Quote:
Originally Posted by MetalJacket
Looks pretty good! Only have two questions/concerns. First - it looks like the belly pan only extends to the inner side panels; did you consider having it go to the outer rail and if so what made you chose not to? Second - you probably won't need that many wing nuts to hold the bumpers on  . Overall though, I like the design. Good luck in 2014! |
We can't go all the way to the outside because we have to put the axles, wheels, etc. up through the bottom. The amount of wingbolts is a bit ridiculous, in the actual robot we would probably take a few of them out. The holes in the bumpers will also probably be oversized and slotted, which isn't represented in these files.
Quote:
Originally Posted by OWilliamson
First off, I'm really digging this chassis 
One thing that I will mention though, is that you might want to consider having a cutout in your belly pan beneath the gearboxes. If you do this you can disconnect the gearbox and then slide it out the bottom. Last year in competition we had a problem with one of our gearboxes, and it was a nightmare to pull it out to perform the repairs that we needed to. It took way too long, and almost cost us a match. It shouldn't compromise the strength of the belly pan too much, and it could possibly be the difference between missing a match or not in competition. |
First off, what gearbox were you using and what was the issue (just for my curiosity)?
We originally had the bellypan cut out under the gearbox (If you suppress Extrusion2 in "Electrical/board/FF14-EP-2-AA Base Electrical Board.ipt" it will go back to this), however since we have never had an issue with the supershifters, we decided that we would take the repairabiity hit and go with taking them out of the top (having a easily removable gamespec element will be a design requirement) in order to get more rigidity. The electrical board is actually 3 pieces of 1/16th aluminum folded and riveted together, making 2 mini-crossbeams for torsional stiffness, having the control board go down to a thin section in-between the motors would greatly reduce the effect of these. A secondary design priority was to have as much rigidity as possible to help with handling, last year we did not have a structural bellypan, nor did we have rigid bumpers; we ended up with great front-back and side-side rigidity, but it was not up to snuff torsionally, which makes it scrub more, and scrub more inconsistently. We're trying to fix the rigidity this year with the belly pan, very heavy bumpers, and a more structural gamespec element. I'll talk to our other guys about it though.
Quote:
Originally Posted by Johnny_5
Careful with waterjetting that thin of material, depending on what kind of machine you are using, you can end up with some pretty bad cuts.
When the machine begins the cut, it uses a much high pressure to first pierce the material and then it lowers it to actually run the cut. Sometimes the back of the sheet metal can blow out with that initial jump.
However, this can be pretty easily solved with the Omax jets (I'm sure Flow does this stuff too) they have a drill attachment that goes on the head to first drill through the sheet. Or you could opt to drill it yourself and then use the camera locating tool to tell it where to begin the cut.
This is an issue we are going to be facing this year. Luckily enough we have 5 pretty large laser fabrication shops that even have CNC press brakes that we are going to ask for sponsorship from.
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One of our sponsors has waterjetted two robots of this same style and thickness without issue, thanks for the warning though.