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Third party software and hardware support forums. => LazyTurn => Topic started by: Kingjamez on December 02, 2010, 07:58:01 AM

Title: Inscribed circle, what am I missing?
Post by: Kingjamez on December 02, 2010, 07:58:01 AM
From the definition in the manual, I expect the tool definition "Inscribed Circle" to be the radius of a circle that will completely envelop the tool. Or it stupid person terms for me, how big of a snow angle would the tool make if spun in a circle.

So using that definition, I created a tool in LazyTurn that is a 55 degree diamond tool that is 3/8" long on its longest axis. So I set the inscribed circle to 0.1875. Attached is a screen shot of the result. LazyTurn creates a diamond that is 3/8" on its short axis and about 0.8" on its long axis. There is no way that a circle of radius 0.1875 could inscribe the tool that LazyTurn created.

What am I doing wrong?

-Jim
Title: Re: Inscribed circle, what am I missing?
Post by: Dan13 on December 02, 2010, 09:19:01 AM
Hi Jim,

Tool inserts are defined by the inscribed circle. i.e. the circle inside the insert and tangent to all its sides. From your description I think you were defining a circumscribing circle.

Dan
Title: Re: Inscribed circle, what am I missing?
Post by: Kingjamez on December 02, 2010, 12:52:16 PM
Hi Dan,
Thanks for the help. When I read page 16 of the manual, it's pretty clear that LT's definition of inscribed circle is not the same as the standard definition for inserts. The verbage straight from the manual says:

"2. Inscribed Circle - Defines a circle, which when drawn about the center of the tool insert, will include the entire tool insert."

However, the actual behavior of the program is working as you describe, a circle that fits completely within the insert.

-Jim
Title: Re: Inscribed circle, what am I missing?
Post by: Overloaded on December 02, 2010, 01:02:09 PM
http://www.machsupport.com/forum/index.php/topic,5767.msg69856.html#msg69856
I thought that was corrected in the manual .... I'm sure it soon will be.
Title: Re: Inscribed circle, what am I missing?
Post by: Kingjamez on December 02, 2010, 01:26:34 PM
Excellent. Thanks for finding that Overlord!

Title: Re: Inscribed circle, what am I missing?
Post by: RICH on December 02, 2010, 05:36:03 PM
The definiton is as stated and shown in the link by Overloaded in the manual. Not sure if Art ever checked and answered my question definitively.
Good grief i only have 375 pages of notes...........!
There seems to be some contradication and will need to look thru a lot of the posts and then check each tool out which LT creates.
Thanks, till then,
RICH
Title: Re: Inscribed circle, what am I missing?
Post by: RICH on December 02, 2010, 05:48:16 PM
The problem discussed was that if  you use the "standard definition" ie; inside of the insert then the manufactures tolerences come into play as compared to actualy measuring  the insert.
So that is where the answers and contradication comes into play.   
RICH
Title: Re: Inscribed circle, what am I missing?
Post by: Kingjamez on December 02, 2010, 06:21:11 PM
Hi Rich,

Quote
"The definition is as stated and shown in the link by Overloaded in the manual."

I guess I'm confused now. The definition in the manual, is very different than the post linked to by Overloaded. The manual says the EXTERNAL circle radius is used. However the most recent version of LT clearly uses the INTERNAL circle radius.  See the graphic I attached in the first post for proof.

-Jim
Title: Re: Inscribed circle, what am I missing?
Post by: RICH on December 02, 2010, 07:23:31 PM
What is the revision of the manual you are looking at?

I have rev8 of the manual, and on page 16 of the manual ,the figures from the link are the same used in the manual.
No where on page 16 are the words "the external circle radius is used". The latest manual can be found in Members Docs.

What LT shows on the screen is a related but different matter i will address at a later time.

RICH
Title: Re: Inscribed circle, what am I missing?
Post by: Kingjamez on December 02, 2010, 07:58:08 PM
Hi Rich, I'm reading from rev 8 as well and I quoted it in the third post in this thread. Does that quote match the current wording? To me rev 8 goes out of it's way to very clearly state that the external circle is the correct measurement. Your right that the figures posted in the thread linked to by Overloaded are exactly the ones used in the manual. Art says right underneath that the figure is incorrect. in the manual I have the text says the red circle is the circle used by LT. From my use of it so far, and from Arts post, I don't believe it is. 

Unless of course I am being dense and don't understand the manual and have very clearly read the completely wrong thing.
-Jim
Title: Re: Inscribed circle, what am I missing?
Post by: RICH on December 02, 2010, 08:48:50 PM
Jim,
Art never got back to me on my question......

Let me now try and explain something on where the / my confusion on the definition exists.
Looking at figure 5.13.2, the figure is dimensionaly correct. Now if you were find and use the "inside" inscribed circle along with the tip radius,
then LT should provide an "image" such that the long length would be 0.758". So let me test that and confirm what you originally posted.

Now, for talking purposes ONLY, should you use the inside circle as given by "some" manufactures with a given radius, and say there is a total tolerence of ( .002")  to the cutting edge,
then LT would not give you a true cut of the profile. This is a different issue.......

Now if you define the tool as using the tip center along with a defined tip radius, and it is by definition a 35 deg insert then all will be fine with the exception  of a too large flank cut depth ( by formula
that would be restricted ). So practicaly speaking even if the tool "looks" too big all may be just fine in the path generation.

RICH


 


 
Title: Re: Inscribed circle, what am I missing?
Post by: Kingjamez on December 02, 2010, 09:58:36 PM
Yep, I agree completely. The tolerance should absolutely be accounted for. In my case I'm using a diamond profile insert so, yep, as long as the angle, and tip radius is correct I should be good to go.

Square cutters at 0 degrees (and perhaps trigon) would need to be accurately defined.

Let me know what you find. When I use 0.379 on a 35 degree diamond as the inscribed circle as per one of the figures in the manual, the tool generated by LT is well over 2" long.

-Jim
Title: Re: Inscribed circle, what am I missing?
Post by: Dan13 on December 03, 2010, 01:46:33 AM
Hi Rich,

I don't think I understand your point about insert tolerances. Define it whatever you define in LT, in the end it all comes down to touching off the bar and measuring the diameter. Furthermore, for discussion purpose, the insert tolerances are much better than what you mentioned. It is in the range of 0.01mm (0.0004") for the critical dimensions.

Dan
Title: Re: Inscribed circle, what am I missing?
Post by: RICH on December 03, 2010, 06:28:38 AM
Dan,
True if you use the tip radius, the range on tolerances vary depending on the tolerance class, insert shape and size.
Let not your heart be troubled as the manual will get fixed. Practically speaking, I am thinking all this will boil down to LT's displayed image size of the insert.
RICH


Title: Re: Inscribed circle, what am I missing?
Post by: RICH on December 03, 2010, 07:39:53 PM
Dan,
Here is what I found.......thanks for bringing attention to the problem.

http://www.machsupport.com/forum/index.php/topic,5767.msg113278.html#msg113278

RICH
Title: Re: Inscribed circle, what am I missing?
Post by: Dan13 on December 04, 2010, 01:02:44 AM
Hi Rich,

Thanks for finding this. Can't take the credit for this, as Jim is the one who found this ;)

As to the tool inserts, the world standard to define the dimensions of inserts is by using the inscribed circle, (except for parallelogram shaped inserts). It is coded in the number of eights of an inch. It is usually a sequence of three numbers along with insert thickness and tip radius. In metric system the insert is defined by the cutting length in mm along with thickness and tip radius. Machinery's Handbook has a good description of the American standard.

Dan
Title: Re: Inscribed circle, what am I missing?
Post by: RICH on December 04, 2010, 06:26:29 AM
Thanks for the info Dan. Only Art can say what is actually used by LT.
RICH
Title: Re: Inscribed circle, what am I missing?
Post by: ART on December 15, 2010, 06:46:14 PM
Hi Guys:

 Srry, havent checked this forum in a bit. "Inscribed Circle" is the circle inside the tool tangent to its edges.. as per standard..

Basically it is used only to specify the tool size, but once the tool is created, only the tool itself is used in calculations, LTurn
is really a complex collision calculator.. All of its paths are the collision responces from the created tool to the part..

 Back to my bevels.. :)

Art
Title: Re: Inscribed circle, what am I missing?
Post by: RICH on December 15, 2010, 07:56:47 PM
Thanks for the clarification Art,
So noted in my manual ........page 16

RICH
Title: Re: Inscribed circle, what am I missing?
Post by: Kingjamez on December 15, 2010, 08:19:07 PM
Thanks for the clarification Art,
So noted in my manual ........page 16

RICH

As I have been saying for this ENTIRE thread, rev 8 of the manual DOES NOT say that!!!!! The manual says over and over the EXACT OPPOSITE of the definition given by Art above. I don't know how I can say that any more clearly so that you'll get it.

-Jim
Title: Re: Inscribed circle, what am I missing?
Post by: RICH on December 15, 2010, 09:17:30 PM
Dear Jim,
I heard you, but required a look and see by Art as to how the programing was done to confirm it. Additionaly a user found a display problem.
Happy that you have read the manual, since i can only write and can't read........ :D
RICH
Title: Re: Inscribed circle, what am I missing?
Post by: ART on December 16, 2010, 08:40:46 AM
One last comment while Im on the run here, .. Yes, the manual was wrong.. but think fer a sec about where the manual came from!!  I wrote LazyTurn because peopel like Rich told me that there was a need. I spent months and months coding it and testing it ( With the help of Rich and a few others ) and its perpetually free.
  However, I do not have time to deal with it in terms of support or any other function overall..so it likely woudl have languished unused by most who dont have the patience to learn how to use it if not for RICH who took on manuals and helpfully provides support to people who ask how to do things. For this Rich has recieved nothing.. ( as LTurn makes nothing ). If theres a misunderstanding, or a mistake, it should be nothing other than noted, but he certainly should never be given a hard time about anything.

  I truly consider LTurn to be more Rich's intellectual product more than mine. He took it from something I gave to users as a "Thanks for supporting me" , and ran with it to make it quite usable by anyone who needs such a program.

    As such, he's one of those unsung hero's of the web who gets little other than questions about this or that, and dedicates some of his time to help. PLEASE dont even consider giving him a hard time about a misunderstanding on design or codeing.. the error's are typically mine, the results are his. :)

Art

 
Title: Re: Inscribed circle, what am I missing?
Post by: Kingjamez on December 16, 2010, 09:18:16 AM
I'm sorry , that last post was not intended to berate Rich. I was just frustrated that he continued to say the manual was correct as written despite all my efforts to say otherwise. So I over reacted as is so easy on the interweb.

I do sincerely appreciate all of Rich's contributions. I have read many many of his posts while learning LT and they have been exceptionally valuable. The manual is well written, and provided all the info I needed to get turning.

-Jim
Title: Re: Inscribed circle, what am I missing?
Post by: ART on December 16, 2010, 11:09:12 PM
Jim:

  No hard feelings... forums dont convey emotion very well. Just thougth it'd be good to have it on the board that Rich is one valuable fellow in LTurns development. When he's wrong, its usually that Ive misinfomred him at some point. :)

Art
Title: Re: Inscribed circle, what am I missing?
Post by: RICH on December 17, 2010, 07:08:24 AM
No need to worry about me since there is a big difference on my end as to how something is taken. I am glad if a user finds something is incorrect, recommends a refinement, or questions something for understanding.
There will be more to come.  Now what happens after the comment is a different story. The base stays firm until impact is reviewed, put into perspective, and confirmed. Imeadiate reaction on my part is to go back and look at all the info.......some things are easy......but in this particular case, conflict was found in the info. Yep, 300 pages of info was reviewed and the question becomes ....why is all working when machining something, so what's really wrong and need an answer to the why part. Call that putting it into perspective.

So when saying "I heard ya"  it includes putting it into perspective and that sometimes is not as easy as one would think,
RICH
 

Title: Re: Inscribed circle, what am I missing?
Post by: ART on December 17, 2010, 09:46:06 AM
I hear ya..

:)
Title: Re: Inscribed circle, what am I missing?
Post by: budman68 on December 17, 2010, 07:37:42 PM
Hey Rich, just got an email advert showing what's coming up in the next Digital Machinist magazine. You're in it about Lazyturn, congrats my friend-

Dave
Title: Re: Inscribed circle, what am I missing?
Post by: ART on December 17, 2010, 07:57:26 PM
Excellent. I'll look forward to that issue..

Art  :)
Title: Re: Inscribed circle, what am I missing?
Post by: RICH on December 18, 2010, 07:16:23 AM
Thanks Dave,
Wasn't sure when the article would hit the street.
I am wondering if there will be an increase in the number of LT users and posters.
Guess we'll have to waite to waite and see.
RICH
Title: Re: Inscribed circle, what am I missing?
Post by: budman68 on December 18, 2010, 07:23:09 AM
Yep, I'll have to find a newstand that actually carries that one. Pretty slim pickins around here with toolmaker type mags.

Dave
Title: Re: Inscribed circle, what am I missing?
Post by: ART on December 18, 2010, 09:41:36 AM
I highly suspect youll see a run on Lturn.. :)

Art
Title: Re: Inscribed circle, what am I missing?
Post by: ART on December 18, 2010, 09:41:58 AM
unless of course its too expensive for them.. :)
Title: Re: Inscribed circle, what am I missing?
Post by: Doughty on January 22, 2011, 06:10:17 PM
I read it there and here I am.  Thanks Rich and ART; and the price is just right.
Title: Re: Inscribed circle, what am I missing?
Post by: RICH on January 22, 2011, 06:28:17 PM
Glad you could afford the trip and hope you'll enjoy the ride. ;)
RICH
Title: Re: Inscribed circle, what am I missing?
Post by: Leeway on January 23, 2011, 09:12:01 AM
I'm here too, but my copy is still in the plastic. ;)
Been too busy trying to get my lathe going the right way to open it up yet.
I have tried a few different things. Dolphin Turn was the biggest. It has some error issues that won't go away, but work aroundable maybe. It will work better at some point once I get my head around how the lathe and tools should actually run and associate with each other.

IMO, it's quite a bit more difficult than Mach3 Mill. With turn and it's documentation though, I am standing on top of the hurdle now. Which way I fall is anyone's guess, but I hope forward. :)
Thanks, Guys. Turn is very cool.
Title: Re: Inscribed circle, what am I missing?
Post by: RICH on January 23, 2011, 09:40:39 AM
Lee,
LazyTurn is not meant to compete with Dolphin Turn as Dolphin provides more functionality and you pay a lot for it.
Suggest you start a new post for any Dolphin issues  since there are users of it and they may be able to help you out.

LT is easier to use than Dolphin for what it does for my nickle!
Frankly it can replace manny of the turn wizards associated with a outside profile.

Would be nice if there was enough users to warrent a pro version of LT at some cost, adding additional functionality, but that's one for Art to determine.

Have fun with it and do look thru the documentation,
RICH 
Title: Re: Inscribed circle, what am I missing?
Post by: Leeway on January 23, 2011, 09:59:37 AM
Thanks, Rich.
I have had my lathe running for a couple years now. I just have simple production parts turned out of brass. I have just been using Mach3 mill and I hand programmed everything like that. Kinda like using Teach, but just by hand.
The biggest problem with doing it this way is it gave me no useful lathe experience. Sure I could turn it on and turn any of my parts, but could not produce a drawing and expect the lathe to do it.

This is also a hurdle I was facing with Dolphin. Not knowing any of the basics makes for a lot of crashes and that is something you really don't want on a lathe. ;)

Anyway, reading LT documentation has given me the basics I need to be able to just set up the lathe as a lathe. I can see the other side now. I was initially just interested in doing some profiling, like chess pieces. I did turn one using LT now so I am on the right track. I have set up my tools now in a repeatable fashion and will be setting up the tool tables to actually run the lathe as Mach 3 Turn wants.
It should then be a bit easier task to use either LT or Dolphin.

The Dolphin thing I have asked about before and never got a workable answer. hat was at the Zone on the Dolphin forum. If you try importing a DXF into turn without using Dplhin Cad, the error says you have never opened or used Dcad. That isn't the case and Dcad apparently must export to DT. I can do that though, so a work around.
T I will look into that soon too.
Thanks.
Title: Re: Inscribed circle, what am I missing?
Post by: Doughty on January 23, 2011, 02:23:02 PM
Well I got a chance to take a better look at LT.  What I am really after is CAM for some simple internal turning.  Looks like LT hasn't got there yet, so the search goes on.  Rich, I would be willing to pay some for this enhanced ability.  Just can't really justify the expense of some of the exsisting programs that do support internal turning. Thanks again.
Title: Re: Inscribed circle, what am I missing?
Post by: RICH on January 23, 2011, 02:30:40 PM
Quote
What I am really after is CAM for some simple internal turning
Have a look at the wizards.

RICH
Title: Re: Inscribed circle, what am I missing?
Post by: Doughty on January 23, 2011, 07:58:35 PM
What wizards are you referring to?  Where are they located?
Title: Re: Inscribed circle, what am I missing?
Post by: RICH on January 23, 2011, 08:21:57 PM
Doughty,
With Mach 3 Turn open click on the Wizards button and then select Turning.
They will generate the gcode.
RICH
Title: Re: Inscribed circle, what am I missing?
Post by: Doughty on January 23, 2011, 08:44:09 PM
Ah!  That's the problem.  I don't have the Mach 3 software.  Thanks.