Mock-up frame poll

[bird2]

Hey guys im taking a poll to see what the most popular frame mock-up material is. we're thinking about pvc conduit (cheap, and bendable with heat). The previous fsae team here used basic 1/4 stock because its easy to put together. what did you guys use?

[bird2]

Hey guys im taking a poll to see what the most popular frame mock-up material is. we're thinking about pvc conduit (cheap, and bendable with heat). The previous fsae team here used basic 1/4 stock because its easy to put together. what did you guys use?

[AxelRipper]

In the past, we've used Solidworks, but this year we switched to Inventor.

[bird2]

whats solidworks?



just kidding...we have the complete frame in SW, we're looking to build a full scale model for physical assessments of fitment and ergonomics

[Adambomb]

Electrical conduit! Cheap, and you can get it to stick together using the MIG in "hot glue gun" mode.

[Jay Lawrence]

We used to use PVC and sticky tape http://fsae.com/groupee_common/emoticons/icon_smile.gif
But not for the last 3 years. Solidworks just makes it easier and quicker. I would certainly suggest a first year team do a mock, especially one who may not be very experienced with CAD (avoid the whole 'but it fit in the model...' dilemma)

[swong46]

with plywood mmm

[Zac]

I've found that foamcore poster board works really well for mocking up nearly anything.

what I think you'll find in general though is that mock-ups are most valuable for a first year team. once you have a finished car to go off of it is likely faster and easier just to make changes in solidworks.

[PeterK]

We've used rebar tacked together.

[Kevin Hayward]

The students at ECU mock up the rear bay with mild steel without proper end prep. It is done in conjunction with the model (i.e. model and mockup changing on the shop floor). It takes about a day to mock it up and ends up being strong enough to hold engines and parts up. The mockups are cut up to keep the steel after the year is done.

The front monocoque chassis is mocked up the same way as the chassis is built (folded honeycomb) but with a discarded panels (from supplier). This makes the front bay mockup useful right to the end of the development. Anything that involves cutting on the final chassis is done on the mock first. The front takes a couple of hours to mock up.

This year the mockup rolled.

I think that taking two days to mockup the chassis very early before the designs have been finalised has led to better solutions, and a more pain free final chassis build.

Kev

[The_Man]

PVC tubes with some quick set expansion joints (Em-seal), and lots of duct tape.

Also, useful in physically visualizing the load paths/deformations specially in torsional load.

[AxelRipper]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by bird2:
whats solidworks?



just kidding...we have the complete frame in SW, we're looking to build a full scale model for physical assessments of fitment and ergonomics </div></BLOCKQUOTE>

Ah... well in that case we use well prepped 1" steel tubing tacked together to validate the CAD model. Then when we do that, break out the tig and finish the chassis.

[jemartin144]

We use solidworks to mockup the frame. Thats the best way to get most things mocked up, but I still made a physical mockup to make sure the cockpit is gonna work. With how dynamic the human body can be I find it best to take a little time to make sure the driver fits and is comfortable.

I used mostly 2x2's and spare bits of wood to mockup the frame, but I also make the body molds, so Im used to working with wood. Also, I was really only concerned with inside dimensions for my mockup. I think i may try PVC next time because it can be made much closed to actual dimensions.

[bird2]

Were goin with conduit, and I managed to get our lab supervisor to buy us a plastic welder to use on some of the joints.

[emd44]

We've used conduit [EMT]. Get it from local electrical supply. Can be bent with a hand bender you can 'acquire' from your university's electrical / facilities dept. Just watch, it's galvanized, so don't snort it after you weld it.

[mech5496]

PVC tubes... Easy and cheap to get, easy to cut, easy to bend with a help of a torch. Then make the joints with paper tape and lay up a few layers of chopped-strand matt glass fiber with polyester-&gt;DONE! That's what we used to do on tubular frames. On our monocoque, we cut several cross-sections on wood and then connected them with cardboard; works pretty well, but could be better... Having to run a resin infusion test on the finished mold (to see how the resin flows into it on glass fiber before building the actual chassis) left us with basically a single-skined glassfiber monocoque, which came extremely handy in drilling test holes and test fitting parts....