![]() |
pic: 6-sided tank drive
|
Re: pic: 6-sided tank drive
Not sure if the 1*1 stuff supporting the bumpers is vexpro versachassis stuff, but if so I'd double layer it or use thicker material. That stuff is really thin for a bumper frame.
|
Re: pic: 6-sided tank drive
Quote:
|
Re: pic: 6-sided tank drive
right; the 1*1 vexpro stock has much thinner walls. I'm not sure which it is.
|
Re: pic: 6-sided tank drive
Quote:
Even with a chopsaw/bandsaw/mill/cnc mill/whatever, it is certainly a better real world design if you round those off to some amount. How critically important is it that you are exactly perfect? In your robot's frame, just about never. Also, just a recommendation, While it is less pretty, using 1/32" (or preferably 1/16" or 1/8") increments instead of decimals is much less of a hassle for whoever will measure the parts, and just a couple clicks in CAD Not trying to be a wet blanket on this design, it certainly is cool, but it would be beneficial for every party involved if you simply rounded to the most convenient dimensions, where there will be an immeasurable difference in performance, but a significant improvement in both engineering design quality, and manufacturing *after all, the entire point of a 6 sided drive like this is for the very purpose of escaping trapping t-bones" |
Re: pic: 6-sided tank drive
Quote:
The weird angles are the result of the not-weird side lengths. The tolerance should be pretty high. Oh, and it's welded 1/8" aluminum tubing |
Re: pic: 6-sided tank drive
Does it meet the 110" rule?
|
Re: pic: 6-sided tank drive
Question for you, how exactly is this useful? I love the design, it looks pretty fancy, but in the long run it will amount to more work and not be worth it if doesn't have any specific benefits compared to a 4-sided tank drive.
|
Re: pic: 6-sided tank drive
Quote:
|
Re: pic: 6-sided tank drive
Quote:
Circles are mathematically the optimal perimeter-to-area figures, but would be difficult to make, and a nightmare to put bumpers on. |
Re: pic: 6-sided tank drive
You can more efficiently optimize the use of the perimeter sizing by moving the front/rear wheels to inside the frame, and making the center wheel wider.
|
Re: pic: 6-sided tank drive
Quote:
|
Re: pic: 6-sided tank drive
Quote:
|
Re: pic: 6-sided tank drive
Quote:
T-bones happen a LOT at the high level of play in certain games. |
Re: pic: 6-sided tank drive
Quote:
|
Re: pic: 6-sided tank drive
Quote:
Someone get these teams some better drivers :confused: |
Re: pic: 6-sided tank drive
Quote:
|
Re: pic: 6-sided tank drive
Quote:
![]() Quote:
|
Re: pic: 6-sided tank drive
Quote:
Quote:
|
Re: pic: 6-sided tank drive
If tbones were rare and could be easily avoided by good drivers you would not see teams like 254,971,973,148,1114,118,1730,33 and countless other elite teams dedicating engineering hours, money and weight to mechanical aids to get out of pins.
This year we were caught in pins constantly and it slowed us down significantly while simultaneously wearing down our wheels. Often less high scoring teams don't face the same level of defense as their higher scoring counterparts so their robots weaknesses are never exposed. |
Re: pic: 6-sided tank drive
Wouldn't a hexagonal shape limit how close you can get to the outside walls of the field? I'd imagine if you skim the wall, you would end up being spun in some direction.
|
Re: pic: 6-sided tank drive
Quote:
Quote:
|
Re: pic: 6-sided tank drive
Quote:
FRC 118- Drop down omni wheels FRC 971 - Unique chassis shape just 3 off the top of my head |
Re: pic: 6-sided tank drive
Quote:
|
Re: pic: 6-sided tank drive
Quote:
|
Re: pic: 6-sided tank drive
Quote:
|
Re: pic: 6-sided tank drive
My students have spent a chunk of their summer designing a hex chassis 8WD because of this very problem; we saw lots of t-bones, and we contributed to a fair number of them. ;) We finished 3D printing the narrow/wide wheels this evening. I've been researching new bumper materials, and the mixing of materials for maximum benefit whether defending or trying to avoid pins. Great stuff!
|
Re: pic: 6-sided tank drive
Quote:
|
Re: pic: 6-sided tank drive
Quote:
|
Re: pic: 6-sided tank drive
Quote:
|
Re: pic: 6-sided tank drive
Quote:
I guarantee 971's chassis shape wasn't there just to look cool. 254 switched to a sail cloth fabric for their bumpers this season just so they could get out of t-bones easier. In a game like 2014, 2011, where defensive t-bones are prevalent and extremely effective, these mechanisms can be very important. However, there are some games, like 2012, where defense was unimportant and not prevalent. It depends on the game, but after this year I see mechanisms like this increasing in popularity immensely. |
Re: pic: 6-sided tank drive
987 had a drop down ball caster on their robot that tey would use to swing out of pins.
I didn't drive it myself so maybe they could tell you their exact experiences with it, but I thought it was pretty neat since it was probably had the highest simplicity to benefit ratio of a secondary mechanism I've seen in a while. |
Re: pic: 6-sided tank drive
Quote:
In 2013 it worked great for us. In 2014 we were forced to place it on our heavy side and it didn't work as well. |
Re: pic: 6-sided tank drive
Have you guys thought about the benefits of an equilateral hexagon? 2851 executed this in 2013 and it improved our offensive ability greatly. Now if only our shooter didn't jam :p
|
Re: pic: 6-sided tank drive
Quote:
|
| All times are GMT -5. The time now is 00:19. |
Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi