delta 20 locating problems

[dodgetruck23]

We have a 5 inch lucas horizontal boring mill with a dynapath delta 20 control.we are having a problem with it locating.It is a point to point machine.The way it was set up was you type in the number you would like to move and it rapid within .100 then hits a fast feed rate till it gets within .025 then goes into a creep feed to the programmed number.Sometimes it over travels and sometimes it will almost get to the number and stop but the cycle light will not go off until you hand crank it to the number programmed.We have changed the 2 clutches out that helped but still have the same problem.Just wondering if there was something I could change in the ladder so it would stop a little sooner and not over travel.Or any other ideas would be a great help.

[jagardner4]

If I understand you correctly, you have a Delta 20CU, a "clutch drive" control. These controls do not use servo drives to position axes; they use one, single speed motor that is "clutched" to the X or Y axis to drive the one that is commanded. Speed is controlled through a transmission with shifters that need to be moved to get the desired speed. The CNC control kept track of commanded position and how far away from that position the axis is. As the axis approaches the commanded end point, flags or "switch" points are turned off. As each successive switch point switches off, the axis slows until, once all points are off, the axes stops.

The distance for the final switch point is set in the Setup mode (mode 5). The other switch points are set in the parameters, which is non-volatile memory (an EPROM).

The prints for the Lucas machine always had a chart showing the shifter positions and associated solenoids and relays that corresponded to axis speeds.

I think you have one or more faulty relays or solenoids. Changing the ladder is impractical and, I think, unnecessary, if you can find the faulty relays and/or solenoids.

[dodgetruck23]

I have know idea where they would be located at.Would they be in the cabinet with the control or where the feeds are at.Its a Lucas 5 inch boring mill.

[jagardner4]

I'll confess that I've never actually seen a Lucas mill, so I don't know the physical layout. I've only ever seen the electrical prints so that I could provide support in writing the ladder program. The last clutch drive I physically worked on was a G & L retrofit.

You may want to call Lucas and see if they have any information they could share. They're on the web at Lucas Precision Machine Tool Group | Lucas Precision Natco Carlton Monarch Olofsson Fermat | Welcome or call 216-451-5588. They're located in Cleveland.