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Un-bending (Straighten) capability for rod, tube or pipe.

andrew_troupandrew_troup Member, Mentor Posts: 1,584 ✭✭✭✭✭
edited November 2015 in Using Onshape
In addition to the ability to un-fold (flatten, or 'develop') sheetmetal, it would be great if the same tools (or tools with a similar interface) were able to un-bend (straighten, or 'develop') rod or pipe or tube, applying a suitable k-factor (neutral axis offset) or bend allowance.

First, it goes without saying, we need a robust and easily used 3D sketch capability, but it is always beneficial to consider future use cases when designing present capability.

The key difference from a user perspective is that bend angles for rod and tube are multiaxial, so the un-bent drawing will need a second figure for the orientation (sometimes called "Phase") of each bend's plane, in the unbent condition, relative to a common datum plane.


Comments

  • _Ðave__Ðave_ Member, Developers Posts: 712 ✭✭✭✭
    +1 @andrew_troup Actually that is quite a nice concept.
  • brucebartlettbrucebartlett Member, OS Professional, Mentor, User Group Leader Posts: 2,140 PRO
    +1 yes please
    Engineer ı Product Designer ı Onshape Consulting Partner
    Twitter: @onshapetricks  & @babart1977   
  • chrisjh777chrisjh777 Member Posts: 207 ✭✭✭✭
    +1
  • viruviru Member, Developers Posts: 619 ✭✭✭✭
    +1
  • shashank_aaryashashank_aarya Member Posts: 265 ✭✭✭
    edited November 2015
    +1
    I feel that nice approach to have this in Onshape would be to add this functionality in transform option where we should able to give various references for bending such as axis, line etc.
  • brucebartlettbrucebartlett Member, OS Professional, Mentor, User Group Leader Posts: 2,140 PRO
    I have alway wanted something like this in SolidWorks, currently I do this with 2 configurations, 1 of an extrude for the cut length, the second of a sweep around a path for the finished shape both using a common profile sketch and some hand cals to work out the extrude cut length.

    Maybe this could also be incorporated with a simple flatten tool and could be use for many different application's where parts are formed from flat material or bar stock.

    Do any other MCAD programs have this functionality?
    Engineer ı Product Designer ı Onshape Consulting Partner
    Twitter: @onshapetricks  & @babart1977   
  • shashank_aaryashashank_aarya Member Posts: 265 ✭✭✭
    @brucebartlett There is similar functionality in Creo where we can use two configurations for single part. e.g. we can make one helical spring of normal length as one configuration. When the spring is being assembled, depending on assembly requirement it can be converted to compressed state by making it flexible. This is second configuration
  • matthew_menardmatthew_menard Member Posts: 96 ✭✭✭
    This is something that I too would like.  As @brucebartlett said, even Solidworks is lacking in this feature.  "Phases" for 3D bent objects would make it extremely powerful too.  My current work around is also using configurations for bent and straight geometry.  I will usually sum the dimensions of the straight lengths and chord lengths of the bends to get the unbent length.  As I think of it, is there a way to dimension the chord length of an arc, as shown below?


    Workflow in Solidworks is to enter the dimension tool, click the endpoints of the arc and then the arc itself.  Just tried something similar in OS and it didn't work.  Thanks for any info, sorry if this is possible and I just don't know.

  • michael3424michael3424 Member Posts: 688 ✭✭✭✭
    +1 - this would be handy for a little home project, bending some electrical conduit.
  • andrew_troupandrew_troup Member, Mentor Posts: 1,584 ✭✭✭✭✭
    edited November 2015
    @matthew_menard
    ..................
    .................

      My current work around is also using configurations for bent and straight geometry.  I will usually sum the dimensions of the straight lengths and chord lengths of the bends to get the unbent length. 
    .................

    That only gets you part way there, if you use the sweep path:  
    the arc length (which I think you are calling chord length?) of the path will not give an accurate developed length for that bend, because each arc radius needs to be relocated to the neutral axis.

     In other words, each arc radius needs to be adjusted to account for the fact that outer fibres stretch more than inner fibres compress (oversimplifying madly).
    In sheet metal terms, the k factor. 

    .................
     is there a way to dimension the chord length of an arc, as shown below?


    Workflow in Solidworks is to enter the dimension tool, click the endpoints of the arc and then the arc itself.  Just tried something similar in OS and it didn't work.  ......

    Similar but subtly different: Activate dimension tool, click each arc endpoint, then HOVER over the arc until you get the preview of arc length. Click to accept WHILE the preview is active.

    Here's how the preview looks:



    I seem to recall that "chord length" is measured as the crow flies, in other words, it IS what you were getting, between endpoints ..... but i could have that wrong
  • matthew_menardmatthew_menard Member Posts: 96 ✭✭✭
    Again, you're right and I'm confusing my terminology...  It is arc length, not sure why I ran with chord, as you are correct that would be the straight line between endpoints.  Thanks a lot though for trucking though all that wrongness, the arc length workflow in OS is something I didn't know about before. 

    Also, the crude sum of the central plane is an "eh, good enough" way of getting the rough length of the handful of bent pins we use.  They are only .010-.015 in diameter, and tolerances are fairly loose so accounting for what is really happening in the bending operations isn't necessary. 

    I'm done confusing terminology for the day.  Thank you very much again though for the arc length workflow.
  • phil_erdley628phil_erdley628 Member Posts: 16 PRO
    +1 These capabilities are critical to making shop ready prints!
  • mattseibertmattseibert Member Posts: 1
    +1 Agreed that this would be an incredibly helpful feature to add. In a lot of ways I feel Solidworks Flex feature could be much better... OnShape could one-up
  • john_mcclaryjohn_mcclary Member, Developers Posts: 3,935 PRO
    +1
  • brucebartlettbrucebartlett Member, OS Professional, Mentor, User Group Leader Posts: 2,140 PRO
    edited May 2017
    How cool would it be to have a tube bending fly out similar to the sheet metal one?  If you have a bent tube, rod, pipe, add an unfold feature and get the part in the straight form with bend lines and table. It's a real pain using Configurations to do this in other MCAD.

    I would be also good to get cut lengths for free-form wires, cables and hoses, but this may come more into the area of a routing module.


    Engineer ı Product Designer ı Onshape Consulting Partner
    Twitter: @onshapetricks  & @babart1977   
  • Josiah_HarthcockJosiah_Harthcock Member Posts: 55 PRO
    Please! 

    +1
  • brucebartlettbrucebartlett Member, OS Professional, Mentor, User Group Leader Posts: 2,140 PRO
    Is there an improvement request we can vote?  this would be a nice feature to have, one that I have always dreamed of. 
    Engineer ı Product Designer ı Onshape Consulting Partner
    Twitter: @onshapetricks  & @babart1977   
  • PMGPMG Member Posts: 2 PRO
    +1 Extremely relevant to the possibilities this product brings. Is there somewhere we can vote for this addition?
  • wout_theelen541wout_theelen541 Member, csevp Posts: 198 PRO
    Is there an improvement request we can vote?  this would be a nice feature to have, one that I have always dreamed of. 
    https://forum.onshape.com/discussion/21906/unbending-straigten-capability-for-rod-tube-or-pipe/p1?new=1
  • glen_dewsburyglen_dewsbury Member Posts: 774 ✭✭✭✭
    @wout_theelen541
    I've been using the frame tool for developed lengths.
    Doesn't get us any closer to 3D sketching though!
    https://cad.onshape.com/documents/8176bf42ef782f8303d3ee92/w/9a054da62eb5b27426d906a3/e/6f421a07d7207af52cd737e9

  • vincent_blvincent_bl Member Posts: 1 PRO
    @wout_theelen541
    I've been using the frame tool for developed lengths.
    Doesn't get us any closer to 3D sketching though!
    https://cad.onshape.com/documents/8176bf42ef782f8303d3ee92/w/9a054da62eb5b27426d906a3/e/6f421a07d7207af52cd737e9

    Is it normal that the measure length isn't the same? 

  • glen_dewsburyglen_dewsbury Member Posts: 774 ✭✭✭✭
    Hmm. I get the same sort of difference from measured to cut list. Haven't been too concerned since the fabricator I'm working with trims to finished size after bending. They also do their own work up for fabrication and use my lengths for quick quoting only. I'm trying to remember a discussion about this topic from a while back but not having any luck. All the tubing that I work with is bent such that neutral axis should be lined up with sketch lengths with neutral axis at 0.5.

    Maybe a question for OS support?


  • eric_pestyeric_pesty Member Posts: 1,877 PRO
    I'm pretty sure I remember a discussion about this around the time the frame tools were released... I think it's intentional to be on the "safe side" of the length calculation, which I think is very difficult to get "right" over the entire range of materials / profile / path shapes...
  • jnewth_onshapejnewth_onshape Member, Onshape Employees Posts: 86
  • glen_dewsburyglen_dewsbury Member Posts: 774 ✭✭✭✭
    Thanks Josh. Previous comment reminder very helpful.
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