Greyt Universal Cascade Elevator and Powercube Claw


#235

I don’t appreciate your sarcastic (or worse, condescending) tone throughout the entire post. And I’m not even the target. If I were you, I’d take your own advise and heavily edit your post. Start by removing “that’s cute”–you’re saying that about an estimate, so how about pointing out where the estimate went wrong?

mman already stated exactly what you were stating, and did it much more constructively.


#236

Advice even.


#237

I hear a lot of discussion around what the students on a team would find most rewarding or engaging. Why on earth would we try to generalize that? I remember a NE team at DCMP last year that was something like 80% programming students and maybe 2 or 3 mechanical students. A team like that might *love *the ability to buy a lift or gripper! I’m sure the programming students would be very rewarded by getting to work with the interesting controls that surround a lift mechanism that they might not have gotten without a COTS solution.


#238

Personally, I dislike COTS items like this, a complete bolt on solution. This is different than small components like gearboxes, wheels, structural members, etc. Those still require work to configure and optimize, the Kitbot is a starting point, a way to at least get you to the event and on the field. Things like the Greyt claw & lift, the REV lift, etc short circuit the learning process, as a current college student I can tell you that looking at the worked out solution and understanding it is not the same as solving the problem on your own and getting help when you are stuck.

When I was a student we built everything custom, it often broke at competition, and while I enjoyed fixing it in a rush, it was a miserable experience for most of our team. The students who graduated from that era have stayed in stem in spite of their experiences, they weren’t inspired by it. Since I graduated the team has adopted a new philosophy and uses a lot of cots components, mostly things from McMaster Carr, Lowe’s, and Home Depot. Linear elevator? Built our own out of garage door track and rollers, worked great, and parts were available at most hardware stores. Ratcheting mechanism to stop the climber from back-driving, broached a nut for the shaft and bolted a Gearwrench on. My experience in three years of Co-ops has been that this is how a lot of engineers do their job, it’s about finding something close to what you need and tweaking it from there, this is an important skill that complete cots solutions deprive the students of.

(The real issue is how do we help a team that only cares about one aspect [Programming] do more of what they care about while not creating an environment where a [Robot] team can’t compete/win, or vise versa)


#239

What is the origin of the price limit on COTS items? I’m not sure I ever learned the purpose.

Hypothetical to those that like COTS items like this: If price limit did not exist, should Snow Problem sell their Ri3D robot (all pieces, painted that pretty blue color and everything) as an upgrade kit alternative to AM14U3?

I am not giving my own opinion here, but if it’s a question about where the line is drawn, where are you comfortable drawing it, and why?

Currently we live in a free-market FIRST economy with some regulation on COTS price and availability. Genuine question for discussion.


#240

It would be literally impossible to assemble the elevator without gaining a full understanding of all bearing interfaces and the various forms of power transmission.

The claw has adjustable width/travel and doesn’t ship with wheels or a suggested configuration. It would be impossible to make a functional claw out of it without gaining a good understanding of your own specific configuration.

Both are currently far from a bolt on solution.


#241

Tell me that gearboxes, wheels, and structural members (IE Chassis) are small components when you don’t have them as COTS. I was around before AndyMark came out with most of these COTS items … and it is a big deal.

The price limit on individual COTS items as well as overall purchasing of COTS items is to (somewhat) balance the playing field. Without it, it would be very difficult for rookie/underfunded teams to compete and be inspired … as they would continually get crushed by “have” teams


#242

I recall seeing the sliding bearing block pictured in the attached thumbnail on 254’s robot at IRI circa 2006, and thinking “how is that fair?” At the time, the Poofs and a handful of early WCD teams had to machine their own bearing blocks. Now these are COTS , and people complain about paying $25 for the parts and associated tensioning cam.

To reinforce Adam’s point: we aren’t just bolting these things onto robots. Using even relatively simple COTS parts effectively requires engineering thought. Using the Greyt mechanism kits requires even more engineering thought. The Average Joes learn to think faster when better parts are available. And we still get to make plenty of parts ourselves.

bearingblock.PNG


#243

Here is my updated opinion and experience related to the Greyt elevator, COTS solutions in general, and what I’m seeing with this game as we hit bag & tag day.

We bought the Greyt elevator (two kits!) But didn’t use them. Our students had already done their homework and came up with an elevator of their own design that was deeply inspired by Adam’s video series, but did some things differently (bearing sizes, continuous instead of cascade, etc.). We built it and are very happy with the performance. If the Greyt kits are non-returnable, we will use them for off season training in the future. I still think they are a terrific product, and I appreciate both WCP and Adam for what they have brought to this year’s game.

I don’t think COTS kits like this are foolproof or even very easy to implement. As demonstrated by the number of threads about elevators that aren’t working, and by what I’ve seen in person and in videos this past week, teams still have a lot of work to do to make them minimally functional. Basically they allow teams without CNC machines or other manufacturing capabilities to build more precisely, if they can do the work to figure out how they function and integrate. We will see a few COTS elevators that work great, and a lot that just make robots more tippy and don’t help teams improve much. At least for this year. Long term, these types of kits may become well understood enough that they are like gearboxes or the kitbot drivebase, meaning they will be used in creative ways that raise the performance level of average teams.

Last thought: if we were worried that we would see cookie cutter robots this year, all using Greyt elevators and roller claws, well. I’m not seeing it. There are some meat-n-potatoes designs (my team’s included), but there is as much variety showing up as I’ve ever seen.


#244

(Spooktober, time to raise a thread from the dead)

This was a fun thread. Now that the season is over, I’m curious how many of these kits were sold and how many made it onto winning alliances.


#245

I’m curious how many made it on to robots at all. I don’t remember noticing any while I inspected robots, but that might just be a region thing.


#246

We used the Greyt Universal Cascade Elevator on our robot, and had a great 'bot and a great season. Our kids were able to do, and learn, so much from:

  • seeing how the thing worked and the choices that were made in designing it
  • interfacing it with the 'bot chassis and drive system, cube-grabber (designed from scratch, we didn’t use the kit for that), potential hanging mechanisms, etc.
  • seeing what happened when they tried to change something (e.g., to put a more powerful motor onto the elevator, add weight in various ways, mount sensors and wiring, use different aluminum rectangle stock than ‘recommended’ for various parts)
  • having something that would actually work BEFORE it was put into the bag, so they could do more programming, driving, etc.

They had plenty of things to strategize, design, CAD (and learned to interface the CAD drawings for the kit elevator with their own for the rest of the bot), build, program and test.

Overall, it was a fantastic option and choice for our generally ‘middle-of-the-pack’ team, to learn some ‘higher level’ skills and lessons (e.g., how to handle it graciously when your robot is fine, but your alliance partner has issues; how to continue improving your 'bot AFTER it gets to the “reliably running and performing its intended functions, with functioning auto code” stage - something we often don’t reach until late into our competitions, if at all).


#247

We were the 1st seed captain at 2 in-season events, won both using the claw. Made to semis in Turing losing to the the eventual division winners. Just finished the last offseason event for the robot and went undefeated.

Using the claw saved us a lot of time that we translated into more drive practice time.


#248

Our robot competed in 83 matches this season with a record of 54-28-1 using the greyt elevator. We bought it when it came out during build season because we knew the custom machined parts that came with the kit would be more effective than whatever we could make ourselves.

We were worried that if we chose to use our own similar but less efficient vex based design we would be at a competitive disadvantage to teams that bought the kit. I guess we underestimated how many teams would integrate the kit into their robots, as I only maybe saw one or two greyt elevators on other teams all year.

For our two regionals we used a 775 pro with a 45:1 versa planetary gearbox to power it and a vex ratcheting vp stage to hold it up. However we experienced mechanical failures related to the elevator in the finals of both regionals (you can see in match videos if you are interested).

In an effort to make the elevator less prone to breaking we modified the motor mount gusset so we could use a CIM motor with a 9:1 reduction instead. This setup served us well for champs, IRI and two more off-season events.

No matter my mixed feelings about advanced COTs parts like this, the elevator was definitely well designed and very effective. If anyone has any questions about our experience with it feel free to ask.


#249

We played with 6911 at Brunswick Eruption who had one of the Greyt claws with a small gas shock on either side as the spring. Worked out pretty well for them in my opinion.


#250

I’m curious about what will happen with GreyCOTS and the like in 2020? Given the extended build season, how many teams will wait for a solution to buy and integrate?

Clearly, some teams benefited a bunch this year and I don’t begrudge them working furiously to successfully integrate into their design within the 6 weeks. They deserve congratulations. How this plays out in an extended season has some pretty serious ramifications, IMHO.


#251

Hi Adam. Our team is interested in your product, but have a few questions before we make the purchase. The questions go as follows:

  1. What are the dimensions of the product?
  2. What is the stationary starting height
  3. To what height will the product reach?

We are trying to determine if the elevator would be adequate enough to reach high enough on the rocket in this years game.


#252

This information can be best understood by downloading and viewing the CAD of the elevator. Here


#253

Note that what WCP is selling is a kit with the included brackets and hardware necessary to assemble the elevator. The tubing you buy separate and cut to whatever size you deem necessary. So to answer your question, it’s really up to you.

Adam, we too are interested in the kit, when do you expect it to be back in stock (currently listed as on back order)?


#254

All, new thread for 2019 here.