Hello,
At the beginning of our build season, we took a pretty big gamble. We decided to go with a complex bogie-drive and attempt to add a reverse 4-bar lift and single flywheel. Now that we are just over two weeks out from our first competition, we have a problem: the entire thing doesn’t work. It can’t lift properly, it can’t shoot a ball very well, and it can’t even climb a single platform, let alone the side climb that it was intended to do (for reference, we were inspired by the bogie drive from 1814D’s early season reveal). About all it can do is flip caps with the pancake method. Needless to say, we are very, very worried and probably getting desperate.
I have come to you today to ask for advice. Should we do a complete rebuild, with a meta 4m drive, 1m intake, 1m descorer, and maybe 2m launcher? What should I consider when doing a complete rebuild? Or should we let it be and try to tune it? I can post pictures if you want, but please know that the build quality isn’t good, and I don’t know if there’s much that can fix it.
With only two weeks left, you won’t have time to build and perfect a launcher, so you’ll want to focus on caps. Build a quick and dirty RD4B with an active scorer. I would suggest:
(V5 motors)
4-6m drive
1-2m rd4b
1m flipper
Try and build it all in one night if possible. Program it the next day/night asap. Then you should get on the field. Assuming you meeting 3 days a week, then 4/6 of your practices should be drive/auton, they are what distinguish good teams from great teams.
Good luck! You got this!
Remember to keep everything extremely simple. Don’t waste time on anything non-essential to your scoring abilites (for example, don’t bother trying to correctly tension chain if that usually takes you a while)
(PS: make sure to document all of this in your engineering notebook, judges like when they see you try things and fail)
+1
It allows you to rebuild over winter break potentially.
I would say you should post pictures but if nothing really works on your robot rn it may be easier to start again then try and fix what you have now. Really just think about what you can get working the soonest.
To avoid situations like this we typically have only one complex first time project like a DR4B going on at a time. Last year we were in a similar situation to yours as we tried to do too many advanced builds. My advice is to build a simple 2 motor, 6 omni-wheel drive that can get on the platform, build something that can flip the caps, and if you have time build a new/fix your shooter.
Good luck!
I would also appreciate some pictures
I disagree here. I’m pretty sure you could build a simple puncher in about a day of work. Much simpler than a possible first time DR4B build. I guess it depends on if you want to go for flags or caps.
Thanks for the responses!
I’ll have access to the robot in a bit to get some pictures. Also, @MayorMonty I’ll ask for some feedback on our current lift, as it is tilted and sloppy and also my first time building one :/.
There are also some scheduling issues, because our “meetings” are actually two 80min class periods (this is an elective, and we’re all seniors) plus one 40min bit on Fridays. I guess the best I can do (I’m the main builder for my team) is really commit an entire weekend to getting the robot somewhat functional, so that’ll work I think. I’ll send updates soon.
Also, @Rick TYler , our coach didn’t or can’t sign us up for much of anything before break. We start with the schoolyear, unfortunately.
I would recommend getting one thing to work really well first, then start to work on other stuff for the competition. Judges like to see a robot that can score than one that hobbles around the field. About the platform issue, you might want to increase contact or decrease weight on your chassis.
Because you have a competition in two weeks time, you should go simple. In my experience, a simple, effective, well-driven bot will beat a more complex one more often than not. Simple, direct drive with a simple lift. My main advice is to don’t get bogged down. You don’t want to be two days out from competition with no robot, it sucks (trust me!). Iterate fast, and get on the field ASAP.
If you have enough pieces you could have one person trying to fix that robot while everyone else builds a second robot that focuses on one thing, such as caps (takes less fine tuning than a ball shooter).
Just a comment on your dr4b if you ever decide to rebuild it I would put the motors on the middle section, and use screw joints when you can.
At the end of this video you can see how a nice screw joint works:
We had a similar problem, where we had an event and wouldn’t make it. We made a simple 4 wheel 4 motor base, a one motor intake, a one motor puncher, and a one motor descorer. We were one of only two cortex teams there, but still ranked second overall.
This is very doable over a weekend, but you have to keep it simple.
Sadly, I have great experience with complete rebuilds. The first thing you need to do is get a good, working chassis together. Salvage whatever you can from the old robot (for us, it was our linear puncher), and put it on the new one.
