V5?


#1

What are common problems people are having with V5 ? we just got ours and would like to be able to prevent common errors before we connect everything


#2

looking at all the existing threads, v5 is commonly problematic and also have quite a few common problems.

What I can see is… battery charging issue and not connecting to the brain.

Caveat: I am still waiting for my regional distributor to confirm the price for v5… so I have not hands on any v5 yet.


#3

It would have been better to allow those who have V5 reply.

The only two issues we encountered:

  • stripping of the motor mount thread
  • not being able to connect to brain using random USB cable - using VEX provided USB cable all worked

Nine batteries - no problem.

Software side - no competition template for Modkit (yet), no multiple open file/projects in VCS, no native versioning. I have not used PROS nor RobotMesh solutions.

20# load on a robot yielded decent battery life. Charging time ok (under 1 hour).

So far so good. Reports on VEX Coaches FB page indicate battery issues - so it may be a supplier issue.


#4

Of course, just that no one was replying for 7 hrs?
In any case, I am just having a dig at v5. Don’t need to get too defensive over who can respond to this thread.

Ps… looking at the number of threads on the charging issues of the battery, don’t think I am wrong to raise that as an issue too.


#5

Absolutely. Keep digging. They need it.

Not really an issue of the new launch, but more just a questionable design decision.

Old motors, pre-393 (not all models, but some) had the motor wire protrude from the same side as the drive shaft. 393 had them opposite. V5 has, for some reason, gone back to the same side. This means if you mount a motor vertically, with the drive shaft coming out on the lower end not the upper end, the wire will also be on the lower end and need to be managed up and around the motor.
VEX Motors.jpg


#6

Ok… I can understand what you mean… I was from the pre-393 era :stuck_out_tongue:

This is kinda sad that they went back to that design… at least some of us were rejoicing when we notice the wire went the other way for 393.

Guess we will need more zip ties…


#7

Yup. It was the first thing i noticed and was very disappointed. I am not sure if they had some design constraint in mind that drove them to revert to this configuration, or if they were just completely oblivious that this was a thing people liked.


#8

If you open one up, the size of the electric motor sort of dominates the other side of the cartridge.

I am leaning toward design constraint


#9

The following issues we have seen with V5 teams. We have three V5s since September 1st and two more are coming soon.

#1. Battery being over charged (this issue seems to be fixed with latest firmware v1.02).
#2. One of the Controller battery drop sudden. We have had controllers with fully charge the day before competition and during the competition, one of the controller’s battery drop quickly. We only experienced this issue with one controller. So, it might be just the battery in this one controller isn’t functioning correctly.
#3. The connectors to the brain are flimsy. If you are using a catapult and depends on how you arrange the brain, the connector to the brain port could become lose (it gets popped out from the brain connection). We secure the connections to the brain and motors with VEX adhesive form.
#4. Built in PID does make motors move funny. You can see and hear the motor running when it move straight, the motors doesn’t seem like it move smoothly straight. However, it does move straight (which is a good thing0. It moves fast and then slows down and then moves fast again on the same moving distance. It is acting as if it is waiting for something in between. I am sure this is software issue and could be fixed or ironed out in the future.

Serious issue:
#5. This is serious issue. VEX V5 Brain port broken/malfunction for no particular reason.
On our November 3rd competition, one of our team got three of their V5 port malfunction without any reason. They have been using this robot since October 6th competition without any issue. They have practiced for hours on this robot without any port issue etc. However on November 3rd competition, one of their port (Port #10) all of the sudden malfunction. They switched to different port and replaced port #10 to port #9. Forty-five minutes later, port #9 and port #17 malfunction again.

Here are some the details on Brain V5 port issue for one of our team:
Port #10 was used for the cap intake (about 4 1/2 feet long) and port #17 was used for lift ( 2 1/2 feet long). These two ports has been on the robot since October 6th competition. The same wires and motors have been on those two ports since middle of September and the team secured the wires really well with zip ties. They have been practicing for hours without any sign of issue.

These two ports do perform little different than the other six ports for the motors. Since port #10 (and #9) and #17 were used as part of the cap intake and lift.

  1. Port #10 and #17 uses longer VEX wires (4 1/2 feet and 2 1/2 feet respectively).
  2. Port #10 (and#9 broke within 45 minutes) and #17 programmed to have brake (meaning they don’t use stop() but instead, they use stop(brakeType::brake). Once the robot is on, the motors connected to those port always use brake. The motors never over heat so it isn’t motor being over heat issue on those malfunction ports.

Other things I have noticed. The team did have the V5 brain cover over the screen. Could heat play a role in the port’s being malfunction? I asked them to remove the brain screen cover and they were able to competes several times without any issue.

I also have spoke to two other teams that also have V5 and they are also experienced port being malfunction. I didn’t ask if they were using long wires, were they using hold/brake function and were the motors over heating etc.

Note: We have replaced the long wires with shorter wires with new motor, the broken port (#9, #10 and #17) never come to live again. The red lights kept on blinking but nothing more. We have waited for a day and reset the brain and retested those broken port but no luck. It looks like once it got itself into black hole, it stays in that black hole.

On the bright side about V5:

  • We like the new battery. You can actually compete with only one battery (if you charge it often). We recommend to have at least two batteries, three is preferred.
  • We really like the new V5 motors.
  • The team members prefer V5’s controller over the Cortex’s controller.

#10

Problems w/ quality we’ve encountered:

  1. Battery died from leaving on charger between meetings. VEX replaces quickly and the update fixes the problem.
  2. 1 motor DOA, mostly,. Seemed like a brush issue (grinding). VEX replaced quickly.
  3. 2 motors died after use. We believe this was from H-bridge shoot through (whining w/o moving). VEX replaced quickly. Don’t know of any fix.
  4. Port 4 on the Brain died at a tournament Saturday. It could no longer power the wrist motor. This motor does not have much load on it so we are not sure why.

Problem with V5 design decision.

  1. Motor Size. Everything is too big. In a world where we get stronger, faster, lighter, lower power devices in smaller packages, V5 went the other way.
    a) Motor no longer fits within the width of a 2x C-chan when mounted in the middle holes.
    b) Motor cannot be mounted perpendicularly within a 2x c-chan.
    c) Motor cannot be mounted in a hole near any inward bend. The mounts are too big and are pushed off the hole by the L of the bend.
    d) Cannot fit a bearing and lock collar between flush mounted motor and C-chan.
    e) Doesn’t seem to work well with zip ties for fast cartridge change.
  2. Motors don’t have the raw power we expected but they appear to have much better endurance.
  3. The aforementioned motor mounts are modified standoffs with very thin rounded end for aligning in the metal holes. They are easy to break but they are replaceable. Hopefully VEX will release 10/20 packs of them.
  4. Controller not like XBox. Buttons below stick makes it impossible to use both simultaneously.
  5. Poor design of the battery charger.
    a) It blocks power strip ports so two chargers cannot be plugged in next to each other.
    b) I know we are going to break the cord on this, it just seems flimsy.
  6. Cannot turn off brain LCD or back light to save power.
  7. Cannot test motors w/o the Brain. 393’s could be powered from a 9v to verify they would spin and to hear if they sound bad.
  8. Have to reset the controller b/c it freeze two or three times a day.

What the teams likes:

  1. Integrated encoder and controller!!!
  2. I didn’t think the team would like the cabling, but without needing encoders or controllers, they are sold on it. It would be really cool if VEX would make sensors and switches/buttons that could be daisy chained.
  3. The new Brain is/will be great. Love the program slots, built in program, lists what is connect to smart ports, the planned features for motors, size of the screen…
  4. Single battery saves area and weight (only place they got this right). No backup battery, no power expander, no power extension cables.
  5. PROS3 for V5. We actually like their choice of LVGL since it has a PC simulator. One team member has written the auton selection with it. He has it almost fully tested on a PC without needing access to the robot.
  6. Didn’t have a field connection problem at our first tournament.

edit: added controller issue and attempted to fix lettered bullets.


#11

You know, some time after V5 is released and it reaches a relatively stable point, I’d love to hear about some of the design and engineering decisions they made and what went into them. Like the decision for RS-485 vs other systems


#12

I hope we see different motors types in the future. specifically smaller motors

I am completely okay with them being weaker, but it would be nice to see other options for systems that don’t need to power the new motors provide.


#13

I absolutely agree. Not everything needs that much power and many things have size constraints (ball intake/indexer and wrist motors would be two for this year).


#14

For us, V5 motors has been great. However, I do agree that there should be an option of smaller motor for V5 where built in encoder isn’t needed.


#15

honestly I would just be nice if they made IQ motors Legal.


#16

Right. Unfortunate thing is that they use I2C for comms instead of RS-485


#17

I mean that can’t be too hard to make an adapter


#18

They also have a 6 pin connector and run at 7.2volts. Also how would you attach them, they arnt really designed for EDR. A motor with similar size and power to the vexIQ motors would be nice though.


#19

I mean in a Ideal world we’d be allowed to use IQ pieces as well.


#20

IQ cables are 6 pin? For I2C you normally have Power, Ground, SDA, and SCL for pins. What are the extra 2 for?