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modelling a twisting cable - pic added

saspinall

Member
Hi


I want to model all the parts to make up a cable which has 3 cores, fillers and an armoured shield. All three though need to helically sweep with a pitch of 1m. Can you do a helical dataum curve then sweep the profile down the helical sweep as the section needs to be drawn on the x,y axis with the helical sweep going down the z axis..if that makes sense....ie the section is at 90 degrees to a normal helical spring section....can this be done....any example parts would be nice to view...


Thanks for looking


Added a picture in zip file....all the coloured sections are fillers etc which, along with the 3 cores need to be swept using the profile shown, down a curve down the length of the cable with a helical sweep of 1 turn per metre...


2012-02-13_103522_cable.zip


Stu
Edited by: saspinall
 
Not certainly exactly what you are asking for... but I'm pretty confident the answer is yes. I have a file I would be happy to share, but despite uploading files with FTP, SFTP, SCP, rsync, and others I am apparently not cool enough to figure out how to upload files here. You tell me how to upload and I'll do it. :]
 
Alt


Thanks for looking, you see in the picture I posted, the three outside parts in different colours, then the internal part in orange, also the 3 cores etc, they all have to be swept down a helical profile of 1 full turn per metre.


Files have to be zipped up in winzip and then in the Post Reply section, you'll see an icon (top right) like a floppy disk, which can upload the zip file


Cheers


Stu
Edited by: saspinall
 
oh , how i like that when you by mistake enter the wrong code aftertyping a long answer,your message disaper...


Anyway, Uploading a file is done by using the icon in the top row, most to the right. (floppy) filesize can be more than 2000kb.


Regarding the initial question, i
 
Cheers Tobias,


If you take a look at the picture I uplaoded in original zip file, the green, purple, and off-yellow outer profiles need to be swept down a profile rotating at 1 turn per metre, as does the middle orange profile and the 3 cable cores and fillers....


Been racking my brains all weekend....lol


Stu
Edited by: saspinall
 
It almost sounded like you wanted the conductor helical
wound but also the cable helical wound, but I think not.
Anyways, I'll upload the file when I get to work but the
jist is:

1: Create a curve feature in whatever shape you want.
This could be a sketched curve that ends up straight, or
a curve through points (spline or single or multiple
radiuses)... whatever it is you want.

2: Create a measure feature that captures the length of
the curve. If you don't want to fully relate everything
and you simply know the length of the curve, you can skip
this and just type in the length later.

3: Create a variable section sweep feature.

3:a: Select the curve you made previously.

3:b: Edit the VSS sketch

3:b:1: Draw a centerline through the 'origin' and at an
angle. Dimension this centerline as an angle from
horizontal. Depending on where you locate this dimension
you can control the right or left-handed nature of the
helix.

3:b:2: Draw a circle on the previous centerline and
dimension it from the 'origin' to specify the radius of
the helix for the conductor.

3:b:3: Tools > Relations. There is a special variable
when using relations here which can be referenced by the
name trajpar (trajectory parameter). This variable
varies (good ol' varying variables) from 0 to 1 along the
length of the curve. So, you can enter a relation along
the lines of (your angular dimension) sd9 = 360 * trajpar
to get a single turn along the length. I will have to
fiddle to confirm the correct syntax but to get 1 turn
per meter you would have something like sd9 =
360*trajpar*DISTANCE:FID_THE_NAME_OF_YOUR_MEASURE_FEATURE
/1000 (assuming mm units and 1 turn per meter).

4: Complete the sketch and the VSS... with a little
luck, there it is.

File to follow within a couple hours hopefully. You
could certainly put all three conductors in a single VSS.
Or, make separate parts for each and additionally for the
insulation pieces and put them in an assembly that
contains the (optionally straight) 'curve' you want to
follow. So many possibilities. :]
 
Thanks Alt, I look forward to looking at the model


I tried the trajpar command yesterday andgot a nice helical edge, however when I come to do a VSS it always defaults the sketch orientation as though you were doing a normal helical spring sweep and I want the sketch in another orientation.


In simple terms if I orientate the model in the FRONT direction, then the curve will be going into the screen around an axis thru the TOP and RIGHt planes and I want to then draw the VSS sketch on the FRONT plane.


Maybe your model will shed some light and once again, thanks for help


Stu
 
I should have mentioned that the manner of specifying the radius for
the helical surface is quite important. If you dimension the length of
the line segment it doesn
 
Tobias and Altendky


Your help was greatly appreciated and its now coming together nicely, don't know what I'd done wrong before and your model, Tobias, was what I was trying but my sketch for the sweep always came at wrong orientation. Couldn't get your model Atl, sorry, wouldn't let me download


I'll crack on and see if I can get all the bits modelled and the assembly done and will post back to you


Cheers guys


Stu
 
Cheers Nawaz,


Have run thru that tutorial a few yrs ago, very good....my problem was that I wanted the sweep sketch to be at 90 degrees to the helical...Tobbo's model helped and I'm sure Altendky's would have too, if able to download


Many thanks for your input


Stu
 
Cheers Guys


Managed a decent modelled assembly of parts from your help/models


Unfortunately too big a size to upload, if you want to see the finished article, then pm me with email address and I'll send through


Stu
 

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