AM' swerve modules

[gorrilla]

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

[fuzzy1718]

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.

[HighLife]

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.

[Mike Schreiber]

Originally Posted by fuzzy1718

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.

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...

[artdutra04]

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.

[Bob Steele]

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.

[Vikesrock]

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

[techtiger1]

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

[gorrilla]

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....

[Gary.C]

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.

[sgreco]

Originally Posted by HighLife

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.

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.

[R.C.]

Originally Posted by gorrilla

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....

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.

[EricH]

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

...Would it not fall under the following?

Originally Posted by Manual 8.3 Intro

However, COTS items that have been specifically designed as a solution to portion of the FIRST Robotics Competition challenge may or may not fit within the FRC intent, and must be carefully considered. If the item provides general functionality that can be utilized in any of several possible configurations or applications, then it is acceptable (as the teams will still have to design their particular application of the item). However, COTS items that provide a complete solution for a major ROBOT function (e.g. a complete manipulator assembly, pre-built pneumatics circuit, or full mobility system) that require no effort other than just bolting it on to the ROBOT are against the intent of the competition, and will not be permitted.

(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.

[gorrilla]

Originally Posted by EricH

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.

good point Eric......

that could be a problem

[daltore]

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).