In this installment, we are going to install the clamp table. The clamp table is the surface you use to attach your stock.
You will need your PC connected to your controller and motors to move the Y carriage into favorable positions to make securing the table a little easier.
In addition to the table, we will be mounting the KReduCNC electronics inside the frame. We will also be doing some cable management in order to get the KReduCNC ready for action.
You will need to following hardware to complete the clamp table.
- 19, #6-32 x 5/8 countersunk screws
- 24, #6 internal tooth lock washers
- 24, #6-32 hex nuts
- 4, #6-32 x 1" machine screws
- 5, #6 washers
- 6, #6 wood screws
- 12, 1/4-20 x 2" carriage bolts
- 12, 1/4" washers
- 12, 1/4" lock washers
- 12, 1/4-20 hex nuts
- 5, 3/8" cable clamps
The table is 15-3/4” wide by 16-1/2” deep. It’s made from 3/4" stock and can be made from particle board, plywood, plastic, or MDF.
The basic table (Figure 1) consists of a single sheet of 3/4” material with counter sunk holes for securing the table to the Y-carriage. In this case, you screw your hold down clamps into the table to hold your stock while it is being machined.
A better table has 15/16” wide slots that are 3/8” deep, shown in Figure 2. These slots hold mini T-tracks (Figure 3) that will allow you to secure your stock with movable clamps.
The mounting holes for the table are counter sunk on the top so that the 1/4" x 2” carriage bolts don’t interfere with your stock. I have found that .28” deep works well for these.
You will need T-Track to attach to the table. Here are links to three different T-Track sources. I used the Kreg on my KReduCNC, but they are all 3/8" thick by 3/4" wide.
You will need enough for six pieces 11" or 12" long, and one piece 15-3/4" long.
The T-tracks are secured to the table with 19, #6-32 x 5/8” countersunk screws, lock washers, and hex nuts, shown in Figure 4. Most T-track does not come with mounting holes, so you must drill and countersink them yourself. Simply clamp the T-track to your table and mark the holes with a marker.
On the bottom of the table the T-track mounting holes will need to be countersunk and the screws cut so that they don’t interfere with the Y-carriage.
To install the T-track, place them in the slots and insert screws into the holes. Secure with a lock washer and nut. You will have to use a rotary tool to cut the ends of the screws flush with the bottom of the table, as shown in Figure 5.
The drawing files for both the plain and slotted table will be made available on my website listed at the end of this article.
As an option, you can forgo the metal T-tracks and use a router to mill some T-slots into the table directly.
Attach the Table
Start by moving the Y-carriage forward, as shown in Figure 6. This will make inserting the carriage bolts a little easier. Line the 12 holes in the table with the holes on the Y-carriage, then insert 12, 1/4" x 2” carriage bolts into each of the holes, as shown in Figure 7.
Turn off the power to the controller and remove the motor connectors. Carefully tip the machine on its side and add a 1/4” washer, lock washer, and hex nut to each of the bolts, as shown in Figure 8. Tighten the nuts.
Place the machine upright and reconnect the motor connectors and power up the controller. Move the table all the way to the back of the machine then back to the front to make sure the table doesn’t contact the sides of the machine.
Mount the Electronics
Now that the table is secured, you can mount the electronics inside the KReduCNC frame. Start by removing all the connectors on the controller.
Next, reattach the parallel cable to the controller. Drill a 5/32” hole in the position shown in Figure 9, then add a #6 washer to a #6-32 x 1” machine screw and insert it through the hole. Secure with a #6-32 hex nut and lock washer as shown. The actual position of the machine screw in not critical.
Secure the cable on the parallel port to the screw with a cable clamp, as shown in Figure 10. Use another #6-32 hex nut and lock washer to secure the clamp. Here I am using a 3/8” cable clamp.
Cable clamps can be purchased from most home centers, and are available in the electrical section.
Attach the board holding the controller to the bottom side of the cleats, as shown in Figure 11. Use six #6 wood screws to secure the board. Drill 3/32” pilot holes to make the job easier.
On the power supply panel, add two #6-32 x 1” machine screws to the positions shown in Figure 12. As before, add clamps and secure with #6-32 hex nuts and lock washers as shown in Figure 13. Secure the panel to the bottom of the cleats with six #6 wood screws as shown in Figure 14.
Rout the power cable over the parallel connector and secure it to the machine screw with a clamp, as shown in Figure 15. Rout the controller power leads as shown in Figure 16 and plug it into the power connector on the controller.
Secure the controller power cable as you see fit using some wood screws, as shown in Figure 16. Note that you can also use the panel screws to attach clamps as needed.
Rout the cable from the three motors through the slot in the back of the frame, then connect them to the controller, as shown in Figure 18. Don’t worry about the layout of the cables just yet as we will come back later and secure them. For now, flip the KReduCNC back over, power up the controller and connect it to your PC. Start Mach3 and test each axis to make sure it’s working properly.
Cable management is very important on CNC machines. Loose cables can be dangerous and cause unexpected shorts and lost connections. On larger machines, we use a cable support system called an E-chain or drag chain. Figures 19 and 20 show a couple of these cable transports on some of my larger CNC machines.
On the KReduCNC, we only need to worry about the movement of the Z-axis cable. It’s a short run so we can get by with a simple system using split loom cable.
Start by attaching a piece of 3/8” split loom cable over the Z-axis wires as shown in Figure 21. It only needs to be about 34” long as we don’t need to cover the complete length of the wires.
Secure the cable to one of the shaft support screws, as shown in Figure 22, using a cable clamp. You want enough cable between the motor and the clamp so that it can move the full range of motion along the X-axis, as shown in Figure 23.
Add some split loom cable to the X-axis wires. Attach the Z-axis motor cable to the X-axis motor cable using some small tie wraps, as shown in Figure 24. You can also use a large cable clamp attached to one of the fame bolts as shown in Figures 24 and 25.
Add a small piece of split loom cable to the Y-axis motor wires as shown in Figure 25. Slip all the excess motor cable into the slot on the back of the frame.
The last step is to secure the wires inside the frame with some tie wraps, as shown in Figure 26. Use a cable clamp to secure the wires to the corner machine screw holding the controller in place, as shown in Figure 27.
This completes the table assembly, electronics mounting and cable management. We are just about ready to put the machine to some work. Before closing I just want to reemphasize that you don’t have to add the slotted table to your machine to start. In many cases I often just add a slab of particle board or MDF for a quick table to get a new machine up and running. This lets me work out the final table later.