Yes. The Venom has front and rear ball bearings, which will allow it to generate slightly less heat, and handle slightly greater load/shock, than the CIM.
That being the case, I would expect that the no load speed and current need to be updated. Are those updates being made?
For the TOF sensor, do you have a Java library for it or how would we implement if using Java?
Updates to the spec have been made. We’ve been measuring no load speeds at 12V, typically seeing 5400+ RPM at 1.9 A. Basically, a 10watt reduction in mechanical friction. We expect this benefit to grow as you compare CIMs vs a Venom of a similar age (during a typical season).
Once you put these motors into a gearbox application is where the real benefit comes in, however. This is where the motor sees some radial load on the shaft and bearings, and the ball bearings are much better suited to handling this load than the bronze bushings were.
It’s on the product page, here is a link directly to the download:
https://www.playingwithfusion.com/include/getfile.php?fileid=7081
We will be releasing LabVIEW, C++ and Java libraries for the ToF module in the next 2-3 weeks. This release will include support for all of the core functions of the sensor and will support last year’s LabVIEW setup. When LabVIEW for FRC2020 is released we will also support firmware updating over CAN.
Thanks,
Justin
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What is the counts per revolution on the on board encoder? We use some encoder intensive positioning systems that require ~2000 CPR or higher for field positioning accuracy.
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The onboard encoder is “8.5 bit” or 360 count per rev (1 degree resolution at the motor). For reference, the “high resolution” CIMcoder from AM is 256 CPR.
Depending on what you’re putting this in (drivetrain, arm, etc), this will give you ~0.007 inch linear resolution on an 18 ft/sec drivetrain or < 0.0001 degree resolution on an arm (assuming pretty high reduction). If you typically installed encoders downstream of the gearbox, 2k count may have been necessary, but remember to start with a linear or rotational requirement and then reflect this resolution need all the way back to the motor output shaft.
-Justin
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If I wanted to press a pinion onto this, is that something that is supported? How do I make sure I don’t crush anything on the back side?
These have essentially the same crush tolerance as a standard CIM as the rear bearing is flanged. It’s worth noting that they’re based on the latest CIM, so the front shaft is ever-so-slightly undersized and most gears slide on without any force. Retaining washers can be installed with standard measures without risk of damaging the bearings, as well.
That said, the rear cover is plastic and will not tolerate much force - if you need to constrain movement, do it on the aluminum.
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Java API documentation for our Time of Flight sensor and Venom motor has been posted here:
https://www.playingwithfusion.com/frc/2019/javadoc/com/playingwithfusion/package-summary.html
The Cpp API isn’t posted yet, but is esentially identical to the Java API.
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Will you be releasing libraries for x86 and aarch64 based systems?
We aren’t building for x86 or aarch64 at the moment and we’re not planning to for the 2019 RIOimage, but I’ll see what it takes to make them available for the 2020 Image.
Speaking of which, the C++ and Java libraries for the 2019 RIO are now available on our website. The easiest way to install them is to open the WPI Command Palette in Visual Studio Code then go to Manage Vendor Libraries then select Install New Libraries (online). Then use this path in the box that appears:
https://www.playingwithfusion.com/frc/playingwithfusion2019.json
The library covers the Venom motor through the CANVenom class, as well as our time of flight sensor using the TimeOfFlight class.
We’ll be releasing LabView wrappers for the library in the next few days
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