We are extremely excited to try out the WCP DS 3 CIM Gearbox, and we are getting ready to place an order for our competition robot next year and our practice robot.
The question we had before we ordered them and any accessories, was what is the shifting PSI and CFM? We always seemed to have issues with our Super Shifters with the shifting component. Is there an optimal PSI that will achieve best performance?
We used the DSes last year, with a shifting pressure of 60 PSI. The shift pressure worked fine, although I wouldn’t say there’s an optimum shift pressure (well, 30 is probably too low, but beyond that…). I wouldn’t try to regulate the air going into the pistons at all (well, besides a solenoid). You want to shift as fast as possible.
Johnny,
We redesigned and made the shifting line on all the gearboxes much better than our previous generation and other DOG shifting gearboxes.
Your able to shift anywhere from 20 to 60 psi. Our team likes to shift somewhere around 40 psi. Sometimes lower so we save air.
Some changes to note:
-Dog is now 1.0625" Diameter and made out of high strength steel (4140).
-The Screw is beefier, but the DOG is now 30% wider than before. Which means your able to easily drill it out .125" and put in a High Strength Roll Pin:
–http://www.mcmaster.com/#95755a239/=pt8p2i
–http://www.mcmaster.com/#97855a180/=pt8p8m
Let me know if you have any more questions, you can also email Support Here.
Thanks,
-RC
Keep in mind there is no guarantee that 6 CIMS will be allowed in 2014. If I remember correctly, allowing more than 4 CIMS has only occurred twice in recent years, 2010(5) and 2013(6), both when a climbing task was part of the game. Vex/WCP has indicated their CIM simulating gearboxes can be used to combine other motors into the shifting transmission, so this may be an option, but you may very well have less than 6 CIMS available. So far 2013 has been the exception, not the rule.
Jeff is spot on,
The other options are:
-Use a MiniCIM which is designed to drop in 1:1.
-Use a Bag/550/775 with a versaplanetary
OR
-Use the new VEXpro CIM-ile
-RC
Last year we also got Mini CIMs which I would argue are the best 5th and 6th drivetrain motors.
We ran a 4 CIM, 2 Mini CIM setup for our robot at Madtown and loved it. No voltage problems, never tripped a breaker, and got all we wanted out of a 6 motor drive. 10/10 would do again if strategical analysis proves it beneficial.
Maybe help me understand here. I understand how the DOG shifting mechanism works, but what are the advantages of using a roll pin over that?
Correct. My only point was to be careful about making assumptions about what might be available in the legal motor inventory, based upon a previous year. It does change. Especially an assumption that might lead you spend a lot of money on a plan before the robot rules come out.
The roll pin referred to here is for replacing the #4-40 DOG shifting screw that goes through the dog. While the high-strength #4-40 screw that comes with the gearbox is plenty sufficient for shifting in drives, some teams using previous dog shifters, or shifting dogs for things other than the drive have had issues with the dog screws bending. The .125" roll pin has a much higher shear strength than the #4-40 screw, so replacing the screw with the roll pin will allow the dog to take much higher loads than before.
In the drivetrain, there is no real advantage using the roll pin. However, for teams making things like kickers, or other high load gearboxes, the .125" roll pin could prove to be a significant advantage.
We have had some bad experiences of failure due to setting up an automatic transmission in the past. Even with the recommended changes, I would have to hear from other teams about its reliability first, before we ever do it again vs. manual shifting when needed.
Sorry to hear about this,
Could you elaborate a bit more about this issue’s you experienced? Are referring to replacing the dog screw with a 1/8" roll pin? Or using the dog for higher loads such as a kicker?
Hopefully we can shed some light on this.