Pinch the holes and drill to the specified sizes.
Put a hole in the middle of the RJ41 (square connector) and DB9 (lower) connector holes that is large enough for the nibbler tool and nibble to the correct size.
Use a file to smooth any rough edges and paint with at least two coats of black spray paint. I used Rust-o-leum matt black paint. This paint requires minimal surface preparation.
Always use safety glasses when using a rotary tool. Trust me - it's easy to get cutting wheels to explode if they twist.
It may be necessary to trim the left side of the main board to avoid the original crystal and to remove the top, left hand corner of the main board to avoid an capacitor.
- Cut the pin strip into 20 pin lengths and insert them into the socket. Put the side with the small bump into the socket.
- Put the cup pins over the exposed pins of the pin strip.
Note that the socket is just used to hold the pin strip and is not used in the project.
- Put the cup pins into the main PCB from the top (making sure they are pressed down as far as possible and solder from the bottom. It is essential these protrude from the top of the board as little as possible.
- Remove the pin strip, leaving the cup pins behind.
- Insert the pin strip (still in the socket) into the PCB
from the bottom and solder from the top. Again, the pin strip should be
pressed up against the board.
Leave the socket on the pin strip pins - it will prevent the pin strip pins from being bent or broken.
- Install the passive components and solder in height order (starting with the least high ones)
- Install the MAX 232 and solder
Check your work! If possible, remove flux using a flux remover to simplify inspection.
Finally insert the new MCU. You may need to bend the pins of the MCU slightly inward. Don't use too much pressure or you could break the pins!
HEQ5 note: Replace SV2 with a 10 pin male header. The interface box will be connected with a 10 pin IDC crimp header and cable (6")
- Cut the socket into two rows of pins. Carefully clean up the left over connecting plastic with a sharp knife
- Trim two pins off one end of each row
HEQ5 note: This step does not apply.
- L2 (The 6-pin RJ41 socket)
- SV3 (The two rows of the wirewrap socket
- R1 (The 1.5K resistor)
The remaining components will be mounted on the metal box for the final assembly.
HEQ5 note: Don't fit SV2 - the control board and interface PCB are wired together so that the interface board can be located outside the HEQ5 covers.
Note: For v1 of the PCB the LED should be reversed with respect to the legend on the PCB.
The LED is in a small, plastic LED mount. The mount is pushed into the hole in the box (from the front) and then the LED is inserted from the rear.
Make sure the led mount is flat against the box and the LED is pushed all the way into the mount.
Once all the pins of the parts pass through the PCB get the PCB level, with the front of the RJ41 socket level with the front of the box (but not any higher)
Then solder the pins of the switch, LED, and DB9 connector.
Do not punch or drill the mounting holes at this mount.
Cut out the square hole using a rotary tool. It is VITAL that you wear safety glasses for this step as there is a good chance that you will break at least one cutting wheel.
Seriously - USE THE SAFETY GLASSES!
Note that this hole will be completely under the interface box, so slight overcutting is OK, but not too much.
Do not remove the template that this time.
- Remove the original MCU from the board using a flat-bladed screwdriver
- Carefully remove the socket from the pinstrip pins
- Plug the main board into the socket on the original controller board
Don't force it - the main board should plug easily in the socket. If force is required then stop and make sure the pins on the pin strip are straight.
At this point it's time to do some testing ....
- Set up the board on the bench. Make sure there are no wire clippings, solder blobs, or tools about to short out the board.
- Attach power and the hand paddle (with the power switch
off).
Use a current limited power supply if you have one. - Set the guiding rate switch to 16x
- Turn the power on and wait 5 seconds. If you smell anything burning turn the power off immediately!
- Press the RA left (or right) buttons. The relay should click
This is the whole initial test and verifies that the CPU is running the mount firmware and is able to accept commands from the hand controller.
The remaining testing will be done after the mount is reassembled.
Ignore the mounting holes - you haven't drilled them yet.
Mark the true location of the holes in the interface box mounting ears and remove the interface box and top cover. They should align with the hole marks on the template, but may differ slightly due to printer tolerances.
Make sure the box is square to the plate and mark where the actual mounting holes will be.
Now:
- Disassemble the controller
- Punch and drill the mounting holes
- Remove the drilling template
- Attach interface box to panel and trim excess screw length
with rotary tool cutting wheel
- Reassemble the controller
Again, remember to use those safety glasses!
HEQ5 note: Remount the mount controller PCB and mount the controller box at a convenient place on the mount.
Time for the final testing:
- Install the control program (as shown in the next section)
onto a PC.
- Connect a serial cable between the DB9 port of the interface box to the PC.
- Start the control program (with the mount on)
- Select the comm port in the comm port menu
- Select the mount information menu. A window should pop up identifying the mount firmware.
If that all works, you're done!
