Viesturs, Motors: Take them off and clean out. then feed the motor with 24V 2amp transformer through a bridge rectifier to see how it runs Monitor the current with oscilloscoop (0.1ohm resistor) to see there are no funnies in the winding. monitor the tacho with O. to see there are no broken segments in the commutator.
While the motor is off check that the ballscrews/slides are in good nick. ROUGHNESS is DIRT in the nut. Clean out. Check backlash, for a cheap customer fill the space between the 2 halves of the nut to take up the backlash, and adjust the thrust-bearings or replace.. For good customer tell him to buy new. Check slide lubrication -- very important-- For gearbox you basically translate the digital codes that represent 0 - full speed into 2 or 3 ranges of 0 - fullspeed with gear info. In the old days we used an eprom for that but I seem to think it has something on the HAL layer for that in EMC. You basically pulse the gear until it snaps into place, when it does not want to go because it is standing on teeths edge you must pulse the spindle motor with a reasonable low voltage from the drive (or from a transformer if it is an AC mains spindlemotor). Toolchanger: check what was there. Basically there are 2 methods, the simple one, which I recommend if you have never done one, is the toolchange command presents a toolchanger SOCKET to the spindle on M6, regardless of the tool in the socket. So its the operators responsebility to have the right tool in the right socket. The nasty way is to have a table in the computer that remembers which tool is in what socket and the right tool is always presented to the spindle on M6, no matter in which socket it is. And the tool taken out of the spindle gets dumped in whatever socket is near, because the table remembers anyway. I found this way rather involved when there is a computer-failure and the table is confused. You normally get to take all the tools out of the tc and set the whole thing up from scratch. j. On Thu, Jul 28, 2011 at 6:19 PM, Viesturs Lācis <viesturs.la...@gmail.com>wrote: > 2011/7/28 Dave <e...@dc9.tzo.com>: > > If it still runs, study the machine with the help of the operator if > > possible. Operators are oftentimes a great source of information. Plus > > if you get along with them well, > > they will tend to help you out if they know that you want to help them > > out. Oftentimes they will reveal quirks in the machine that you will need > > to accommodate with the new system. > > I am not sure if it is possible to run the machine. They say that they > were working with it and then something happened to control cabinet. > Mechanically machine is said to be fine, but I doubt that I have a > chance to test that. > But the operator is there on site and since he is the only guy to work > on their CNC machines, there is nobody else for him to talk about cnc > stuff but me, so I feel that the task of making a contact is partially > solved by default. > > > The tool changer, gearbox and spindle will probably be your biggest > > challenges. > > Yes, that is what I suspect. I am now trying to get some information, > how they are intended to be working. That toolchanger even looks > complicated, so I expect to spend some time figuring out, how that > stuff should work and then some more time actually getting it work > that way. > And then there is a spindle gearbox, which expects some signals from > CNC controller to electrical valves to change the gears, so I will > also have to spend some time reading about gearchange component to > understand, if that can be used. > > > Are you tying into the existing motor/drives? > > Yes, client says that motors and drives are fine. I hope so. > BTW, what is best way to test that? Can I test it by removing motor > from machine and applying some small voltage (for example, +1.5V from > AAA battery) to input of servo drive? > > I suspect that I will spend some time, figuring out, how to tune > feedback loop in those drives - they are analog drives with +/- 10V > input from cnc controller and there are tachogenerators on motors to > provide feedback to servo drives and resolvers to provide feedback to > cnc controller. I have no idea, how they are meant to be tuned. > > > Make sure you are clear on what they want and expect before you start > > taking it apart. Misunderstandings can be expensive. > > Do You mean - what do drives want in terms of input signal from CNC > controller and motors and what type of mode - velocity mode or torque > mode do they operate? Or do You mean what does client want? The first > one definitely is easier to handle :)) > > > If you don't have a detailed agreement, write one up and have them sign > > it before any work starts. > > Thanks, actually I have had my lesson on working without a contract > and outlined technical details and have experienced those > "we-never-told-you-something-like-this" arguments. > > > Also take lots of high resolution digital pictures before any work > begins. > > Thanks, it did not come into my mind to save as much information about > initial situation as possible. > > > What brand/model of machine you are looking at? > > It is GF 21 71 S 5, produced in 1989 in USSR, pretty big machine. > > Viesturs > > > ------------------------------------------------------------------------------ > Got Input? Slashdot Needs You. > Take our quick survey online. Come on, we don't ask for help often. > Plus, you'll get a chance to win $100 to spend on ThinkGeek. > http://p.sf.net/sfu/slashdot-survey > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ Got Input? Slashdot Needs You. Take our quick survey online. Come on, we don't ask for help often. Plus, you'll get a chance to win $100 to spend on ThinkGeek. http://p.sf.net/sfu/slashdot-survey _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
