Anyone have any idea on what the actual specs are on these motors? Has anyone tried testing them out yet? The label on our motor is definitely for the M7-RS775-18, but I’m weary of trusting a sticker.
Please note that the 18V version of the RS-775 was included in the KOP
Part number M7-RS775-18
link: http://banebots.com/M7-RS775-18
The data on our web site is for the motor at 18V, it nominal Voltage
The data on the green sheet is for the motor at 12V, what FIRST will use it at
We opted to donate the more powerful 18V motor because we believed it would be more useful to FIRST teams than the 12V model. The 18V motor will operate fine at 12V with reduced performance as given on the green sheet.
The label on the motor is correct, all FIRST legal motors supplied by BaneBots will have an appropriate orange label to ease inspection and reduce confusion.
Our less powerful 12V RS-775 (M7-RS775-12) IS NOT FIRST LEGAL to the best of our knowledge.
Thank you, I really appreciate your attention to detail. I made graphs off of the specs on the Banebots site but knew that the 18v data was wrong for this application.
The range of power provided by the Banebots KoP motors gives more “good” options for motoring our mechanisms.
By the way I really like the RS-550-12-Backshaft. This allows us to place a 100 count encoder directly on the motor and would be a great option for next year.
Be sure to check with the Q&A whether that’s legal. (After all, it’s a different motor with a different shaft, despite the electrical internals presumably being identical.)
I was making a suggestion for future years. I wouldnt dream of putting a non KoP motor on a competition bot.:] This is a setup we use on our half size proof of concept bot. The easy encoder mounting made feedback and CAN testing much easier. The encoder resolution is crazy. It would be very nice to have easy encoder mounting available on game play motors. To see some really interesting data on the RS-550-12 connected to a 20:1 P-60 go to http://www.chiefdelphi.com/forums/showthread.php?t=88193
I just tried to order 12 of the 775 motors on the BB web site and they said they are out of stock. Is BB holding them for the custom gearboxes? When will they be available?
Thanks for the support.
Paul
PS - I personally appreciate the decision to use the 18V version over the 12V version. These will be much better for FRC teams even at 12V.
Can someone explain their decision for using the 775 over the 550? The specs for the 550 seem to be most similar to the FP motor from previous year. And other than a higher current pull, I don’t see much of a reason to use the 775.
Thanks for the reply. Will the CIM-U-LATOR gearboxes come with our choice of motor already installed? If not, could you outline the procedure for installing them (trying to gauge if it is something we can do at our main shop or would need sponsor help)?
The 775 maxes out at ~270W (peak speed), while the 550 is around ~250W. The 775 is also closer in terms of both speed and torque to FRC applications, meaning less reduction will be needed to utilize it effectively. This outweighs the minor differences in current draw, imo.
Somewhat related question: Feeding the motor through the 2.7*1 CIM-U-LATOR gearbox gives it a free speed of ~4700 RPM. Is this close enough to the CIM’s ~ ~5300 RPM free speed to be useful? I fear that the motor will “fight” the CIMs being 11% slower. Is that a big enough gap that I should be worried?
No, I wouldn’t worry. Consider that under load both will be significantly slowed, which means that both will be trying to move your robot or manipulator in the same direction. The only time it really would matter is in the free running state. However, matching them more closely will obviously increase the efficiency of your mechanism.
I’ve read that comparing free speeds isn’t the best way to match motors. Perhaps there is a better way experimentally (put the motor under identical loads and calculate speeds?).