KOP Drivetrain vs Voucher
 

Hopefully not discussed extensively somewhere else:

What is your team deciding on? Drivetrain or Voucher? and why.

Re: KOP Drivetrain vs Voucher
 

Voucher, we only ever used the KOP Drivetrain once and have found a custom drive that suits our needs so the voucher just makes more sence

Re: KOP Drivetrain vs Voucher
 

We made a BOM and figured out that you could budget 2 custom shifting gearboxes(without raw materials) and enough sprockets to build an 8wd with the voucher. We will be using the voucher for sure.

Re: KOP Drivetrain vs Voucher
 

We've never used the Kitbot, and if we want to, we have plenty already. Voucher for us.

I think if you are at all unsure of what you're doing in the drivetrain department, it's best to play it safe and get a Kitbot you might not need. Kit frame material is very useful for other purposes (appendages, making a cart out of the 2010 kitbot, etc)

Re: KOP Drivetrain vs Voucher
 

I think we're going with the kitbot... we've used it all but 1 year so far, and we don't really have any drive train plans that would be any better. Having the option though... it's something we'll be looking into for future years!

Re: KOP Drivetrain vs Voucher
 

KoP.
Even if we don't use the KoP on our chassis, it's good structural material to have - even if for offseason projects.

Re: KOP Drivetrain vs Voucher
 

We're definitely taking the voucher, but we will miss having the kitbot. We've used it in the past as the "demo unit" for our robot quick build sessions. It's also been a decent drivebase to have around in the first week or so for prototyping/test bed type stuff.

However, that functionality isn't necessary, just more of a nice-to-have, thus voucher.

-Brando

Re: KOP Drivetrain vs Voucher
 

We will be using the Voucher for sure but I wouldn't recommend that for most teams.

I would suggest that at least 80% of the teams out there should use the KOP or "KOP on steroids" and focus their energy on game play.

Re: KOP Drivetrain vs Voucher
 

KOP.

We have never used belts and would like to make the tranistion and we see the new KOP system as a great learning experience for our students and we could implement it into a custom drivetrain. $450 isn't a lot of money to raise to off-set the vouched and we use the kitbot frame as a test chassis a lot!

In future years we may choose the voucher if it is still around we shall see!

Re: KOP Drivetrain vs Voucher
 

We are going with the voucher, we prototyped a WCD over the summer and love it. Also if we need it we have enough materials from the last 2 years to build 2/3 kit bots.

Re: KOP Drivetrain vs Voucher
 

Just a word of warning to those saying "we have old kitbots if we need it", that is fine for prototyping or practice chassis, but may not be competition legal. In the past, the rule has been that a previous kitbot is legal only if it is identical to the current kit version. Since we know for sure that this year's kitbot is significantly different, unless the rules change there is a high probability that previous kitbots will not be FRC2013 legal.

I only point this out in case some teams, especially 2nd year teams, are considering taking the voucher and then relying on a previous kitbot for their chassis or having it as a fall-back option if their custom drive doesn't work.

Re: KOP Drivetrain vs Voucher
 

The old Kitbots are still COTS items. As long as they are unmodified, they would be legal under previous years' rules.

Re: KOP Drivetrain vs Voucher
 

The difference being cost accounting - a previous year's kitbot that is not identical to this year's kitbot would have to be accounted for cost-wise on your BOM. This year's kitbot is "free" on the BOM and doesn't count toward your total cost for the robot.

Re: KOP Drivetrain vs Voucher
 

My mistake, I was thinking of a previous ruling when the kitbots were considered "custom" and were not available as COTS items, meaning they were unusable for future competition seasons.

Re: KOP Drivetrain vs Voucher
 

I probably have to go back and read the exact post, but our team is probably going to be looking at using the voucher. We haven't used kitbot in a while, and with our off season experiments, we're looking at using 80/20 and going to tubing soon. However, i don't know if the KOP includes the motors, belts, or transmissions. I do want to take a look at these timing belts and not having the motors would be a bad day. If the belting system is good and with the new wheels, this kitbot actually looks really good.

Re: KOP Drivetrain vs Voucher
 

As much as my teacher likes the whole new belt idea, I'm pretty sure we'd rather go with the voucher... Depending on the game, we would like to use mechanums this year and make our drive train. Seems like different games require different drive trains, and better maneuverability is always going to be a plus....

Re: KOP Drivetrain vs Voucher
 

256 is going with the voucher. I've been designing a new custom drivetrain that utilizes our steel tubing, so we're super excited to be able to get the $450 to AndyMark. Maybe we'll get to use shifters! :D

Unsure on whether you want the voucher or Kitbot? Here's something that'll help:

Do you have a custom drivetrain that's been proven to work that you've spent a long time perfecting and carefully designing, with all the math and physics done?

If no to any of those parts, kitbot is probably a good idea. Plus, this year it's an awesome kitbot.

Re: KOP Drivetrain vs Voucher
 

Yes, but is it really $450 worth of aluminum?

While it's not my decision, my recommendation has been for the voucher. We DO have a custom drivetrain we've been using for several years that's near perfect and works very well. But if we didn't, Kitbot is a good choice.

Re: KOP Drivetrain vs Voucher
 

We are going with the KitBot. Although we are planning on making a custom chassis over the next few months, we may not be able to get it to a decent level before build season. It will also be interesting using belts instead of chain.

Re: KOP Drivetrain vs Voucher
 

Probably voucher -- we're still debating (and are waiting to see how our fundraising goes this weekend, because we blew our budget last year and need to make wise decisions with limited funds.)

As for the gates belting, it's awesome. We used gates belting and sprockets on our octocanum drive last year and it worked without a hitch.

Re: KOP Drivetrain vs Voucher
 

I'm working under the assumption it's not just aluminum. I'd think it's also the belts, sprockets, gearboxes, etc. associated with the chassis.

Re: KOP Drivetrain vs Voucher
 

I think this is one of the leading incentives to getting the KOP chassis this year over the voucher is the belt drive system.

Re: KOP Drivetrain vs Voucher
 

Every medal 2815 has won* has been driven by a derivative of the kitbot.

So we'll be getting the kitbot.

*Edit: For those reading this later on, that's three gold medals and one silver in four seasons.

Re: KOP Drivetrain vs Voucher
 

We haven't decided yet as the discussion is still going back and forth over the KOP chassis vs what to spend the voucher on. I suspect we may end up with the KOP chassis and the belt drive system for no reason other than it gives us another off the shelf option in case we want it.

Re: KOP Drivetrain vs Voucher
 

SuperNerd, a "new custom drivetrain" really doesn't sound like one that's been proven to work and you've spend a long time designing. Conciser whether or not you're making a smart decision given your own guidelines.

Re: KOP Drivetrain vs Voucher
 

More or less. I'm just saying it's usually a smart idea to know that what you are using works before using it in a build season. The kit of parts was designed by engineers, and has gone through vigorous testing, something custom you design in season may not be as effective, since it hasn't been tested much.

Re: KOP Drivetrain vs Voucher
 

For us the decision was a hard one. We usually build kitbots, so the KoP was the reasonable choice, but we weren't enthusiastic about using belts.
We thought of using the voucher to buy all the raw materials for a chained kitbot but that proved inefficient. We ended up deciding taking the KoP and during week 1 deciding whever we want to use the belts or buy series #25 chains and sprockets.

Re: KOP Drivetrain vs Voucher
 

We're using 1114's "Kitbot on Steroids" modification this year. Within the next month or so we should be assembling a practice chassis with a second control system so we can get some extra driver practice. There may be a few modifications next year to make it work with belts, but it should work fine.

Re: KOP Drivetrain vs Voucher
 

Just curious - why don't you like the belts? They are more efficient than chain, don't stretch, and require little maintenance.

Re: KOP Drivetrain vs Voucher
 

I've always been wary of belts in drivetrains, due to the more stringent tensioning requirements. Chain is much more forgiving of a little slack, and the efficiency difference is negligible for FRC drivetrain applications.

Re: KOP Drivetrain vs Voucher
 

I know... Belts are better, but we don't seem to get along with them.
We're always a quarter of an inch off in our builds (oh, that cursed quarter of an inch), and with belts being unresizable and barely stretchable, that's a big problem for us.
We also have to make changes often, and having to take the entire set of wheels down every time you want to move the belt is a hugh waste of time (not to talk about the mess and nerves the spacers create).

Re: KOP Drivetrain vs Voucher
 

I've popped plenty of chain, but never a belt. Teams afraid of using belts should... outgrow their fear!

Re: KOP Drivetrain vs Voucher
 

Hey, teams using belts are eligible for the Gates Corporation scholarship...

2,000 towards college sounds like a good enough reason to use belts to me.

Re: KOP Drivetrain vs Voucher
 

You express some concerns that a lot of teams encouter when they think of belts. They do have their advantages but your design needs to be solid and your mechanical team has little to no room for error. The smallest amount off creates slack leading to ratcheting. :eek:

However, I am optomistic that Andymark will produce a solid, easy to use system that is easier than previous KOP chassis to assemble and maintain! :)

Re: KOP Drivetrain vs Voucher
 

Team 4183 is probably going with the voucher. We have mentors with drivetrain design experience and access to laser-cut aluminium. Using those resources and a $450 voucher, we could probably design something significantly better than the KOP drivetrain.

Re: KOP Drivetrain vs Voucher
 

Does that require using the KoP belts and/or using belts in the drivetrain, or any belts on your robot?

Re: KOP Drivetrain vs Voucher
 

I'm not sure, but I think that any belts can be used.

Re: KOP Drivetrain vs Voucher
 

I thought only veteran teams could get the voucher?

Re: KOP Drivetrain vs Voucher
 

I believe 4450 is the starting rookie number for this year.

-RC

Re: KOP Drivetrain vs Voucher
 

I thought a "veteran team" was defined as an team on it's 3rd year?

Re: KOP Drivetrain vs Voucher
 

The unofficial sequence:
Rookie (1st year)
Sophomore (2nd year)
Veteran (3rd year or more)

The official sequence, however, lumps sophomores in with the veterans:
Rookie (1st year)
Veteran (Everybody not classed as a rookie)

4183, by the official sequence, is a veteran, and therefore eligible for the voucher.

Re: KOP Drivetrain vs Voucher
 

Ah, thanks that makes more sense.

Re: KOP Drivetrain vs Voucher
 

Use of adjustable (sliding) bearing blocks allows you to easily move/adjust belts...we'be been using belts since 2007 without any problems and love the results.:D Gates has been an awesome, supportive resource and is committed to helping other teams gain the benefits we have seen over the past 6 years.

Re: KOP Drivetrain vs Voucher
 

As far as I'm aware, there are no sliding bearing blocks in c-channels :P
We'd have to wait for the KoP to arrive befor making the final decision.

BTW, I might have not mentioned this, we did have some good experiences with belts (in which cases we did use the sliding bearing blocks), it's the fact you don't have maneuvering room that troubles us.

Re: KOP Drivetrain vs Voucher
 

Not sure what you mean by maneuvering room. Belts/sprockets don't have to take up much room...some teams even put them in their box tubing frame. Do you mean maneuvering room to access the belts?

Re: KOP Drivetrain vs Voucher
 

What he means, as evidenced by his earlier posts, is actually closer to "margin for error". If you don't place your holes right--say, off by 1/4" in a given direction--belts may be close to impossible to get to work. If you can't handle the risk of being off by 1/4" routinely by adjustment in the belt tension or length, then maybe belt isn't the right choice. OTOH, if you can, then it's something to think about.

Re: KOP Drivetrain vs Voucher
 

Sorry for not being clear... Though I want to believe I'm a good English speaker it's still not my native language.

What I also meant is that it's harder to be accurate with belts (for me at least): it's harder to check alignment of timing wheels than that of sprockets, a small point that may and have resulted in hours of stress and puzzlement when things get stuck and sound like they're dying in a car crash. The simile may be more accurate to chains but hopefully the point still stands.

Re: KOP Drivetrain vs Voucher
 

Did I miss something? How do you what this years Kitbot has in it? I did not like some of the extra stuff that was just throw in that we have not used for years but what is so different that every-one is going with a voucher? How money is provideed in the voucher?

Re: KOP Drivetrain vs Voucher
 

Please read here first

http://www.usfirst.org/roboticsprogr.../blog-09-07-12

Re: KOP Drivetrain vs Voucher
 

While the lengths of belts may not be adjustable like a piece of chain, you are by no means left without any way to solve these types of issues.

Belts can be purchased in single tooth increments for almost all types of profiles and pitches. If you know exactly how much you are off in your implementation compared to the original design, getting another belt should be doable. Incorporating a tensioner, even something simple like a piece of Delrin on an aluminum standoff can work as well. You don't necessarily need a spring tensioner, or something thats adjustable, there are ways to get by with relative simplicity.

Of course the simplest way to solve these issues is to measure twice(or thrice) and cut once.
-Brando

Re: KOP Drivetrain vs Voucher
 

The option is now available on TIMS on the right hand side. Be sure to update your selection.

Thanks AndyMark and FIRST for this option!