Lofting (I suppose)
Lofting (I suppose)
(OP)
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
Brian






RE: Lofting (I suppose)
Check out:-
Thread559-41468
Thread559-58350
and for an alternative multi-body method Thread559-44827
RE: Lofting (I suppose)
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.
http://www.EsoxRepublic.com
RE: Lofting (I suppose)
RE: Lofting (I suppose)
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.
RE: Lofting (I suppose)
Regards,
Scott Baugh, CSWP

http://www.3dvisiontech.com
http://www.scottjbaugh.com
FAQ731-376
RE: Lofting (I suppose)
RE: Lofting (I suppose)
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?
RE: Lofting (I suppose)
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
RE: Lofting (I suppose)
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
RE: Lofting (I suppose)
RE: Lofting (I suppose)
RE: Lofting (I suppose)
RE: Lofting (I suppose)
RE: Lofting (I suppose)
Regards,
Scott Baugh, CSWP

http://www.3dvisiontech.com
http://www.scottjbaugh.com
FAQ731-376
RE: Lofting (I suppose)
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.
RE: Lofting (I suppose)
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
RE: Lofting (I suppose)
RE: Lofting (I suppose)
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
RE: Lofting (I suppose)
RE: Lofting (I suppose)
I took a stab at this without seeing your model.
<http://www.esoxrepublic.com/models/>
SpiralCut.zip
There are two models: one with section normal to helix and one with section plane through cylinder axis.
http://www.EsoxRepublic.com
RE: Lofting (I suppose)
Thats the same thing I did (on SpiralCut2). See here is my problem. Turn on 'Axis 1' and zoom in really close. There is still a double line from the sweep. If anyone was wondering why I am worrying about this is we are working with our shop to get them import the SW model to mastercam. I forsee double lines laeding to a lot of trouble in the future.
Thanks,
Brian
RE: Lofting (I suppose)
RE: Lofting (I suppose)
Regards
Scott Baugh, CSWP

http://www.3dvisiontech.com
http://www.scottjbaugh.com
FAQ731-376
RE: Lofting (I suppose)
Have you been to the optician lately ... just kidding.
RE: Lofting (I suppose)
RE: Lofting (I suppose)
Regards,
Scott Baugh, CSWP

http://www.3dvisiontech.com
http://www.scottjbaugh.com
FAQ731-376
RE: Lofting (I suppose)
RE: Lofting (I suppose)
Creigbm, you aren't depending on the screen output to make this determination, are you?
RE: Lofting (I suppose)
If I understand you correctly, you are making what I call a barrel cam. The only way I have had success makeing these in Solidworks is to make a cylinderical surface, draw your path on the surface and create an offset the width of the follower. Trim the surface into two pieces with the path and its offset. Then thicken the cylindrical surfaces the depth of the slot. Surfaces always thicken perpendicular to the surface. This will give you the perpendicular walls you want with a constant width from the offset trim. I hope I made myself clear, if not let me know here in the forum and I will email you an example.
Timelord
RE: Lofting (I suppose)
TheTick
I'm thinking the same as you, It seems like it's the screen resolution that's at fault here.
Creigbm
Can you measure between the "double lines. Also can you capture a screen shot & send the jpg or bmp file to us.
timelord
That seems like an unecessarily complicated way of creating a relatively simple feature. I know surface thickening definitely has it's place, but I don't think it's here.
RE: Lofting (I suppose)
RE: Lofting (I suppose)
Use the [img] tag to show images from any web server. Be sure to use the entire url to the image you want to use including the "http://"
(no line breaks)
This can be found under Process TGML which is under Step 2 Options of posting a thread.
Regards
Scott Baugh, CSWP

http://www.3dvisiontech.com
http://www.scottjbaugh.com
FAQ731-376
RE: Lofting (I suppose)
You need to be able to place the file onto a web server & then reference it here using
{img http://www.yoursite.com/filename.gif}
NOTE you will have to substitute the {} for []
if you don't have access to a web server then email as before & perhaps one of us can publish it.
RE: Lofting (I suppose)
RE: Lofting (I suppose)
RE: Lofting (I suppose)
RE: Lofting (I suppose)
<http://www.esoxrepublic.com/models/>
Creigbm--02Apr2004.zip
RE: Lofting (I suppose)
The Tick
Could not open the zip file. Tried from several different machines & several downloads, but kept geting "corrupt file" message. Anyone else have the same problem?
RE: Lofting (I suppose)
This has been a problem. I contacted my web host (Yahoo). They insist it's a problem with the downloader's web server.
Some people have no trouble at all. I just tried it at home; no problem. My work computer has trouble sometimes. That is why most of my download points list actual bit count.
There are some programs out there that can help from the downloader's end.
<http://www.getright.com/>
<http://www.internetdownloadmanager.com/>
<http://www.bpftp.com/> Bulletproof FTP (I have this one)
<http://www.netants.com/> free
<http://www.freshdevices.com/> free
http://www.EsoxRepublic.com
RE: Lofting (I suppose)
TheTick
OK, ignore that last post ... FYI, if I "open" the file direct from your site it works fine ... but I cannot do a "save" from it.
Creigbm
After seeing the files I am now more confused than ever (admittedly an easy task) but ... what are we supposed to see???
Other than the profile not being drawn on a plane perpendicular to the helix (which would be correct if a round cutting tool was used) & an undercut being shown in the jpg (but not in the part), I cannot see what is wrong.
So ... apart from working brain cells ... what am I missing?
RE: Lofting (I suppose)
RE: Lofting (I suppose)
As your machinist correctly pointed out, the difference is so small as to make no difference in the real world, but if you were needing to do further work with surfaces in SW, this could cause problems.
I have tried various methods to eliminate the mismatch but without success & unfortunately I can offer no explanation.
Anyone else have any ideas? If not I would submit this to your VAR or SolidWorks to see if they can offer a solution or reason or identify it as a glitch.
RE: Lofting (I suppose)
RE: Lofting (I suppose)
RE: Lofting (I suppose)
Creigbm
You should still submit problem to VAR & SW.
RE: Lofting (I suppose)
RE: Lofting (I suppose)
RE: Lofting (I suppose)