This design was based off of what I got to see of 1114’s bot in 08. The rest of it is a “best of the best” group of characteristics and building techniques taken from my 3 years of building FIRST robot drives. However through 3 years, we have never used more than 4 wheels.
Specs:
Weight is 49.5 lbs. as pictured minus battery
6: 4" ifi traction wheels with 1/8" drop in the center
4 Cim in toughboxes: We have never shifted before and this is simpler, lighter and cheaper.
Speed is geared at 9.4 fps but can be changed easily through new ratios in the TB or new sprockets after the TB
Frame is 1X1 .125" wall Aluminium tubing.
Long chain is tensioned by sliding a small bolt and nylon spacer complex. (see picture)
Shorter chain is tensioned using an AM floating tensioner.
Electronics board is 1/8" polycarbonate with an aluminum angle support for the battery and 1/4" plate under the compressor.
I would love to get some feedback on potential failures or successes of my design.
Looks pretty good, but I’m a little concerned with your tensioner. Is it at all possible to make it stretch between the two 1x1’s so that it’s not under a cantilevered load? You’re also going to need to be really careful while welding this together (I assume it’s welded), because if you’re even a few degrees off it won’t line up right.
Side comment:
If you could stick with the normal background while rendering, it makes your design easier to look at.
I see some similarities to the KOP chassis, looks proven.
You don’t need a 1/4" plate and 1/8" polycarb is still pretty heavy, try some thin stuff with holes in it for zipties. The BG is distracting. The welds don’t have to be perfect because those are dead axles as long as your wheel ends up perpendicular to the ground. The chain run concerns me because if you lose the long chain you’re out the whole side. The tensioner should work fine.
Great looking chassis… Though there is one thing that I have noticed. The placement of the Jaguars worries me a bit because they tend to overheat. Placing them under the already heated CIM’s and having them not get the ventilation they need could potentially burn them out. Believe me, I have seen Jag’s go. This is just something I picked up on. The Chassis looks great though.
Along with the non-cantilevered tensioner, I would recommend using an idler sprocket on a bearing. Using precise spacers, this will help keep the chain inline, and will also lower the resistance of rubbing on a round idler.
+1 to Ike and 548 Swimmer, your chain tensioner is going to get wrecked!
I would switch the locations of your electronics and battery/compressor, get the battery and compressor nearer to your CG and (hopefully dropped) center axle. This lets you see the lights on the jaguars and sidecar more easily which can be very useful for debugging or trouble-shooting.
I would also lose the lexan and mount everything on a piece of high-quality plywood. You’ll probably be able to eliminate all of the 1/4" aluminum plate under there and it will really help your chassis stiffness. It’s really easy to mount and re-configure electronics on plywood too.
