Build Blitz CAD

Beat us by 23 minutes! CAD files for both teams are now available at the Build Blitz website -

Thank you Grant! Btw, are you going to be at any of the Michigan events again this year?!?!

Wow awesome! Thanks Grant

No problem! My participation in Michigan events is TBD right now; flights from Texas to Detroit are pricy, and I’ll be working with team 148 this year as well. I’d love to make it up for at least one district, if not MSC, so come say hi if you see me!

A question on the files-- will there be significant changes to the Team JVN chassis as it is released as the 2014 drive in a day? If so, will they be significant in terms of adding/removing functionality?

Overall, kudos to both teams. Full CAD models in 3 days is no mean feat when many struggle to produce even partial models in the course of a season!

Here’s my special request for the 2014 Drive in a Day: add this hole.

That allows direct drive gearbox mounting using the centered 1.125" bearing hole with tube axles on the outer wheels of a 6WD. The outside hole is 10.50" from the center hole, an integer multiple of 0.50" for convenient use of #25 chain with no tensioners required (ignoring chain stretching… yes, I know it happens). There isn’t a convenient place to put a hole for 4" wheels (that bearing hole on the outside is in the way), but this is a workable spot for the 3.25" wheels. You’re already my heroes, but if you add this hole you’ll be even bigger heroes to me.

Did they post their reveal videos yet? I’ve looked, maybe I missed them. I watched the live stream but the quality is super bad and its split up.

Ummm… sure! Good idea. :slight_smile:

Wow. That is just about the coolest thing ever.

At JVN and BuildBlitz - Great job on the media and robots. The resources for teams are invaluable and a great example of the design process in action.

I have a question about the Choo Choo and the Lexan tab mentioned in the blog. I do not completely understand how the Lexan is used with the alignment and cannot find it in the CAD drawings. I know a picture was posted in the blog but could not wrap my head around how this tab was used.

Can you explain or post of a picture?


We ended up not using the lexan tab at all, and just using the box end ratchet wrench.

Thanks Aren.


Additional choo-choo question.

Am I missing something in the model, or will the choo-choo interfere with itself as the large gear rotates? I’m assuming in the haste of Build Blitz, CADing spacers was not high priority, but I’d like to make sure.

This was one casualty of trying to liveblog while our team of stellar engineers worked faster than I could type - at one point it was the plan, but as Aren said, the ratchet wrench + limit switch ended up working fine.

The idea was that the tab hung down vertically in between the two gears of the choo-choo. During normal operation, the larger gear spun clockwise, brushing the lexan out of the way (think sort of like a playing card in a bicycle spoke). However, if the system tried to backdrive, the interface between the two gears would reverse, choking the lexan tab into tension between the two gears and locking it up.

Thanks for the response Grant.

Is the 3D printed CAM the black tab on the hex shaft? Is this the tab that was used in conjunction with a limit switch that is not shown?

Thanks again - learning still from the Build Blitz and the follow up CAD.

This is correct, the CAM was a quick 20min print job.

Just so you know… we’re referring to that as the “Nemo hole” in house.
“Does the Rev2 Rail have the Nemo hole in it?”
“Yes, and I also added a mirrored Nemo hole for Dead Axle configs.”

He wasn’t kidding.

Our team finds that to be pretty entertaining. We did end up choosing Drive in a Day as our frame - it’s a nice system in that it’s pretty quick to build and does what we need it to do.

This year it’s a tough call between AM14U, VersaChassis, and Drive in a Day. They’re all really nice, flexible, well thought-out drive bases that a team can put together quickly.

Just saying, I’ve been looking at the model for the 2014 drive in a day and want to express my thanks to anyone who worked on it (from TeamJVN to Nemo’s input). You guys have managed to make one of the most feature-packed chassis I’ve ever had the fortune of laying eyes on. Truly hats off to the guys at VexPro.

Now to convince my team to use it!