Re: [FTC]: NEW ROBOT DESIGNS!
 

Very inspirational posts to this thread showing pushing the limit with the new materials allowances.

I see FTC moving more to a manufacture and design competition for some teams with the new rule changes. I am the team lead for our overall program and do not get much time to work with the FTC program. I am excited to see the new designs such as your team(s) have posted in this thread. Hopefully we will see more teams post pictures and designs. I feel that is one of the unique features/strengths of FRC.

Just wondering how you are moving your elevator? I notice what looks to be pulleys, will it be actuated by a series of pulleys? If so, what thread/cord are you using?

Norman

Re: [FTC]: NEW ROBOT DESIGNS!
 

Hi all,
We are rookie Team this year in St. Louis, seems the shoulder/Arm/Wrist is popular. we have that basic design but are having serious stability issues, Tip over danger, motor torque and other challenges. the U-Channels are just too heavy. is it true that if your bot tips in competition, the referee will set you back up?

what areas of the competition are you focusing on?

We jumped right into getting rings on pegs. I was suggesting a bull dozer approach. if time is running out, easy points could be earned by pulling all rings to the floor and sweep them to the center board.

what other quick and dirty point gains would you suggest for Rookies?

Re: [FTC]: NEW ROBOT DESIGNS!
 

I agree that the new direction of FTC for allowing use of additional materials will be good for the program, and it will help to better train the younger students on the kind of fabrication skills and creative design thinking that will directly carry over to the into the FRC program.

We are lifting our elevator for a maximum travel of 28" using some no stretch, 600 lb. test, kevlar cord in 3/32" size -100 ft for $16 at this source:

http://www.qualitynylonrope.com/mm5/merchant.mvc?3/32

We will use two 3" or 4" Tetrix wheel hubs (rubber removed) as our cord winder "drums", and the cord will wrap 3.5 or 2.5 times around these nylon wheel hubs.

The cord will feed both on & off each of the winder drums in two directions, one end will pull for lifting and the other end, when winder drum reverses, will pull for lowering, since there is a fair amount of friction with the slides we are using.

-Dick Ledford

Re: [FTC]: NEW ROBOT DESIGNS!
 

With our 1.5" lift platform maxed out to nearly 18" on width, we were barely able to fit in the cube at the 1st competition.
Our motor/wheel spider modules do slide in or out by loosening just three tee slot screws, so, fine tuning them for maximum size is fairly easy.

With the limited 30 pt. score boost that an only 1" lift can give, compared to getting another row bonus or two during the end game, we have decided to remove the lift platform. Unless we can rebuild another lift in a more compact and less defendable way, that can quickly raise our partners at least 10+ inches, we feel that end game time would be better invested in scoring rings for more row bonuses.

It turned out that even with near 18" of width and a not so steep slope, most partners still had trouble driving up the ramp, and defending our lift by merely blocking access to a lift mechanism proved to be much easier to do, than it was to overcome, especially once the lift platform was deployed (too hard to maneuver much around blocker with protruding platform).

-Dick Ledford

Re: [FTC]: NEW ROBOT DESIGNS!
 

our robot tell me what you think?

Re: [FTC]: NEW ROBOT DESIGNS!
 

our robot, tell me what you think?

Re: [FTC]: NEW ROBOT DESIGNS!
 

More recent PICs.

Electronics removed.
Elevator set up for only up to level two testing (currently 15" limited).
Scissors wire carrier.




We have determined that by lowering our aluminum platform 1" (raising wheel modules actually => relative to platform), we can reach level three on scoring rack with the only two stages of our elevator and thus avoid having to penetrate the plate with any holes for our other (longer) elevator columns - YEAH!

-Dick Ledford

Re: [FTC]: NEW ROBOT DESIGNS!
 

Very inspiring photos and images. I like the use of materials other than the tetrix such as the 80/20. Do you have experience with using 80/20 previously? Do you utilize CAD in your designing?

What is the weight of your robot?

Thanks again,

Norman

Re: [FTC]: NEW ROBOT DESIGNS!
 

Norman, thanks for the encouraging feedback.

We are not currently using CAD but our freshman are finally taking on the task of learning it. I do not do CAD myself, but will pick it up as the freshman progress.

Since we do both FTC and FRC, we do have a few years of 80/20 experience, but this year is the first one using their linear motion items. The key to success with 80.20 is in mastering all the ways to use non-standard fasteners and hole drilling to make strong joints and connections, Gusset plates in corners are also essential for the larger FRC robots.

We have reached the stage where we know how to maximize our designs to take advantage of the inherent flexibility that the slots allow, as far as fine tuning and repositioning our structure and the mounting of our modules. Our elevator and gripper module have 3-axis repositioning by just loosening slot screws. Our complete motor/wheel modules just slide out radially by loosening 3 slot screws on each. With the small amount of man hours our team can muster, there is no way we could do a robot with this level of design without using the 80/20 type of system.

With three years using 80/20 we now have a huge inventory of related standard and specialized fasteners. This year I discovered that we can adapt their 10-32 slot nuts to work in both the 20mm and the 1" size frame.
Since we tend to buy longer fully threaded screws (flat & button head socket screws) and then dremel cut them to the specific needed lengths this has helped a lot. Cutting 1/4" and 6mm screws with the dremel is tedious.
I cannot overemphasize the importance of a large and varied inventory of fasteners when working with the 80/20 framing system.

We only just got the fully assembled robot together yesterday and I have not had a chance to weigh it, At our unofficial Illinois competition today I will try to find a scale, check it and then post here. We are in the vicinity of 40 pounds by my estimate.

-Dick Ledford

Re: [FTC]: NEW ROBOT DESIGNS!
 

With electronics and bumpers/guards, plus 5 pieces of slotted channel as ballast on right front corner, we tip the scales at just over 35 LBS.

We made it through our 1st unofficial competition with no real mechanical failures, only tuning issues.
Our electronics were troublesome, though considering how last minute they were completed, not that bad.
OH, and we were able to score on the 2nd level, as planned, but our driving is stily not very good.







-Dick Ledford

Re: [FTC]: NEW ROBOT DESIGNS!
 

Here is a link to a video of our FTC bot in action. This was from the finals at the Kentwood qualifier. http://www.facebook.com/#!/photo.php?v=538191479525268&set=vb.100000032622989 &type=2&theater

We removed the rings during autonomous and then picked them up from the floor.

Re: [FTC]: NEW ROBOT DESIGNS!
 

I like how all the rings shoot all the way down the slides to get nearer the platform, but still do not roll away in every direction. Floor pickup seems easier too, especially one at a time.

The elevator seems quite fast and the short arm reach seems just enough for coming in to score from different angles, often avoiding the wood edge.

If you can only further upgrade the gripper to pick up two at a time and then individually score them, this could really become a very high scoring bot.

-Dick Ledford

Re: [FTC]: NEW ROBOT DESIGNS!
 

What materials did you guys use for the elevator? Do you have any pictures?

Re: [FTC]: NEW ROBOT DESIGNS!
 

The main elevator segments are Igus slides (shortened) from the FRC kop. There are three of them, but two are fastened back to back to get sliders on both sides of the subassembly. The sliders on the back of the first stage are attached to the frame, and the sliders on the front of the first stage are attached to stage 2. The lift mechanism is cascading cables. I don't have a great picture that shows how the elevator works. Here is something:
http://www.facebook.com/#!/photo.php?fbid=533218163374240&set=o.4476507419464 38&type=1&theater

Re: [FTC]: NEW ROBOT DESIGNS!
 

I like the way that your robot worked, but we ran into a problem at competition when a sister team tried a similar design and similar autonomous routine.

Your robot may have been in violation of the possession rule <GR2>. Forum entry 12 in game rules and game play seems to match your situation and seems to indicate that you should have received multiple 10-point penalties. Was there any discussion by the refs?

In our case, we had to change our autonomous and teleop so that the rings were never on the robot, despite them sliding off immediately, but of course they didn't get as close to the pegs and sometimes rolled quite far when we did not give them a ramp.