Air drill setup . How dose it work ?

[steve4460]

I would like to know how the air drill setup works and how it gets hooked up . I have seen some picture on here some where a while back , but there was not much detail on how it works .
I am hoping that it solves the problems I am having drilling 1/4 " shelf peg holes . I am using a bit that cuts on the end and it still gets pushed up in the router and then the rest of the file dosen't cut right .
dose anybody have any pictures of the airdrill setup?.
Thanks

[stickman]

I have been working on some air tool things.. kinda like the air drill.. well I am in the preliminary stage. What I would like to know more, is the controls and switches? What is all involved? Where is a good place to find air pneumatic information?

Jay

[ckurak]

Stephan,

Maybe it is time to replace your collet? I cut LOTS of holes for shelf pins and the bit does not move up.

[steve4460]

Hi Charles
The collets are fine, It happens on both of the once I have .Plus I wouldend mind using a compretion cutter for cutting and a different one for the drilling . That way it saves on tool changes .

[ron brown]

"The collets are fine, It happens on both of the once I have ."

Could it be BOTH are worn? Many companies recommend changing collets every "X" hours. The only times I have had router bits slip have been bad collets or operator not tightening properly.

Somebody "borrowed" one of my collets and used it in their hand held router, leaving me his worn out collet. My spare parts box always has several brand new collets and inserts. If I find one slipping I remove the insert, throw it away and use the nut on the next insert.

Ron

[elcruisr]

Collet life is much lower than most imagine, sometimes a few hundred hours (that's from the manufacturers) and that's on good brands. You can get away with alot in a hand held router but on a CNC machine things get alot more critical because of the loads involved. Before it starts to slip from wear there will probably be increased runout and that will degrade cut quality and tool life. And if you drop one on the concrete floor it's going to be a bad bet to keep using it, don't ask me how I know!

Eric

[stickman]

Does anyone have more pictures or drawings of an air drill setup for the shopbot? Has anyone worked with pneumatics, air cylinders and control? I find this type of movement and control interesting and would like to experiment with it.

I did find some vacuum generators... thought about using these for vacuum pods.

[gerald_d]

Jay, this (http://www.mechmate.com/Forum/messages/47/142.html?1134068262) may be useful.

[stickman]

What are the black control blocks?

[gerald_d]

The big one looks like a 4/2 valve - I guess it is to drive the air cylinder up or down. (Sort of a control relay for pneumatics)

4/2 means 4 pipes / 2 positions

one pipe to compressor
one pipe to exhaust
one pipe to top of cylinder
last pipe to bottom of cylinder.

the "fifth pipe" (coming horizontally from right)is the pilot (in electrical versions the pilot becomes a wire)

[richards]

Jay,

Pneumatics, air cylinders, valves, etc. are not difficult to control with a computer. Disregarding the entire mechanical side of things, a very simple air interface can be controlled with one output signal and two input signals. A three-way valve, to control a spring loaded air cylinder, is either on or off. If the air cylinder controlled the z-axis movement of an air drill, and if the air supply to the drill were either manually turned on/off by the shopbot operator or activated with a cam switch as the air cylinder moved, simply turning on the air cylinder would drill a hole. For safety, you'd want to have an input sensor at the retract end of the air cylinder's motion to verify that the drill was retracted before moving the gantry. To verify that holes were actually being drilled, you'd want a sensor at the actuated end of the air cylinder. (I learned the hard way, when designing pneumatics for the photo industry, that assuming that an air cylinder will extend when commanded overlooks the compression effect of air.)

The electrical interface to the output signal could be a 120VAC SSR (solid state relay) with 3-32 vdc control. If one side of the 3-32 control were tied to 5VDC and the other side were tied to the output signal, then the SSR would become active when the output signal went active (low/zero VDC). If the AC side of the SSR were tied to a 120VAC valve, and if the valve were plumbed properly, the air cylinder would do its thing. If the SBP file contained code that kept the output line active until the "down" input switch were sensed, a hole would be drilled.

That's a very simplistic overview of controlling an air device. Mechanically, you'd have to have robust stops on both the UP and DOWN limits of the axis. You'd have to have air reduction control so that the air cylinder didn't "slam" against the stops. And, you'd have to have a robust linear guide so that the holes were drilled with precision.

[steve4460]

Very good info as always. What output controles the pnuematic cylinder on a 48 x96 Alpha ?. Where do I tell the software that I want the airdrill to drill holes ?.Also what input is used for the limit switches ?. Can anybody help ? I am almost ready to hook this up ,and pictures will folow if it works .
Thanks.

[richards]

Stephan,

I think that you're leaping ahead from the theory of what to do, to actually building something.

As far as I know, you can use any output that is not being used by some other device. You can also use any two inputs that are not being used.
Turning the output on is easy. Use the following command:

SO, 1,1
SO, 2,1
SO, 3,1
SO, 4,1

Of course, 1,1 turns on output 1, 2,1, turns on output 2, 3,1 turns on output 3 and 4,1 turns on output 4.

Turning the outputs off is just as simple:

SO, 1,0
SO, 2,0
SO, 3,0
SO, 4,0

1,0 turns off output 1, 2,0 turns off output 2, 3,0 turns off output 3 and 4,0 turns off output 4.

If I were you, I would look at the zzero.sbp file that shopbot furnishes. It will show you one way to handle the inputs. Of course, instead of setting the z-axis in motion and then waiting for a switch input, you would simply loop through an empty routine until the switch input was detected.

You can also study page 77 of the User's Guide for help on using the input switchs.

As far as telling the airdrill where to drill, I would use an offset from the router/spindle and then modify the design or the code to account for the difference. For instance, if there was exactly 8-inches between the router/spindle and the airdrill, I would add something like this to my sbp code:

&airdrill_x = 8.00
'
JX, 15 - &airdrill
GOSUB DRILL
'
JX, 16 - &airdrill
GOSUB DRILL
.
.
.
DRILL:
' Turn on air cylinder
SO,3,1
'
' wait for an input switch
ON INPUT(2,1) GOTO AIR_OFF
'
' loop until input switch 2 is active
LOOP:
GOTO LOOP
'
AIR_OFF:
'
' turn off air cylinder
SO,3,0
'
ON INPUT(1,1) GOTO FINI
'
' loop until input switch 1 is active
LOOP2:
GOTO LOOP2

FINI:
RETURN

[steve4460]

Thanks Mike

That would have taken me a while to figure out .
I'll let you know if it works .

[cip]

Stephan:
ShopBot uses input #3 for the air drill and has a setup for the offset in part wizard. they also have a custom command "C8" that when executed drills one hole, so you move to the desired XY location plus or minus the offset and execute "C8" and the hole is drilled.
Hope this helps as well.

Mike

[steve4460]

That is where the X,Y limits are hooked up to?.I ment where the limits for the air drill are hookup to . Thanks for that C8 trick .
Here is a nother question .
I have this ball screw driven Z axis and I would like to hook up a 25:1 asm98aa motor to it, the ball screw moves 1/4" per turn . What would be the numbers to enter to make this work?. Where do I set this up ?. I know that the motor might be overkill but that is the only one I have with the matching drive that works on the alpha controll board .
Thanks for the help .Pictures will follow when its done .

[Ryan Patterson]

I would like to add the commands to run this drill with CabinetPartsPro. Does any one have the custom cut file used by the C8. If so can you email it to me at coastalcarpentry@cabinetpartspro.com (mailto:coastalcarpentry@cabinetpartspro.com)

Thank you

[Ryan Patterson]

Thank You Paul
CabinetParts now has an option to use the air drill.
Ryan