Cannot quite understand how to use variable and circular pattern to make a twisted linear pattern

AnotherOnshapeUser

Hi.

I want to make a linear pattern follow a helix shape.  I found this reference, https://cad.onshape.com/documents/56f126bae4b08ab14ced4841/w/a8f3624b3331998720a39e49/e/db414f14854946aa7926c6ae which uses a variable of 35 degrees (what is going on there?) and a circular pattern and some other tricks.  I cannot duplicate it.

My pattern is a bar that I want to repeat (500 times) and twist through a helix of 36 degrees' rotation.  Can't do it.  What are the exact steps?
thanks!

NeilCooke

See the second video here to see how to use variables in patterns: https://forum.onshape.com/discussion/2675/improvements-to-onshape-february-11th-2016/p1

AnotherOnshapeUser

Neil, while it's important to understand using variables in patterns, that link does not tell me how to make a pattern into a spiral shape.  Thanks for the info, though!

Krz

@AnotherOnshapeUser Neil's link explains but... not fully. It seems they added important option in Linear pattern since that (2016). It is "Apply per instance".

See my sample play.

https://cad.onshape.com/documents/b644e6b161245a75d1c697d8/w/8594eb75d40737180ab2b177/e/b7878db807c2f01aac61a3fb

NeilCooke

@AnotherOnshapeUser can you not just use a curve pattern? If you share an image of what you're trying to achieve I can show you the best method.

AnotherOnshapeUser

Thank you, Neil, I did figure it out after about two hours.  You have to make, say an extrude first.  You are going to extrude it over and over again, rotating it a little bit each time as a variable increases.
Then you create a variable, and give it a value of 0 degrees.
Then make a Circular Pattern, choosing 'Feature Pattern' in the pattern, and select your extrusion for the pattern.  Then you rotate it, but instead of writing in the number of degrees, you put in the name of your variable.  2 rotations, it will not even appear on the screen.  It will show 0 degrees where you just typed in the variable name, which was very confusing to me trying to figure out what someone else had done.
Then you create another variable with the same name, only instead of degrees you write "#variable Your Variable + 5 deg" so that this new variable has a value of X degrees more than the variable you named zero.  Get it?  You'll make multiple copies of the extrude, each one adding 5 more degrees.
You have to move the variables so that they are all BEFORE the original extrude, this is an important gotcha.
Then you do a linear pattern, select 'Feature Pattern', and choosing your Circular Pattern as the pattern, and underneath it in the same box choosing your new variable that will add 5 degrees or whatever every time.
If you did it right, it works great.  Hope I saved somebody some time. Be well.

Jake_Rosenfeld

@AnotherOnshapeUser

It is possible to use feature pattern to recalculate variables, but I do think that it's easier to just follow Neil's suggestion and use curve pattern over a helical edge.

AnotherOnshapeUser

Jake definitely right, curve pattern is great, I did not notice it!