VEX Robotics Relaunches VEXpro Product Line with over 120 New & Improved Products

[JVN]

Originally Posted by SuperNerd256

Do you plan on releasing different sizes and widths for the VersaWheels?

Not for this season. We made the VersaWheel in a very universal size which we thought teams would use -- for other sizes we have the traction wheels:
http://www.vexrobotics.com/vexpro/wh...on-wheels.html

[JVN]

Originally Posted by AdamHeard

IF this is the case, what is your recomended method for mounting a 4x2 traction wheel live axle. A single hub?

A single hub is more than enough to transfer the torque. So I would recommend a single hub, and a hex bearing for piloting on the other side.

[Paul Copioli]

Originally Posted by AdamHeard

IF this is the case, what is your recomended method for mounting a 4x2 traction wheel live axle. A single hub?

The hub designs are such that only one side needs a Versahub to transfer the torque. We initially intended that the hex would be timed to a certain VersaHub feature, but we quickly realized that we could not meet our pricing targets with such a requirement so we relaxed the requirement.

Our reasoning for relaxing the requirement was that since the full torque load could be taken by one hub, then a hex bearing can be used on the other side if you are worried about deflection. As it turns out, the bearing solution is less expensive for the customer anyway.

Paul

[AdamHeard]

Originally Posted by Paul Copioli

The hub designs are such that only one side needs a Versahub to transfer the torque. We initially intended that the hex would be timed to a certain VersaHub feature, but we quickly realized that we could not meet our pricing targets with such a requirement so we relaxed the requirement.

Our reasoning for relaxing the requirement was that since the full torque load could be taken by one hub, then a hex bearing can be used on the other side if you are worried about deflection. As it turns out, the bearing solution is less expensive for the customer anyway.

Paul

Thanks. I wasn't worried about torque, but supporting the shaft on the other side. For some reason I thought the wheel bores were 1.25, not 1.125. What you and John suggest is a really clean solution, I like it.

[Jared Russell]

Originally Posted by AdamHeard

Thanks. I wasn't worried about torque, but supporting the shaft on the other side. For some reason I thought the wheel bores were 1.25, not 1.125. What you and John suggest is a really clean solution, I like it.

It's also a great use for the handful of seized hex bearings we have collected through the years.

[JVN]

A few people asked about whether we would sell the shifter shafts independently. The answer is "yes" and they're already live on the site (linked from the kit contents section of the Ball Shifter page).

Short Output Shaft (w/ gears) -- as used in the 3-stage gearbox.
http://www.vexrobotics.com/vexpro/ge.../217-2793.html
Without gears... just the shaft:
http://www.vexrobotics.com/vexpro/ge.../217-2791.html

Long Output Shaft (w/ gears) -- as used in the 2-stage gearbox.
http://www.vexrobotics.com/vexpro/ge.../217-2792.html
Without gears... just the shaft:
http://www.vexrobotics.com/vexpro/ge.../217-2790.html

-John

[Andy Baker]

Originally Posted by Paul Copioli

We initially intended that the hex would be timed to a certain VersaHub feature, but we quickly realized that we could not meet our pricing targets with such a requirement so we relaxed the requirement.

Paul

For those folks who need this alignment requirement, the hubs at AndyMark meet this need. Previously, our hubs did not align with the holes, but they do now. I pulled 19 off of our shelf and put them on a Cross Hex Tube. These are in stock now:



Sincerely,
Andy Baker

[AllenGregoryIV]

JVN or Paul, can you explain how the VersaPlanetary motor connectors work? I've looked through the CAD and I see the set screw, the collar type thing with the slit and the place that it goes. My real question, "is the setscrew the only thing keeping the motor engaged?" I do like the access holes for the setscrew, and that you can swap motors with out removing the gearbox from the robot.

I'm excited to get VEXpro parts in.

[Paul Copioli]

Originally Posted by AllenGregoryIV

JVN or Paul, can you explain how the VersaPlanetary motor connectors work? I've looked through the CAD and I see the set screw, the collar type thing with the slit and the place that it goes. My real question, "is the setscrew the only thing keeping the motor engaged?" I do like the access holes for the setscrew, and that you can swap motors with out removing the gearbox from the robot.

I'm excited to get VEXpro parts in.

Allen,

The motor connection that the VP uses is one of the more counter intuitive engineered items I have come across in my time as an engineer. This technology is used on industrial robotic gear boxes all over the world and is becoming the common adapter for high rigidity, low backlash applications.

There are two basic principles at work:

(1) The motor pilot is not used, but the shaft is actually used as the pilot.

(2) The set screw really isn't used as normal set screw (clamping on a rigid shaft). It is used as a clamping lever to squeeze the C-coupling into an ellipse.

The C-coupler (collar type thing with the slit) and the input collar (the thing the C-coupler fits into are precision machined for an exact slight clearance. In addition, you use a specific C-coupler based on the motor shaft diameter. There is a different coupler for 3mm, 1/8", 1/8" with knurl, and 5mm shafts all with the same OD so they fit in the input collar. The clamping screw is tightened (don't really need that much tightening torque) and turns the C-coupler into an ellipse which locks it in place with no backlash. I have accidentally hand tightened a coupler before and it still locks solid. It took me over 9 months of rigorous testing when I was at FANUC to approve this technology for use on our robots, but after the testing I was sold. easy for replacing bad motors, easy for replacing the gear sets, and no more press fitting gears on motor shafts.

Now for high end motors like industrial robots use, this next benefit really isn't a benefit, but for some of the less expensive, non-high tolerance motors we use in FRC, I have found that this next benefit is really helpful:

Since you do not have to completely clamp the motor face to the VP mounting face, any shaft runnout misalignment between the motor shaft and motor mounting face is completely mitigated by just hand tightening the mounting motor plate mounting screws. Since the screws only act to keep the motor case from spinning, they only need a little loctite and hand tightening.

We will have detailed diagrams on how this all works prior to kickoff.

Paul

[thefro526]

Originally Posted by JVN

All,
I've been updated on this -- though this was our original intent, it proved cost prohibitive to do this. The hexes and VersaKeys will NOT be consistently aligned.

-John

John, Now that the hexes and Versakeys will not be consistently aligned, how would you recommend doing the following:



(Picture is of a gear being used on one side of a wheel, versakey on the other, just in case the photo gets removed/updated to reflect changes)

Would you replace one of the hex hubs with a bearing hubs and then rely on the gear's hex and VersaKeys to transmit Torque?

[JVN]

Originally Posted by thefro526

John, Now that the hexes and Versakeys will not be consistently aligned, how would you recommend doing the following:



(Picture is of a gear being used on one side of a wheel, versakey on the other, just in case the photo gets removed/updated to reflect changes)

Would you replace one the hex hub with a bearing hub and the rely on the gear's hex and VersaKeys to transmit Torque?

Yes, that's exactly what I'd do. The single gear is more than enough to transmit the torque. You may just need a pilot on the other side, depending on the width of the wheel.

-John

[Aren_Hill]

Turns out a 1/2" hex bearing on the other side to pilot is more cost effective than another hub anyways.

[Donut]

Originally Posted by JVN

All,
I've been updated on this -- though this was our original intent, it proved cost prohibitive to do this. The hexes and VersaKeys will NOT be consistently aligned.

-John

Does this apply to the 1/2" keyed hubs as well? I am assuming so but wanted to confirm anyway.

[JVN]

Originally Posted by Donut

Does this apply to the 1/2" keyed hubs as well? I am assuming so but wanted to confirm anyway.

Yes, this applies to those.

[Lil' Lavery]

And I had just finished putting together my pre-season orders. Back to the drawing board.