Air Drill
 

Is anyone interested in mounting a drill onto their z-slide in order to drill system holes or has someone already done this? From looking at some of the photos posted here it looks like there would be room to mount one. I'm interested in doing this when I start my build.

Yes, the Shopbot has this setup, looks like it is setup with a pneumatic linear actuator. I am interested in a source for a similar setup for point to point machining. Check this out http://www.shopbottools.com/videos/PRTalphaCabDrill.wmv 29.5MB!

The link has changed

http://www.shopbottools.com/videos/Drilling.wmv

Hi Ros, Not sure if it’s only on my side but your link is not working for me :confused:

Right click and save as.

Thanks :o

Gary G. Campbell attached an air drill directly to his spindle. By adding a pneumatic (linear) cylinder he was able to build his device without adding a 2nd Z-axis. You'll find his posts on the Shopbot forum.

Can anyone explain how you would setup the control on something like this. You would need to plunge and turn on the air at the same time. It would also probably be more efficient if you could turn off the air while transitioning to the next hole. I have a pretty good ideal on how I would setup 2 drills but I just dont know how I would control them.

One thought that came to mind is proximity switch to turn on and off the pneumatic solenoid.

Russell-

You set up the linear cylinder so that in the up position, it's completely out of the way of the main cutter in the spindle. In the down position, it's far enough below the main cutter that the main cutter is out of the picture.

So once you fire the linear cylinder, it's a different machine; the air drill is below the main cutter. Then you just run the control as if the main cutter and spindle aren't there. Plunge using the Z axis (way above where you would plunge for the main cutter).

If you wanted yet another drill (a total of three cutting elements), then the second drill would work the same way.

Brad, I have the mechanics down but I would like to know the code that you would needed to extend the linear cylinder and the code that would turn the drill on and off at certain heights. Do you match it up with a tool number in mach or do you have to mod a post processor to get it to extend. I would also like the drill to turn on a quarter inch above the work peice and turn off on the extract. Air drills can drain a compressor in no time. I have a 33 gallon and I know that it wouldnt be up for 100 holes with drill going the whole time.

Russell, I can't tell you the exact code; it depends. You would not match it with a tool number. I think. I'm not a Mach expert, so I'm speaking in terms of general GCode.

You will have an output that represents energizing the linear cylinder. You need to map this to something in gcode - could be the standard mist or flood cooling functions ( M7 or M8), or perhaps a user defined code like M101.

So your gcode would move to the correct position, move the Z axis high enough that after you fire the code, the bit will be 1/4" off the work, and then hit the M101. Then
you do a G1 moving your z-axis to the desired depth at the desired speed, and back out again. Then you turn off the M101. Assuming that you build to have the air both extend and start spinning the drill in response to the same signal.

Perhaps Mach has a clever way to do this in a post-processor? The general model is that you have a signal output that enables air flow, thus extending and starting the drill. You use GCode to get to the right position and safe height, then hit the signal output, then use GCode to drill down and up, then cancel the signal output, and move on to whatever is next.

I will troll through the mach forum. I want to say years ago I remember reading about a wizard or macro that did just this but I cant remember where I saw it or how it worked. Ideally I would like to mount them on their own z axis but we will see how it goes.

Russel, I would not attempt to do the turn on/off at various heights out of G-code. I would do a mechanical system that needs a single instruction to start and then another instruction to stop (open and close a single valve A). The rest of the logic being handled at the drill head by valves/springs.

Cylinder of type that air pushes down and a spring pushes back - (saves the compressor)

As an option, as cylinder goes down, it passes a valve B that starts the drill (air also supplied from valve A). I think this is unnecessary, unless the cylinder has a lot of wasted stroke at the top to drain the compressor.

As cylinder reaches bottom, it hits a switch that tells mach to wait 0.5 secs before moving the axes, and switches the first valve A over so that it vents the air from the cylinder to allow spring return.

Not know that much about air control, I know that Gary used an sliding table. Looking at the pictures again, I do not see any air hose going to that table. The table pushes the air drill to the depth that is needed. I thought I posted those pictures here before.

Russel are you going to do point to point drilling for cuboards?To spare you a lot of work get yourself some drill bits with a 10 mm shank dia and use your router/spindle to do the drilling for you.You do get the drill bits in various dia.You will find that air is more expencive than electricity.Set your spinle speed lower then you can drill away.cut2d from vectric have a drill feature.Gerald where were you last week I thought I saw You somewhere;)

Gary and I exchanged some emails about his first air drill (the one that was mounted directly to the spindle housing). Here's a general description:

1. The sliding table's pneumatic cylinder extends the drill bit below the normal cutter.
2. A sensor tells the controller that the slide is extended.
3. The air drill is turned on.
4. The Z-axis is lowered to drill the hole
5. The Z-axis is raised.
6. The sliding table's pneumatic cylinder retracts the drill to a safe level
7. A sensor tells the controller that the slide is retracted
8. Normal cutting continues.

Richard,

I thought it was a pneumatic table but I don't see any air hose attached to it.

Those steps are very helpful.

Thanks and nice to hear from you.

Gerald,
I was thinking the same thing with mechanical means. My thought was to build a 2nd Z axis and mount an inline air drill simular to the router. Instead of having the proximity switch tell the computer that there is no more rail, it would tell the soleniod to turn on or off. I wouldnt have to change any of the gcode but I would have to tell mach which spindle to use. After reading a little on the forum it sounds like they will be suppporting multiple spindles here shortly if they havent already.

Hennie, I know that air cost a lot to produce but you have to consider some of the other options out there. I looked into one tool changer and the cost was very prohibitive. Then to think about all the tool changes or setups that would be required for a single sheet cut. Air starts to look cheap.

Russell,To build a dual z for the purpose of mounting an air drill would be
unneeded.The piggyback solution has been used for years with great success.This little air drill has taken over the job of my $6000 line boring machine,or just plain boaring machine.:) I made it a point to speak with
Gary months ago regarding air drill knowledge.(good idea). I ended up using a in-line Ingersoll Rand drill, there ind. line,5000rpm, low noise,less air ,good runout.This will take care of most of the air issues.On Mach3 the air drill
is identified as G-55.It has x and y offsets while z is the same as G-54 .Z offset is recognized by the tool table only. You do need to provide macros, M-12
corresponds to activate signal,while M-13 deactivates signal. Mike R. is electrically correct with his point of sensors (when is he not?).This is however a place where you can elect to skip the sensors.The reason being is that the pneumatic retraction action is so fast that that you don't run over the drill.My cycle time between 32mm holes is about 2/3 of a second,not long enough to turn on and off for air savings benefit.
Mike, good to see your post,your input is as always highly valued.

Hello Ron
 

Just few questions for clarification:
Depth of the drilling is set just on the beginning of the drilling (z axis movement), after all the drill movement is done by pneumatic cylinder ?
How is the drill retracted ? There is just one air inlet on the top of the cylinder.
Two drills possible?

Hi Jstransky,
Yes, there is only one air inlet,the drill movement (up and down) is governed by mechanical stops within the pneumatic cylinder.The drill is retracted when the air solenoid closes and the remnant air exhaust through the drill ports,allowing the spring
in the cylinder to retract the drill.
Two drills -no problem.

Hello Ron,
 

Thanks, that's much more clear now.
How does a G code for the drill looks like, when ther is no Z axis movement ?
How would you control two different drills ?
How do you setup drill bit offset to have a correct hole deph?

Thanks in advance.

Hi Jstransky,
The setup of a single drill or multi drills is the same.You must identify your drill/s in work offset page ,G-54 could be the main spindle G-55 could be the air drill A
G-56 could be air drill B ,then listing your X,Y differentials from the main spindle.
The Z offsets should be the same as the main spindle.
Then go to the tool table,label your tools. This is where you show the Z offset or
height differentials between the three tools.I must say a special thanks to Mike R.
for helping me through this at a time when I knew very little about the operating
software.

Hello Ron,
 

What I do not understad how you start the drilling process.
1, Bring the drill to required coordinates- X, Y
2, What starts the drilling process ?
There is no Z axis movement
3, Do you have to execute the output, for example for cooling ?
4, If I understand well the G code is done manualy?

Hey Jstransky,
In use,your g-code instructs mach3 which spindle is to be used---it is all automatic.
I also have on my Mach3 screen ,manual air on , air off buttons.The screen btns.
are for other purposes.Your software cad/cam program should be able to write G code indicating which tool does which job,from there its all automatic.

Hello Ron,
 

That's clear for me.
How you generate the g-code ? Do you have to edit it manualy to change Z-axis movemnt into air on, drillling, and air off sequnce ? Or you use same macro ?

System with Z-axis movement is clear for me:
1, turn on offsets x,y,z
2, air on
3, drill all holes with regular G-code
4, air off
5, turn off offsets x,y,z

You have to add just 4 line into G-code which was previously used with main spindle.

Could you make a simmilar explanation for you system, please.

Hi jstransky,
There is no manual edit to do. G-code defines which tool ,g-54 or g-55, if g-55 air
drill is selected ,mach 3 interprets for offsets and sees macro m-12 sending a signal to the output side of the board ,energizing the solenoid and engagement of the drill.
After the holes have been drilled, macro m-13 turns off the drill,then g-54 the main spindle goes to work. More specifically heres the code rundown.
M6 T2 ( drill tool)
G43 H2 (apply tool length offset)
G55 (offset for tool)
M12 (turn on drill)
G4p.5 (.5 sec pause for drill )
Now you drill them there holes.

After you drill them there holes.
M-13 (turn off drill)
M6 T1 (spindle tool)
G43 H1 (apply tool length offset)
G54 ( offset for the tool)
Now the big dog G54 goes to work----all automatic.

Hello Ron,
 

Just for clarification.
Once you run M12 code the cylider is activated and drill is running, the Z axis stepper takes care about Z axis movement to drill the holes.
When drilling is done run M13 and deactivate the cylinder.

Thanks Ron I understand it completely now.

Hi jstransky,
Yes.