External vs. Internal Stackers

I feel like the other conversation is getting quite cluttered, so I’m going to try to continue it here.
Personally I think the main problem with internal stackers right now is fine tuning. Most stackers use DR4B’s that use 4 motors, which is quite overkill. Also, a lot of teams are using two motors right now for their mobile goal intake, even though you can get away with one, as proved by the OSIZR. I think as teams start using better motor distribution and using less heavy, more fine tuned bots the chance of an external stacker winning against an internal will start to diminish to almost zero. Also, my team has found that the key to good driving (minus auto functions, of course), is fluid driving. The more you can multitask and fluidly deliver scoring objects, the more time you will save and the more points you will score.

Most teams using 4 motors aren’t utilizing the full potential. With a light build, a 4 motor DR4B could actually use 5:1 speed motors for a total ratio of 3.25:1 which, in my opinion, is very nice for speed. Other teams are playing it on the safe side because of heavy constructions hence 4 motors and 5 or 7 to 1 is required for their robot to function xD

Not to mention that if you rubber band properly, the only thing you’re fighting against is friction when lifting and lowering, and that’s what grease and metal washers are for.

I definitely agree, at this point in the season robot’s are not completely optimized yet. I am sure that later in the season there could be 2 motor DR4B’s (I’m talking about at worlds), because the cones are literally like .2 pounds, If you made a DR4B out of half aluminum c-channels, It would be super light. Or maybe I’m being too optimistic. We’ll see…

Why wait till worlds?
It has already been done… abt 5months ago… :slight_smile:
Look at 8059Z singvex reveal…
In fact, back then, we were already saying that we can further improve the gear ratio, even with 2motors.

2 motor 5:1 hs is rly rly good. Works super well for us.

We have a team with a double chain bar and they are finally working on optimizing it and using rubber bands. They were just tournament champions last week without that optimization. There is a whole lot of room for growth with that design. Without rubber bands, they have the first (lower) stage using 2 high speed motors with 1:5 gear ratio and the second stage using 1 high speed motor (but they just changed it to turbo).

Now with more mechanically optimized arms and fine tuning the program, this will be an interesting robot.

They are also hoping to share the drive and mogo lift motors allowing them to have 8 turbo speed motors on the drive and 4 of them also on the mogo lift.

Right now, it can only internally stack 12, but they want to increase that a bit. Currently, they can put a stack of 10 in the 20 point zone.

Do you mean 5:1 as in 5:1 speed ratio or as in 1:5 torque ratio.

If you can rubber band well, you can counteract weight and leverage to the point where they are pretty much irrelevant.

I am in favor of internal stackers, but I am giving externals one last chance for my next competition. For weight-saving on DR4Bs I would go with converting some bars into standoffs. If done right, ot can shave off a good amount of weight.
(Fyi: This is the last time I am making a DR4B this season. The ratio of weight to efficiency just doesn’t work for me. I was convinced by someone else to try them one more time.)