Team 68's 40 days of chassis Design.
 

So I have decided to CAD up 40 potential chassis's until kickoff ::ouch::.
Ya... Feel free to ask questions, give advice ect.
The Robot Renderings may not be to detailed due to lack of time.:mad:



It's like Brainstorming with Hours of effort and cool pictures.

Re: Team 68's 40 days of chassis Design.
 

Things I like: she is pretty :D

Things that could use improvement/addition:
-Gearbox and chain run mounts should always be added to your CAD, they are pretty much the most important thing in a drive train besides the frame.
-Twisting forces are going to be rough on the two drive pods. Due to their cantilevered nature.
-1/4" plate is way to thick for this application, I think you will lose a lot of weight with less material and some well placed spacers.

As a side note, why CAD 40 drive trains and spend 60+ hours when you could just do a napkin sketch? (I do admit CAD is fun, but it isn't really a necessary part of engineering design)

Re: Team 68's 40 days of chassis Design.
 

Day 2 ... and I have took your advice and added a transmission, but this design was finished 2 days ago so I did not make it out of thinner aluminum or add spacers for structural integrity.




The 6X6 were designed for climbing stuff, life steps or ramps, they were done days ago so they have no trans.
The big problem with this design is... Where do you mount the bumperes...

And I am doing this for fun/ Practicing my cad skills.:ahh:

Re: Team 68's 40 days of chassis Design.
 

Yeah mounting bumpers would be insane. Nice design though. :D

Re: Team 68's 40 days of chassis Design.
 

The mecanum wheels are mounted incorrectly on image16.

Re: Team 68's 40 days of chassis Design.
 

I think most engineers would disagree with the latter half of your statement.

Re: Team 68's 40 days of chassis Design.
 

I would claim that it isn't necessary but it certainly makes it easier. Hand drafting is still a perfectly viable way of designing a product. I think what Alex could have said was that CAD is not necessary for working through the rough stages of an idea.

Regarding this entire thread, Instead of doing 40 different chassis please consider doing a couple chassis with several revisions of each. I like the concept of giving yourself a short time line as it will increase your skills but I think this would be a better use of time if you got something you could use out of it.

Re: Team 68's 40 days of chassis Design.
 

An important part of the skillset for CAD-ers is DFM and CE. Are you working closely with your teammates to ensure that your team has the tools and expertise to actually make what you are drawing?

Re: Team 68's 40 days of chassis Design.
 

Very cool project, and I am sure your 40 designs will inspire others along about January 8th or so :)

Re: Team 68's 40 days of chassis Design.
 

I hope so that would be awesome!:D

Re: Team 68's 40 days of chassis Design.
 

Just for clarification, I don't discount CAD as an engineering tool. I do however believe it is best to work up to it with sketches, rough technical drawings, and calculations first. Without CAD I wouldn't likely have a job I could tolerate :P.

Re: Team 68's 40 days of chassis Design.
 

Day 3...Hear you go.:)


This one ^ was from inside the support bar. In regards to weather or not we can make these chassis the team owns a cnc mill and a couple lathes so we can make alot. Previous years have been much more extravagant than our last robot. What killed us last year was our drive train, we did not "Keep it simple stupid"

Re: Team 68's 40 days of chassis Design.
 

Wow thats a lot of milling on those side pieces. You might consider going to a thinner tube wall thickness (1/16" over 1/8"). It would probably lighter than the heavily pocketed 1/8" wall thickness tube that you have there and might be stronger too.

Re: Team 68's 40 days of chassis Design.
 

In addition to Nick's comment I also have to point out that with this system you will run into the same problem you did last year once you decided to lock your wheels. This frame will drive forward and back very well but will not turn.

Re: Team 68's 40 days of chassis Design.
 

Ya I probably should have used eater an omni wheel in front or and 08 KOP wheel.

And I have had about 6 chassis done before any comments about wall thickness came into play, so the future designs may be thinner.

Re: Team 68's 40 days of chassis Design.
 

Nick's points are very valid though; try to reduce the time invested in such things, especially when you can just use smaller tubing and leave it whole.

Re: Team 68's 40 days of chassis Design.
 

You have a SuperShifter and a sprocket reduction driving a 4 inch wheel. That can't make for a very fast robot at all. What were your thoughts regarding gearing? Am I missing something?

Re: Team 68's 40 days of chassis Design.
 

All of these look really nice, but there seem to be some practicality issues.

For example, you should give some thought as to how you plan to join the metal on Day 1's design.

On Day 2's design, you have a completely rounded edge on your sideplates. Admittedly, this looks awesome, but ask yourself if you want to invest the time in rounding an edge completely.

Day 3's design looks really good. The only issue I see (and this isn't crucial) is that your axles are press-fit into the tubes. This could work, but you would have to weld your axles in place. An alternative would be to tap the ends of the axle and bolt the axle from the outside of the tube. With this method, you would have to put bearings on the wheel (dead axle). Instead, you could press-fit the bearings wherever the axle passes through the tube and fix the wheel on the axle (live axle).

Overall, they look really nice! Keep up the good work!

Re: Team 68's 40 days of chassis Design.
 

Just... Wow... Congrats on making a number of different designs in such a short time span. Looks like most of the faults I can see straight off have already been covered but those are minor fixes if you wanted to fix them.

While I can't say anything about the designer, I can say that your observation about an unaltered SuperShifter would be correct. In fact, when our own team came across this problem a few weeks ago we had to do some work to figure out how fast exactly we wanted to go. After doing so, we figured out how to change the gear/sprocket ratio to to do that. Part of the solution was to use some alternate cluster/output gears available from AM to adjust for that. The other part was to slightly change the driving-driven sprocket ratio.

My .02$

Re: Team 68's 40 days of chassis Design.
 

Wait, how do you cut your aluminum like that? A cnc machine? Our robot chassis is very "crude" every year, just aluminum bars welded together without any thing fancy. I assume you guys start with aluminum sheets and cut it out and weld it? Is it any stronger? I would assume a solid bar is stronger but looks ugly

Re: Team 68's 40 days of chassis Design.
 

Look at this UGLY chassis! :rolleyes:

Welded tube is by no means a bad frame design, many teams obviously believe it superior to the plate sandwich setups many teams run. We run a frame annually very similar and heavily influenced by the one linked.

Re: Team 68's 40 days of chassis Design.
 

Done correctly sheet metal can be more than strong enough. And it does look rather cool too. It requires more specialized equipment, though.

That said, there's nothing inherently keeping a bar stock chassis from looking pretty sleek.