Nothing but Dewalts???

[Jeffy]

Originally Posted by geomapguy

Hasn't anyone used http://www.chiefdelphi.com/media/papers/1592 lately??

It looks like a relatively easy-to-make two-speed gearbox. And for the price it definitely beats any COTS shifter.

Any thoughts??

For drive trains, I don't think they are a great option.

However for manipulators, they have a lot of nice features (anti backdrive, built in clutch).

I saw http://www.robotmarketplace.com/products/0-DEWUT.html in servo magazine this month. They don't list anti-backdrive as a feature, but I bet it is. Could be retrofitted with an FP or RS 550/775 fairly easily I'm sure.

[billbo911]

We used them in 2010 and 2011 with FP motors for various mechanisms, but have not used them for driving.
They work great and allow some nice tuning of speed and torque as needed.

That said, with all the different options out there now, we most likely will not be using them in the future.

I think the best thing we learned from using them is how to modify transmissions to work with different motors.

For example, in 2012, we used a 395 motor and a transmission from a "Globe Motor" to control the rotation of our turret.

[Seth Mallory]

From what I have read in the rules you can use any drill for a transmission as long as you use a First motor. 192 used a Harbor Freight angle drill 3 years ago. It made a quick angle gear box with correct reduction that was needed. As long as other teams can buy the drill you use it should be legal.

[StevenB]

To echo what everyone else has said, the recent offerings from AndyMark, VexPRO, and others make Dewalts a poor choice for a drivetrain. I built a drivetrain with them back in the summer of 2007, and we competed with it at a couple off-season events. They were nice solid transmissions, but there were a number of little issues (size, mounting, manufacturing) that make them less attractive today. Shifting with a servo worked, but wasn't particularly smooth. In my experience, using a servo to shift a DeWalt isn't better than an AM. In both cases, the servo moves slowly and with relatively little power (relative to pneumatics, which go, "Bang. Done!").

Dewalts may still be a good choice for a manipulator of some type because of the anti-backdrive or clutch. However, given the effort involved to actually make them work, don't make the decision based on cost. In FRC, spending three or four days to save $50 is rarely worth it.

[magnets]

The dewalts couldn't really shift on the fly. If you were driving, and you shifted, you first heard a screeching noise, one side of the robot stopped moving, the robot started turning, then one side made a crunching noise, shifted into gear, spun the robot, then (if you were lucky) the other side would fall into gear a second or so after. If you're interested, check out 118 in 2007. They used a dewalt gearbox, and were really successful.

However, there are a TON of things out there that use motors really similar to the RS 550 and 775. You can grab gearboxes from these all you want. You can find leaf blowers, circular saws, drills... Who knows, maybe you'll find something better than the drill!

[Greg Needel]

The last time I used NBD was in 2010, and not in the drive train. From my perspective the best advantages of them was having 2 (or 3) ratios that you easily change on the fly for speeds. Also because such a wide array of motors could be adapted to them it kept the robot design flexible with many power and speed options all with the same mounting configuration. I think there is still no gearbox that provides the same level of flexibility but some of the offerings from Cots suppliers come close now. The other thing that I loved about them was the clutch, for things like intake mechanisms which have the potential to jam.

At this point I think the only place I would consider using them again would be for an intake or conveyor, but even then I would have to do the cost vs time benefit for the flexibility vs some of the cots parts with no modifications required.

[JDNovak]

Team 16 used Dewalts for our drive train from 2005 through 2008. We shifted them most of those years without much trouble. They didn't shift perfectly but they never failed. They went to the finals on Einstein in 2008 without causing any trouble after falling off the wall every match all season (flopbot). We might still be using them if it wasn't for weight.

We have also used them in a dozen other places over the years, especially when we needed anti-backdrive. The locking pins may take a little rotation to catch but the dead weight of the robot never broke them throughout 2010.

I wouldn't hesitate to use a Dewalt the next time there is a need. I've broken enough other gearboxes to know their limits.