FTC - Tetrix kit vs. Matrix kit?

[Mr. B.]

Question to all FTC teams/mentors...I will be adding the FTC program this coming fall to our FIRST program offerings and wanted to get input from FTC teams as to which FTC kit they would recommend Textrix or Matrix we purchase? I've been reading the kit descriptions but figured that asking those who have used these kits would be the best path to go! I would appreciate your input and thoughts on this topic!

Thanks,

Mr. B.

[CENTURION]

I don't think you'll find many people who've used both.

We (My team, plus the four others run through BadgerBOTS) use Tetrix, and it's... alright. It has a lot of flaws, but I don't know if the Matrix kit is any better; I've never used it.

Tetrix has the advantage of being far more popular (at least in the USA), and so you'll have a much easier time getting help from other teams, borrowing spare parts, etc.

Honestly though, we try to stay away from the kit, because while it's nice for quickly slapping things together, Tetrix rails and parts are much more expensive than custom-made pieces, and generally weaker. But that strategy is dependent on you having access to at least a basic machine shop (Which pretty much every FRC team does already). For instance, here's part of our drivetrain from this year. There's some tetrix parts up above (Frame, motors, sprockets, standoffs, axles), but the majority of the structure is either custom machined (There are some custom axles and spacers inside there that you can't see too), or off-the-shelf (Andymark wheels, sprockets and bearings, 80/20, etc).

Overall, I find the Tetrix kit to be pretty frustrating, but that could be due to the fact that I'm much more used to making and designing things from scratch. And again, for all I know, the Matrix system might be just as frustrating.

Those little Tetrix D-shafts are pretty much junk for a lot of applications, you can't really transmit force through them, because the set screws will just dig in and the hubs will spin on the shaft.

Tetrix motors are also notoriously prone to burning out if you stall them for more than a second or two. And if you attached an encoder to that motor, you're out of luck, because the encoder can't be removed without damage. Again, I don't really know if Matrix is better in this regard.

[coalhot]

I've used some of the earlier Tetrix stuff (back in 2010 and 2011), and Matrix stuff more recently (this past season). The Matrix kit material is much lighter then the Tetrix, the electronics are wimpier, and a lot of the hardware is just not worth the price. Definitely go with the Tetrix.

However, with the more lax, FRC-style FTC rules nowadays, we're looking to do most of the body/frame work with custom materials (probably 1x1 box) and just using Tetrix electronics.

[Andrew Lobos]

Originally Posted by CENTURION

Tetrix motors are also notoriously prone to burning out if you stall them for more than a second or two.

The new Tetrix v2 motors have a lot of improvement in this area. We have not burned out any v2 motors this year. We had one instance where a gear in the integrated gearbox shattered, but overall they have been good to us.

At our local kickoff, the presentation from Tetrix spec'd the v2 at being able to be stalled for "over 2 minutes" without smoking.

Originally Posted by CENTURION

And if you attached an encoder to that motor, you're out of luck, because the encoder can't be removed without damage.

I have had success with removing the encoder disc from the shaft by gripping the sides with a needle nose pliers and pulling it off. Then I used the tools from the encoder kit to put it on a different motor.

[Jalerre]

As being one of few teams who has used both kits I must say I like Tetrix far more than Matrix. We used Matrix this past season and it was a terrible experience. The plastic gears slipped a lot, the screws stripped easily, and the parts are very filmsy. That's not even mentioning that we burned through all the servos provided in the kit. You apply even a little pressure to them while the robot is on and there done for. My favorite build kit personally is Vex but of the two Tetrix is the way to go.

[JTN]

I hope this explains why my team uses Matrix over Tetrix.
http://youtu.be/lDmdjNbFbQg

[Chief Hedgehog]

As an FRC Coach that is ready to start one (possibly two) FTC teams in the Middle School ranks - I am a bit concerned after reading these posts.

I thought that by going with one or the other kits (Tetrix vs. Matrix) either would be a great building block.

Now I am concerned about spending that type of money on either if they both have severe disadvantages.

Where do I go from here? I do not want to strap my future coach(es) with sub-par equipment.

[atucker4072]

Originally Posted by Chief Hedgehog

As an FRC Coach that is ready to start one (possibly two) FTC teams in the Middle School ranks - I am a bit concerned after reading these posts.

I thought that by going with one or the other kits (Tetrix vs. Matrix) either would be a great building block.

Now I am concerned about spending that type of money on either if they both have severe disadvantages.

Where do I go from here? I do not want to strap my future coach(es) with sub-par equipment.

What specifically are you concerned about? Is it more so the electronics/motors or the structural hardware?

[Mr. B.]

Thanks for everyone's input! JTN will you be out at IRI in July? Would love to speak with you in person if possible. Let me know! Looking forward to seeing more posts on this topic! Much thanks!

[ehochstein]

I would suggest going with Tetrix. I have experience with both Matrix and Tetrix, by far Tetrix has been the easiest one to work with. I haven't run into any issues this year with what they provide for parts. With Matrix I have run into many frustrations. The electronics do not work well at all, I am still unable to get my Matrix control box to communicate with the NXT (in LabView).

Buy Tetrix kits, they work super well, they're easy to learn and they come with a ton of resources. Just remember to order your kits ASAP.

[JTN]

Yes, I will be. I'm sure we'll see each other because our pits should be close together. The Matrix motors are a bit weak and the set screws could be a bit sturdier, but proper dimpling on the shafts and locktite in the right places makes the Matrix kit reign supreme. The push pins make prototyping so easy and the parts fit together in a much more fluid manner than do Tetrix parts. I can post some pictures if requested, but I'm too lazy to resize them all until then.

[CENTURION]

Originally Posted by Chief Hedgehog

As an FRC Coach that is ready to start one (possibly two) FTC teams in the Middle School ranks - I am a bit concerned after reading these posts.

I thought that by going with one or the other kits (Tetrix vs. Matrix) either would be a great building block.

Now I am concerned about spending that type of money on either if they both have severe disadvantages.

Where do I go from here? I do not want to strap my future coach(es) with sub-par equipment.

Working around the inadequacies of the system is a challenge, one that I think it's good for the students to deal with. Either way, you're going to have to use one of them at least for your electronics.

The Tetrix system isn't terrible, it just has a few shortcomings here and there, which provide a good opportunity for the students to learn about which systems work, and which don't. As I showed with the drivetrain earlier, it's possible to find a happy balance between Tetrix and custom parts. There are actually some kind of cool things built into the system, like how the motor output shafts are eccentric, it provides a built-in chain-tensioning system.

[JohnFogarty]

Originally Posted by Mr. B.

Question to all FTC teams/mentors...I will be adding the FTC program this coming fall to our FIRST program offerings and wanted to get input from FTC teams as to which FTC kit they would recommend Textrix or Matrix we purchase? I've been reading the kit descriptions but figured that asking those who have used these kits would be the best path to go! I would appreciate your input and thoughts on this topic!

Thanks,

Mr. B.

Back in my day. We didn't have all these choices.
It was Tetrix or nothing.

Tetrix has it's flaws. However, having messed with Matrix a little bit this past season. I think I'll be sticking with Tetrix until I see a need for some small matrix components. The V2 motors are the best revision yet. Even I haven't burnt one out yet. (I was very good at killing V1 motors.)

Originally Posted by JTN

I hope this explains why my team uses Matrix over Tetrix.
http://youtu.be/lDmdjNbFbQg

I'll counter with this is why 3864 uses Tetrix.
http://www.youtube.com/watch?v=z94A1GlU8Xk
Our robot is the one that the Y-NOT bot's team is face towards most of the match. It's pretty cool to me that it seems that 92 and 3864 came to very similar conclusions on the best way to score blocks. It was sad that we never played together in San Antonio.

Finally a throw back to my first season as captain of GForce. (Now Global Force). We had some pretty stellar rookie results. (World Championship Winning Alliance). http://www.youtube.com/watch?v=F59FXI30jzw

I'll be at IRI as well. Volunteering more than likely.

[jvriezen]

The rookie FTC team I worked with this past year decided on Matrix. I believe they were the only matrix team at three or maybe even four of the events they attended (two qualifiers, MN State, and Super Regional)

We were not impressed by the Matrix plastic gears and wimpier axles, so ended up getting some parts machined by a local company that allowed us to interface some Matrix motors to Tetrix gears and then AndyMark 4" wheels. It ended up working fairly well (as you can guess by the events we attended)

The plastic push pin rivets do allow for quick prototyping of structures and can be very handy.

[Andrew Rudolph]

Whenever students or other teams ask me for FRC as to using a certain component (usually mecanum drive) I always say to them "look at what you have seen on Einstein"

The same applies to FTC and looking at DaVinci. I dont even think a matrix team got picked at the world championship.

But more so, tetrix has been around for almost a decade now, Matrix only a few years. So there are lots of resources out there when pertaining to using tetrix parts for your bot. Whenever I have held the matrix components they seem to be very...value engineered.