AM' swerve modules
 

So Ive been thinking(for awhile).....

Why has'nt AndyMark come out(developed) with a swerve module?

Other than the obvious manufacturing difficulties(and costs..etc..)

I know this would help alot of teams out.....
And I think it would be a great seller;)



Just a thought:o

Re: AM' swerve modules
 

Somethings are better left off andymark. If AM came out with a swerve module then teams would learn little from putting it on their robot. In my opinion the less items used that are right off the shelf the better. If that is how most robots are built, what lessons are learn building it other than wether the product works or not. Just a thought.

Re: AM' swerve modules
 

There are many teams that don't have the ability to make their own serve modules. I think this would be a great way to even out the playing field.

Re: AM' swerve modules
 

There's always the option "some assembly required" Sell the components for the module, but not the assembled module itself, possibly a swerve drive kit, that way students are still assembling and learning how everything fits. However, I do agree with you, but it does teach teams to use the resources available to them...

Re: AM' swerve modules
 

At least to me, an entire swerve module is too much of a completed mechanism to sell directly to FRC teams.

A gearbox or wheel or hub or sprocket is fine, as there is still a lot of thought left to the teams on how to apply it to make it work. But selling entire (or even partial) mechanisms or assemblies takes too much thought away from teams and begins to turn FRC into a "plug and chug" competition.

Swerve is one of those things that you really need to have the resources available to do it right, from the wheel modules, to the frame, to the software to control it. If your team really wants to do swerve but doesn't have these resources, recruit a local machine shop, company, university, or fellow FIRST team to help you, as you'll learn a lot more in the process.

That being said, there are plenty of very successful robots in FRC that use plain 'ol skid steer drive trains.

Re: AM' swerve modules
 

After doing our first swerve/crab drive this year.
The easiest part of this type of drive is the module.

The real difficulty is in the control of the modules.
Figuring out how to mount the proper type of encoder and using them to allow the operator to use the drive efficiently is the toughest part.

We will continue to refine both our module design and our control algorithms.

As far as AM making them... I am not sure if this is a good idea.
For purely business reasons.... I am not sure how many would really get sold.
They would also be pretty pricey...

The other issue is "leveling the playing field" ... I guess the question is where does it end? Should we all just be bolting together AM or other pieces and making a robot?

We learned a great deal this year by designing and implementing this type of drive. At Atlanta we saw several different versions... some were very simple and worked very well.

In the pit next to us we made new friends with team 1927 from Biloxi Mississippi... they had a really nice, simply made swerve module very similar to ours that they had come up with. Ours was more complex and required CNC work... there are many designs... all of them worked...

If anyone wants our design they are welcome to it. We will make it available to anyone that asks.

I do make the warning though... the control is the hard part.

Re: AM' swerve modules
 

I agree with what Art said about swerve being over the line of what I think teams should be able to buy.

In addition to that I feel that AM carrying a swerve module would lead to almost as many robots with bad or non-functional drivetrains as robots with improved drivetrains. There is a lot more to building a swerve drive than just the design of the module. I think that AM carrying a swerve module would lead many teams to think that swerve is now "easy" and try and implement it without having or devoting the necessary resources to make it effective.

EDIT: Looks like Bob beat me to a very similar message

Re: AM' swerve modules
 

When you talk to Andy it seems like drive gear boxes are even hard to sell to FIRST teams as far as providing technical support for them. I have said the same thing too many times that the hard part about a swerve is controlling it. As far as AM selling them, they do just fine without them and have many great products. I don't see any reason for them to go and start selling swerve modules, when many of the teams that use them have enough machining capability already to make them. Swerve modules are custom machined parts the kind companies charge a lot of money to machine, people would be paying an arm and a leg if a company was out there selling swerve modules. Then, there is the issue of having to have x amount of them on hand without even knowing if your going to sell them if you decide to offer them. In conclusion, I am sure AM could design a swerve module but actually having a big enough market to sell them is the question. Mr.O'connor and Bob all have good point about this leading too not as many good robots also, case in point teams using the AM mechanums when they first came out.

My two cents,
Drew

Re: AM' swerve modules
 

good opinions' guys!

I was thinking along the same lines too..

maybe not the entire module, but more like having just the "box"

I agree that This may not be a "great" idea..just something that COULD be nice for teams that have limited machining capabilities....

Re: AM' swerve modules
 

I too agree with Art. Eh, it would be kewl to have the swerve modules for sale but think about the cost and the effort to do it. Maybe the housing of the swerve/module. I like their current line of parts.

Re: AM' swerve modules
 

Swerve is an advantage. This year my team found it be quite useful to have in tricky situations. Swerve bots, when turning or moving can more easily evade. When your wheels are actuated, it helped keep traction as opposed to skidding.

That said...most years I have observed that swerve doesn't offer as much of an advantage as it appears. I have seen "cool" swerve bots put to shame by skid steer bots with experienced driving. Swerve is also generally a little heavier than skid steer. This can take away from weight on the manipulator. Remember, you win when you score, and you score with your manipulator, not your drivetrain. Swerve is creative however and can win lots of awards. If people had modules made for them, they likely wouldn't get an award. Swerve is cool to toy with in the offseason, but if you look at the winning robots, they very rarely do they have swerve. (yes...Wildstang you are amazingly awesome). All I'm trying to say is that swerve will not really help all that much to make someone better, you are pretty much just as well of with skid steer. Teams with skid steer are no worse off than teams with swerve, so honestly I don't think giving people the ability to do swerve will help the playing field be evened. Swerve is a good learning experience when building and it gets awards, but the competitive edge just isn't really there. True swerve can do a little more than skid, but it can't really do as much as it appears to. (sorry for this rant, don't mean it against any teams with swerve, as there are some very good and competitive teams with swerve, it is more of a personal opinion. It's more that my team has this idea that our goal is to make as "cool" and complicated bot as possible and I think the coolest robot is the one that is simple and wins). Honestly, I don't think it would be a bad idea if AM made swerve modules, I think it'd be kind of cool to give more teams the option of doing swerve.

Re: AM' swerve modules
 

It would be great, but most teams end up finding a veteran team and asking them for help or fiinding a local sponsor that can do the CNC work for them.

Re: AM' swerve modules
 

If AM were to sell a complete swerve module...

...Would it not fall under the following?
(emphasis mine)

Granted, you'd need 3-4 modules, but I could sure point out that all you need is one for steering...

Why are the AM gearboxes, etc, not violations of this? Because you could use a Supershifter or a Gen 2 on your arm or intake. It would take more engineering, but it can be done. Gear ratios still have to be calculated.

If AM sold a crab module, assembled or not, the team would bear the responsibility of showing that it had been designed into the robot's design. After a bit, teams would stop buying because of this (or because they prefer to make their own). Not exactly a profitable business venture.

There are two further things that I would like to note: 1) the rules may change for next year and 2) this paragraph has been the same for just about as long as I can remember.

Re: AM' swerve modules
 

good point Eric......

that could be a problem:rolleyes:

Re: AM' swerve modules
 

Any team that says they simply don't have the resources to be able to make a swerve drive is deceiving themselves. This year the ausTIN CANs, team 2158, made a 3-wheel swerve drive completely out of 3/8" lexan, using a band saw, drill, and a jigsaw. It was plenty sturdy for this year's competition, and the modules never gave us any problems, it was the motors that we were using (i.e. back to the control part). We decided to use the two FP's and one BB motor for the drive, and the Banebots caught fire 4 times throughout the competition. Over the summer, we're redesigning the system to use CIM's with continuous rotation (this year's modules only rotated 270 degrees), also primarily out of lexan and made completely by hand, that can stand up to forces of a 120-pound robot reversing direction at full speed with high-traction wheels on carpet. We already have a design, and all of the parts look to be checking out. It CAN be done no matter what team you're on, and with what resources.

I will reemphasize the issue of control, also. We steered the modules independently with the two Nippon-Denso window motors and one globe motor. The window motors jammed many times before we could get them aligned correctly, and we had to replace the globe motor when the mounting screws sheered off and jammed themselves into the holes of the gearbox. To measure the angle, we had a 10-turn potentiometer on each wheel that meshed to the module with band saw-made 3/8" lexan gears (a small one for the pot shaft and a large one as the entire top part of the module). By not declaring the location of the pot inputs correctly, we ripped wires off the robot several times when the modules started rotating out of control. Not to mention, when centering the modules (take the gear off the pot and turn it slightly until the module rotates to center, then center the pot again and put the gear back on), my hand has been sucked into the robot. There was much blood, and I still have a scar. That gives you an indication of how precarious having a ton of moving parts on your robot can be. Controlling swerve drive is not all about trigonometry.

The point of FIRST is not to have a level playing field. There are always teams out there with way more money and resources than your team ever will. The point of FIRST is to learn something and utilize the skills that your team DOES have to beat those teams. Selling a complete swerve module would probably detract many teams from their skills and make them think they would win if they just used swerve drive. If it's not in your repertoire, your team should either focus on getting it in your repertoire (i.e. LEARNING how to MAKE swerve drive), or focus on something you're already good at (like driving regularly).

Re: AM' swerve modules
 

I'm all for it.

We should try to raise the floor, not lower the ceiling.

Re: AM' swerve modules
 

ugh time to pull out the 6wheel swerve actuated center drop cad files
didnt want to resort to this :P

Re: AM' swerve modules
 

I'll just grab that 6WD mecanum drive that's been posted... might make it rigid, though.:p

Re: AM' swerve modules
 

Have you seen the new FP Planetary Gearbox?

Re: AM' swerve modules
 

I would say that something like this could have its advantages. The problem of making a specific swerve module does present itself, this is a little too specific to really sell for a first competition. However, I could easily see AM selling a generalized turret module because whenever I would thing of making a turret, or swerve this was always the area that I got hung up on.

Don't get me wrong, i'm never a fan of standardizing any piece of the robot. I always built a custom frame when I was a student on a team, this was one major reason that I was never a fan of the kit bot. I was always disappointed when I walked into a team pit to find that they had used the kit frame cause I didn't get to see anything new.

But to see the other side of the argument, I've been working on computer vision and specifically motion tracking on a mobile platform. The overall idea of the algorithms behind this task (ie. optical flow, image segmentation) are well within my grasp as a sophomore in college. However, I could never apply the linear algebra or the mechanics of the algorithms behind these, which is why I turn to libraries like Opencv which has the mechanics already finished for me. Yes I could learn a lot from writing my own mean shift segmentation on an image, but if I use the library I can write some very cool code much faster. In the same way, if AM offered a swerve module a team could get a working robot much faster and perhaps be able to implement some very cool control algorithms.

Re: AM' swerve modules
 

One thing that hasn't been mentioned is actually interfacing such a product with team designs. How would such a module be designed to be mounted on a team's frame, given the great variety in design and construction techniques between teams? I don't think it would be possible to make a module that fits the size, cost, and mounting constraints of enough teams to make it a commercially feasible venture.

Re: AM' swerve modules
 

The thing with that paragraph (and also the one preceding it in the beginning of 8.3) is that it's unreasonably vague. I suspect FIRST puts it in there as an obstacle to those who might attempt to bring such a thing to market, and as a warning to teams about such products, rather than because they think that it's enforceable with any sort of consistency. (It's not even a numbered rule, which makes it doubly unclear how it's supposed to be enforced....)

When the test is effectively "I know it when I see it", the inspector doing the inspecting should be allowed to be flexible about the interpretation. Generally speaking, the most equitable way to enforce loosely- (or worse, poorly-) constructed rules is to give the teams the benefit of the doubt.

Plus, even if a COTS assembly was intended for use in FIRST competitions, and provided a complete solution for a major robot function, and was thus impermissible, it could still provide a function that could be used in many different ways, rendering it acceptable. There's no priority given to one condition or the other, so which is it: legal or illegal?

If the "rule" isn't a rule (in the usual sense), is blatantly unclear, and enforcing it requires a judgment of the designer's intent, I don't see any way that this can be reasonably and consistently applied over the range of possible COTS parts. That's different from being a safe bet, however: FIRST may think that there's no confusion, and act accordingly.

The economics of the situation look good, though: charge $250 per module, and sell some accessories that can be arranged in several different configurations (like different motors, different wheels, or mounting strategies), and you've got a winner.

Re: AM' swerve modules
 

So, why aren't the andymark mechanum wheels against the "spirit of the competition" but a swerve module is? After all, by using AM mechanum wheels teams learn nothing about machining, CNC usage, roller molding, etc.
Same thing with the gearboxes.

(This isn't directed at anyone in particular, just a general question)

At some point you have to draw a line, what's the justification for putting it here? And what other things are prohibited by the same logic?

Re: AM' swerve modules
 

General answer: A set of mecanum wheels is not a "full mobility system". A set of swerve modules could be, or not, depending on how complete they are. A gearbox is not.

Using the examples in the rule is probably a reasonable way to evaluate it.

Re: AM' swerve modules
 

I can pretty well guarantee that a set of swerve modules isn't going to be moving anything without a frame attached to them and motors and gearboxes to spin them. I'd say under the current wording individual swerve modules would be permissible, especially if the wheels themselves are not included. (which I wouldn't expect them to be.)

As for rather it's in the spirit of FIRST I say it really just depends on the team. Some teams will have the resources to build a swerve drive and others will not. An Andy-Mark solution would not be the best choice for everyone anyways, so there would be plenty of teams building their own swerve drives. In fact I would hazard a guess that most teams that currently build swerve would keep building their own since they have it pretty much down pat.

Currently you can basically buy all of the components you need from AM to build a robot without doing any machining.(Wheels, gear boxes, and kit frame.) So I don't see the harm in adding a swerve module. In fact, I can see the argument being made that having such a thing available could be better for creativity and the design process. It adds another area of thinking into design. "Do I invest the time and effort into designing and build a subsystem to my exact specifications, or do I spend money, save time, and attempt to use an off the shelf product not specifically designed for my machine?"

Whether it would be economically feasible for AM to do it is a whole other story. Can't imagine swerve modules would be cheap to produce.

Re: AM' swerve modules
 

I'm all for AM to sell the swerve/crab/snake drive kits. I don't think that the basic kit would fall into the "COTS for FIRST only" there are lots of other roboteers that buy stuff from AM.

A few posters pointed out that the hard parts are not the swerve drive but the mounting onto the robot and the control system, and I agree. I don't see anything wrong with buying a part to make some robot assembly go faster. It's how its done in the "real world", COTS over custom, COTS wins a lot of the time.

When we first started out we traveled to Canada each summer to hand dig 50 tons of aluminum ore and 100 tons of coal. Our grant from Alcoa gave us access to their smelters. We turned our coal into electricity and used it to smelt our ore into a thousand pound aluminum billet. We then machined the billet into the parts we needed for the robot. With a small team this left little time to do detailed design or control systems.

Since then we've relied on suppliers like AM and McMaster. This has freed up lots of roboteer time to work on design, assembly and control systems. And it's paid off, our robot this year did not need any major repairs in the pits and we won an award for our design and control system.

We did look at swerve drives for this year and instead built our 6+1=3 drive that worked very well. But it would be nice to have a swerve drive option that we could bolt into place and spend the more important time of integrating it into the system.

Re: AM' swerve modules
 

Let's think, for practicality's sake, about 'what IF' AndyMark DID make a generic swerve module. Let's think for just a second about the risk involved. AM put their shifting transmissions out, and for a time they sold well...that is, until 2009 rolled around. AM learned this year just what kind of impact niche products have on their ability to roll through inventory in FRC. How many teams bought Super Shifters this year? What if FIRST releases a game in the next couple of years that negates any need for a crab/swerve module in the future? The risks are great, whereas their efforts could be spent in other areas that FRC teams need. I for one am a fan of the hex bearing they recently put out ... such a small innovation that opens up a world of design for custom gearboxes built from COTS AM parts.

Besides, teams need to be able to create the partnerships necessary to manufacture something as complicated as a crab/swerve module. If you venture out, 30, 50 miles even just to find the right CNC'er or Waterjet facility then that's a relationship you'll use in other aspects of your bot -- not just the drive train. I say this because recently found a guy with a waterjet who's 20 miles away who we will negotiate a deal with for next year's bot. It took years to find him, but we finally did. Had we been given the items we needed for that particular robot piece this year, we wouldn't have even bothered looking for that relationship.

Finally, upon attending 118's crab module conference in Atlanta, then seeing the multitude of very different designs that were in Atlanta (111, 118, 88, 548, 1885, and several others), one would have realized that there is NO one-size-fits-all solution to crab design. There are too many design parameters, too many external systems effected, and on top of that many decisions have to be made for control that also effect how the crab module is designed in the first place.

Re: AM' swerve modules
 

There are a lot of ways to make frames too, yet AM and IFI each make a single frame kit that many teams use successfully.

The ability to design and fabricate a coaxial swerve drive is beyond most teams, and could probably be done by a company such as AM so that it's affordable, efficient, and somewhat universal. I expect that they would be open to suggestions for design parameters, hopefully from teams with experience with this stuff. It could be designed to be sort of universal, with a standard 6 hole sprocket hub for the steering, and a standard 1/2" keyed shaft for the drive, and allow the users to install their choice of standard sized 6" wheels with the standard 6 bolt sprocket pattern, or a common hex sized hole. The mounting flange could be designed to be easy to adapt to different types of chassis, including the kit chassis.

I've heard that Andy Baker spends a lot of time sitting around doing nothing, so this would be a great project to fill up a small portion of his free time. :)

Re: AM' swerve modules
 

I have seen (very effective) swerve modules made with a single piece of 4" square tubing and a drill press. The assertion that you need a full machine shop to make a swerve drive is false. Yes, it might be prettier, lighter, and more efficient with the help of a CNC, but isn't that true of any mechanism in FIRST?

Re: AM' swerve modules
 

A few years ago, a team or few and a company were looking into pairing up to sell complete, disassembled tank tread drive modules to teams without a frame. This very issue was brought up, and as far as I know, the module still isn't commercially available to teams, even though the debate was never officially settled. Just sayin', there's different ways to look at "complete solution".

Now, if AM sold the parts for a swerve module, well, I can sure think of some uses for bevel gears or a swerve module's box section that aren't in the drivetrain, say, in an arm mount.

Re: AM' swerve modules
 

I would like to bring to the attention of this thread http://www.team221.com/ which sells a full mobility system specifically designed for FRC teams, I know of at least 2 teams that used it this year. Does this violate any specific rules or is it a COTS item? Keep in mind this was used THIS YEAR in competition (as always rules change)

I would feel an AM swerve module would fall under the same category as an AM gearbox, who says I have to use a swerve module for a drive system? Maybe I want to use it for a turret or as a roller I can change the direction of.

And besides, as it stands right now you can build a robot from the current KOP with some wire strippers, some allen wrenches, some wire, and a couple lengths of chain. Arguing that it would make it so students don't learn anything is pointless, that fear, if valid, has already come true. (Im not getting into the debate of if it is valid or not)

Re: AM' swerve modules
 

I would think that it would be ok for AM to market a swerve box. But not a full system.

If just the box was marketed, then teams would have to still find all the other parts involved in a swerve.

1) Motors (choosing between F/B Steering, L/R Steering, Individual steering, all together steering, and so on.)
2) Sensors (Teams would NEED to find their own sensors)
etc.

Just the box would be fine, but AM would have to release the CAD's so that teams could design mounts.

For those people that say that swerve mounts have to be complex, look at our bot. We have two square lazy susans from McMaster per swerve module. (Total of 8 on the bot) That is it. No fancy plastic rollers or CNCed parts for the mount.

Re: AM' swerve modules
 

:) Jim - it was great to finally meet you in Atlanta.

Using this same logic, we might as well have all teams fabricate their own screws, since all of the students don't know how to use a lathe well enough to cut threads.

There have been hundreds (maybe thousands) of students who have used AndyMark shifter gearboxes and holonomic wheels and have been inspired. Many of them see what is available and create their own better systems. To say that these students are learning nothing is insulting.

I am definitely in favor of helping get swerve modules available to teams who do not have the engineering or fabrication resources to do so. We do not have concrete plans on doing this currently, but we are looking to help another company provide these sub-assemblies to the open market.

One of the nice things about operating AndyMark is knowing that many of our parts are used outside of FIRST. We sell gearboxes and wheels and TekTrays to many places outside of the competition robotics market. To tell us what we can and cannot sell is silly and short-sighted. I think that it is wiser to suggest limitations on what is allowed on a FIRST robot as opposed to telling a privately-owned company what they can and cannot sell.

For instance, we are looking to sell fully-assembled drive bases soon. Customers outside of FIRST are asking for this, and we will sell these. Will these be legal for FIRST teams? probably not... but that is not for us to decide.

I appreciate all of the comments in this thread.

Sincerely,
Andy Baker

Re: AM' swerve modules
 

Note that the Universal Chassis system sold by my company is in fact a "kit," does require assembly and is not supplied with motors or transmissions of any sort.

Frc27, frc696 and frc910 used the chassis with great success this season!

Ironically all three teams purchased a Universal Chassis because it was similar, or identical to assemblies they already manufactured or designed, not because it was a game breaker that gave them an unfair advantage.

All feedback has been very positive to date.

Re: AM' swerve modules
 

Thanks Andy lol:D

I was kinda dissapointed that I dident get to meet you in Atlanta, but i got to talk to alot of other great people;)

Re: AM' swerve modules
 

It's not so insulting when you realize that my post was actually a question and not a statement.

The part of my post that you didn't quote:
I didn't say it was a good thing to draw the line here, or that it should be drawn somewhere else. I fail to see how this legitimate question is insulting to anyone. In fact, I support the development of these "swerve boxes".

Re: AM' swerve modules
 

Due to so many different variables when making a swerve and how there is a varying amount of complexity from one to another I don't think it would be a big deal if AM made a simple swerve module.

In regards to my quote, I've never seen this on the site before, are there a lot of other things like this on AM that are away from the normal pages of the site?

Re: AM' swerve modules
 

I stand corrected, 3 teams :)

I do not believe that swerve, no matter how well built, is a game breaker. Especially if it were to be supplied as a "kit" similar to the Universal Chassis system. Most teams have more than enough brains to design a swerve system, a lot of us just do not have either the man power or the tools to do it. It isn't a learning gap, it is a ease of manufacturing gap.

Re: AM' swerve modules
 

Plus, as was stated before, it merely provides another part of the design process. Build your own or "settle" for what someone else has made. I only say settle because chances if AM did make a swerve module it wouldn't fit the needs of everyone who wanted swerve. Different gear ratios, different dimensions, and other such things. So you have to decide if you want to design your own module to perfectly match your criteria, or go with something that doesn't match perfectly, but get's the job done, and saves you time.

It doesn't remove anything from the design process, it just adds another question.

Re: AM' swerve modules
 

I for one would find it very useful if AM or another company sold some Swerve modules or components thereof. We purchased the 8" mechanum wheels a couple of years ago and never used them in competition, but there are an important part of my class and robotics curriculum. Currently we building our third robot using those wheels and has nothing to do with a competition robot. They have provided my students with excellent learning opportunities since we lack the machining resources to make our own. The same would be true of the swerve modules. They would provide an excellent opportunity for my students to learn about that type of system whether or not it was used for a competition.