do is 20 ipm or less. I'm not in a hurry, only quality first. I will be building the mechanical part of the machine myself, and will be very sturdy, but the motors will never be put through high load. The "x" will have the most weight on it, and don't believe it will exceed a 100lbs.
I do have a budget, but don't want to fall short, I will spend as needed.
Thank you in advance for anyone's recommendations, on parts, or person to contact.

Dennis

[NC Cams]

We went thru abject misery and LOTS of money to get our nearly pristine Bridgeport mill to hold tolerance in X & Y in the realm of what you're looking for (0.0002 or 0.0003) and can barely do it. IT take time, money and patience and a lot of wisdom with regard to machine tool building to tune-up a production machine to meet such tolerances.

Plan on using ONLY the finest in ground ball screws - I'd call HIWIN. Similarly, use ONLY super precise ball screw bearings (true ball screw bearings of P4/Class 7). These will cost nearly $850/bearing set for 20TAC47's for a Bridgeport and you'll need a set for each the X & Y axis.

Don't even hope on holding 2-3 tenths consistently with used/worn gibs. Unless you get a lazer mapped table, end to end accuracy will hardly be tenths capable, even on a new machine. If you can't map the screw/table motion, forget holding tenths over the whole table.

Stepper resolution may or may not hold tenths - it all depends on gearing and/or microstep potential of motor. Might want to consider servos as these support analog motion better - the high end CNC's we use for our stuff that needs tenths accuracy uses very good servos. This can subsequently rule out Mach type controllers as they don't support servo feedback to the PC.

Hence, I'd plan on building a servo based machine and if so, plan on spending LOTS of money. Or, reassess your needs and adjust them according to the realities of your budget.

To hold tenths, you might be better off with a jig grinder. In such cases, a continuous path Moore should easily hold tenths but it won't mill very well. Nothing that more cubic money won't solve....