Helical Sweep

[Kevin Hesch]

Good Morning All,

 

I'm looking for ideas on how to sweep a cube along a helical path through a cylinder removing material where they intersect. This is for a feed screw type application. Or how to get the correct 2D geometry to sweep knowing the pitch of the helix, and the dimensions of the cube. If that explanation made no sense, let me know and I'll try to elaborate.

 

Thanks,

 

Kevin

[crazy^millman]

You made perfect sense to me. I would do a couple thing frist. I would set up layers and create a couple copies of my part information(if you want to name views to remember where everything is ok I do).

 

The next things is create all of your 2d information in the top view or side or front what ever you want to work from. The next thing you want to do is create all you other gomentry in the other view for reference of such that you feel you need.

 

When you have all of this you will then want to copy to other layers.

 

I would then creat my solids for each part in other layers. Then make copies of those solids.

If you want to get really fancy you can go into your solids manager and name the solids also up to you.

 

Then use the chook thehelix or something close to that if you have 8.1.1 cause i just looked and dont see it in 9.1 sp1 that is another topic i can see. Then you have several options on how you do the remove. You can go back and do a solid sweep path and do remove. You can create the solid along the path the same way execpt create the body. At that point you can use boolean remove in solid. That should take care of removable parts.

 

I think you will have to play with the helix to get start, end, radius, increment angle and the other things right but that is a powerful Chook for doing those types fo things. They have a word Doc explaining what everything is in the Chook Folder good luck.

 

[ 08-01-2003, 10:04 AM: Message edited by: Millman^crazy ]

[Roger Martin from CNC Software]

FYI,

 

In MC v9.1

 

Create -> Next Menu -> Spirial/Helix

[Kevin Hesch]

I don't think we're on the same page here. I'm going to put a file on the FTP called Helical sweep.MC9 that explains maybe in better detail what I'm trying to do.

 

ftp://www.ppcadcam.com/Mastercam_forum/MC9_files/Helical sweep.MC9

 

Thanks,

 

kevin

[crazy^millman]

See helps to put it out there for the helix. I think i remember now have not needed it yet so wasn't sure thanks for the info Roger. Kevin I will take a look. Can you check the link asking for a user and password?

 

[ 08-01-2003, 10:11 AM: Message edited by: Millman^crazy ]

[crazy^millman]

Here is what I was talking about doing see if the part made will help you see what I was talking about. The only thing you can not do it make your soild the same width as the pitch if you do it could never work. You would then be tryign to create a cylinder cause the srew would be the same place as if it where solid. Take a look and see if you like it. Good Luck

 

Here is the link.

ftp://www.ppcadcam.com/Mastercam_forum/

 

Crazy Millman

 

Sorry all unless someone want to give me a zipping program or a link it is not.

 

[ 08-01-2003, 10:33 AM: Message edited by: Millman^crazy ]

[Kevin Hesch]

I put a space in the filename by mistake just go to the MC9 directory and download Helical sweep.MC9

 

Thanks,

 

Kevin

[cadcam]

Millman^crazy , Please do me a favor and follow the standerd of putting all files in the correct folders.

Please reread the Upload instructions at the top of this page.

[Kevin Hesch]

Millman,

 

The file you posted swept a 2 dimensional part along the path that represented the middle of my solid cube. The result I'm looking for is if you swept the 3 dimensional cube along the path. If the cube was able to spin freely the result you sent would work but the cube is locked in position by guidrails therefor it is not just the cross section of the block used for the cutout, I believe that it is the cross section of the block on a plane tilted at the pitch of the helix. Hopefully this makes it a little easier to understand.

 

Thanks for the response!

 

Kevin

[Roger Peterson]

http://www.winzip.com/

 

 

HTH

[crazy^millman]

My bad sorry. Maybe one day I will do something right around this place 2 days in row got people mad at me around here thinking about not coming back.

 

 

 

 

Just kidding I didnt want to rewrite his so was not sure where to put it so went with the safest place I thought he would be able to get it.

[cadcam]

I have renamed Millman's file by ading Millman to the file and re-uploaded the file to the MC9 folder.

[cadcam]

I am make the suggestion not sayong I was mad.

It help when file are in the right place and not such a mess.

Now you know and all is good.

[crazy^millman]

Ok I got a thing to throw in here. This is wierd I made that part and you did get it right. Well I can not recreate that same part it keeps giving me an error path curve not smooth within 5 degrees. I am using 9.1 sp1 on well look in that later got to go meet some customers. I just was wondering if you did a sweep of that 2d at the front on of the box and then the back of the box would create what you are looking for was trying to do it but then got this. But really without knowing the 6 factors of your certain helix I could make models all day long good luck I will Check Back This Afternoon and see if you got some help from the other great people around here.

 

I knew you were not mad CADCAM just trying to be funny.

 

Hey if this were easy everyone would do it is what they tell me all the time so us Crazy enough to enjoy it need to stick togehter. Oh well good luck on your project catch you later.

 

[ 08-01-2003, 11:25 AM: Message edited by: Millman^crazy ]

[McRae]

Kevin,

 

I should keep my mouth shut, but you picked the scab. If you must waste your time, continue along here.

 

We have been searching for a general blend for creating these types of components for a dogs age - search the forum to see. Secondly, when you try cutting these surfaces that you have created - Mastercam WILL crap out and not produce true shape.

 

My suggestion is to come clean with your prospect that the tools are not in the software and for the love of God - don't use the "Reinian" sales attitude that it will just work... When it doesn't it will be your fellows in the binder.

 

[ 08-01-2003, 12:29 PM: Message edited by: Andrew McRae ]

[Zero]

Well...I uploaded a file called HELICAL_SWEEP_EZRA.zip to the ftp. This is something I did real quick in Rhino and did a boolean remove in MC. Take a look and see if thats what you were after...although after re-reading your post I think I might have similar results to what millman did (I'm not sure, I didn't take the time to dl the 2 meg file on my 56k ).

 

Zero teh back to teh drawing board

 

[ 08-01-2003, 12:54 PM: Message edited by: Zero ]

[Müřlıń®]

Sorry I just have to ask....

 

I havent looked at your file but it sounds to me like you are drawing a screw....why?

 

Murlin teh ask too many questions

[steve f]

Kevin, the problem you have is a tough one but not impossible. Correct me if I'm wrong here but this is my interpretation of what you're trying to accomplish. You want the 2D cross section of a groove on a cylinder created by keeping a cubic remove tool stationary and turned at an angle to the pitch of the groove while spinning the cylinder and moving it along the spinning axis at certain rate to accomplish the desired pitch. I think what you want is the result of cutting helix on a shaft with one of those endmills engineers think you can buy that'll cut square internal corners in a pocket (I heard Sandvik is coming out with them next year ). Unfortunately, this can't be done using boolean remove or anything like that in Mastercam...you're going to need hard core math to find the 2D sweep cut profile.

 

The groove side walls will be undercut at an angle dependant on the size of your cube, cylinder and length of pitch. The undercut will continue down (in cross section view) to a point defined by the radial distance from the trailing or leading edge of the cube to the center of the cylinder. The rest of the side wall distance to the floor of the groove would be some kind of ellipse or sline and the floor of the groove would be flat as long as the pitch angle wasn't more than 45 degrees. At angles beyond that only crazy things happen and my head is starting to hurt now so I'll just stop now.

 

I think you might be on your own with this one.

 

Good luck anyhow!

 

steve

[Kevin Hesch]

Thanks for your responses everyone we're trying to figure out if there is a mathamatical formula we can come up with to produce the profile.

 

Cheers,

 

Kevin