Lofting (I suppose) 1

[Creigbm]

Here is my situation. I have a cylindrical can and I wish to mill an 1/8" deep slot all the way around it. This slot however needs to be tapered such that the tool itself will move downward ('z' direction) as it is rotated around. This will give the appearance that it is spiraling downward as you rotate the can. I am trying to us a loft, however, I am having trouble establishing guidlines that will curve with the outside of the can while moving downward as well. I have some pictures that I can e-mail if that would clarify. Thanks for your help in advance.

Brian

 

[CorBlimeyLimey]

Sounds like you need to use a Insert > Cut > Sweep

Check out:-
thread559-41468
thread559-58350
and for an alternative multi-body method thread559-44827

from (the City of) Barrie, Ontario.

Everyone has a photographic memory. Some just don't have film.

 

[TheTick]

The centerline of the slot bottom is a spiral.
Insert --> Curve --> Helix/Spiral

Try making your slot constant depth. Extrude a surface that represents the spiral bottom, then replace the bottom face of the slot with the spiral face.

Due to illness, the part of The Tick will be played by... The Tick.

http://www.EsoxRepublic.com

 

[CorBlimeyLimey]

Deep sigh .... I really have to start reading these posts, at least twice, before I jump in with both feet ..... in my mouth.

"It is better to keep your mouth closed and let people think you are a fool than to open it and remove all doubt."

from (the City of) Barrie, Ontario.

Everyone has a photographic memory. Some just don't have film.

 

[JNR]

Tick, I don't think that gets him where he wants to be does it? He had a tapered tool going progressively deeper - thus the slot would get wider at the top. Wouldn't your method have a constant top width but varying depth and bottom width?

John Richards Sr. Mech. Engr.
Rockwell Collins Flight Dynamics

There are only 10 types of people in the world - those who understand binary and those who don't.

 

[SBaugh]

Maybe I'm reading this wrong, but if you just want to go around a cylinder, then why don't you make profile and make a Revolved cut?

Regards,

Scott Baugh, CSWP

http://www.3dvisiontech.com

http://www.scottjbaugh.com

faq731-376

 

[TheTick]

He doesn't mention having a tapered tool.

 

[CorBlimeyLimey]

Creigbm
Methinks you need to explain your problem again. We appear to have several different interpretations.
Are you trying to make your spiral slot:-
1) constant width - increasing depth
2) constant depth - increasing width
3) increasing depth - increasing width

Also is you cut profile rectangular?

from (the City of) Barrie, Ontario.

Everyone has a photographic memory. Some just don't have film.

 

[Creigbm]

Ok, lets try this again

I am trying to mill a slot in a can that will move down the can as you turn it. It is almost like a helical cut, with a constant width and depth. I tried creating this using a loft but I am having difficulty with creating the guidelines (If you are wondering why I am using a loft, I cannot find a way to create a revolved cut that will 'spiral' down the can so I am using a loft to add material rather than take it away. This is a backwards way of doing it and not the most efficient.) Think of it this way. Take your pencil and spin it between your fingers. Now with your other hand, put one finger perpendicualar to the side of the pencil and move it down towards the eraser. I am trying to create the cut that your finger would make if it was cutting into the pencil. Hope that helps to better define the problem. Thanks for all your input so far.

Brian

 

[CorBlimeyLimey]

In that case my first post would be correct!

However, in your original post you said "This slot however needs to be tapered such that the tool itself will move downward ('z' direction) as it is rotated around

So I'm still confused

from (the City of) Barrie, Ontario.

Everyone has a photographic memory. Some just don't have film.

 

[Creigbm]

The slot itself is not tapered (wrong terminology). I will have to tryout the cut sweep (I have been only using lofting).

 

[TheTick]

Try a sweep with a path and a guide curve. Make a helix for the path on the surface. Make a second helix of same length and turns but larger diameter for a guide, to orient the "cutter path".

 

[Creigbm]

I just tried creating a sweep using a helix for the path. It works, however (and this is where I am getting picky), if you zoom in really really close you can see that there is a double edge where it seems like the sweep is not following its path 100%. This is what I did if you would like to see what is happening. I created a sketch of a square that would serve as the milled slot. Then I created a helix a number of different ways (corner to corner, center to center). They all worked in the sense that the cut was created. Then I turned in the centerline and zoomed in really really close to notice there is a sbouel line (in wireframe) or a slanted edge if you are in shaded mode. I was reading up on lofting and sweeping in 2004 and they claim to have updated it but it is not fixing this problem. If there is a better way to do this, please let me know.

 

[CorBlimeyLimey]

Send the file to the address listed in my profile. I will take a look.

from (the City of) Barrie, Ontario.

Everyone has a photographic memory. Some just don't have film.

 

[SBaugh]

Why don't you add a guide curve or two into your sweep? You can use Guide curves in Sweeps but you can only use 2. Lofts are unlimited to me knowledge.

Regards,

Scott Baugh, CSWP

http://www.3dvisiontech.com

http://www.scottjbaugh.com

faq731-376

 

[Creigbm]

SBaugh,

I tried adding four guidelines to create the loft feature (one at each corner) with no luck. I even added an extra profile midway through the loft/sweep and noticed that even though the guideline went straight through the corner of the profile, the loft itself did not represent that. There was still the appearance of a double line.

 

[SBaugh]

What SW version are you running and SP?

From one of your posts it sounds like your using SW03. If that's true. Then I think your seeing and bug in SW03. I thought they fixed it in a later SP of 03 but I'm not certain anymore.

Let me know... You can send me the file if you want to. My email is located at my website.

Regards,

Scott Baugh, CSWP

http://www.3dvisiontech.com

http://www.scottjbaugh.com

faq731-376

 

[Creigbm]

I am using SW04 SP3.0. I just e-mailed you the file Scott. Thanks for your help.

 

[SBaugh]

Creigbm,

Please send a message to this account (See below) and I'll reply with a different account, for you to send the file too. My credence email account is messed up and I'm not receiving any emails right now.

credence69_REMOVEME_@_REMOVEME_hotmail.com

Remove all the "_REMOVEME_" and then send.

Regards,

Scott Baugh, CSWP

http://www.3dvisiontech.com

http://www.scottjbaugh.com

faq731-376

 

[TheTick]

I'd like a whack at this. Email address in profile