CHAINING PROFILE OF A PART. TRYING TO CREATE 1, CONTINUOUS CHAIN

[honeybunches]

I was some how able to manage this before but now all I am creating are multiple chains. I am using contour to profile a curved part. As I try to build the chain around the part, I get errors that the selected chain does not touch the branch point. If I select broken chains, it will create a new chain and start point.

 

Do I need to work on the wire of the part or is there a trick to easily create a continuous chain around the profile of a part? I am wondering if I have issues with my model and that is creating much of a problems. Wire looks good to me. Brought in in an STP file. No additional lines creates for the profile.

[Tony35]

did you analyze chain?

sounds like you have a gap somewhere in the chain i have run into this before and the gap was like .0002 trim them together or connect the points then re analyze chain to see that it is 1 chain

 

HTH

[MotorCityMinion]

A few options are available. Change all the entities in the chain to the same color, all entities that intersect the the chain to another color, then adjust the tolerance on the chain and use the color mask. 2d chain? Select c-plane prior to chaining. If some of the entities lay in a 3d plane or or fall on a slightly different plane, you can use xform translate to bring them all up to the same plane, then trim them if needed. HTH

[Joe788]

Motorcity hit it.

 

Mastercam is asking if you're trying to go down the vertical line, or continue on along the profile. At the top of the chaining pop-up box, there's a button for "CPlane". You most likely have it on "3D".

[Colin Gilchrist]

Did you try the Create Boundary C-hook? This can give you a good result about 80% of the time.

 

Try this if you have a complicated part:

 

Do a Surface Finish Contour Toolpath.

 

Create an endmill that is .001 in diameter.

 

Set your Maximum step down to 20.0.

 

Set your depth limits to absolute.

 

Set the Minimum and Maximum depth to -.05 (or whatever depth you want the chain to be at).

 

In the advanced settings, set it to "Automatic", the top option.

 

Also, turn the filter on, ratio 1:1, and set the total tolerance value to .001. Also, turn on "create arcs in XY".

 

This will give you a single contour cut at the depth you specify.

 

Now go into backplot and choose "Save as geometry" and enter a level.

 

Just a little trick I've learned over the years. This will give you a nice, simple, filtered chain that is .0005 excess on your actual part.

[honeybunches]

I will look at some of these ideas tomorrow but I can tell you have tried 2D, 3D, Cplane, etc, all come up with the same error. I just wish I knew how I did it before. In a previous op, I chained the whole thing as one chain but I know I struggled before. Get to the point of just pushing buttons until something is close I guess.

 

I am really not sure if our model (step from Catia) is what causes issues or what but every part seems to have issues for us.

[Superman]

are you working from a solid or surfaces ?

if you create curves from solids, a lot of problems disappear.

 

Creating curves from all surfaces will give untold endpoint errors, double entities, un-joined chains.

[honeybunches]

What we found yesterday is the chain is complete but there are several pieces of it and one was VERY hard to find. Serious zoom to get to it. Is there not an "easy" button to chain the entire profile? maybe an easier way to chain around parts rather than selecting the 50 some chains that make up the perimeter?

[gcode]

Catia to step to Mastercam has always resulted

in troublesome models for me.

Sometimes Solidworks converts them better,

sometime Mastercam does a beter job.

 

Try the chook FindOverlap.

It is pretty good for finding and fixing overlapping enities in wireframe

also

Analyize/chain can find and fix many errors

Use window chaining to select really dirty chains.

and

as a last resort crank up your chaining tolerance

The default setting is .0002, try bumping it to

.001 This will allow chaining to "jump" small

gaps that may be dificult to find

[honeybunches]

Thanks a bunch for the info. I will certainly take a look at your suggestions when I get to work on Mon. Gotta spend some time with the family on Sun.

 

Thanks again.

[3R!< W3NG3R]

I always ,first ,change sides, delete duplicates, and then the find overlap c-hook. Solves lots of problems. Even then, sometimes I sometimes get entities that are not the same or overlapping, but have the same endpoints.

[Colin Gilchrist]

Instead of spending all the time trying to clean up a dirty set of wireframe, my method gives you a single chain with no branch points in about 2 minutes.

 

I used to do the whole, delete duplicates, find overlap, analyze chain, adjust chaining tolerance dance.

 

On most solids it really isn't an issue. It is the bad models you get, either a bad solid, or a set of surfaces that is awful that really cause you headaches.

 

Another thing you should probably check: Is the "create edge curves" checkbox turned on in the "options" dialog box?

 

If the model you are importing already has wireframe in it, this button will cause Mastercam to generate a second set of edge curves on the model. This can cause some serious problems when you are trying to separate the wireframe you want to use for toolpaths.

 

HTH,

[Thad]

quote:

---

I always ,first ,change sides

---

 

Eric,

 

Can you elaborate? I don't see how this is relevant to cleaning up geometry.

 

Thad

[Thad]

quote:

---

Is there not an "easy" button to chain the entire profile? maybe an easier way to chain around parts rather than selecting the 50 some chains that make up the perimeter?

---

If your geometry is "clean," (trimmed, no branch points, no overlapping entities, etc), it's a one click operation.

 

Thad

[Jayson Kramer]

Viper1 Share your file. as we really don't know all that you are dealing with. or a screen shot might get us closer.

Or email me the file and an Idea of the profile you are trying to chain.

[robh]

Will "sihouette boundary" chook work for it?

[Cannon]

quote:

---

Will "sihouette boundary" chook work for it?

---

It might work in a very simple part but usually gives very rough chain that only loosely follows the part profile. It is meant to do toolpath boundaries only. It would be very powerful tool in chaining also if it worked more accurately.

[Mike-T]

Slice works well for me. Only keep wireframe that refs toolpaths.

[gms1]

On top of some of the suggestions already mentioned, I also occasionally use this method.

 

Xform - Project - 1.00 (copy)

Put the result on a different lvl then run overlap chook with delete duplicates.

[Jayson Kramer]

Viper1 you have mail.

 

Use toolpath Contour and use Solid chaining sense it is a solid. review my file I sent you.

[honeybunches]

Jay, I have tried using solids chaining but not having much luck in a 1 button chain. Do you still have to select each section of the solid to build the chain? Was the model acceptable IYO?

[3R!< W3NG3R]

Thad, I do change side first, because if two arcs are overlapping, but on different sides, delete duplicates doesn't always catch it. It may be a bit redundant with find overlap. Sometimes old habits die hard.

[Choward]

one more thing for you try,when you are in the chaining mode,first go to options and at the bottom you will see chaining tolerance.put the tolerance up to .001 or .002 and see if that helps.

[robh]

"combine views"for trouble chaining and trimming.a note to myself,info from someone on this forum but never tried it as yet.

[3R!< W3NG3R]

Sorry, but I meant combine views, not change sides.