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# Rail cut out problem

Creator

Hi!

Thanks for the Solid Edge support in this forum. I am trying to cut out a guiding rail in a cylinder and cannot get the right cut or always get an error. The cut out is meant to be a guiding rail for a pen mechanic.

This picture might illustrate further what I want to do:

I created the rail with by wrapping a sketch onto the cylinder and doing normal cut-out. The problem is that the width of the cut-out increases along the radius of the cylinder while the pin does not (and should not).

So, how can I get a good rail into the cylinder?

So far I tried:
- Normal cut on the wrapped sketch (image above), but rail width increases along cylinder radius
- Sweep cut on the wrapped sketch, but I get a non-tangent error
- Loft cut along the wrapped sketch, but getting similar errors

Would be great to find a solution for this and sorry, if this is really a beginner question.
Thanks!

16 REPLIES

# I don't have an answer for you right away, but the first...

Retired

I don't have an answer for you right away, but the first thing I'd like to know is how you're going to produce this part. How you model the slot will depend on if you're going to machine or cast this part. If you're going to machine it, I would try to set up the cut the way a CNC would cut it.

In other software, the way I would do it would be to have a straight line going down the axis of the part, and a curve on the surface of the part, then create a rectangle with a centerline where one end of the centerline follows the line on the axis, and the other end of the centerline follows the curve on the surface. This keeps the "cutter" (rectangle" perpendicular to the surface and perpendicular to the path at the same time.

The only problem would be the area on the upper left of the image.

There are some other ways to do this. Etch the shape onto a cylindrical surface, then thicken the surface, and use ruled surfaces to make the sides of the cut always parallel.

I'm gonna play with this to see if I can come up with something that works in Edge. Cool part.

Retired Community Manager for Solid Edge. This account is no longer active.

# Re: I don't have an answer for you right away, but the first...

Creator
Hi MLombard,

Thanks for your answer. I intend to use this on a rapid prototyping machine.

Nevertheless, I have thought the same way as you about cutting out this guiding rail. When I do a sweep cut of a rectangle (the tool) along the curve of the pin (a wrap of a sketch), the cut out rectangle gets tilted. This is not the motion that the pin would do and so the part would not work. Maybe this picture further illustrates:

http://s11.postimg.org/wx5bm4m1f/Untitled2.jpg

I tried using the Sweep Cutout Axis Step to avoid this twisting, but not sure if I understand it. If I use the cylinder axis I get this error: "The input lock direction is invalid".

Any idea how to avoid the twisting?
Thanks again!

# Re: I don't have an answer for you right away, but the first...

Gears Esteemed Contributor
Hi there,
Somewhere around, probably the BBS [closed forums] there was a run down on constructing a barrel cam setup, not too disimmilar to your needs here....will keep looking and see if I can find on it, and if so, if it can be shared here.
Sean Cresswell
Design Manager Streetscape Ltd
Solid Edge ST10 [MP8] Classic [x3 seats]
Testing: Solid Edge 2019

# Re: I don't have an answer for you right away, but the first...

Creator
@SeanCresswell: Thanks, would be great if you could find that example.

@MLombard: I also tried making it starting with surfaces, but I am not sure how to use the ruled surfaces: They don't seem to allow me to make the cut-out faces parallel either.

Any ideas?

# Re: I don't have an answer for you right away, but the first...

Gears Esteemed Contributor
Found the posts on the topic, and looks very much like what you want.....just awaiting permission to repost the 2 video's here.
Sean Cresswell
Design Manager Streetscape Ltd
Solid Edge ST10 [MP8] Classic [x3 seats]
Testing: Solid Edge 2019

# Re: I don't have an answer for you right away, but the first...

Creator
Thanks, Sean, looking forward to it. Hope you get permission.

What is the source of the videos? Maybe I can get access there too.

# Re: I don't have an answer for you right away, but the first...

Gears Esteemed Contributor

They are personal screen recordings via "Screencast".....but maybe you won't need them...
The crux of it seems to be,...draw your complete cutout path [ceterline, with "Symmetric Offset"] as a sketch to wrap, wrap the sketch, then use a "Normal - Cutout"

EDIT: upon trying this process myself....it appears NOT to solve your issue, of a tappering cut thickness.

Sean Cresswell
Design Manager Streetscape Ltd
Solid Edge ST10 [MP8] Classic [x3 seats]
Testing: Solid Edge 2019

# Re: I don't have an answer for you right away, but the first...

Creator
Thanks. Got to the same conclusion with the normal cutout. As it is normal to the cylinder surface the cut out thickness increases along the cylinder radius. That is unless I am missing some setting about that type of cut-out.

Do you think the screencast will still help?

# Re: I don't have an answer for you right away, but the first...

Gears Esteemed Contributor

No it's probably not much help....was done to a shallow depth, and the path was not as convoluted as yours.

I'll give it some more thought when I finish work in a couple of hours....no doubt someone will come up with the solution, way before I get to back it.

Sean Cresswell
Design Manager Streetscape Ltd
Solid Edge ST10 [MP8] Classic [x3 seats]
Testing: Solid Edge 2019