If you could change one rule

[Rickertsen2]

this thread is getting off topic

[Karthik]

Originally Posted by Rickertsen2

this thread is getting off topic

I've split the thread. For discussion of Sanddrag's idea that teams should strive for higher levels of quality, please see the following thread.

http://www.chiefdelphi.com/forums/sh...ad.php?t=40099

[Elgin Clock]

Originally Posted by Gdeaver

I'll go with Lavery's wish to restrict the materials and methods. Give the students a box of raw materials that includes all permited parts. This will stress thier brains instead of the teams pocket book.

I disagree.. I don't want to see cookie cutter bots. Although, the financial advantage for a "kit bot, and that's what it would be.. a kit bot, would be a good thing.

But still.. I don't like the idea of a "kit bot".

Take this year for example, I was glad that FIRST offered the kit chassis for teams to use but I would HATE to see the mandatory implementation of that chassis alone for every team. I personally hated working with the kit chassis for the simple reason of loose nuts and screws and washers to affix things together with. When crunch time comes in the pits, a neat robot (custom machined by your team) helps you and loose hardware that is hard to work with hinders you.

While something may be said about keeping the rules fair and making robots uniform for fair play, I think that weight, and size restrictions make that possible.

As for rule changes. I agree with Billfred.. I want to see what teams want to do with the shipping containers and other "currently non kit" things that our parts come in.

I mean c'mon.. we let that tape measure rule slide in 2002 for the reason of "we wanted to see what the teams would do with them." ie: explore creativity.

Why not do the same and make up for that horrible idea for legality of tethers announced so late in build way back then by letting the same apply for the packing materials. But this time let it be known the rules of that on day one of build.

[Rickertsen2]

As an extension to my earlier post, i would like to give a few examples to highlight the absurdity of the pneumatic actuator rules. Last year, we had two 1 1/16" bore cylinders on our robot. When we went up for inspection, we were rejected, because the custom cylinder order form allows only for 3/4", 1 1/2" or 2" bore cylinders. I welcome any attempt to explain the rationale for such a thing. 1 1/16" is between 3/4" and 1 1/2". Does that particular size pose a safety hazard? That must be it.

How about this. For the 3/4" and 1 1/2" cylinders we are required to order them with DP mounting (1/4" pin in the back). If we want to, we are allowed to press the pin out leaving a 1/4" hole, but we are not allowed to order the cylinders with DXP mounting (no pin. just a 1/4" hole). Pressing the pin out and ordering a cylinder with DXP mounting leave you with the EXACT same result, but one is illegal.

There are other useful mounting styles that are prohibited as well such as the D mounting style which allows a cylinder to be mounted by two screws inserted near the front, perpendicular to the cylinder as a whole.

What about rod-less cylinders (picture a pneumatically powered linear slide) prohibited?

How about locking cylinders. These would be a heaven for multi-positioning. Seems like these would lead themselves to innovation to me.

How about multi-position cylinders. I can imagine all sorts of neat mechanisms with these. Again, great potential for all sorts of innovative mechanisms could be made with these.

How about double ended cylinders (a normal cylinder but with another rod sticking out the opposite end)

These are only a small sampling of the prohibited pneumatics actuators available that i think would be of great benefit. I could see logic in restricting parts such as off the shelf pneumatic grippers, but the parts i mentioned above a far from pre-built solutions. They are all very fundamental components.

[Cory]

Originally Posted by Rickertsen2

I welcome any attempt to explain the rationale for such a thing. 1 1/16" is between 3/4" and 1 1/2". Does that particular size pose a safety hazard? That must be it.

My guess is that it's because it's part of "leveling the playing field" Bimba offers us a limited number of select bore and stroke cylinders for free. I imagine the reason we're only free to purchase those specific cylinders above and beyond that quantity is so that the team that only is able to get the free ones, and not buy more has the same cylinders as the teams that could buy anything in Bimba's catalog.

If that makes any sense.

[Rickertsen2]

Originally Posted by Cory

I'll go back and look at the game rules and such, to determine my final answer.

But in the meantime, my interim answer would be to eliminate those darn SLU lugs and let teams use the old connectors.

I didn't like those a whole lot either, but they weren't THAT bad. You will not get a better connection than a properly crimped crimp on connector. If some cannot handle this task, others should not be penalized. These parts were not readily available which made it difficult to find replacements. I think it would be a good idea to include them in the kit but not make them mandatory. At the very least, other similar setscrew connectors should be allowed as alternatives.

[Tristan Lall]

Originally Posted by mechanicalbrain

OK, let me explain myself on that one. Like obviously it would have to be on an unlicensed frequency (and some regulations as to the voltage of the transmission) that does not touch the 900 MHz that the robot runs on I'm thinking 2.4 gigahertz (which in fact is most common for camera transmissions). In fact the rules do allow for cameras and even for those cameras to transmit, its just that if you transmit to the control station the camera is no longer a non functional decoration and illegal.

Two clarifications here:

• It's the power ("wattage"), not the electric potential difference ("voltage") that is of concern when dealing with a transmitter (though powerful transmitters often have high-voltage components).
• On-board cameras which transmit independently of the radio modems (using frequency bands other than 900 MHz) are allowed, provided that approval is granted by a FIRST Engineering representative.

[Cory]

Originally Posted by Tristan Lall

Two clarifications here:

• On-board cameras which transmit independently of the radio modems (using frequency bands other than 900 MHz) are allowed, provided that approval is granted by a FIRST Engineering representative.

His issue was he wanted to see teams be able to pipe the feed onto a monitor in the driver's station, which was discussed ad nauseam elsewhere.

[Tristan Lall]

Having dealt with the chaos the pneumatics cause at inspection time, I think there's a need for some simplification of the rules.

If it's decided (by the ones making the rules) that for 2006, pneumatics will still be substantially the same in terms of the types of devices allowed, then I think the rules should be broad enough to allow all sorts of variations on a well-defined theme. The rule might allow, for example, "any unmodified pneumatic cylinder rated by its manufacturer for operation at 120 psi, with the following characteristics...", followed by a chart or detailed description of exactly what's allowed and what's not. A good start might be "non-repairable, single-ended, non-rodless, with optional magnetic piston, with optional piston seals and/or rod seals, with nominal diameter of ≤2 in, and with stroke ≤24 in"; note the absence of things like the material of the cylinder, the mounting method, the types of ports, the types of seals, the manufacturer or the source.

By not specifying a Bimba part number, it avoids the difficulty of cross-referencing an identical cylinder from Parker (because of small differences in design), and it potentially opens the door to the many other manufacturers who also produce similar apparatus. I hasten to add, of course, that if the intent is to generate business for Bimba, a sponsor, then it is reasonable to restrict teams to using their products. If it's the capability, not the brand that's important, then we should broaden the rules.

This also has the advantage of eliminating inspection decisions based on the letter of the law, rather than the function of the cylinder in question. By careful examination of the rules, updates and Q&As from last year, inspectors at Waterloo and Toronto had access to a reference of the exact model numbers from Bimba and Parker that met all conditions. Even so, there was interpretation involved, when really, there was no need for it. For example, is a Bimba cylinder with suffix DXP equivalent to a DP? It was decided that (for Waterloo and Toronto) they would be treated as being DPs, because mechanically, a DXP is a DP, with dowel and clevis brackets deleted and nuts substituted. The cylinder itself is the same, incorporating provisions for both mounting styles, and the hardware is COTS (for both types). But since the DP was on the official form and the DXP wasn't, by some fractured logic, if the sticker on the side said DXP, it was to be rejected, even if it were being used as a DP. (We chose to set aside the actual letter of the law, and substituted a reasonable, ad hoc modification of that rule. So sue us, or rant about the inconsistent officiating.... Even though the inspectors would have been within their rights to reject a DXP, it serves nobody's interests to appear as heartless bastards who would take pleasure in watching a team pull their cylinder off, because of exactly one extra letter on a sticker.)

Rickertsen2 pointed out that there are a lot of other pneumatic devices that are safe, cost-effective, widely available and useful. As simple a measure as permitting anything from within the Bimba general catalogue would allow for a substantial variety of new capabilities for the robots. On the other hand, if FIRST tends toward Dave's opinion that sometimes there is too much variety in the types of off-the-shelf mechanisms permitted, it would be a simple matter to scale down the rule to permit "anything from pages [some range] of the 2005 Bimba catalogue". In either event, the arcane, arbitrary pneumatics rules need some readjustment in order to ease the burden on teams and officials alike.

[Steve W]

Ah, the old pneumatics problem. I guess that the easiest way to answer Rickertsen2's question is : It is a rule. That's it. There doesn't always have to be a reason for it. We don't always know the reason for it. We don't always agree with it.

That being said I will agree that something should be done to open up a few questionable rules with pneumatics. The problem may be that FIRST doesn't have the resources at this time to tackle this type of rule change and it is better to err on the safety side (Don't jump on this safety comment) than to have a perceived accident.

[Al Skierkiewicz]

For my two cents, the rule about SLU 70 connectors is just wrong. SUA is a family that is the same but a better fit for rookies to use, wire, solder. Veteran teams should be ble to use a better crimp or solder connector as they see fit. The SLU is used for specific purposes and is not designed for shipboard use. Translated that means it doesn't work in environments that move. Teams that have trouble soldering the SLU would have a better chance with the smaller terminal.
Another rule that drives me crazy is wiring to valves should be allowed to be the smae size wire as the valve is supplied with. In most cases that is #22.

BTW for rookies reading this thread, the Guidlines and Tips document should be required reading for all rookies before touching a tool.

[Bill Beatty]

Remove all restrictions on the manufacture of spare and replacement parts. I mean true spares that do not change the form or function of the robot. It would help hold down costs and be more like the "real world experience" in sparing up for the next scheduled campaign.

"Mr. Bill" Beatty

[meaubry]

Eliminate the quota on the number and kind of motors or pnuematic actuators you can use - let the battery, storage container & pump, along with the overall weight define the allowable number. Each design (team) would need to find the appropriate balance between available power and usage.

[ChrisH]

Originally Posted by Tristan Lall

Having dealt with the chaos the pneumatics cause at inspection time, I think there's a need for some simplification of the rules.

Rickertsen2 pointed out that there are a lot of other pneumatic devices that are safe, cost-effective, widely available and useful. As simple a measure as permitting anything from within the Bimba general catalogue would allow for a substantial variety of new capabilities for the robots. On the other hand, if FIRST tends toward Dave's opinion that sometimes there is too much variety in the types of off-the-shelf mechanisms permitted, it would be a simple matter to scale down the rule to permit "anything from pages [some range] of the 2005 Bimba catalogue". In either event, the arcane, arbitrary pneumatics rules need some readjustment in order to ease the burden on teams and officials alike.

On the other hand I don't feel like the inspectors should have to memorize multiple pages of the catalog to be able to tell whether or not a cylinder has been modified. Modification of any actuator increases the risk of failure. Failure can have dramatic consequenses and lead to injury or death. There was at least one case I know of where a team modified a clinder in a way that was potentially hazardous. It made it through two inspections before being caught precisely because the next inspector down the line was intimately familiar with the cylinders and what they should look like. The modification was done so well that it looke like the cylinder belonged that way.

By limiting the types of cylinders then people who are not pnuematics experts have some chance of catching these things. But then I'm from the Dave Larery school of thought.

BTW I do think the rule about having to use the FIRST pnuematic tubing is a little rediculous. I'd say any tube or fitting with the required pressure rating should be OK. One team managed to make their own coiled tube by heating the kit tube. You think that didn't void the rating? but it was technically legal even though it would have been better for them to use a tube that was made that way and wasn't.

[Ken Patton]

Originally Posted by dlavery

I think that we should look for potential rules that can be made MORE restrictive, and scale back the "almost anything goes" philosophy that has become associated with the robot construction rules over the past several years. I believe that this philosophy has lead to a lot less true creativity and innovation in the robots, as teams have just gone out and bought solutions to design problems rather than creating solutions from a kit part that was never intended to do the job for which it would now be used. I would be all in favor of adding more restrictions back in to the robot construction rules to bring back some of the real creativity that every team displayed during the early years of FIRST.

-dave

I have to disagree. The type of creativity that gets applied when a team is coming up with a new use for some existing piece of hardware or software is different than the creativity required to successfully implement some new design concept. At the risk of being a bit flippant, I would call it "junkyard engineering" versus "real design."

Not that JE is unimportant. We all do it! Its fun, cheap, and fast.

As someone already mentioned, the unrestrictive type of rules would not prevent teams from taking off-the-shelf items and creatively using them.

But... the restrictive type of rules would prevent teams from implementing great NEW ideas, because presumably there would be material or content limitations.

Take for example, the omni wheel. Some might think that AndyMark pioneered its use in FIRST because they are the ones who make it easily available to us all. But before AndyMark, there were teams that concepted and designed their own. I would suggest that Team 67's use of their own omniwheel design in 1998 was due to the relatively unrestricted nature of the rules back then (ignoring the fact that even then the rules were relatively restricted compared to today). If teams were given a choice of only using wheels from a certain source or kit, would any of us have the chance to learn to deal with scrub by designing something new?

The above might be too restrictive of an example, but hopefully it gets the point across.

What was more creative: Beatty's use of a bucket from page xyz of the SPI catalog for the base of their detacheable skewer in 1997, or the concept of a detacheable skewer?

My vote is for allowing teams to create something from nothing. I occasionally tell people that the magic part of engineering is the ability to make something from nothing. Making something from something-else is not as impressive in my opinion. It is not as inspirational. And (again my opinion) its all about the big I.

Ken