Mixing XYZ toolpaths with AYZ toolpaths?

Topics related to wrapped rotary machining in Aspire or VCarve Pro

Re: Mixing XYZ toolpaths with AYZ toolpaths?

Postby TReischl » Fri Jun 26, 2015 8:01 pm

Actually 4D, you did not understand what I was getting at with:

"How does one go about telling customers they need to convert degree dimensions on a drawing to inches on a flat part layout?"

Here is something very simple to show what I mean:

Capture.JPG


Just show me where the wrap/unwrap feature manages that layout?

I did not bother to dimension and draw the whole thing out. But that partial pocket is a good example, where is that boundary supposed to be drawn on a flat layout?

Yes, I can calculate it, but is not something that is "simply" done (to use your adverb). Pros who have been in the industry know how to do it, but then those are not the guys going down to Rockler buying Sharks either, who have never seen CNC before yesterday much less know how to do the calcs required.

Obviously the easiest way to machine this part is to issue a simple "A35.5" then mill the flat and pocket. . .but then you will not see what you are doing before you run it.

BTW, that is not a ridiculously hard part. I pulled most of it from my archives.
http://www.tedreischl.com

Low Profile CNC Router Vise
User avatar
TReischl
Vectric Wizard
 
Posts: 1966
Joined: Thu Jan 18, 2007 6:04 pm
Location: Leland NC
Model of CNC Machine: 8020 Build 48X36X8 RP 2010 Screenset

Re: Mixing XYZ toolpaths with AYZ toolpaths?

Postby TReischl » Fri Jun 26, 2015 9:22 pm

The reply I made above was to illustrate a point about doing rotary axis work.

Wrapping is NOT a bandaid produced by lazy programmers to sort of look like true rotary axis work. There is a real need for it. But is more of a "feature" of a comprehensive rotary programming package.

One possible solution I would put forth to produce a more useful rotary package would be to allow the user to enter into an "indexing" mode. At the start he enters the degrees of rotation for that section of the programming. The software does not show him an unwrapped view but rather the orthographic view from that angle. Features are entered and tool paths created.

The problem with this method is that no CAD packages that I know of would produce the necessary rotated views that another package could automatically read and know what to do with.

So, if someone were to do it most of the drawing would need to be done within that one package.
http://www.tedreischl.com

Low Profile CNC Router Vise
User avatar
TReischl
Vectric Wizard
 
Posts: 1966
Joined: Thu Jan 18, 2007 6:04 pm
Location: Leland NC
Model of CNC Machine: 8020 Build 48X36X8 RP 2010 Screenset

Re: Mixing XYZ toolpaths with AYZ toolpaths?

Postby 4DThinker » Sat Jun 27, 2015 12:09 am

The width generated by the wrapping gadget is the circumference of the cylinder. A 3" cylinder is 3 x pi or 9.425ish. Divide it by 360. Make your 1-degree distance a system variable for ease. The wrapping gadget could do that for you. To locate any indexed area offset from zero on the unwrapped plate take the per-degree value and multiply by the number of degrees. Use the center of a flat area offset from Zero to get the cylinder to rotate to where a flat pocket can be cut by the perpendicular bit. Any XYZ work done in that area could be cut with XYZ moves after the A move to get there, if there was just a toggle to distinguish index moves (A only) from rotary moves (AYZ) and 2.5D moves (XYZ).

It shouldn't be hard to have the cursor position show what degree it is at on an unwrapped material plate as you scroll across the screen. Perhaps on the lower bar. I currently draw a temporary line at zero, then move it the distance my above math has resulted in to be a center reference for any work to be done around it on the cylinder. The software could make this easier, by letting you move any vectors a number of degrees rather than a distance across the unwrapped block. A 3D view of the cylinder could be in another window and updated as any vectors (color coded maybe) or components are added in position for AYZ (wrapped) or XYZ (perpendicular to center) toolpaths. The 3D view could rotate as the cursor moves across the unwrapped field.

I come from a school of thought that prefers to work on how to do it rather than find reasons it can't/won't/shouldn't be done. What I would love Aspire to be capable of relating to rotary axis work doesn't look (to me) like an impossible stretch from where it is right now. Vectric has delightfully added features I've suggested since I started using V-Carve at version 5. It has gone from being a not-too-useful CAD program (compared to Autocad which I was used to), to being more useful and direct (than imported drawings) at getting what I draw in it quickly to tool paths. The programmers need something to do to make version 9 (or 10 or 11) worth upgrading to, and I offer up my needs and suggestions for their perusal. Just because it seems hard to implement doesn't mean it has to be. Easy or hard it can be very rewarding when you end up with a better (rotary design/toolpathing) solution than anyone has thought of before.

4D
4DThinker
Vectric Wizard
 
Posts: 982
Joined: Sun Sep 23, 2012 12:14 pm
Model of CNC Machine: CNC Shark Pro

Re: Mixing XYZ toolpaths with AYZ toolpaths?

Postby TReischl » Sat Jun 27, 2015 12:52 am

What I would love Aspire to be capable of relating to rotary axis work doesn't look (to me) like an impossible stretch from where it is right now.


You said that exactly correct "(to me)". . . . . .

I come from a cad/cam software development background as you have no doubt figured out by now. People have seen too many movies where "whiz kids" bang on a keyboard for a couple of hours and VOILA! this marvelous program runs. What tripe.

The software writing takes work as you can well imagine. The casual user never realizes that a programmer spends a huge amount of effort controlling user input to prevent errors. He does not realize the programmer spends time making sure 0 doesn't occur in divisions (that leads to nasty errors). What goes on behind the scenes would astound most users. However, what is even more work is laying out a plan on how to market the software, provide support and have a model that incorporates the vision of where the software will eventually go.

If I had typed in a manual "Add an @ sign at the beginning of a file name and the post will . . . . ." my competitors would have ate my lunch AND dinner.

A lot of things in software look like they are simple, easy, (and all those other words to add weight to an argument in favor of implementing them) to the user. . . . that is just not the real world of software development.

If the Vectric Team had an easy solution to the rotary issue, they would have been marketing it long before you thought of it. I doubt they would be happy with my solution if they are looking well into the future. The future is certainly not an "@" in front of a file name.

Just a side note, you do realize they would have to alter every single postprocessor to incorporate your suggestion. . . that is a cost and it is recovered how?
http://www.tedreischl.com

Low Profile CNC Router Vise
User avatar
TReischl
Vectric Wizard
 
Posts: 1966
Joined: Thu Jan 18, 2007 6:04 pm
Location: Leland NC
Model of CNC Machine: 8020 Build 48X36X8 RP 2010 Screenset

Re: Mixing XYZ toolpaths with AYZ toolpaths?

Postby 4DThinker » Sat Jun 27, 2015 2:01 am

We are more similar than you know. I also spent time conceiving of, programming, testing, improving a 3D CAD program back when the OS was DOS and Visual Basic was my friend. Just one of my programming projects then. I'm far from being unaware of what programming requires. My "IA-CAD" used an assembly (language) call to manage line drawing fast enough to not bore the user. It lasted until Windows showed up and I lost easy mapping of screen position to 3D coordinate. It filled a need to generate perspective views of interior designs from any point of view. I wrote plotter drivers and managed digitizer inputs well enough that our Landscape Architecture students would use it to make digital 3D models of their topo maps with trees and buildings as blocks (referenced IA-CAD files) you could position and rotate in your current drawing. Then hit P on the keyboard to see it all in (glorious wireframe) perspective. Two clicks to change your point of view. I'd screen key presses for accepted input, and debug the program overnight when students would report unexpected results/behaviour. The update would be on all lab PCs the next morning. This program so increased demand on the college lab that we shortly moved to requiring students to buy and bring their own PCs to studio. 1987 or so.

So "me" is an experienced programmer. A programmer with experience in CAD. I had subroutines and libraries to call for unique functions as I needed them. IBM came to campus once to sell the CAD program they had come up with then, and left shortly after I showed them the BASIC IA-CAD program that my students were already using to win design competitions with. I'm an old fart now though, and love what Vectric is doing for CNCs. They get paid to keep improving their products with sales of their products. I've happily thrown my money at them, and convinced my school to do the same. They already have a generation or two of past post-processors that no longer work, and it is safe to assume that there will be new generations. The machine manufactures don't seem to have trouble coming up with their own updated PPs when new features (like tool changers or rotary axis) are added to their line. You download them from the manufacture's web site. I see code behind every function, and although it may not be the code that is actually there, it is code that could accomplish that function. Much the same way I see toolpaths (and ways to create them) behind joinery and furniture parts now. That is why I know what I propose isn't impossible or unfeasible. Would you prefer no further progress be made along this line?

4D
4DThinker
Vectric Wizard
 
Posts: 982
Joined: Sun Sep 23, 2012 12:14 pm
Model of CNC Machine: CNC Shark Pro

Re: Mixing XYZ toolpaths with AYZ toolpaths?

Postby TReischl » Sun Jun 28, 2015 8:07 pm

They get paid to keep improving their products with sales of their products.


No they don't. They get paid for the current product/version the customer purchases. They are not being paid to keep improving their products.

Yes, the revenue can be used to do updates but that is at their discretion. Yes, we all demonstrate a bit of faith that whoever we purchase from will continue development.

I have included the following as an example of something simple. When the part is set up by the wrapping gadget the distance around the shaft is used as one of the axis, I will use Y for this example. The y value of the workpiece is pi * 6 or 18.8495. Pocket or mortise would be drawn where? Yes, the centerline could be put at an ordinal point, but what does the user do when describing the width of the pocket? Key in the actual dimensions? But that would not be consistent with locating other features rotated around the circumference, those would need to be trigged out (or use the cad program to find them more easily). And that is just for centerlines, other features just get worse. All very inconsistent, all very messy, all leading to gross errors.


Capture.JPG



As others have pointed out the current Vectric model does not support your idea. Sure, a simple mortise might work out fine, but then users have a nasty habit of moving on from there (just like your students). One band aid leads to another, resources are spent creating bandaids, not on robust solutions. Not a good model to operate a business on.

And IF we are actually paying for future development as you tend to believe then I think the money is best spent on robust solutions rather than quick, dirty and lowdown solutions to make a handful of users happy.

And all of this does not address the issue raised previously about getting an ROI for their developments efforts. It is easy for someone to say that if they write it, the users will make it pay off. Uh huh, I have first hand experience with that. . . .never happened. I would love to see Vectric come out with a great 4th axis piece of software.

Long gone are the DOS days when we slapped features on willy nilly. I go back to MS Basic Pro (which could be compiled) and using HALO drivers for graphics. Actually I go back to the TI 994A and the Commodore 64, but I did not write any commercial software on those machines.

When it comes to things like this I think along these lines:

"If I knew a few really good programmers who wanted to write this kind of software, would I hand them over thousands of dollars in the hopes that I would get a ROI on my investment?" Short answer: not only NO, but HECK NO!!!!

Right now, one thing I would really like to see before anything rotary is an impovement in the roughing algorithm. None of us like watching it cut air, none of us are enthralled with "rest machining".
http://www.tedreischl.com

Low Profile CNC Router Vise
User avatar
TReischl
Vectric Wizard
 
Posts: 1966
Joined: Thu Jan 18, 2007 6:04 pm
Location: Leland NC
Model of CNC Machine: 8020 Build 48X36X8 RP 2010 Screenset

Re: Mixing XYZ toolpaths with AYZ toolpaths?

Postby 4DThinker » Mon Jun 29, 2015 1:05 am

My TI-99/4A and Expansion box are still somewhere in this house. So is the cassette tape player used to store programs on. I won that computer in a give-away by throwing my name into a prize box at a newly opening Target store in Harvester Missouri. Never had an interest in the Commodore 64 but did write commercial programs for a little Sharp PC-1500 computer that had a 4-pen plotter on it.

I'll end this with just a request to the Vectric programmer: Consider some of the improvements I've suggested for the rotary capabilities of your products.

Knowing that "ain't gonna happen" is just one of many possibilities. ;)

4D
4DThinker
Vectric Wizard
 
Posts: 982
Joined: Sun Sep 23, 2012 12:14 pm
Model of CNC Machine: CNC Shark Pro

Previous

Return to Wrapped Rotary Machining

Who is online

Users browsing this forum: No registered users and 2 guests