VEX pro 775, broken terminals

VEX pro 775
https://photos.app.goo.gl/FnDOcv8R4bNnL5KF3
https://photos.app.goo.gl/Lgahie1WNaqx7y3J3
The connecting terminal of the VEX pro 775 broke while trying to take it off of our robot.
Is there any way to salvage this? Maybe a replacement terminal or soldering the wire to the inside? Or the best way to open it up?

Any lead will be appreciated

pardon but the images doesn’t seem to show up



I don’t think there’s much you can do without running afoul of rule R34.

The integral mechanical and electrical system of any motor must not be modified. Motors, servos, and electric solenoids used on the ROBOT shall not be modified in any way, except as follows:
A. The mounting brackets and/or output shaft/interface may be modified to facilitate the physical connection of the motor to the ROBOT and actuated part.
B. The electrical input leads may be trimmed to length as necessary and connectors or splices to additional wiring may be added.
C. The locking pins on the window motors (P/N: 262100-3030 and 262100 3040) may be removed.
D. The connector housings on window, door, windshield wiper or seat motors and Bosch motors (P/N: 6004 RA3 353-01) may be modified to facilitate lead connections.
E. Servos may be modified as specified by the manufacturer (e.g. re programming or modification for continuous rotation).
F. The wiring harness of the Nidec Dynamo BLDC Motor may be modified as documented by FIRST in the “Nidec Dynamo BLDC Motor with Controller” Screensteps article.

Unfortunately it seems like you’ll have to write it off. Repairing the motor tab isn’t covered under part D.

You could use it on a practice or offseason robot but I wouldn’t trust any solder connections to those tabs.

I can just picture in my mind’s eye some well-meaning student pulling, twisting, and bending that tab

trying to get the connector off :eek:

This has been a problem vexing (pun intended) teams since the FIRST build season (…again). In fact earlier this season this question was asked on CD. Unfortunately that motor like the thousands of others across the FIRST community over the years should be displayed on a wall and used for teaching purposes only–that is the only use it can provide your team now. It is one of the first things we teach rookies each year and yet we’ve had to replace two already this year!! Go figure.

Save it as an example of “what can happen”

I also like to keep a few dead ones without tabs around to toss on mechanisms that are “in work” and still being bashed around in assembl steps (which is when lots of tabs get knocked and bent for us). Then when the thing is finally assembled you get a free practice run at swapping the motor out :slight_smile: We always design 775 mounts to make the motors easily accessible so this isn’t really a difficult swap.

~Zac

It looks like you might have enough length on the terminals to solder them on to one of these:

https://www.therobotspace.com/ProductDetails.asp?ProductCode=trs%2D775C

Now, whether or not that’s a good idea is still questionable, I’m not sure I’d use it on a competition robot for fear of the leads coming off, but it would make the motor at least “usable”.

^ +1

I would say there’s plenty there to solder to securely. And if using one of the new boards, you should be fine.

That’s really terminal-ly bad.

But seriously, you can’t fix that under rule R34, as said before.

Ozzyboards sells a cheaper one as well, with a US distributor now too: [http://ozzyboards.com/775-inline-powerpole-connector/
http://ozzyboards.com/775-inline-powerpole-connector-cover/

Honestly, though I like the robotspace board for our uses, that Ozzyboards connector will probably be an easier fit with the shorter tabs.

You should be able to solder 12AWG at a right angle to what remains of the tabs. Running the wire down the side of the motor and using one or two cable ties around the motor case provides very effective stress-relief. I would be careful about using the motor on a competition robot( due to a risk of connection failure) but for a practice robot or prototyping/testing it’ll still be fine.

In regards to the TRS-775 Connect, due to the thickness of the supplied spacer( it is around 1/8" or 3mm), it is unlikely to work for this application.

We use a much thinner 1.2mm spacer, which should allow it to work in this application. Additionally due to the reported very-tight fit of the TRS-775, it will probably be difficult to get your bent motor tabs to fit. We did several prototyping runs to ensure the correct fit and thus you shouldn’t have an issue doing so with our product.

Feel free to send me a PM with the height of the tab that is remaining and I can check if it will work :slight_smile:

Does anyone know if something like the TETRIX motor power cables used in FTC exists for FRC? Our team broke a tab off of our 500 motor and we’re not sure if we can repair or interface with it. Something like a plug that can fit over the motor terminals would be useful, even if it means we lose access to the rear shaft.

The Tetrix Motor Cable is just right angle spade terminals inside an injection molded case, so one for a 500 class motor is unlikely to provide much benefit. If you have a small amount of motor tab remaining you should be able to solder a cable directly to it at a right angle.

I meant that it might be useful in the future to prevent this from happening again. In the meantime, we’re swapping our old Banebots motors with the Fischer Price motors.

What Fischer Price motors do you mean ?

Do you mean AndyMark 9015 motors? If it’s not those, you aren’t going to have a fun time at inspection, given that the original fisher price motor has been illegal since 2013.

Using FPs is bad, but I found globe motors on robots at competition this year. They’ve been illegal for 10 years now :eek:

Please clarify what you meant by “found them at competition”.

Do you mean they passed inspection and were on the field competing ?