Is 4 neos enough for a west coat drive?

Got it, the screws are not fun. I agree. Especially the ones that are secured with Loctite.

To their credit, REV did publish guidance on removing the tiny screws. If they get a chance, perhaps the next iteration will use larger ones? M3 would be much easier to handle.

We have found that the M2.5 screws can be removed reliably using a new, sharp 1.5 mm Allen wrench, and some careful attention.

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What ratios and wheel size were you using in that set-up? Pure kit-bot, or did you opt for a different wheel or ratio kit? Were you traction limited with 6 NEOs? Would you have been traction limited with 4?

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Granted, guidance was provided; however, when the proper tool is used carefully and the tool yields under torque, does this still sound like a wise setup?

A better method might have been to avoid any OEM thread locker and caution the teams that they need to apply thread locker prior to finally assembly.

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This would have almost certainly led to far more failures than the failures caused by careless students stripping a tiny screw. A huge chunk of teams would miss this advice or not do it.

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I am certain you are correct.
This was far better.

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Which did happen to Vex, unfortunately. I helped two teams dig out set screws that screwed their way into the Falcon rotor. But yeah, I would definitely hope Rev makes those screws easier to remove (or the back shaft of the motor easier to access for pressing).

back on topic, I also highly recommend @jessek’s drivetrain simulator for answering questions like "how much faster (for a given total current, over a given sprint distance) do 6 motors make me over four: ILITE Drivetrain Simulator, v2020

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Yeah, I suspect far more teams use keyed pinions instead of ones that need to be pressed on too, adding an extra step that most teams wouldn’t even think of.

Maybe in a future revision, Rev could add some kind of support to the inside back of the case so pinions can be pressed on without disassembly? No idea how much that would affect performance and weight, though.

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A small hole in the back of the casing would suffice to allow a user to stick a pin through to support the back of the shaft. 6-8mm would be perfect.

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Idk what’s up with y’all’s situation (there’s a couple dozen) and not being able to work with the NEO screws, but I’ve literally never had an issue with every hex and torx tool I’ve tried and several different batches of motors. Chinsy little L thing, “precision” (cheapo) screwdriver bits, fancy Wera and Wiha dedicated tools, etc. No issues whatsoever. There’s either a lot of variance in the threadlock application and tool quality, or everybody has completely forgotten how to remove small screws.

Not blaming you, just genuinely perplexed. Could also be due to people only speaking up when they have an issue

On the other hand, I’ve twizzlered more than enough allen wrenches getting the long setscrew out of the end of Vex .5" stroke pancake cylinders.

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Both tools, shown in the image, are Wera allen keys.

Our drive gearboxes required press-on pinions. With the construction of the NEO, the case needed to be removed to press on the pinions. Our highly skilled students were able to remove cases on most of the motors; however, there were a few that had one stubborn screw. For those motors, we look for applications where a keyed pinion is required.

We loved using the NEO’s last year, and we were set to repeat … perhaps next year.
In the future, we will likely order motors with pre-pressed pinions, as this will remove the risk.

That’s why we had to remove those little b-----ds!

Luckily, we read CD and stocked up on allen wrenches and replacement screws – they are basically “one use only” items.

I agree, a small hole, with a rubber plug, would have helped a lot!
We had to drill/easy-out TOO many of those horrid screws.

In general, if you are having trouble with a Loctited screw getting stuck, the solution isn’t to torque it so hard that you break your screwdriver. Red and blue Loctite gets substantially weaker with the application of heat. CAREFUL use of a heat gun can be used to soften up the Loctite enough to get the screws out.

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Good advise. Heat is a simple way to attack Loctite.

We use a solder iron to heat the fastener as if trying to solder a wire to the head. Nice localized heating method.

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Yep had to put on pinions. I mean I know the housing has to be held on somehow but really? Anyway, I’m sure they’ll address it at some point. Otherwise the NEOs were good.

To be clear, even an experienced adult mentor can pretty easily strip those screw heads. I don’t encourage the students to touch them.

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I can’t agree more. An ILITE simulator setup should be a standard requirement for any student proposing a drivetrain config. It really is a great tool.

To put another perspective as well on this from 2019, going from 4 to 6 NEOs both helped us 1) push through defense and 2) accelerate faster around defense, though I have no evidence besides an empirical evaluation of our performance (we used 4 NEOs in our first competition and 6 in all others).

2019 Bot: Kit drive with 8" pneumatic tires, 12.75:1 toughbox gear ratio. Went the entire regular season on 4 CIMs, switched to 6 NEOs before IRI and noticed a dramatic improvement in acceleration (almost too dramatic for this robot, we could easily pop wheelies) & turning.

2020 Bot final config: two 6" pneumatic tires on the front, 4 standard 6" kit tires in the center & rear using a 10.71:1 toughbox gear ratio with the 3 motor thriftybot plates. The picture above is from much earlier in the season, but during practice we popped a 6" tire and couldn’t get any more as they were out of stock. Keeping the pneumatic tires on the front of the robot seemed help dampen the impact with floor bar, not that we went it over it much.

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