[FTC]: FTC Expands the kit of parts option for next season

[Andrew Remmers]

Originally Posted by team F.T.C 4240

So now we get to also use VEX?!?!? Just kidding, but this platform is very similar to the VEX platform. It looks inexpensive, it has plastic gears (not a big fan, unless to want to build a light weight flying robot), all the metal parts look very much like VEX, as in if you wanted to alter it then you could just bend it, unlike the C-channel or really any of the Tetrix building materials. ... It doesn't look all bad though, because they have some pretty cool pieces like the belt drive, which looks like it could come in handy. My guess is most teams that have done FTC for a couple years will mostly use Tetrix with a few of the cool pieces of Matrix, but probably wouldn't use it for anything that needs to be robust. That's just my thoughts on the new Matrix kit.

I'd like to elaborate on this a bit. From more of an Engineering stand point.

First on my list.
-Gears.
--Plastic gears are not all bad. If its made of the right material, and is the right thickness they should be plenty strong. From what it looks to me the Matrix gears are VERY high quality (from what I could tell) I have no idea what material they are, I was told Polycarb (which is good) But other materials also have better properties. I hope that they choose quality over quantity to be completely honest.

It looks more user friendly like VEX, but unlike Tetrix it does not look robust in any way what so ever, which means the first time you get rammed into a wall or pushed across the field, the robot would fall apart or get damaged.

This part has me a bit. Irritated I guess is the word. The metal looked like it was 1/16 inch thick. (same as any Tetrix material) However It appeared that it was bent on a CNC break. Meaning its probably some grade of 5052 AL. I use 5052 AL on all my FRC robot designs as most parts need to be bent into shape. 1/16 inch AL with bends is plenty strong as long as you make the flanges long enough. Team 67 in FRC mind you does all 1/16 inch sheet metal on their drive train, and it holds up FINE. To say that the first time you get rammed your robot will fall apart is a bad conclusion/review, as if this does happen. Its not from the strength of the metal, its from the lack of engineering.

- Andrew

[team F.T.C 4240]

Originally Posted by Joyride_67_1902

I'd like to elaborate on this a bit. From more of an Engineering stand point.


This part has me a bit. Irritated I guess is the word. The metal looked like it was 1/16 inch thick. (same as any Tetrix material) However It appeared that it was bent on a CNC break. Meaning its probably some grade of 5052 AL. I use 5052 AL on all my FRC robot designs as most parts need to be bent into shape. 1/16 inch AL with bends is plenty strong as long as you make the flanges long enough. Team 67 in FRC mind you does all 1/16 inch sheet metal on their drive train, and it holds up FINE. To say that the first time you get rammed your robot will fall apart is a bad conclusion/review, as if this does happen. Its not from the strength of the metal, its from the lack of engineering.

- Andrew

The metal looked like 1/32 inch to me (note it is held together with plastic pegs like lego), but its almost identical to VEX, I've used VEX and it does not preform well when there is contact involved, my team and I made that VEX bot as robust as we could and it took a great deal more work to get it competition ready, mostly because the kit it self is so flimsy. Say you take a VEX bot to the FTC world competition and it get rammed into a wall by a 52 lb robot (like ours this year), don't you think something would break? All I'm saying is the new matrix kit is less robust then Tetrix but has some cool pieces that could be useful on a FTC bot, although I wouldn't use it to build a FTC robot. As for your FRC robot, you wouldn't use 1/16 inch for the base of your robot, it would be used to more less to plate the robot.

[Scott_4140]

Did anyone get more information on the controllers, DC Motors, Servos and Battery? Are they compatible with their Textrix counterparts?

[l0jec]

Originally Posted by Scott_4140

Did anyone get more information on the controllers, DC Motors, Servos and Battery? Are they compatible with their Textrix counterparts?

It looked like they combined the motor and servo controllers into a single housing and the comm wires controllers appeared to be the same ones (with the RJ12 connectors) used with the NXT.

Other than that I didn't get a lot of details. Didn't even get the voltage of the power supply/battery, so how power distribution would work with Tetrix is still an open question unless someone knows. Hopefully it would not require a separate battery & on/off switch for students to remember. I hope that FIRST would provide a power distribution panel to handle such a situation?

[Scott_4140]

If there is any chance of combining electronics between Matrix and Tetrix, they would both need to run of 12 VDC. FTC referees will still need a single switch to disable robots. You could accomplish this with another control box, but requiring 12 VDC compatibility shouldn't be that difficult to design to.

I wonder if controllers can be mixed on the same sensor port. That could add significant flexibility. The Matrix controllers appear slightly larger than the Hitechnic controllers.

[Andrew Schuetze]

Originally Posted by team F.T.C 4240

(note it is held together with plastic pegs like lego)

Not piling on rather suggesting a correction. l0jec posted that the plastic rivets are intended for rapid prototyping and for competition one would logically use machine screws.

[Andrew Remmers]

Originally Posted by team F.T.C 4240

The metal looked like 1/32 inch to me (note it is held together with plastic pegs like lego), but its almost identical to VEX, I've used VEX and it does not preform well when there is contact involved, my team and I made that VEX bot as robust as we could and it took a great deal more work to get it competition ready, mostly because the kit it self is so flimsy. Say you take a VEX bot to the FTC world competition and it get rammed into a wall by a 52 lb robot (like ours this year), don't you think something would break? All I'm saying is the new matrix kit is less robust then Tetrix but has some cool pieces that could be useful on a FTC bot, although I wouldn't use it to build a FTC robot. As for your FRC robot, you wouldn't use 1/16 inch for the base of your robot, it would be used to more less to plate the robot.

1/32 is way to thin to be what it was. VEX is also plenty strong even as Aluminum. Its made from the same material 1/16 5052 AL sheet bent on a CNC break. I don't see any well engineered robots falling to pieces on the field in VEX. As for the 52 pound robot thing. VEX robots are normally much lighter (at least the ultra efficient ones) However that being said there were some 60 pound wallbots at worlds this year. Its a trade off really. One thing I will say is that I wont deisgn with Matrix unless they make the right kinds of strutcutral parts, parts like Long C channel for instance. I don't trust the L brackets all to much for the main structure of a drive train those are "flimsy"
It also seems to me that their shafts are different sizes than Tetrix, which means I hope to god they make shaft couplers. Thats one thing that Tetrix even needs to make. But Tetrix and Matrix both have their major and subtle differences. Tetrix not needing nearly as much work as Matrix to make a robust robot. But Matrix I have a feeling will make things smaller. Overall next year shall be fun.

- Andrew

P.S. 67 Team H.O.T. did a 1/16 inch sheet metal drive train this year. Almost made it to Einstien. 1/16 is plenty strong, if done correctly.

[Jrc4055]

I think these parts are going to be used for the more intricate systems on FTC bots. Tetrix will be used more for chassis, and the heavy-duty stuff. And think about it. Why would FTC use these parts if it weren't because of next years game? Perhaps there are going to be more precise manuevers we have to perform that Tetrix can't handle.

[CougarRobot]

We spent some time at the booth talking with the Matrix people. Their system is based on 9V not 12V so even though the parts might integrate mechanically (Matrix is based on an 8mm grid while tetrix is based on a 32mm grid) the electrical components would likely require a separate set of wiring for power.

I was told that the 9v motors are slightly less powerful than the tetrix 12V motors we are currently using. They also have built in encoders. I would be interested in seeing what options we have to connect multiple motors in parallel on a single circuit and control them with a single shaft encoder the way we do with our tetrix motors.

[krisloz]

Can someone put me to speed here please.

Lego Education and Tetrix are no longer working with each other (or so I heard), so Matrix will be replacing Tetrix?

[Andrew Remmers]

No Matrix is simply an addition to the FTC competition legal parts. As far as I have heard. Mainly will be used by international teams at first and then slowly introduced to the state side competition.

Thats what I have heard.

- Andrew

[Andrew Schuetze]

I had not compared the Tetrix and Matrix metal gauge until this morning when I had been asked to measure after casual observations and assumptions and posting in another thread here on CD.

I've got both in house and have used them both now for summer robotics camps with no real issues. Big difference is in the angle beam and not much difference IMHO for the flats and corner connectors (1/64 or 0.015625)

Angle
Tetrix 0.12500 (1/8)
Matrix 0.06250 (1/16)
Flat Plate
Tetrix 0.078125 (5/64)
Matrix 0.06250 (1/16)
Corner Connector
Tetrix 0.078125 (5/64)
Matrix 0.06250 (1/16)
U-Channel
Tetrix 0.078125 (5/64)

The beauty of the expanded FTC raw materials list is that one can purchase aluminum stock in a couple of sizes if you really need what one kit has verses the other.

[Andrew Schuetze]

Originally Posted by CougarRobot

I was told that the 9v motors are slightly less powerful than the tetrix 12V motors we are currently using. They also have built in encoders. I would be interested in seeing what options we have to connect multiple motors in parallel on a single circuit and control them with a single shaft encoder the way we do with our tetrix motors.

The servo motor controller that we used in our summer camp has a single connection for the motor that includes the encoder so not possible to connect more than a single motor per channel. Really cleans up wiring but may need to find/build motor extension cables.

[gblake]

Originally Posted by team F.T.C 4240

... I've used VEX and it does not preform well when there is contact involved, my team and I made that VEX bot as robust as we could and it took a great deal more work to get it competition ready, mostly because the kit it self is so flimsy. Say you take a VEX bot to the FTC world competition and it get rammed into a wall by a 52 lb robot (like ours this year), don't you think something would break?

You must be joking.

Drive down to Northern Virginia to chat with me, or ask some of the many Maryland groups using Vex parts to show you how to build a sturdy Vex bot. There is absolutely no doubt that the kit's structural parts work just fine.

The thousands of teams that use Vex equipment successfully in VRC, in Best, and for other purposes, are prima facie evidence that your assertion is just plain wrong.

I have personally used both Tetrix and Vex parts and have a pretty good grasp of their major similarities and differences.

As for the assertion that a 52Lb bot (made from anything) might damage a bot made out of Vex structural materials. Well DUH. A 52 Lb bot hitting a 15 Lb Tetrix bot hard is also likely to damage the 15 Lb Tetrix bot. Similarly, a very large car smashing into a very small car will probably inflict more damage than it suffers. Also, an M1 tank hitting a car would destroy the car and probably not suffer any damage at all. However, that's not the point, and neither your example, nor these I dreamed up are evidence that supports your thesis.

Blake

PS: I'm glad to see that FIRST is expanding the parts teams can easily incorporate into FTC bots.

[PhilBot]

Originally Posted by team F.T.C 4240

The metal looked like 1/32 inch to me.

From the photos it looks more like 3/32 to me (more than 1/16 but less than 1/8)

TETRIX metal is more than 1/16" maybe 2mm since it is a metric system.

Phil.