Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: mckoz on October 25, 2010, 08:46:58 AM

Title: Tube/pipe coping or notching
Post by: mckoz on October 25, 2010, 08:46:58 AM
I can't seem to find the right topic, so my apologies if this has been answered.  I'm finishing up a Mach 3 machine with three axis plus a rotary table that mounts in either vertical or horizontal orientations, and I'd like to know if there is a plugin or relatively simple method to program in various tube / pipe fitting cuts.   It could be done with an end mill similar to the way RMD does it with their manual TN-800, or with a profile cut using a small mill or plasma torch with the pipe rotating. 

Cheers
Title: Re: Tube/pipe coping or notching
Post by: BR549 on October 25, 2010, 09:42:46 AM
GO to the CandCNC website and look at their 4th axis plugin. It does what you need I believe.

(;-)TP
Title: Re: Tube/pipe coping or notching
Post by: Cartierusm on October 25, 2010, 11:15:06 AM
I don't know if there's s a simple way to do it, i just checked out the CandCNC website out of curiousity and couldn't find the plug in.

Anyway, what do you use for CAD/CAM? What I use is Rhino and RhinoCAM and what I do is draw the part and the thing it's going to go to and then slice the tube from the other part to create a tube miter, then I use Curve>Duplicate Edge and that gives me a line that is the shape of the miter, then I use the 4th Axis engrave option to follow that line.

NOW I've never actually cut a tube miter this way YET, but will be later this week and this seems as though it might work.
Title: Re: Tube/pipe coping or notching
Post by: mckoz on October 25, 2010, 11:20:21 AM
I looked at their website as well and didn't see the plugin.  I use Solidworks, but haven't picked a cam program yet, still undecided.  Very interested to hear how your miter works, but designing the cutout inside of Mach3 would make fabrication of racing frames much easier than drawing each one.  I found an interesting program called http://digitalpipefitter.com/ , and if it worked with Mach3 (it doesn't), it looks ideal.
Title: Re: Tube/pipe coping or notching
Post by: BR549 on October 25, 2010, 04:42:08 PM
MY BAD it is called rotary plasma, But it appears to be for HIS products only. But you may want to ask Tom anyway.

Sorry.   I saw several others in the past that may work I will look them up.

(;-) TP

Title: Re: Tube/pipe coping or notching
Post by: BR549 on October 25, 2010, 07:08:51 PM
Digital pipefitter >>> outputs in DXF >>>>>> import into Cad and clean up the drawing>>>>>>import into Sheetcam to convert to Gcode >>>>>>

Into CNCwrapper to convert to 4th axis Gcode.

Kinda long winded BUT it works, (;-) TP
Title: Re: Tube/pipe coping or notching
Post by: mckoz on October 26, 2010, 09:26:38 AM
Whew!  Considering all the different ad hoc cuts you have to make during fab, that would be a large body of work.  Well, if no one else has any other ideas, I'll contact the guy at digitalpipefitting and see if he'd be interested in doing a plugin/screen set for Mach 3 - I don't think I'm the only one who could use this, especially for more exotic materials where a hole saw type cutter won't work.
Title: Re: Tube/pipe coping or notching
Post by: BR549 on October 26, 2010, 12:13:28 PM
Digital pipefitter does not output Gcode(;-)It only does prints and DXF drawings. What type of exotic materials are we talking about???

(;-)TP
Title: Re: Tube/pipe coping or notching
Post by: mckoz on October 26, 2010, 12:19:31 PM
Chrome moly, titanium, thin wall mild steel, some types of aluminum alloys; they all get hosed up or don't work at all with a hole saw type coper/notcher.  Sometimes you have very long copes due to curves and small angles between tubes, and even with the right material and the right holesaw, I'll have more than 10" of travel to get the coping right. 
Title: Re: Tube/pipe coping or notching
Post by: BR549 on October 26, 2010, 01:39:35 PM
OK we have done the the same here except I use a carbide tipped boring mill to do the cutting on the hard stuff.

Plasma WILL make it a lot easier but requires some cleanup.

(;-) TP
Title: Re: Tube/pipe coping or notching
Post by: BR549 on October 26, 2010, 07:16:22 PM
I got with Les at Sheetcam and he had a POST that will convert the Y axis to Axis moves. SO if the pipefitter package could put out a DXF profile without all the other stuff added in then it could be

Pipefitter-dxf >>>> Sheetcam >>>>>>> Mach.

Closer, (;-) TP
Title: Re: Tube/pipe coping or notching
Post by: BR549 on October 26, 2010, 07:18:48 PM
I got with Les at Sheetcam and he had a POST that will convert the Y axis to Axis moves. SO if the pipefitter package could put out a DXF profile without all the other stuff added in then it could be

Pipefitter-dxf >>>> Sheetcam >>>>>>> Mach.

AND IF pipefitter could be made into a plugin to SheetCam then it would be a NICE package.

Closer, (;-) TP
Title: Re: Tube/pipe coping or notching
Post by: mckoz on October 26, 2010, 07:20:24 PM
That is closer!  I sent their main email address a query and directed them to this thread - it will be interesting to see if they respond...
Title: Re: Tube/pipe coping or notching
Post by: mckoz on October 28, 2010, 03:11:19 PM
TP:  Well, bad news and some "I don't know" news.  The developer, Stan, of the Dig Pipe Fitter program can't do anything because of some non-competes.   He did offer this bit of information, and I thought based on your experience it might be worth testing:


"There is a DXF export of the template itself.  No toolpath offset is available.  That DXF file is intended for documentation but once you have the polyline from the DXF file you could manipulate it as you wish.
Please go ahead and download Digital Pipe Fitter from the website.  It will even print and export DXF files in a limited way to let you test your workflow. To print or export a DXF from an unlicensed installation: use the Branch Joint and set the branch angle to 53deg.  Export to DXF is under the print menu item."

What do you think?

David
Title: Re: Tube/pipe coping or notching
Post by: BR549 on October 28, 2010, 06:17:59 PM
David I already tested all of that (;-) I knew it worked. I was just trying to trim down the total number of steps to get a simple coped joint ready to cut.

The DXF has a LOT of extra stuff on the drawing that you have to clean up then you can CAM it and produce a cut file that can be used on a 4th axis plasma.

(;-) TP

Title: Re: Tube/pipe coping or notching
Post by: mckoz on October 28, 2010, 06:29:07 PM
Figures.  Too many steps make it hard to justify.  Oh well, I'll keep looking, maybe somebody will have an "in cnc" solution down the road.
Title: Re: Tube/pipe coping or notching
Post by: BR549 on October 28, 2010, 06:48:56 PM
A wizard COULD be done IF one was really good with all the math involved to calculate the profile based on selected profiles and sizes.

I'll keep a eye out for a solution for you.

(;-) TP
Title: Re: Tube/pipe coping or notching
Post by: mckoz on October 28, 2010, 06:49:54 PM
Thanks !
Title: Re: Tube/pipe coping or notching
Post by: BR549 on October 29, 2010, 12:03:54 AM
Looking at the math (which is  way over my head(;-) ) It may be possible to do this as a Macro with a programable front end. You would input P1 diam P2 diam and cut angle.  THen Mach would convert the Yaxis to Aaxis code and run the parametric gcode and cut the profile.

Maybe, IF I can decipher the math.

(;-) TP
Title: Re: Tube/pipe coping or notching
Post by: Chestermarine on October 29, 2010, 06:19:56 PM
Hello All:
This is an intriguing problem. I believe it may lend itself to a simpler solution, but not as visual as a CAM program. If you slice a tube at a given angle, the line at the tube surface is a path in X, (the long axis of the tube) and angle A, the corresponding point as the tube rotates. This is assuming that the tool/spindle centerline, or the plasma torch remains over the tube centerline, Y, as the tube rotates. Therefore, a series of point pairs, X,A will drive the machine along this path. Furthermore, each 90 degrees of rotation is a mirror image of the previous 90 degrees. This path can be calculated in Excell. I can expound on this further, if interested.

Regards,
John
Title: Re: Tube/pipe coping or notching
Post by: BR549 on October 29, 2010, 07:09:59 PM
The math involved can be seen here:    Http://metalgeek.com/static/dan/derivation.html

It can be made simpler than I stated earlier as the formula calculates the Y as every 2 deg rotation of the profile so that will translate into a rotary A axis directly.Then it solves for a X displacement to create the profile.

(;-) TP
Title: Re: Tube/pipe coping or notching
Post by: Chestermarine on October 29, 2010, 11:14:22 PM
How about a paper template marking fixture, using a "laser pointer" to simulate tube #1, and a mandrel the same diameter as tube#2, with a paper wrapped around?

The laser "tube" can mimick any diameter, and be rotated by hand. The paper holding mandrel is on a pivot, to duplicate the required angle of intersect; both "tubes" centerlines intersect. Make as many pencil marks on the paper as you think necessary for the precision of the plasma cut. Also, the paper holding mandrel must be able to be rotated 180 degrees, to get the opposite side of the cut, depending on the type of intersect.

Use "teach mode", and a pointer in the spindle, to follow the paper template on the real tube, using the rotary table, and you get the real program, without math, or CAD programs. In addition, if desired, you could draw an "offset" line from the laser marked path, to account for plasma cut width. No math; no CAD programs; no file manipulation; no "Big Bucks!"

John
Title: Re: Tube/pipe coping or notching
Post by: BR549 on October 29, 2010, 11:56:27 PM
I think the idea was to input 5 values and cut the tube (;-)

(;-) TP
Title: Re: Tube/pipe coping or notching
Post by: Chestermarine on October 30, 2010, 02:31:26 AM
Sorry about that. I missed the "input 5 values" part, but did read the "or relatively simple method to program in various tube / pipe fitting cuts. "
part.
Regarding the "Tubefit" site, and equation #9, they mention plotting templates, and using templates for the best fit. etc.
That equation #9 could be put into Excell, but de-bugging and testing could be quite a task.
Waiting for non-existant, or hugely expensive software could be a bummer.  Regarding a macro, Mach3 doesn't even have a reliable probing macro! This problem is orders of magnitude more difficult.
This tube intersect problem is a good one!  Good luck on finding a viable solution that meets your needs.

John
Title: Re: Tube/pipe coping or notching
Post by: BR549 on October 30, 2010, 12:07:07 PM
You would NOT run it as a macro. It would be a Parametric Gcode program that has a programable front end.

YOu would set the parameters such as

P1Diam
P2diam
Angle
Offset
Thickness

Then as the gcode file ran it calculates each point on the fly and does the move to the next point.

Mach does parametric Gcode VERY well.  Mixed VB gcode??? NOT so well(;-)

(;-) TP
Title: Re: Tube/pipe coping or notching
Post by: Tony Bullard on October 31, 2010, 02:35:23 PM
"YOu would set the parameters such as

P1Diam
P2diam
Angle
Offset
Thickness

Then as the gcode file ran it calculates each point on the fly and does the move to the next point.

Mach does parametric Gcode VERY well.  Mixed VB gcode??? NOT so well(;-)

(;-) TP
 
I'm working on a VB program that writes G Code from the parameters above. The output looks like this.
G01A 123 y6.456
G01A 124 y6.789
the A is in degrees and they Y in inches. One problem-- how is the feed rate controlled? Also, How do you address the rotary axis? In degrees? Also you can't mirror the quadrents unless the pipes are at 90*and then not if the pipes aren't on the same center line.
 
Title: Re: Tube/pipe coping or notching
Post by: BR549 on October 31, 2010, 02:55:25 PM
Hi Tony, I have a parametric Gocde program already done and it works very well. I am waiting on permission from the math author to use his calculations.

THe equation that works the best is #6 from the deriative math.  It best suites the plasma process and straight cuts based on the 90deg angle of Z and XorY

A axis is controlled in deg of rotation.   YorX axis is controlled in programed units (inches or MM)

F###  sets the feedrate

Are you doing it as a VB macro or just using VB to create the Gcode file??

(;-) TP

Title: Re: Tube/pipe coping or notching
Post by: Tony Bullard on October 31, 2010, 04:17:24 PM
Hi TP, I wrote this program years ago in Quick Basic to print out wraparound temples. I’ve since modified it to write scripts to read into AutoCAD for printing and now it writes G code to a file. It’s still in QB and I’m working on getting it into a VB stand alone program. The problem with the feed rate is it should be in surface units per minute. The Y is in inches/min and the A I assume is in revs per minute. Apples and oranges. I’m just dry running it in Mach but a 2” pipe and a 6” pipe both take about the same time to run with the same feed rate. Humm. I’ll attach some files. See what you think.

Tony

Title: Re: Tube/pipe coping or notching
Post by: BR549 on October 31, 2010, 04:53:40 PM
Tony to run correctly you need to set the Axis diam correction to the same as the pipe diam. This way the A and X/Y axis feedrate willl be calculated better. AS is mach will only go as fast as the slowest component(normally A axis in deg)

Look on the settings page and input the tube diameter in the Axis DRO for corrections to apply.

I have a frontend macro that runs from inside the Gcode to program the parametric side  AND set the diam setting in the DRO

(;-) TP
Title: Re: Tube/pipe coping or notching
Post by: BR549 on October 31, 2010, 05:12:45 PM
Tony I ran your code and it looks good.  If you are interested you might want to consider building your application as a mach WIZARD. It could generate and LOAD your gcode program.

I have not been smart enought to figure out the Wizard creation so it is best left for others(;-)

(;-) TP

Title: Re: Tube/pipe coping or notching
Post by: Tony Bullard on November 01, 2010, 07:21:40 AM

Thanks for the info TP. I would have no idea of how to write a WIZZARD. Sounds like a good Idea. I'm going to be away for a few weeks and will check back to see how you're coming with your frontend macro. I have no idea of how that works either. I'd be interested in understanding that process. There's a few more things I need to add to my program like which side of the run pipe to offest the branch pipe. That could be function of which direction the "A" turns.

more later,
Tony



Title: Re: Tube/pipe coping or notching
Post by: BR549 on November 04, 2010, 11:51:41 AM
OK GUYS, The Tube Coping program has been setup in the MACH TOOL BOX section. There are 2 basic version 1 has a programable front end that asks the right questions and you fill in the blanks. You WILL need to set up the M1222 macro and place it in your macro directory.

The other you change the Gcode variable values before you start. It is setup for X/A motion at the present.

Have fun, (;-) TP
Title: Re: Tube/pipe coping or notching
Post by: Cartierusm on November 04, 2010, 02:38:35 PM
Very cool. Good work.
Title: Re: Tube/pipe coping or notching
Post by: Captain Midnight on January 16, 2011, 01:20:43 AM
How do I navigate to the  MACH TOOL BOX section?
Title: Re: Tube/pipe coping or notching
Post by: Hood on January 16, 2011, 03:20:49 AM
How do I navigate to the  MACH TOOL BOX section?
Look down near the bottom of the forum and you will see the Downloads section then there is a child board called Mach ToolBox.
Hood
Title: Re: Tube/pipe coping or notching
Post by: Captain Midnight on January 19, 2011, 05:40:38 PM
I found it, thank you.