Turbocharging is a method of making use of the heat energy of an engine to improve its power and efficiency. There is no such thing as a turbo gear. Can’t we just call them 240 rpm gears? We already have hundreds of high school builders thinking what robots are using is a six-bar link, let’s not let them think you can turbocharge gears. (Real 6-bar linkages.)
The rpm of the motors is just one part of the calculations involved in a gear train’s final speed. I can, for example, build a very high-torque mechanism with 240 rpm geared motors by choosing the right ratios and final wheel or other end effector diameter. I think some folks are getting a little non-engineerish when discussing the new motor gear options. I see some clear advantages in robot packaging using the new gear option for certain uses, but there is nothing about them that is inherently good or bad. Do your math!
240 RPM motors are a terrible idea on 4" wheels, but 3.25" would give you the equivalent of 1:1.95 on 4" and 2.75" would give 1:1.65. (I put them in terms of 4" wheel speed because it’s easier for me.)
The new wheels and new gearing eliminates the need for almost any external ratios with sprockets or gears. You have nine combos with direct drive.
240 rpm is definitely possible on four inch wheels (as demonstrated by oyes). It would definitely take careful planning and a very good driver to control it. With the rules this year making defense very difficult, I could see a few teams pulling it off.
I wouldn’t say that per say, Vex did just release brand new wheels.
Say all our ratios are set to 4in wheels and our 4 motor “standard” ratio is 1:1.6, comparatively:
Turbo Gears on 3.25in wheels give an equivalent ratio of 1:1.95
Turbo Gears on 2.75in wheels give an equivalent ratio of 1:1.65
Given these are all directly driven and having a low center of gravity with the smaller wheels will likely be a popular design choice, I see a pretty good fit for these gears. I’m interested in seeing the 1:1.9 ratio in action as it may help boost speeds on lighter bots while not overkilling the ratio with 1:2.4.
Edit: As Aaron said, 240rpm is totally possible on 4in wheels (6 motor drive - YouTube)
We had a ratio of 1:1.9 (High Speed and 18:15 chain) and were very happy with it. We had a six motor drive, and although the robot was really fast and also decently powerful. In fact, we got pulled for spot checks 3 times at Worlds because of how fast the robot was. So yes, the 240 rpm gears with the new wheels is very well doable.
Interesting. I originally saw Skyrise as a much more defensive game, but now I suppose it could really go either way.
Personally, I won’t be running 240 RPM motors on 4" wheels, but with 6 or 8 motors it’s definitely possible. I was originally talking about a standard 4 motor drive which would overheat rather quickly against just about any pushing, but then again you never know.
The intent of the 393 Motor Turbo Gear Set (4-pack) (276-3527) is very straightforward: we know there are times where VEX users wish to have something spinning at faster than 160 RPM. We also know that any gear reduction adds inefficiency to the mechanism. By allowing users to increase the output speed of the 393 Motor module VEX users can get higher speed items without adding inefficiency outside the motor.
We imagine this will be valuable in any number of applications, however there was one original idea which drove the design. We wanted teams to be able to direct drive the 2.75" diameter (small) VEX EDR Wheels and get a similar driving speed to the current direct driven 4" diameter VEX EDR Wheels.
Now teams can use smaller wheels, and get the same ground speed.
We know that some teams will use this new gearing to make their robots faster – but as most of you know, there are other constraints limiting the speed a VEX EDR Robot can reasonably achieve.
And I thought you were getting us set up for “Hover Havoc” the game played on the Swept Away field where you have to go over the wall to score. I’ve already started forming the plexi sheets into rotor blades. :rolleyes:
Well I was at Worlds when they announced the “Turbo” gears so we (my team) immediately went to the store there and bought 4 of them. Put them on my robot (base) which promptly didn’t move at all. Now granted my robot was 20lbs so probably wasn’t the smartest idea at the time. Ended up costing me a match because we had no time to change them back. Lesson learned from this A. Don’t experiment at worlds unless you have lots of time.
B. I don’t know how well they will work for the base unless you have a nice light robot but it might still have slow acceleration.