2017-03-22 VR3 Meeting

Owned by Devon Copeland
Last updated: Mar 26, 2017

Date

Attendees

Agenda

  • Get feedback on chassis
  • Explain our design intent and timeline
  • Learn about any useful tips and trick they may have for the chassis

Minutes

  • 1¼" - 0.049 has the same weight but higher stiffness than 1” - 0.065

  • It’s often a good ideal to start with a larger OD for the outside tubes & main hoops and then reduce the OD and wall thickness for the bracing and triangulation

  • Triangulation is key

  • You should add the structural members to the Solidoworks part in the same order that you would weld the chassis. Always add a member and then trim, don't add all the members and then try to figure out the trim order of everything. 

  • Bending:

    • Double check that all bend radii are allowable for the tube OD and wall thickness being used

    • There must be 4.5” of straight tube between bends

    • For low volume production and one offs its usually better to opt to replace welds with bends where possible. Although it is cheaper to slit a bent tube in two have two tubes trimmed, we will save 3 times as much at welding time as we would save by eliminating the bend. 

  • Trims: 

    • Through tubes (tubes that end without a fish mouth and are either open or capped) should be extended past their intersection with other tubes. This prevents “disappearing welds”. The tube below should be extended to avoid the gap shown

    • Radii on trims should be no less than 1/16"
    • Through holes in tubes should be on center

  • Solidworks Tips:

    • Solidworks’ cut list recognizes tubes that are perfectly symmetrical. This is okay but sometimes it makes mistakes which VR3 will usually catch. The more important thing is that every tube is a separate structural member. 

    • Let Solidworks do the cultist numbering (turn on automatic updates) until the model is sent for production. As soon as it is sent to VR3 to be cut, the cut list should be frozen and the numbering should stay fixed. If a tube is added, it will need to be manually added to the cultist. This way tube numbers don’t change after they are cut and labeled. 

  • Drawings

    • VR3 Will make drawings for all the bent tubes (the most important things they need on the drawing from us is the cultist and the assembly view with all the item bubbles). 

    • Design of tubular scriptures is done by centreline but it is more practical to annotate the drawings by outside tube edges (easier to measure while welding).

  • Mounting points
    • Through holes can be machine into the tubes and a smaller tube and be welded inside the hole as a bushing. For example, a 1/2" - 0.095 tube can be used for a 5/8" bolt. 
    • Small sections of square tube can be trimmed to make mounting brackets. 
  • Welding
    • It's best if all tubes are positioned in their final position before welding. 
    • It's best to start with planar weldments first (hoops and bottom) when adding structural members

Notes from the VR3 Team on our Chassis

Action items

  • Chassis team needs to look into what is required for E3 to weld our frame + what is the best way to make a welding jig.