The PRSalpha air drill has been designed to function and mount exclusively with ShopBot’s PRSalpha line. This document will discuss the mounting and installation of the PRSalpha air drill as well as the programming necessary to use it.

The PRSalpha air drill is a pneumatic drill with a 3/8” capacity chuck that is controlled through the software to turn on and off. The Double Valve allows for the cylinder to plunge and then activate the drill only when needed, to save on air consumption. The depth and speed of plunge of the drill are determined with the z axis, allowing for multiple hole depths within the same setup. The PRSalpha air drill is designed for point to point drilling in a variety of materials. While it is possible to drill into mild steel, the pneumatics were not intended for this purpose.

The PRSalpha air drill turns 2,500 RPM’s with a required 90 PSI (6.2 bar) of clean, dry air. The air drill has a consumption rate of 5 cfm (36 scfm) with a torque output of 45 lbs. in. (5Nm). Decibel levels on this unit are around 84 dB. Hearing and eye protection should be worn at all times.

This unit is not recommended to be used on PRSstandards due to the possible loss of Z position that may occur with the open loop systems.

Spindle Mounting Plate

                               

In most instances the spindle plate will have already been mounted to the spindle body when you received your spindle. Depending on what era your spindle mounting plate was produced, this plate may need to be updated. To see if your plate qualifies, look down the side of this spindle mounting plate. If there are NO ¼- 20 holes down the ½” edges, then an updated spindle plate is needed. If you do have these holes on the ½” edges of your spindle mounting plate and are assembling the ShopBot for the first time, please continue to the spindle mounting instructions. If there are holes in your spindle plate and you are just now adding the PRSalpha air drill to your machine, continue to mounting the drill cage.

          

If you have a spindle mounting plate without the ¼ - 20 holes on the edge, remove the spindle and plate by loosening the six socket head mounting screws that hold them to the Z-axis with a ¼” hex key. Once removed from the Z-axis, remove the 4 flat head screws that attach the spindle mounting plate to the spindle. Disregard the spindle mount without holes on the ½” edge.

Take the spindle mounting plate with the ¼- 20 holes on the edge (SB# 001620) and using the flat head screws previously removed, attach the plate to the back of the spindle. Please notice the holes on the 1/2” edge. The hole that is .375” from the end should be in the direction of the threads of the spindle. Use the 6 socket head mounting screws to remount the plate and spindle to the Z axis. Re-square the Z axis head if necessary.

 

 

Mounting the Drill Cage

                            

Position the drill cage with the angled side facing down. With the (8) ¼ – 20 x ¾” button head socket cap screws, loosely mount the drill cage to the holes in the ½” edge of the spindle mounting plate. Using a square make sure that the front face of the cage is square to the machine bed. Tighten screws firmly.

Mounting the Air Drill(s)

                                

Position the air drill inside the drill cage. On the drill cage notice the arrangement of holes on the front face of the cage. These holes are arranged so that two air drills may be mounted inside the cage. Drills may be mounted one in the center of this area or one on either side of center.

Consider the lengths of drill bits that will be used before mounting the air drill. The pneumatic cylinder has a 4” throw, so longer bits may cause the air drill to be mounted in the highest mounting position. Not to worry though, the air drill is easy enough to reposition by removing these six button head screws and moving the air drill up or down.

Attach the air drill plate to the drill cage by selecting the desired position. The air drill has eight holes that are spaced in 1” increments that allow for the air drill to be mounted in one of three height positions. Use the (6) ¼ – 20 x ½” button head socket cap screws to mount the air drill loosely to the cage. Use a square along the extruded track to square the air drill to the machine bed. Tighten screws firmly.

Note: Remember that the tip of the drill bit, when extended, will need to be lower than the bit in the router by a distance greater than the depth of the holes to be drilled. In other words, “don’t let either drag”.

If possible, try to set the resting height of the drills equal to the material thickness plus the safe Z height. This is only a rough estimate for now, the actual known locations of the bits will be found in the Zeroing the Air Drill(s) in the Z or A axis section of this document (towards the end).

Connecting the Air Drill(s)

Locate the cables with the 90° connectors. Position the connectors so that they mate to the pins on the solenoid valves, and hand tighten. (As pictured above) the right solenoid valve will control the cylinder’s travel (up/down), and should be connected to output 5 for a single air drill installation. The left solenoid valve controls the drill turning (on/off), and should be connected to output 6 for a single air drill installation. Label the cables (Drill & Cylinder) so not to forget which is which.

Note: When a second air drill is installed, connect air drill #2’s right solenoid valve to output 7 and the left to output 8.

Take the female ¼” disconnect end of the air line and connect it to the male ¼” disconnect of the air drill. Route both the air supply line (air hose) and the cables from the 90° connectors thru the energy chain. Connect the air supply into an existing air line. Route the wire from the solenoid plug into the side of the control box.

If you are only installing one drill at this time, you can skip the next part and move on to the wiring section of the installation.

Connecting a second Air Drill

                                           

When two air drills are present use the air line splitter (002187). Disconnect the air supply before beginning the installation of the air line splitter. Remove the 3/8” Push-in connector from the 90° elbow of air drill #1 (this part will be reused).

                       

Thread the air line splitter horizontally into the elbow and re-install the earlier removed 3/8” push-in connector. Re-insert the 3/8” tubing from air drill #1 and connect air drill #2 with the new section of 3/8” tubing. Plumber's tape (not provided, but cheap and widely available at hardware stores) is recommended to reduce leaks. Re-connect the air supply when done.

Note: With the double valve air drill, it is currently only possible to connect two drills. Label the wires from the air drill for tracking purposes (drill #1, drill #2, etc.) to avoid confusion.

Wiring the air drill(s)

WARNING: Disconnect your machine from the power source before working on the wiring. Failure to do so may lead to electric shock and/or damage to your machine.

If you ordered your air drill at the same time that you ordered your ShopBot, the wiring of the relay board was most likely pre-installed for you. Verify that this is the case before proceeding.

See Relay Diagram for PRSalpha for reference (shown below).

For the primary air drill (drill #1).

Connect a wire from position 2 (or the desired position) on the relay board to output #5 on the control board. This will signal the solenoid to activate the cylinder to plunge to depth. Place a second wire from position 3 (or the desired position) on the relay board to output #6 on the control board. This will signal the solenoid to turn the drill on/off.

For the secondary air drill (drill #2)

Connect a wire from position 4 (or the desired position) on the relay board to output #7 on the control board. This will signal the second air drill’s solenoid to activate the cylinder to plunge to depth. Place a second wire from position 5 (or the desired position) on the relay board to output #8 on the control board. This will signal the second air drill’s solenoid to turn the drill on/off.

Air Drill to Relay board connections

Locate the black/brown and blue wires from the air drill labeled Cylinder. Connect the Black/Brown wire to the NO of relay position #2 and the blue to a ground (V- on the 24v power supply). The relay position COM will need to be wired to +24V (V+ on the 24v power supply), in order to power the solenoid on the air drill.

Locate the black/brown and blue wires from the air drill labeled Drill. Connect the Black/Brown wire to the NO of relay position #3 and the blue to ground (V- on the 24v power supply). The relay position COM will need to be wired to +24V (V+ on the 24v power supply), in order to power the solenoid on the air drill.

 

Relay Diagram for PRSalpha (Air Drills)

Check to ensure that all wires between relay board and the control board correspond to like output positions, ground, and 24v power. Reconnect power when complete.

Manually testing the Air Drill(s)

WARNING: Pay close attention to the following instructions. Failure to do so may cause bodily harm.

Once the air drill(s) have been wired in and are connected to an air supply, test the unit. The air drill is equipped with a pneumatic slide valve that manually controls incoming air to the units. With the slide valve in the up position, the slide prevents any air from entering the system. Make sure that there is no drill bit in the air drill and that the chuck of the drill is greater than 4” above the machine bed. Make double sure that all hands and any other items are out of the area directly beneath the air drill. Move the slide valve into the down position to allow air to flow into the system.

                                             

Use the small yellow switch on the solenoid to manually test the air drill. With a small screw driver turn the switch clockwise a ¼ turn. As picture above, the left solenoid will turn the drill on/off (OPT 6/8) and the right will trigger the cylinder on/off (OPT 5/7). This should active the pneumatic cylinder or drill for the duration the switch is turned. Once the switch is released, the cylinder will return to the top of its cycle or the drill will turn off. If this performed as expected, continue. If not, check that the air supply is on and that you have 90 PSI going to the drill.

 

Testing the Air Drill(s) Through the Software

Now that the air drill can be switched on and off manually, the air drill(s) activation through the software should be checked. Move the slide on the air drill back to the down position (Drill on) as directed above. Make sure that there is no drill bit in the air drill and that the chuck of the drill is greater than 4” above the machine bed. Make double sure that all hands and other items are out of the area directly beneath the air drill.

Power-up the control box and the SB control software. Once the SB control software is open go into the KeyPad mode (K). On the KeyPad screen click on the output switch for the appropriate air drill. Air drill #1 cylinder will be activated with output #5; air drill #1 drill will be activated with output #6. . Air drill #2 cylinder will be activated with output #7; air drill #2 drill will be activated with output #8. With output switch #5 in the on (up) position on the KeyPad, air drill #1 should cycle on and plunge to full depth and stay there until output #5 is turned off (down). All other outputs should respond accordingly. If all air drills are in working order continue.

Tip: ALT + (Output #) will toggle the selected output on/off.

Finding the XY Offset between Air Drill(s) and Spindle(s)

 In ShopBot Control software version 3.5.4 or higher, use the Tools > ShopBot setup (TS) command to run through the setup routine. This will set your home position, Z zero plate thickness, and the offsets between multiple spindles and air drills. The software provides instructions throughout the program.

For more information refer to Finding Offsets for Multiple Spindle / Air Drills document.

http://www.shopbotdocs.com/Finding-offsets-for-multiple-spindles-air-drills.html

 

Zeroing the Air Drill(s) in the Z or A axis

Caution: The air drill z height location references the location of the bit zeroed in the spindle. The spindle bit(s) must be zeroed before the bit in the air drill(s) are zeroed out.

First zero the Z (and A axis) spindle(s) with Zzero.sbp (C2) (or Azero.sbp) to find the location of the router bit. Open the file Drill Offset.sbp to zero the bit in the air drill(s).

WARNING: Pay close attention to the following instructions. Failure to do so may cause bodily harm.

 

Make sure that the slide valve on the air drill is in the on/down position. Click OK. The file will raise the designated Z (or A) axis up to 6” then activates the drill’s cylinder to plunge to full depth. Make double sure that all hands and other items are out of the area directly beneath the air drill.

               

Place grounding clip on the drill bit and place the Z-zero plate below the bit. Click OK.

      

Type in drill position 1-4 for which drill location is needed to be zeroed. Click OK. The Z (or A) axis will move down until contact is made with the plate then move up a little, move back into the plate at a slower speed, then retract.

Make sure that the slide valve on the air drill is in the ON position before resuming cutting. Click OK.

Repeat the above steps for additional drill zeroing.  PLEASE NOTE: If one of your bits breaks, slips, or is replaced, you must re-zero that drill before using it again.

 

Checking Your Variables for the Double Valve Air Drill
Only necessary for SB control software Prior to V3.6

If you using ShopBot control software prior to version 3.6, it is necessary to upgrade to the most current software (http://www.shopbottools.com/mSupport/controlsoftware.htm). Open up C:\SbParts\Custom\my_variables.sbc. Scroll to the bottom of the file and find the area named ‘Manual Tool Change Numbers. There will be several variables under this heading. At the bottom of this list, verify that the variable &DrillType=1 is there then save the change.

What’s this do?

In early versions of the software the &DrillType= variable was not in place. By adding the variable we are able to update variables when the ShopBot Setup routine [TS] is run.

Note: FYI &DrillType=1 designates the Double Valve Air drill and &DrillType=0 the Single Valve.

ShopBot Threshold [VC]

Trigger ON Threshold
Sets the Z or A level at which the designated switch is turned ON during a plunge. Trigger move is a vertical move of the Z or A axis while there is no motion in the X or Y axis. If the threshold is above the Z start height of the move, the Output Switch will come on when the vertical move starts. Inches or mm.

Trigger OFF Threshold
Sets the Z or A level at which the designated switch is turned OFF during a pull-up. Trigger move is a vertical move of the Z or A axis, with no motion in the X or Y axis. If the designated vertical axis does not pull above the threshold height, then the Switch is not turned off. Inches or mm.

Note: In the Fill-In sheet shown, the ON Threshold is set to 1, triggering the Air Drill to turn ON as it moves below 1”. The Off Threshold is set to .75”, triggering the Air Drill to turn OFF as it is raised beyond .75”.

 

 ---- Warning ---- Warning ---- Warning ---- Warning ----

The Threshold settings in the Fill-in sheet above may not be optimal for all situations. It is important to understand where the Z-axis is zeroed to, and what the Z pull up (safe Z height) is during the design phase of the part.

For example: Zeroing the Z-axis to the top of the material and having a Z pull up distance of .25 will never trigger the drill to turn on. Because the On/Off thresholds are never reached, the drills will fail to function and plunge into the material without the drill turning on, possibly damaging the part or the drill unit itself.

An example where the Fill-in sheet setting would work well would be: Zeroing the Z-axis to the table bed and having a Z pull up of 1.125”. This would allow us to drill a ¾” sheet of material fairly comfortably because the bit would clear the material’s surface by.375” between moves. As the drill moved down, as it passed the 1” threshold the drill would cycle on and drill to depth. Upon reaching the desired depth, the drill would then retract, continuing to turn until it passed beyond the Off threshold of .75” at which time it would stop turning and continue upward to the Z pull up height of 1.125” that was designated in the design software.

Creating a File using the Air Drill(s)

The following instructions have screen shots taken from PartWorks. In any other software that outputs the PRS air drill post, the setup is essentially the same. When you select a tool from the database, it must be a tool that can be recognized by air drill software. This tool will be used to generate toolpaths in the same way the software would normally process a drilling operation, however, the tool number will dictate which air drill will do the drilling in the case of multiple drills.

First, draw/ layout what needs to be machined just as you would with any other toolpath. Here is a simple series of holes:

When the toolpath is ready to be created, select the holes to be drilled and open the Drilling Toolpath tab. Set the depth for the holes (above Cut Depth 0.375), then select the tool to be used.

 

 

In PartWorks, the database will have PRS Air Drill tool templates already. The templates are named PRS Air Drill Position #1 - 4 (Define Dia.). These templates all have a default diameter of .25 in the geometry of the tool. You can edit each one of these to match the drill bits you are using. The most critical portion of any of these templates is the tool number located at the bottom of the window. This information identifies which drill holds the bit for this toolpath.

Note: Most other software packages that have posts for ShopBot will have the ability to define a tool number.

To create multiple tools for each drill position: Highlight the template you wish to duplicate, then click the copy button at the bottom of the screen. Select the new copy and change the (Define Dia.) in the Name. Enter in new geometry info, angles, feeds and speeds, and any other info that would be needed. Then click Apply to save the tool.

    

 

Once an Air Drill tool has been selected, calculate the tool path. When all toolpaths have been calculated, order them (top to bottom) in the order that they need to be cut, then save all toolpaths by outputting the code with either post: Shopbot TC (Inch)(*.sbp) and Shopbot TC (MM)(*.sbp).

These posts will recognize all spindle and drill positions based on the tool number designated within the design software.