[brianbonedoc]

I found this suggestion online so I can't take credit but it seems to work.

Is there any problem adding C-axis parameters to Mach3 mapped to the same pins as the Pulsar spindle?

That way I can use the C-axis to do the rigid tapping and still leave the A-axis open for the rotary table, and I don't have to open up the cabinet everytime.

It seems to work out fine - I tried it cutting some air, and the steps/unit are 166 in mach3. I have the C-axis motor speed down to about 100 in/min to keep things nice and slow.

When I type in the commands C20 Z-1.0, it rotates exactly 20 revolutions CW and Z goes down 1 in, just like when I had the A-axis set up like this.

Now if I can only figure out how to get SolidCam to output rigid tapping code - it only seems to have G84 which mach doesn't like.

-B

[Novakon]

This is a very good thought. To switch over to the C axis would not do anything to aid in not using the switch on the BOB. Here is a little history, and what will be coming:

When the rigid tapping feature was introduced a couple of years ago, Mach3 didn't have the capability to simultaneously control spindle free running and precise control as needed for rigid tapping. Software changes for Mach3 are pretty much done until Mach4 comes out. Brian, from Newfangled solutions, does have a Pulsar and will be doing software integration with Mach4 which will be released "someday". Then the rigid tapping capability will be integrated with the G-codes and it will be a whole new story.

In the mean time, we are limited to the number of input pins available using the older parallel port so we decided to share the pins with the 4th axis. Basically, the BOB defaults to the 4th axis and it controls the spindle in precise rotation mode like a 4th axis. If the spindle turns on from the spindle control, the BOB simply switches over to the servo driver control for the spindle inputs. When the spindle control has stopped, it reverts back to the 4th axis inputs. So dual control is not possible with out more control lines. This is why there is a switch on the BOB to allow either tapping or 4th axis control, but not both.

This brings us to the next part....

Since we believe Mach4 will take some more time to mature, and also work out any bugs, there is another option we are moving forward on. We have made the ESS board standard with each mill. On the ESS board, there are additional ports we can take advantage of. There is in design, an advanced BOB that will have an additional connectors to utilize these extra pins from the ESS. With the ESS, we can directly control the spindle separately from the 4th axis. This will also allow full control.

We have provided fully functional post processor utilizing the rigid threading capability for the Pulsar. They are available in the BobCAD/CAM software using the following link:

BobCAD/CAM V27 Download

In the near future, the new BOB will be utilizing the additional ports of the ESS. Both BOBs will be available for different prices and will be available at time of purchase depending if the rotary table is desired. Special upgrading prices will also be made available to existing customers wanting to add the rotary table at a later date.

We hope this helps define the operation of the rigid tapping and the assets needed to implement it. We will continue to develop this new technology and you will most certainly see it on the Pulsar series of milling machines.

Regards,
Novakon Team

[brianbonedoc]

Thanks for the explanation! So i take it that I am not going to do any damage the way I have it mapped.

[Novakon]

No, there will be no damage changing the mapping for the axis control from A to C. At this point it is all cosmetic. I would really love to see Mach4 up and running, but the schedule keeps moving outward so we will compensate with hardware.

Regards,
Novakon Team

[brianbonedoc]

Well apparently you Mach3 doesn't like the spindle and C axis using the same pins at the same time. If C axis is active the spindle won't operate. But it does work if BOB switch is set to Tapping mode, then you CAN use the A axis and spindle together without a problem.

[LeeWay]

I think that is how you have to do it.
The switch does use the spindle as A axis when in tapping mode.
I never turn the switch off from tapping mode. I just keep it there.
Of course, I am not trying to use a 4th axis either.

[brianbonedoc]

Yeah too bad - I thought I had an elegant solution, but I guess not. If the BOB had another output I could assign to C axis and hook up rotary table it would be perfect.

[LeeWay]

Before you call it a nogo, what version of Mach are you using?

[brianbonedoc]

.066 thats what came w/ the pulsar

[LeeWay]

That is what I am using too. I did try other versions and did not have good results. One version would not home correctly and the other version would not operate the spindle.
You might try version .062 or .057.
I think Gerry mentioned that those two versions seemed to have the fewest glitches and were the most stable for most users.
I haven't tried either of those though.

What you are wanting to do SHOULD work.

[brianbonedoc]

To be honest - I have had 'gremlins' in my machine, but I never know if that is operator error or truly Mach errors. I agree that it should work - because why would it work on one axis and not another one.

[brianbonedoc]

So I ended up writing a modification to the Tormach Post Processor for SolidCam that I found online, it converts the G84 and G84_peck into G code that the Pulsar likes. It basically converts the tapping cycles to A and Z movements. I arbitrarily decided the peck cycle would go 4 turns CW, then 2 turns CCW, then 4, etc. Here's a sample of the code output when I tell SolidCam to use the G84peck. The first part drills the pilot hole, then the tapping routine is below. I added comments so the user could figure out what Mach is supposed to be doing.
If any of the gurus see anything funky please chime in. I know the code is a little weird w/ the extra Speed commands but it doesn't affect the machine movement.

N1 (TOOL 3 - DIA 0.2)
N2 (TOOL 5 - DIA 0.25)
N3 G90 G17 G40 G80 G00 G50 G94 G64 G20
N4 M06 T3 H3
N5 (D-drill2)
N6 S4000 M03
N7 G00 G54 G90 X1.4239 Y1.8388
N8 Z0.5
N9 G98 G81 X1.4239 Y1.8388 Z-0.5 R0.1 F5.
N10 G80
N11 Z1.
N12 M05
N13 G00 Z2
N14 M06 T5 H5
N15 (D-drill1)
N16 S0 M05
N17 G00 G17 G54 G90 X1.4239 Y1.8388
N18 S200
N19 S0
N20 Z0.5 M00 (Make Sure Mode is Set to TAPPING and press Start)
N21 G98 G00 X1.4239 Y1.8388 Z0.1 (Rapid To Start Height of Tapping)
N22 G91
N23 F10.
N24 A4. Z-0.2 (Start CW Tapping A-axis is rotating Spindle)
N25 A-2. Z0.1 (CCW rotation to remove Tap)
N26 A4. Z-0.2 (Start CW Tapping A-axis is rotating Spindle)
N27 A-2. Z0.1 (CCW rotation to remove Tap)
N28 A4. Z-0.2 (Start CW Tapping A-axis is rotating Spindle)
N29 A-2. Z0.1 (CCW rotation to remove Tap)
N30 A4. Z-0.2 (Start CW Tapping A-axis is rotating Spindle)
N31 A-2. Z0.1 (CCW rotation to remove Tap)
N32 G00 A-8. Z0.4 (CCW rotation to remove Tap)
N33
N34 G80
N35 Z1.
N36 M05
N37 G00 Z2
N38 M30

Here is the video:
You will notice at the end of the tapping cycle the spindle seems to stop like the pulley is slipping or something, not sure what the deal is.
No comments about the cheap Harbor Freight hand tap I am using. . .

[daniellyall]

very good work

[vmax549]

That trick ONLY works if you have a step/direction spindle servo drive. Then you have to calculate your tapping depth x C revolutions.

A really slick way is to add a formula to C through a Mcode Set C to the Threads per inch you are tapping. NOW the C will follow
Z at the thread TPI. then just call the depth of the hole and the C will do the turns for what ever depth you go.

Say you set up for 20 tpi (formula C= Z*20) then call Z-1.00. Z will go to -1 and the c will make 20 turns. You have to set up C to rotate backwards because the C will follow the direction of Z-1 = C-20

When you are done tapping call a Mcode to reset the formula to" C= C" and you are back to normal control.

(;-) TP

[brianbonedoc]

TP- yes all the Pulsars have servo spindles so this only really works on those. I did do it your way for the G84 cycle but that was too easy and for peck tapping I wanted it to back out slightly each cycle which proved more challenging for a non programmer.

[vmax549]

HIYA Brian Did you say you tried setting Caxis to the same port and pins as the spindle. (steps per = steps for 1 turn). Did it work out ok G1 C10 = 10 turns.

If so I can show you a really slick way to do rigid tapping using Canned cycles in mach3.

Just a thought, (;-) TP

[vmax549]

Even Peck tapping (;-) completly programable from the canned cycle Q controls the peck depth just like the big boys.

(;-)TP

[SCzEngrgGroup]

Terry,

Did you get yourself lost again? This is CNCZone, not the ArtSoft forum.... :-)

Regards,
Ray L.

[brianbonedoc]

TP - please tell! That'd be great. Thx!

[vmax549]

Does you machine work as I had asked ? mapping the C to the spindle

(;-) TP