Sketch Arc is Preventing Squares from Resizing Properly

[oo7_golden_1]

Hello 360 community! I accidently posted this issue in the wrong forum section the other day and another community member was nice enough to direct me here.

I am trying to create an adjustable model based off of a Fibonacci spiral. I drew up a quick sketch of a Fibonacci spiral, tested it to make sure that it was constrained and adjustable and everything seemed to work as expected. When I started building it again I cannot seem to get all of my arcs to work correctly.

The model is fully constrained as it should be, but when I adjust my initial square’s size (which I built the sketch off of) Fusion errors and tells me to check pretty much everything in the model.

After some deleting to try and pinpoint the issue, I believe I have narrowed it down to some Arcs causing the problem.

It’s strange because some arcs work and some do not. I have uploaded the model to demonstrate.

To replicate the issue, adjust d1 (found on the smallest square next to the origin point) notice how the model adjusts, then add an arc (I used 3 point arcs) into one of the empty squares to try and add to the spiral. Then after drawing the arc try adjusting d1 again. Instead of adjusting as it should (like the other squares with arcs) it seems to break the render and cause fusion 360 to fail at the computation.

As you can see the arcs SHOULD also adjust accordingly. The empty squares should allow similar arcs but if I add arcs to those squares the arcs ARE constrained but they prevent d1 from being adjusted.

I tried using a fit point spline instead of arcs but the spline does not stay within the squares, and sometimes doesn’t seem to render properly and I need the model to be precise.

Does anyone have any creative advice on how I can build this properly? Or on why I cannot seem to add arcs to the squares in question without the arc causing resizing problems later on down the road?

[oo7_golden_1]

I have been working with multiple sketches already... but you gave me an idea on how I might be able to overlap the cut lines after all... 

I will have to think about how to make it work...
I was hoping there might be a way to combine the offset lines or something so that they were one continues line instead of multiple lines based off of the arcs which made up the original spiral. Or draw a single spline and then use it in place of an outline with a sketch dimension attached to it or something... But that might not be possible... Or use a single spline in place of multiple arcs... I cannot seem to get a spline to be as reliable as an arc though.

[laughingcreek]

an idea-

[oo7_golden_1]

I am fighting with tech today. Lots of brain lag and user errors... Disregard this reply. 

[oo7_golden_1]

I am fighting with tech today. Lots of brain lag and user errors... Disregard this reply. 

[TheCADWhisperer]

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@oo7_golden_1 wrote:

I created an offset of the spiral

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@oo7_golden_1 

Thin Feature is much less computationally expensive and easier for the user too.

No need to double up offsets. Get Lazy!

[oo7_golden_1]

@laughingcreek That is interesting. I have not really played with Patterns on a Path at all in fusion yet. I kind of need it more 2d though.
I thought I might be able to rotate the spiral (on different sketches) and then just extend the cut lines over the spiral, then if I resize the the spiral it wont matter because the cut lines are not part of that particular portion of the sketch. The cut lines remain stationary and the spiral expands or is made smaller.

This negates the design that @TrippyLighting put forward though because rotating the sketch breaks all of the horizontal and vertical constraints. So... maybe building the arcs with rectangles as a reference was a better idea on the whole because then I can rotate the first square 15 or 30 degrees and the rest of the model would/should rotate along with it.

[oo7_golden_1]

I have not really used the thin extrude feature yet either. But I can see how it would be extremely useful. Thanks for pointing that out @TheCADWhisperer.
So, lets say that each of the sections of my spiral is going to be its own piece to make up a bigger spiral and I wanted to sketch all of the pieces vertically to add text and what not. 
I found that if I cut the spiral into sections and then created a circular pattern from the origin point... I could suppress all but one of the patterns and it would create a vertical row of each section of the spiral one on top of another which makes working with them and text a LOT easier. The problem is that because each section is constrained to an arc if the sketch scales too much in one direction the constraint gets de-railed off of the arc and or the adjustment doesn't go through at all. 
So, I thought, Hum... If I want to make a spiral with 12 parts I could cut the spiral every 30 degrees from center. Create a sketch of the spiral, copy the spiral from the first sketch, finish the sketch, create a new sketch, paste the copied spiral into the new sketch, constrain it to the origin point, rotate it by 30 degrees, draw a line strait down from the origin point, draw a line 15deg on both sides of that centered line, extend those two lines past/over the spiral and then the two lines wont be attached to the spiral and it wont matter if I resize it or not.
If I do this I would have to break the horizontal and vertical restraints making @TrippyLighting design, which I liked, impractical. So, a square that I can rotate by 30, 60, 90 deg etc might be the ideal choice after all.

[laughingcreek]

your describing a bunch of workflows that seem convoluted.  can you illustrate what your ultimately trying to end up with  (real world objects, hand drawing sketches, etc)

[davebYYPCU]

I got to agree with Alex, very convoluted description.

Considering there are 30 degree segments on a clock, you want twice that.

If the cutting does not have to be square to the curve, then Split Body, with 15 degree array of lines, will do it.

Might help....

[TheCADWhisperer]

@oo7_golden_1 

https://www.youtube.com/watch?v=CjTc94Bymzk

I accidently inserted video 6 seconds into the video - be sure to Rewind to the beginning to see the Reference Citation to Wikipedia.com 

Edit: Yikes! I misspelled his name.  Don't rewind and you will never see it.

[oo7_golden_1]

Hey there Fusion 360 Community

@TheCADWhisperer That was a great video and I learned some good nuggets of information. I made sure to like and subscribe and also left a thank you in the comments.

Things I learned from your wonderful video:

Coincident Shift Click for mid-point constraints

Learned about the full round fillet (I had always just selected the corners before) this is better as you described that you do not have to input a radius dimension which is really nice.

I am still struggling with my project. I can constrain and draw everything out just fine. It’s the resizing later that is killing me. Fusion just fights me no matter what I end up trying. Been working on this dumb thing for days now and just cannot get it to resize correctly.

As community members have pointed out I have been too vague when describing what I am trying to build.

@davebYYPCU guessed what I am attempting to create and that is a clock. A clock with a Fibonacci Spiral as the hands as well as the graduations/marks which tell what time it is. At this point though I might seek other spiral options as the fibonacci spiral is fighting with me at every turn.

I do not have any problems building the clock, it’s the resizing later that I am struggling with. If I need to adjust the radius of the spiral and go to adjust it fusion just crashes or throws 100 errors. I have tried dozens of methods and have rebuilt my clock 6 times now and I still have yet to discover how to make resizing later possible.

I want the ability to adjust features of the clock later or else I could just draw it in a visual editor, save as a DXF, import it into fusion, extrude everything out, and be done with it. The problem with that is if I have to make an adjustment to something then it’s a nightmare later. So, I am trying to force myself to do everything in fusion for later adjusting as needed.

Its just not working though.

Yesterday I had the idea to not link any lines to the spirals as I figured linking to the spirals was what was causing problems. I could overlap everything and extrude as necessary. But again, I try to resize my arc size and Fusion just crashes.

Here is an upload of my latest failure at trying to create an adjustable sketch that I can reliably resize later.

[oo7_golden_1]

I need to increase the size of the spiral BUT when I try to adjust the size of the initial arc fusion FREAKS OUT and just refuses to resize the arc and by extension the spiral as a whole. I have tried to build these arcs many different ways and I just cannot seem to get them to adjust properly. Its become quite frustrating. Am I just asking too much of Fusion360? At first I figured its my inexperience and lack of knowledge (and still might be) but dang, its been many many many hours troubleshooting (days even) and I just can not get it to adjust like I need it to.

[laughingcreek]

so, I would argue there are exactly zero reasons for all your sketches after the first sketch.

patterning in sketches is not a good idea.

see attached for an approach.  you'll note fusion is perfectly happy to resize this.

[oo7_golden_1]

How would you create spiral marks which go outward from the center? I need to be able to cut out the size of the clock hand itself + a little wider so that I can create an insert plus a lip for that insert... Its a complex puzzle of a model. I do not know how to build it outside of a sketch...

[laughingcreek]

*

[oo7_golden_1]

Thank you for the demonstration @laughingcreek... Ill have to play with your model, break it down to better understand it and then see if I can apply it and make it work for my project. It is certainly outside of the box I am used to working in.
I like to sketch and draw everything out and then build off of that. But that might not be possible for this particular project. 

[oo7_golden_1]

After a power nap I think I can see more clearly what @TheCADWhisperer was trying to convey when he brought up using the “thin feature”. His model “Whisper – Thin Feature” used the thin extrude as an additive example (an extrude new body) BUT it could also be used for subtractive applications (cutting into an existing body). Thus the “No need to double up offsets. Get Lazy!” comment. Which suddenly makes a lot more sense.

I do not need to sketch all of the offsets and cuts (which I have been doing) when I can just utilize the power of the extrude feature and try to work outside of the sketch environment as much as possible.

It seems that fusion prefers users to work primarily in the solid workspace as opposed to the sketch workspace. Would that be a fair observation?

I think this might be what @laughingcreek was also trying to emphasize when he uploaded his “fib2 LC” file.

It seems like patterns and offsets seem to be less taxing and less prone to errors when being applied to a feature within the solid workspace than when done using a sketch.

So, this is something I am going to have to work towards as far as self-improvement, as I have always focused primarily on building a good 2D sketch and then using that sketch not only as the foundation of the project but also for building almost entirely off of as opposed to just using the sketch as a starting point and then performing the bulk of the work inside of the solid workspace.

Thank you for your patience, guys. I am self-taught through trial and error and it seems like there is always something new to learn about an existing feature or a more efficient and or cleaner way to accomplish something in fusion360.

I appreciate all of your help.