I have a Dyna-Mite2200 CNC mini mill. This machine had 6 air pencils(dentist drills) mounted in place of the usual Servo drill press head. It was used to drill a series of holes from .007 to .012" in little shock tubes held on a fixture on the table. This one job is the only job this machine has ever run. Only ever used the Y and Z travels. Not that it matters, the cast iron in this thing is HARD. The table and the ways are ground and extreamly smooth. I took off the air pencils and am thinking of mounting a Clausing 85** head that I have kicking around. That would be neat! I could use one of my 90vdc motors (size of a truck starter) and power supply, mount the motor sticking up like a BP! It looks like I could also move the column in twards the table by re-drilling the base. This would loose some throat but shorten things up, and help ridgidity. Oh yea, the problem, and question to you all, is two of the motor driver boards (mounted on the motors) are messed up. I got a quote for almost $600 for each. That was two years ago. Not gunna do it. I was not sure of the protocall this mill used, but I see from reascearch that you need +5v, pulse, direction, and ground. I am thinking something like a Geko drive might be usable. The motors on the mill look like 8pole (wierd, I know) steppers. Anyone know what protocall this thing uses. Maby I should give up the stock computer and try one of these PC driven software programs. Basicly, the point is, I want to get started in CNC machines. I thought this dyna might provide some practical experience in the learning process. I have a ton on motors and drives, not sure how all this stuff works, but I want to learn how to make something cool out of all this stuff. I have stepper amps, DC brush servo amps, AC brushless servo amps, and some moton controllers. I eventually want to cnc the Bridgeport that I have. Question about that, Most DC servo type mills have rotary encoders on the motors. Would not a linear encoder, like a DRO, be more accurate? (as no lash to compensare for, gearing, ballscrew,etc.) I know AC brushless servos have resolvers for commutation, do they also typicaly also give position feedback? I do see why (speed) steppers are for smaller applications. It seems the Geko drives will accept stepper input pulses and run a DC servo. I think this will be the way to go with my BP. If servo systems can use linear encoders, can a DRO encoder be used to input to the controller? If so, I have Mititoyo DROs mounted on my machines. I also have a Digamatic protocall to serial port connection uploader box. Perhaps this could make the scales readable by the controller? By controller, I am leaning twards a PC base system. There are a few out there, not sure what is good. Some are $800-900 and some are free or only like $100. Thats cool. Sorry for the scattered format of my questions, just that I have a few ways I want to jump in to this CNC thing, I just don't know where to start. Thanks- --Doozer
- posted
20 years ago