20 Replies Latest reply on Jan 18, 2011 3:02 PM by Tim Dougherty

# How to wind wire around a rectangular bar?

Hi,

I want to wind wire in a helix-type shape around a rectangular bar. The length of the bar is 260mm. Each strand of wire is separated by a constant distance of 1mm from the adjacent strand. Therefore there will be 260 turns over the length of 260mm. How can I create a the recessed track for the wire on the rectangular bar?

Thanks,

Matt

• ###### Re: How to wind wire around a rectangular bar?

Matt,

Is this on the lines of your idea?

-Shawn

• ###### Re: How to wind wire around a rectangular bar?

Shawn,

Impressive - this is very close to what I need. Thanks.

Instead of a square bar, can it be rectangular?

Regards,

Matt

• ###### Re: How to wind wire around a rectangular bar?

Matt,

I assume that you problem is similar to winding a rectangular coil spring. You can probably do a search on that phrase to get a sample part. As I recall, the technique is to use two surfaces, a spiral surface and an extruded rectangle with fillets in the corners. Put an intersection curve at the intersection of the two surfaces and use that curve to sweep your wire profile, or in your case, your wire clearance cut.

I would sweep just one or a few turns and then pattern the cut, as it is likely to be faster.

I think you can make the spiral surface with a simple line and sweep with twist, rather than using the helix feature.

Jerry Steiger

• ###### Re: How to wind wire around a rectangular bar?

Thanks Jerry,

I tried something like that, but the slot takes on a shape as it would were the coil winding around a circular bar. I will keep trying some iterations of this though.

Best regards,

Matt

• ###### Re: How to wind wire around a rectangular bar?

Thank you Jerry for the support on this.Yes I did find some manufacturers of rectangular coil springs which is also helpful.

Best wishes,

Matt

• ###### Re: How to wind wire around a rectangular bar?

I was imagining a rectangular helix from Matts first post.  Quick and dirty and not without issues... I projected split lines, manually winding up my rectangular surface model.

There's an issue using a 1.0mm profile for the 'wire', so it's set at .98 or .99.  It also does not want to do a combine of the 13 bodies shown..... or combine/subtract them from a solid extruded from the rectangular surface profile. (Yet)  I'm sure I can get there though.  Maybe only patterning the sweep twice, or going back and adding another revolution of the split lines.

• ###### Re: How to wind wire around a rectangular bar?

Thanks Tim.

This looks good. If there is some way to now generate the core that this coil is wrappd around it would be great. I can't seem to figure that out. I thought this problem was going to be easy but it's a real toughie.

Best regards,

Matt

• ###### Re: How to wind wire around a rectangular bar?

Matt if I get you right, after having the coil, must be just a matter of creating an offset from the coil surface, and then cut the core with that surface (cut with surface) or if both are solids using the combine feature with subtract, being the core the main body and a copy of the coil (simple duplicate)  being the body to combine.

• ###### Re: How to wind wire around a rectangular bar?

Hello Victor, I have not tried your suggested solution yet, but will give it a try. I believe I have a solution at this point.

Best wishes,

Matt

• ###### Re: How to wind wire around a rectangular bar?

Matt,

After generating your wire, create a regular extrusion that you are using as your 'stock' rectangle. Make sure it is a seperate body (UN-check the "merge" checkbox when you create the exrude). Then you can use the Combine tool, along with the "subtract" option, to cut away the rectangle where the wire goes.

http://help.solidworks.com/2010/english/SolidWorks/sldworks/LegacyHelp/Sldworks/Features/HIDD_DVE_FEAT_COMBINE_BODIES.htm

Do you need to do it in an assembly, instead? Then try the cavity tool. Here is a video of how to use cavity:

• ###### Re: How to wind wire around a rectangular bar?

Matt,

This goes in conjunction with what charles has explained...

The attached model should be what your looking for.

• ###### Re: How to wind wire around a rectangular bar?

Hi Nick,

I think you are on the right track, but the slot for the wire needs to be deeper into the bar on all four sides and the bar cross-section needs to have an aspect ratio of 3:1 (the width is 3 x the height).

I need something similar to the attached model, except the circulr helix needs to be rectangular.

Thanks!

Matt

• ###### Re: How to wind wire around a rectangular bar?

Many thanks for your support Charles.I will give this a try!

Best wishes,

Matt

• ###### Re: How to wind wire around a rectangular bar?

The attached contains examples of how to create non-circular coils.

The same process can be used to create a Swept-cut around a non-circular shape.

• ###### Re: How to wind wire around a rectangular bar?

Hello Kelvin,

Thanks for shedding some light on this.  I still hate springs but this eases the pain somewhat.

Best wishes,

Matt

• ###### Re: How to wind wire around a rectangular bar?

Using Kelvins rectangular spring model works, except there is an anomoly with the path.

It looks like the circular helical sweep makes the cut path non-linear going along the sides.

Take a peak straight down the cut path.  This one is 3:1 with 1mm seperation.  (.999 wire)

• ###### Re: How to wind wire around a rectangular bar?

Well, if you can't get a bigger hammer, just keep on hitting it.  After obsessing over this one for too long I have to call it quits.

But I did get what I think you are looking for.  This is 31 x 11 x 26mm lg, 1mm wire.  You can pattern the body X10 to get your 260, then combine.  I had it there but file grows to 20+MB .

If you are going to make changes, I recommend rolling back to that feature, then stepping forward again.

• ###### Re: How to wind wire around a rectangular bar?

Well done Tim. This is a real toughie for sure, so thank you so much for getting resolution here.

Best wishes,

Matt

• ###### Re: How to wind wire around a rectangular bar?

Very nice Tim. What do you use the delete body for at the end? Does that save on file size instead of just hiding the surfaces?

• ###### Re: How to wind wire around a rectangular bar?

Thanks Michael,

Body delete is just habit for me to clean up model geometry on files that may end up in China    I didn't check if it affects file size.

I thought I had this one with just the initial surface sweep/knit, then I tried using trim surfaces on either end thinking I could knit the whole works into a solid, but each end would always end up with a tangency problem on one corner...... no matter where I set the cut plane.  Grrrrr   got me so mad I had to make it work !