Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: lgr on March 29, 2011, 03:11:20 PM

Title: 4th axis setup
Post by: lgr on March 29, 2011, 03:11:20 PM
I've read most of the 4th axis posts and haven't seen my problem so I'm hoping somone can help. I'm setting up my forth axis on a camtech router that has been converted to Mach 3 with a CNC4PC, C11G board. Everthing has been working great for a year and a half but now I want to try my forth axis. I'm using Rhino 4 and Rhino Cam 2.0 basic with the 4th axis option. I set up the "A axis" so one revolution equals 360 on the DRO,the problem is when I run the machine at 200 inches a minute feed rate the A axis is rotating at 200 degrees per minute which slows the other axis down as well. Also what is "ROT 360 rollover " and "Ang short Rot on G0"used for? I've checked off "use radius for feedrate" and "A rotations enabled" not sure if that's correct or not. In the rhino cam post there is an editable value under Multiaxis motion, angle value, scale factor, not sure what it's for but I have a request into Mecsoft for the answer. Thanks for your help
Title: Re: 4th axis setup
Post by: RICH on March 29, 2011, 04:57:17 PM
Info on configurable items such as "Rot 360 rollover" can be found in Mach3 Installation & Configuration Manual, page 5-37.
Attached is a summary of what is in the manual relating to feedrates.
RICH
Title: Re: 4th axis setup
Post by: ger21 on March 29, 2011, 05:00:15 PM
In the A diameter DRO on the settings page, you need to enter the diameter of the part, if you have Z zero at the surface of the part. If Z zero is at the center of rotation, enter .001 in the A diameter.

This should give you the proper feedrates. "Use Radius for Feedrates" is only active if the A diameter DRO is not = 0
Title: Re: 4th axis setup
Post by: lgr on March 29, 2011, 09:29:19 PM
Thanks for the reply, The machine came with a Mdrive 34 plus stepper for the rotary and it was set at 6320.0894 steps in the previous software. Unfortunately with that motor I can't change or verify the  resolution without a special cable and software. By using a degree wheel i was able to calculate that it is traveling 1 revolution for every 11.9 degrees indicated on the DRO. The number I get to correct the resolution is (360/11.9) X 6320.0894= 1911195.34 and I believe that's too high for 25kHz. any suggestions?
Title: Re: 4th axis setup
Post by: Hood on March 30, 2011, 05:05:08 AM
Increase the kernel
Hood
Title: Re: 4th axis setup
Post by: lgr on March 30, 2011, 12:01:57 PM
Thanks for the suggestion Hood, How do you make changes to the kernel speed "stick" I've changed it in the driver test program and it says excellent up to 65000. and I've tried to change it in the diagnostics page too and it jumps back to 25000. What am I doing wrong?
Title: Re: 4th axis setup
Post by: Overloaded on March 30, 2011, 12:39:15 PM
Under Config/Ports and Pins.
Be sure to restart Mach after your selection.
Title: Re: 4th axis setup
Post by: lgr on March 30, 2011, 03:59:56 PM
Thanks for your help so far, sometimes I think it would be easier to train beavers to look at a photo and then chew out the shape I want.  I have the DRO showing 0- 360 for each  revolution of the A axis but when I run the code it does at least 1 revolution for each line of code I've talked to mecsoft and the say it's not the Rhinocam or post any ideas? Here's a bit of the code and I said each line causes the A to rotate at least a revolution it takes forever before it makes an X move.

G00 G49 G40.1 G17 G80 G50 G90
G20
(4th Axis Parallel Finishing)
M6 T2
M03 S1
G01 X1.0000  Z6.3750 A0.000 F150.
Z6.2500 A0.000
Z6.2499 A-1.145
Z6.2500 A-1.718
Z6.2499 A-4.307
Z6.2500 A-4.781
Z6.2499 A-10.135
Z6.2500 A-12.053
Z6.2499 A-22.961
Z6.2500 A-23.534
Z6.2499 A-29.088
Z6.2500 A-30.233
Z6.2498 A-33.869
Z6.2500 A-34.442
Z6.2499 A-39.223
Z6.2500 A-41.141
Z6.2499 A-54.540
Z6.2500 A-55.685
Z6.2499 A-65.448
Z6.2500 A-66.593
Z6.2499 A-69.576
Z6.2500 A-70.802
Z6.249
Title: Re: 4th axis setup
Post by: Hood on March 30, 2011, 05:06:09 PM
Thanks for your help so far, sometimes I think it would be easier to train beavers to look at a photo and then chew out the shape I want. 

Well almost done that already see pic ;D

Can you attach your xml please.
Hood
Title: Re: 4th axis setup
Post by: lgr on March 30, 2011, 05:16:41 PM
I thought only Canadians could do that LOL. Thanks for your help it's just got to be one switch or something simple but I can't find it.
Title: Re: 4th axis setup
Post by: Hood on March 30, 2011, 05:26:02 PM
Try removing the Rotational Rollover from General Config and see if that helps.
Hood
Title: Re: 4th axis setup
Post by: lgr on March 30, 2011, 06:24:36 PM
I removed the "rot 360 rollover" and that seemed to fix the ratio, but now it's back to being stone slow. I removed the "Ang short rot onG0" as well and didn't notice any difference. I've tried the rotation radius at both 6.25, and .001 no change. Any axis that runs with the 4th axis slows right down to a crawl even though "units a minute" reads around 330, is that degrees a minute? I have the machine set to inches. This is the case when going to "zero" as well. The A axis motor speed is set to around 2000 the sllider will let me go to about 7000. Thanks
Title: Re: 4th axis setup
Post by: lgr on March 30, 2011, 06:37:34 PM
Just to add some ifno to the above, with the feed set at 300 it took 4 minutes to run through 200 lines of code and that's just a test cylinder no detail on the object what so ever.
Title: Re: 4th axis setup
Post by: Hood on March 30, 2011, 06:39:06 PM
Yes units on a rotational axis are degrees so 330 degrees per min.
There are settings for radius on I think settings page, try entering 0.0001 for the A and see if that helps, Ger is the guy for rotational axis so maybe he will pop in and advise.
Hood
Title: Re: 4th axis setup
Post by: lgr on March 30, 2011, 09:08:23 PM
I've played with the radius a couple of times both .0001 and the 6.25 which is the rad for the part in the test file, without any change. Any suggestions for soft limits/  I set them at +999999. and -999999. not sure if thats right it doesn't mention 4th axis in that section of the manual.
Thanks for all of the suggestions. I'm going to give up for now and index it with the the jog buttons every 20 degrees or so and run it in 3d. I have to get some parts out for Monday and I've got 3 full days into computer wrestling with only a small amount of progress. If you think of anything let me know
Title: Re: 4th axis setup
Post by: lgr on April 14, 2011, 06:42:40 PM
I'm back! Finally got the project made and shipped by indexing the 4th axis with the jog buttons and running a normal 3d file. Now I want to trouble shoot it again without the deadline pressure. I did some more reading on the forum and i wondered if someone can comment on these ideas. I was trying to run the file of off a USB thunb drive which I now understand is a no no and I'm running off of a motherboard mounted parrallel port and no stand alone graphics card. Would you suggest adding a high quality parrallel port card and a stand alone graphics card or a smooth stepper card or some combination of both? Thanks for your help.
Title: Re: 4th axis setup
Post by: lgr on June 14, 2011, 08:41:10 PM
It's June already and I still haven't got this 4 axis working properly. Just a quick update I added a stand alone graphics card and increased memory to 2 gb and stopped running programs off of a USB thumb drive. i also bought a smooth steeper card but I haven't got that installed yet. The combined motion seems a lot smoother now. The problem is every time I try to run a 4th axis program and the G code calls for movement even if it's only 1 degree the 4th does a complete revolution
before any of the other linear axis move. For instance if you look at the code below, the "A" or 4th axis rotates a full revolution until it hits the A -1.818 location then the Z moves from  Z5.4337 to Z5.4337 the 4th axis does another full revolution until it reaches A -2.727 and so on. Why would it not just move from A-1.818 to A-2.727 with out  doing a complete revolution? Any suggestions would be appreciated.
G00 G49 G40.1 G17 G80 G50 G90
G20
(4th Axis Roughing)
M6 T1
M03 S4583
M8
G01 X0.0000  Z6.7306 A0.000 F200.
X0.0000  Z5.4091 A0.000
X0.0000  Z5.4337 A-1.818
X0.0000  Z5.4452 A-2.727
X0.0000  Z5.4455 A-3.182
X0.0000  Z5.4410 A-3.636
X0.0000  Z5.4318 A-4.090
X0.0000  Z5.4174 A-4.545
X0.0000  Z5
Title: Re: 4th axis setup
Post by: Tweakie.CNC on June 15, 2011, 03:18:49 AM
I think you may need to change to Incremental mode to achieve that. Change the G90 to G91 on the first line.

Tweakie.
Title: Re: 4th axis setup
Post by: RICH on June 15, 2011, 06:21:27 AM
G91
G0 A-1.818......... rapid / rotates to that angle  at max velocity
G01 F200 Z5.4452 ......Z move at the commanded feedrate
G0 A-2.727  ......... rapid / rotates to that angle  at max velocity

You can play with the above trying different checked Rotation in Config but should just index.

RICH




Title: Re: 4th axis setup
Post by: BR549 on June 15, 2011, 10:35:07 AM
The 4th axis should not be a problem BUT it requires a FAST A axis to do basic 3d work. The combined moves can ONLY move as fast as the slowest component (A axis) . Using Radius COMP is required for MACH to be able to correctly comp the feedrates. Even then the calculation is BASE on how fast the A can move.

IF you need XAZ to go FASTER make the A go faster. The rest of the axis's will follow (;-)

Just a thought (;-) TP
Title: Re: 4th axis setup
Post by: Katoh on June 15, 2011, 11:07:42 AM
lgr
I have a 4th axis on my machine, and it seems to work quite well, its not super fast, but its a lot faster than 200deg/min.
Of memory it runs a revolution every 10secs.
I dont really have much advise to offer, but if you like I can send you my XML file and you can look through it to see if and what differences are between yours and mine, especially in the configs and motor tuning.
My 4th axis is my B axis as it runs parallel to the Y, and I'm using CNC4PC bo.boards, I cant see why or what could be at fault.
Title: Re: 4th axis setup
Post by: BR549 on June 15, 2011, 12:26:38 PM
Now an interesting side bit.Long ago I did play with a macro to monitor the Z height and apply a FRO based on Z height above the A. That was before Brains and the macro was a bit slow. BUT it did help.

Might be time for someone to try a Brain or a plugin.

You could base it on IF A & XorY are moving then Zheight x PIE =area.  That might be able to help adjust the FRO to speed up the comp in 3d moves.

Hopefully Ver 4 will properly adress the issues. (;-)

Just a thought, (;-)TP
Title: Re: 4th axis setup
Post by: Richard on June 15, 2011, 02:35:20 PM
I wrote this program for a test and measured my results with a contact tach (probably not real accurate). All the option boxes left unchecked.

G1 F150 A720 X5
G0 A0 X0
M30

radius comp on with radius of 4" chuck, measured feedrate was 32 ipm
radius set at 0.0001, measured feedrate was 45 ipm

To get my feedrate up to 150 ipm I had to set a feed rate of F540 ( this was with chuck radius entered)

Richard
Title: Re: 4th axis setup
Post by: RICH on June 15, 2011, 04:43:02 PM
Is the 4th axis driven by a stepper?

RICH
Title: Re: 4th axis setup
Post by: lgr on June 15, 2011, 09:02:55 PM
Thanks everyone. I'll try your ideas, Rich it's a stepper machine. Katoh I would like to try your XML file, thanks for the offer.
Title: Re: 4th axis setup
Post by: Greolt on June 15, 2011, 11:11:08 PM
Now an interesting side bit.Long ago I did play with a macro to monitor the Z height and apply a FRO based on Z height above the A. That was before Brains and the macro was a bit slow. BUT it did help.

Might be time for someone to try a Brain or a plugin.

You could base it on IF A & XorY are moving then Zheight x PIE =area.  That might be able to help adjust the FRO to speed up the comp in 3d moves.

Hopefully Ver 4 will properly adress the issues. (;-)


Unless I am having a bad day and completely miss the intent of what you are saying, this feature already exists in Mach3.

It is often referred to as  "Use Radius for Feedrate".   The calculations were all wrong for a long time, but were fixed Christmas before last, and now works great for me.

Greg
Title: Re: 4th axis setup
Post by: BR549 on June 15, 2011, 11:32:19 PM
SO you are saying that MACH can adjust the feedrate blend based on the height of Z off the A axis centerline automatically ?
I must have missed that.

(;-) TP
Title: Re: 4th axis setup
Post by: Greolt on June 15, 2011, 11:44:44 PM
Yes.

It gives the called for feedrate of the tool through the material at any given radius.  Within certain constraints.

Ascertains the radius by taking the value of the Z axis DRO, together with the  "Rotation Radius" DRO.  (IMO this DRO could be better named)

Greg
Title: Re: 4th axis setup
Post by: BR549 on June 15, 2011, 11:48:35 PM
OK COOL but if it runs from the Z height what is the DRO for ?? I'll have to do some testing next week.

(;-) TP
Title: Re: 4th axis setup
Post by: Greolt on June 15, 2011, 11:51:29 PM
OK COOL but if it runs from the Z height what is the DRO for ?? I'll have to do some testing next week.


It is needed if Z axis origin is not at the centre of rotation.  So in effect it is an offset value.

Greg
Title: Re: 4th axis setup
Post by: BR549 on June 16, 2011, 12:17:56 AM
OK so in  nut shell IF your Z is above 0 it runs off the Zheight and IF your Z is below 0 it runs off the DRO values.

COOL, I ll have to test it again, (;-) TP
Title: Re: 4th axis setup
Post by: Greolt on June 16, 2011, 12:32:07 AM
It always uses both values.  Adds them together.

Greg
Title: Re: 4th axis setup
Post by: Richard on June 16, 2011, 01:31:27 PM
Thank you Greolt, I did not realize the z axis value would effect the feed rate, mine was set at +6.8 when I ran my test file.
Set it back to 0.0 and a axis flew!
now I think I understand cncwrapper better too.

Thanks again,

Richard
Title: Re: 4th axis setup
Post by: Katoh on June 17, 2011, 01:39:38 AM
lgr
I have sent you a pm. hope it helps.
Title: Re: 4th axis setup
Post by: BR549 on June 17, 2011, 05:24:26 PM
HI Greg IS there any instructions for the new radius comp . It acts backwards here witheverything I try.When it needs to slow down it speeds up.

If I turn off comp it is constant rotation like it should but I can't  figure a combo to make work correctly.

HELP, (;-)TP
Title: Re: 4th axis setup
Post by: Greolt on June 21, 2011, 05:57:39 AM
Sorry for slow reply.   Elderly Mother is in hospital for emergency heart operation.


The documentation as far as I can find is scant.  The web site includes the following,

Using Mach3 Mill pdf for version 1.84+.
Section 6.2.2.7 mentions "Diameter/Radius correction" but it is vague and does
not explain its use. No explanation that this is an offset value.

Mach3 Install and Config Guide pdf
Has no mention of this feature.

Greg
Title: Re: 4th axis setup
Post by: BR549 on June 21, 2011, 06:29:36 PM
OK  ;D Maybe Brian can explain how it is suppose to work ????

thanks (;-) TP
Title: Re: 4th axis setup
Post by: Greolt on June 21, 2011, 06:48:22 PM
Here is a copy of an explanation I wrote somewhere else,

====================================================================================

All axis move in units per min.   With a rotary axis those units are degrees. 

So what is 60 ipm on the linear axis (desired speed of the tool in the work), is 60 degrees per min for the rotary.

That 60 degrees per min angular feedrate will make the tool move through the work at a speed dependant on the distance the tool is away from the centre of rotation. (in your case, very slowly)

So Mach has a feature to compensate the rotary axis feedrate, to accommodate differing radius that the tool is cutting at.

It is activated via the Toolpath Setup menu.   Check "Use Radius for Feedrate"  All the other settings in this box are to do with the toolpath display window.

On the Settings page there are three DROs labelled "Rotation Radius".  IMO they would be better labelled "Rotation Radius Offset"

They are to tell Mach the distance that the relevant axis origin (Z in this case) is offset from the centre of rotation.  (A axis in this case)

So if you are machining on the outer surface of a 10 unit diameter job and Z axis origin (zero) is set on that outer surface, then the correct value for the "Rotation Radius Offset" DRO is 5.  The distance that Z origin is OFFSET from centre of rotation.

If, on the other hand, the Z axis origin is at the centre of rotation (my preferred method for most jobs) then the correct value for "Rotation Radius Offset" DRO is zero.  The distance that Z origin is OFFSET from centre of rotation is zero.

Mach takes the Z axis DRO value and the "Rotation Offset Radius" DRO value and adds them together to ascertain at what radius the tool is cutting at any one time.  Then compensates the angular feedrate to have the tool move through the material at the desired speed.

Maximum velocity as set in motor tuning is honoured, so that will always be the upper feedrate limit.

Now there is one little "Gotcha".   A zero value in the "Rotation Radius Offset" DRO will automatically disable the entire feedrate compensation feature.  This is a known bug and is being addressed by Artsoft at this time.  Hopefully it will be fixed soon.

The workaround for this, is to use a very small value (eg. 0.001) in the "Rotation Radius Offset" DRO when zero is the correct and desired value.  Small enough to have no measurable effect on feedrate, but not zero.

===========================================================================================

The last bit about the zero value disabling the feature has been mostly fixed in the dev version, but does apply to the lockdown version.

Hope this is of some help.

Greg
Title: Re: 4th axis setup
Post by: cncrudi on April 26, 2012, 07:49:55 PM
 Need Help!!!   ???

First sorry for my english!

I also have some problems with Setup the 4th Axis.

I also use RhinoCam to calculate the Toolpath for Mach.  Every time i use the 4th Axis Operation (roughing, ect.) , the Output of PP write the negative ,,A,, - Values.  The simulation of Rhino the workpiece turn cw and mach will turn it ccw. I try to change the entries in the PP, but the result is everytime the same. the axis in mach turn different to Rhino, cause the output have negative A- Values.
The changed entries in the PP of RC have no reaction. ( manually entrie for cw = ,, -,, for ccw,, +,, )
 
If i use the indexing axis and mill the workpiece step by step (mill first plane, turn 90, mill second plane, turn,....) the PP will accept my entries in the PP for ccw and cw  turn. ( but different direction, ccw ,,-,, and cw ,,+,,) .
result of them is an wrong workpiece. My test file was an turbo wheel with backward blades. the blades at the sheet are right dir.. on the mach screen are left.  i try to change the stepper setup, but this is not the problem. i can do i want, the simulation in RC , the toolpath in Mach and the direktion of axis are not the same. i can´t put it in the same way.
 i have no idea.  ???

Please Help!
 Rudi

Title: Re: 4th axis setup
Post by: Greolt on April 26, 2012, 09:33:35 PM
Rudi

Mach will only display rotary axis toolpath if it is designated "A" (not B or C)

And will only display it correctly if the rotary direction is per convention.    Some users like to have a rotary axis turn in the opposite direction to convention.  Don't know why.

Conventional direction is as described in the Right Hand Rule.  See Pic.

Greolt
Title: Re: 4th axis setup
Post by: BR549 on April 26, 2012, 09:36:09 PM
YOu need to change teh seting for the A axis in Config Ports and pins. Change the DIR active low setting then it should rotate in the correct direction as the code commands.

(;-) TP
Title: Re: 4th axis setup
Post by: cncrudi on April 26, 2012, 11:14:41 PM
THX for quick answer!!

Yes i try the setup, change entries in port and pins, but the main direction in RC Simulation is cw, not ccw. So the toolpath is different to mach.

what is wrong!?

Best regards.
Rudi 
Title: Re: 4th axis setup
Post by: BR549 on April 27, 2012, 05:38:03 PM
ARE you sure you have the correct POST for MACH3 4th axis ?
Title: Re: 4th axis setup
Post by: BR549 on April 27, 2012, 05:54:25 PM
Can you post a copy of the program to test here?

(;-) TP
Title: Re: 4th axis setup
Post by: cncrudi on April 27, 2012, 06:38:28 PM
Hey!

You got my message?
I´m now sure to 90% that mach ist the problem, cause the PP make just a ,,simple,, code with negative entries on A. But the constellation from the dir and the axis are ok. just the toolpath in mach is reverse. if i jog the axis the dir are also ok. maybe mach displayed wrong or maybe the toolpath ok to !? (i told you).
for example,... if the tool is fixed on z,.... the axis turn cw, but if you fixed the axis and turn the tool it will be displayed ccw.!?!? right or not??

The PP on RC is one from 5 PP for Mach (Mach1 to Mach3, it seems all the same). In RC is an PP- Editor where i can inspect what´s happend and i can change something. The PP File are open and show all important entries for working.
Once i can´t change is the standard dir from 4 Axis Milling  Process (or i can´t find the right key) , the indexing dir i can change.
last  the output code of RC can´t have as much impact of the displayed toolpath.

I  was testing today the things i wrote you, and all works fine ( regardless of the toolpath of mach).
I thought before that i can see always the same path. RC SIM/Mach/Workpiece.
It seems to be a wish.
Thats the last working constellation.

i´ll wait for message

best regards
Rudi

...
Title: Re: 4th axis setup
Post by: cncrudi on April 27, 2012, 06:39:46 PM
I send you PM.

BR Rudi
Title: Re: 4th axis setup
Post by: BR549 on April 27, 2012, 07:19:14 PM
THE A axis AND MACH3 should match. IF NOT fix it.

IF the CAM and MACH do not match then you need to correct the CAM side.

(;-) TP
Title: Re: 4th axis setup
Post by: cncrudi on April 27, 2012, 08:16:13 PM
--- ;D--Yes!!....

I Try to fix it..... ;D, but how??

Thats the reason why i ask  here!!!  :)

You read the code? i´s very simple code. in  what way in this code can change toolpath on Mach??

The standard turn dir with the  entries from  the neg. values i can´t change. i think that is not the problem, because if i write the same code in MDI i have the same effect.

Do you think about the different Dir from Path and Axis?? Maybe it shows normal.??

BR  Rudi
Title: Re: 4th axis setup
Post by: Greolt on April 27, 2012, 09:00:52 PM

I Try to fix it..... ;D, but how??

Make your rotary axis turn in the direction as indicated in the Right Hand Rule as shown above.

If that is done, then Mach3 will be correct and the rotary axis will be correct.

That just leaves the Post Processor that you are using in RhinoCam.

I am not familiar with RhinoCam but there should be a setting for the rotary axis output.

Greolt
Title: Re: 4th axis setup
Post by: BR549 on April 27, 2012, 09:05:04 PM
RUDI I looked at your Gcode and MACH3 is doing exactly what the Gcode says to do according to standard A axis configuration. The A axis rotates exactly in the direction the Gcode says to.

IF you want the PROGRAM to do something different you will have to figure it out in RhinoCam. All you need to do is correct the rotation.

OR you can take the Gcode and do an edit in notebook and replace all A- with A. Then the program will run the opposite of what it does now.

IF your A axis is running backwards to the MACH3 toolpath display you need to correct that part in MACH3 change the DIR pin active low for A.

(;-) TP

(;-) TP
Title: Re: 4th axis setup
Post by: cncrudi on April 27, 2012, 09:53:51 PM
Yes!

I know that the axis  do what the code says and it is similar to the convention. I wrote you with pics in Mail.
But if i change the the Port and pin config, only the axis dir change, not the displayed toolpath!!! The axis rotation is correct with RC Code, the RC Sim and the conventions!!

now. all the ,,Problem,, is the reverse toolpath shown in Mach. the axis rotary it´s ok.

Ger.  I changed and play with all the values (port and pins) in config !!!! I will get not any other constellation,

BR. try to put the code to mach and play with Port and pins, so you will see that only the turn dir change, not the path dir on Mach!

For the next example, if Mach accept all written code, it will be the same if have negative or positive values. the Toolpath have to follow in same dir.
RC give out everytime negative A Values in Standard Mill Operations (not indexing) and rotade cw!!! That is fixed in RC and is right to the conventions!!! I can´t change, cause i t is programmed and normal in RC !!!! Also i can´t edit the whole Code, cause by example my turbo wheel have more than 2000 lines with A values!!
 By the way, a lot of People use RC with MAch. 

BR. What do you think about axis way´s and tool way´s??????
 I try to explain, if the tool is fixed ( Z) ,....and the axis rotate cw, shows the moving tool ccw on a fixed axis.!!!!! Thats what Mach shows.
could it be the solution????

BR Rudi
Title: Re: 4th axis setup
Post by: cncrudi on April 27, 2012, 09:59:15 PM
BR.  if you load the code in Mach, your screen shows like mine sended screen picture???

If you run the code, in witch dir the toolpath rotade on screen??? cw or ccw??

BR Rudi
Title: Re: 4th axis setup
Post by: cncrudi on April 27, 2012, 10:06:58 PM
I will Post the code !  I hope its help.
Just a simple code without any magic things!  >:D

The RC Sim turn cw!! And the Code follows for A axis rotate cw!
Title: Re: 4th axis setup
Post by: BR549 on April 27, 2012, 11:19:05 PM
Standing in front of the machine the Top of A axis should move towards the BACK of the machine or  Y+ direction With a pos move(A+).

THe top of A axis should move towards you or in the Y- direction with a neg  move (A-)

AND that is what it does. WIth your code in NEG A the top moves toward the front of the machine or in the Y- direction.

(;-) TP
Title: Re: 4th axis setup
Post by: Greolt on April 28, 2012, 06:18:52 AM
Standing in front of the machine the Top of A axis should move towards the BACK of the machine or  Y+ direction With a pos move(A+).

I believe that description is wrong.   But that is the difficulty of such descriptions.  They can be easily misunderstood.

Hence the Right Hand Rule.   Here is another type of visual representation of the Right Hand Rule.

Greolt
Title: Re: 4th axis setup
Post by: cncrudi on April 28, 2012, 06:46:35 AM
Yes Greolt!!!

Thats what i want tell. I try in this time to make a picture that shows the situation now.

Greo.   I was take your rules some days ago and try to recalculate the right way of dir,..... with the following solution.

Its the same code from RC to Mach Screen to Workpiece.

so. in the result that mach shows!!! the reverse Dir, but rotate the workpiece right.

( Or it will show ,,only,,  the toolpath and there are maybe normal to show reverse )

BR Rudi
Title: Re: 4th axis setup
Post by: BR549 on April 28, 2012, 04:36:33 PM
(;-) LOOK at it again, We are talking which way the "toolbit" travels . NOT the stock.

IF you look at a kneemill the table travels BACKWARDS to the way the toolbit moves on the stock yet the toolbit is what sets the direction of the axis.

How I described is ALSO how MACH3 does it "HERE". That is WHY I described it as I did.

(;-) TP

Title: Re: 4th axis setup
Post by: Greolt on April 28, 2012, 05:25:55 PM
OK I'll leave it with you Terry.  ;)

Greolt
Title: Re: 4th axis setup
Post by: cncrudi on April 29, 2012, 08:14:43 AM
BR and Greolt....

it seems  we  talk about the same thing in different ways.  ;)
i try to exlain the way of tool and axis in the last post.
maybe my message is hard to understand, so sorry for my english. 8)

before i was confused about the different rotary direction from RC between standard and increment rotary operations
and also the displayed screen in Mach. before i thought  the mach screen have to displayed in the same direction.

After checking the conventions i have  figured out,  the PP of RC  have wrong values.
(The direction in standard ops. was cw and the increm. ops was ccw.)  ???

Now the situation is written in last post.
It seems to be ok that the Mach screen shows revers (tool way) like the description of kneemill.
It look strange, but it seems to be ok.

if someone have another opinion, please tell.!!

i have to tell thank you for your help.

Best regards
Rudi
Title: Re: 4th axis setup
Post by: BR549 on April 29, 2012, 09:47:27 AM
RUDI I do not know of any way to change the MACH3 toolpathing.  IF you want the toolpath to match the RC you must change RC.

IF you want to ignore the MACH3 tolpathing and want the RC to MATCH the AXIS direction then switch the direct of the axis  so it follows RC and you ignore MACH3 toolpathing.

Your choice, (;-) TP
Title: Re: 4th axis setup
Post by: cncrudi on April 29, 2012, 12:24:58 PM
Hello!

It´s not possible to change the standard output from RC.
All i can change in RC PP is adjust the increment rotation in relation to the standard rotation.
The negative output of A i can´t change. I told you this is fixed writen by program.
Also i can´t change the displayed standart direction of Mach.
So it seems i have to live / accept the displayed reverse Toolpath.
The Axis rotate in Match to RC now.

Maybe Greolt have some idea.

BR Rudi
Title: Re: 4th axis setup
Post by: BR549 on April 29, 2012, 12:36:27 PM
MOst Cams you can change the output code to suite youself through the POST processor.

(;-) TP