I have a customer that has a ~ 48X48 techno router that has the original set up. it was a basket case where several of the motors were damaged but the machine itself was in good shape. Her sent me the motors/ housings and cables to reuse what I could. He wanted to upgrade to a newer control system using Mach3 so I quoted him a price to replace the existing XYZ motors but reuse the existing housing and cables. I built him a G540 control unit in my metal case. The problems that I enountered were:
1. the existing cables were not stock techno cables
2. the amphenol connectors on the motors were in poor condition
3. He wanted a brake on the z axis
4. Some of theextruded motor housing were in bad shape.
I looked up the specs for the stock motors and while they were not listed for the exact motor I was able to deduce from the part number that the stock motors were ~260 oz in but were the old standard round type motors. I replaced all three with 385 oz in square high efficiency motors. They fit the existing extruded housing fine except for the Z axis. He did not send me the correct housing for that so the brake portion will stick out above the housing about 1 inch. He says that he will replace the extruded housing later
The Z axis motor did not come drilled for a standard nema 23 brake. I had to machine an adapter plate and I had to remove two of the long screws that hold the motor laminations and end plates and grind about a 1/4" off them so that I could install 3mm X 8 screws to mount my adapter plate. The brake then fit nicely onto the adapter and the motor. Since he did not send me new amphenol connectors for the motor housing I was forced to remove the existing pins and repin the motor power, limit and brakes wires. It took some time to remove the pins to disengage the locks on the pins using various jewler screwdrivers. To connect the existing cables ends that were cut off to the G540's db9 connector I used the same 4 motor power wires and wired them to pins 6through 9. I used a 3.48K resistor on pins 1 and 4.
I also split out the remaining wires and added connectors for the limit switches and brake which could not be connected to the G540 DB9. The connectors were then wired to the G540 terminals. The brake was wired to a DPDT switch. one set was wired one of the poles that runs to the PS and brake and the other pole was used for the estop/ engage disengage. That way when the
estop/engage disengage switch is in the run mode the brake is released and the motor can run. When the switch is tripped it disengages not only the motor windings but also engages the brake to prevent the Z axis from dropping.
If anyone plans to change out their motors or their control unit I recommend the G540 and 385 oz in square stepper motors and Mach3 software. I would do one thing differently. I would machine my back panel for db9's and move the G540 completely inside the case. Then I would wire the back panel db9 to the db9 motor terminals on the G540 and the other pins to the terminals on the G540. That would eliminate the external connectors for the limit, brake and relays.
Camtronics, inc. -- CNC with Dan Mauch
low cost cases for gecko products.
stepper and servo motors
kits and assmebled custom systems.