question on project from MastercamU.com

[DWAS]

i am enrolled in the mastercam university x4 mill design and toolpaths and have a question about the bike fork tree in section two. I have drawn this and completed it as the video shows. The method in the video is to Xform translate in the z direction to create the 3d part. If i wanted to, how would i extrude this so i can make it a solid? I keep getting errors like "no valid closed chain selected for non thin-wall extrusion" or "operation requires planar chainset". I have gotten the part to where there are no lines on top of one another and i know this because when i hold shift and select a line the entire part outline is turning yellow. So i know i am selecting a completed chain.

Can anyone tell me what I am doing wrong, and if this is possible then how do i do it. Also, could someone tell me what is meant by these error messages?

Thanks

[DWAS]

also, if anyone knows; what exactly is the difference between an extrusion of a body and a boss? in what ways does the program see them differently?

[DWAS]

??? anybody

[Superman]

Originally Posted by DWAS i am enrolled in the mastercam university x4 mill design and toolpaths and have a question about the bike fork tree in section two. I have drawn this and completed it as the video shows. The method in the video is to Xform translate in the z direction to create the 3d part. If i wanted to, how would i extrude this so i can make it a solid? I keep getting errors like "no valid closed chain selected for non thin-wall extrusion" or "operation requires planar chainset". I have gotten the part to where there are no lines on top of one another and i know this because when i hold shift and select a line the entire part outline is turning yellow. So i know i am selecting a completed chain. Can anyone tell me what I am doing wrong, and if this is possible then how do i do it. Also, could someone tell me what is meant by these error messages?

I'll see if I can enlighten

"operation requires planar chainset".
picture a circle, whatever angle this is drawn at, it will always lie on a plane and this can be "extruded" to make a solid body
--usually 3 poiints on the selected profile defines the plane, now if any other point on that same profile does not lie on that same plane, then you would get the above error
solution=== use Xform Project to flatten the profile before extruding


"no valid closed chain selected for non thin-wall extrusion"
picture a rectangle ==== this is classed as a closed shape, and can be "extruded"
--Xform translate one line in the Z plane ( then this cannot be chained to form a closed contour suitable for extruding and will give the above error, same would happen if you had a tiny gap in the selected chain ( the red and green arrows don't meet )

[DWAS]

thanks Superman, are you familiar with the project I am talking about? The thing that confuses me about the "no valid closed chain" is I can select the entire outline by holding shift and selecting a line, so to me that would tell me that the chain is closed. Does the computer not recognize that it is closed because its outline lies on different planes?

Also, do you have an answer to my other question about the boss and body?

Thanks

[Superman]

Sorry, not familar with that project
When you chain, do the green and red arrows display on the screen at a different place that is not the endpoints of the 1st selected entity

Another method you can use to see if it chains correctly, is to change color by chaining.

Also, do you have an answer to my other question about the boss and body?

BODY= is a solid entity
BOSS= is a solid entity create then added to a BODY in 1 single sequence ( if more than 1 solid body is on-screen, you will be asked which body you want to modify )
CAVITY= is a solid entity created then subtracted from a BODY in a single operation ( same goes if more than 1 solid on-screen )

To define what is happening longhand
you would create the solids then do a "booleen Add" to join the 2 solids into 1....this is Creating a BOSS

Try this:- all wireframe is drawn on Z0 plane
---set color-dark blue, create a 2"x 2" rectangle, set color grey, then extrude it in the Z- direction of 1"
---set color dark blue, create a 2" circle in the center of the rectangle, extrude ( Create boss ) in the Z+ direction of 1"
---create 1" circle in center, extrude that 1" ( create cavity), thru all, both directions....can't see it....[Alt-S] to un-shade the solid so you can select the 1" circle, [Alt-S] to toggle the shading ON

You have created only 1 solid entity and then modifed as you went along
---the "history" of this solid is in the solids tab of the op manager
now shading OFF, select the 1" circle, and analyse entity, change the diameter to 1/2", accept.... the solid history has gone "Dirty"...regen all solids
----your model now shows correctly with a 1/2" hole thru the middle


Note to new users....always keep the cursor on the screen area you want to apply any keystroke on....it is very easy to select screen entities to delete, move the cursor, then push the delete key BUT, you moved the cursor onto the operation manager area.......you are now deleting toolpath operations, not drawing entities
You should be prompted " Are you sure? " BE CAREFUL on what you are answering too.

[lovecnc2003]

thanks

[DWAS]

I guess I thought if you select a line that is part of a shape and hold shift while you are doing it, the entire entity will change to a different color, or at least change up to the point of where the chain ends, so with the entire chain changing color it is a completed chain.

As far as the boss (sorry for re-asking) if I create a solid and want to create a boss coming off of it I could move my z to that plane, create a circle, and extrude a body. If i extrude and create a boss, I'm not seeing any kind of difference. The solid still looks the same weather i created the boss as an extruded boss or an extruded body.

Is there a way to do an x form project and make it appear as a solid? I have never used that command before.

[Superman]

Originally Posted by DWAS As far as the boss (sorry for re-asking) if I create a solid and want to create a boss coming off of it I could move my z to that plane, create a circle, and extrude a body. If i extrude and create a boss, I'm not seeing any kind of difference. The solid still looks the same weather i created the boss as an extruded boss or an extruded body.

After you select the chains to extrude, an arrow ( with a conic tip ) appears to show the extrude direction, ( your chaining direction defines the extrude direction, make sure you select multiple chains going in te same direction, this will make things easier in the future )

If this arrow appears and it points in the wrong direction to what you want, check the "Reverse direction" box, before accepting.

If the function has already been done, ( say you did it the wrong way )
edit the actual solid history
>> op. manager >> solids tab >> "Select" button to pick the correct on-screen solid >> "geometry" is the entities the create the feature, parameters are the settings for the extrusion )
After editing, the solid will go "dirty" and will need to be updated on the screen, so regen the solid

Your boss may be extruding in the wrong direction
go into the solid history and find the parameter for that "Extrude Boss" and check the reverse direction, then regen that solid