I figured now that school has started here in the US for most, it’s time to reveal our summer bot. We were able to become the vex international Summer Games finalists with it, thanks to 7842D and 1879!
https://drive.google.com/folderview?id=0B2li6k7Njw7lNjlOTDlqM0JCUk0&usp=sharing
Here are the specs.
4 motor 1:1 drive
4 motor 7:1 reverse double 4 bar lift
2 motor claw belt intake
Pretty solid robot you have there! It looks very light from the videos–how much does your robot weigh?
Hey Ben,
Nice to see the videos with your robot! Happy my rd4b design worked out well for you 
Still using it for your current robot?
Thanks,
Marco
Thanks. It’s pretty light, about 15lbs. Out alliance captain weighed 30lbs so compared to them we were very light.
Haha thanks, it’s worked very well, with a few personal tweaks of course. Currently we are still using the same lift, but the manipulator has been completely redone. We’ve realized you have to be able to do skyrise sections AND cubes to do well, and when the lift reaches high enough to easily score 7 sections, why not do it.
I’m glad it has! And I’m sure a few tweaks have been needed, same here
Alright, yes being able to do both is very important in matches so you don’t have to rely on your alliance for doing the other scoring and instead you can score both by yourself if necessary. I’m glad you’ve found the lift design to be useful though 
Maybe I could get a video from you for inspire?
And that’s the exact reason the summer games finals were a blowout, the skyrise builder broke down… Sure why not. Give me some time and I’ll get one together
Yeah it looked like that 
and alright thanks! You have my email
Nice robot!
I guess that this year we will split between hook cycle and side roller dumper for cube intake! Much like shovel and top roller in sack attack.
One question. Since your bot is only 15 lbs, you should have no pressure going 1:1.6 for your base with four motors. What is the reason you chose 1:1? More reliability pushing cubes I guess?
Anyway nice job and good luck! Great start so far. We are still playing around with our lift…
Solid robot! Awesome that you got something working that well, so early in the season look forward to seeing any changes that you make
Don’t forget a good needle intake, those seem to be holding their own. I’m kinda curious which of the 3 will come out on top by the end of the year.
We had 1:1.6 but we were overheating through qualifications. If you want that ratio you really have to baby it on the field this year, from what I’ve experienced so far. 1:1 is slower but seems to hold up better. I can’t remember the ratio but the new 3.25s on high speed motors might prove ideal…
Thanks, it’s a miracle how well it came together for a first build…
High Speed w/ 3.25 wheels is equivalent to about 1:1.3 with regular wheels.
That’s about what I thought it was, but I wasn’t sure. Thanks!
I would like to add that his drive base utilizes compound chaining, his anti-tip deals create a bit of drag and frequently run into game objects, and that Ben is by no means a gentle driver. If those 3 issues were addressed, I’m pretty sure he could go a bit higher.
Also, I could help Ben make a decent 1080P video and get it on youtube on Monday, if he wants to, so that you guys can all see what we are talking about.
Haha, true enough. All of those are on the list to fix.
A suggestion, try to be less harsh when offering critique to other teams on the forums, especially when they are from your own club. For example:
“Do you have any concerns about your anti-tip mechanism creating drag or running into game objects? It seems to me like you were having trouble with this.”
Constructive posts are always better received here than harsh criticisms.
As to the robot, it looks very strong! Are you planning to add a skyrise section grabber in the next version?
Already added, along with a much improved intake. I’ll post some more videos after our next comp(Utah opener on the 27th). 8 on 7 is pretty fun to do
I noticed on your lift and on all the other rd4b I’ve seen this yr that you have the motors mounted on the middle section of the lift. Is this just to overcome slack? Because it seems like that would just be lifting extra motor weight as opposed to mounting the motors to power from the bottom section
We mount our motors in the middle section and yes it is to overcome slack, but also to decrease total friction. If you’re using gears to connect the two arms, then those gears will have a certain amount of friction. If you add more gears to power it at the bottom, rather than using the gears that are already there, then you’re adding more friction.
There also isn’t much space at the bottom of the lift on most rd4b robots so motors don’t fit very easily.
That, and it helps distribute the power better so it lifts smoother and there isn’t as much strain on the system