Thoughts on the new AM14U 2014 KOP Drive train?

[Qbot2640]

Originally Posted by Shu

I'm sorry but we haven't got a chance to look at this in CAD yet but has anyone looked at making a square chassis by cutting ~2" off each end. I am sure this will require new belts but are the front/rear axle holes available for this. This keeps the front and rear wheebase the same.

Yes - front and rear axle holes are available for removing two inches on each side (front and back). This would result in the closest six wheel "long" configuration available without drilling new axle holes, and would give you a center drop. We examined this last night, and decided to remove one inch from each, thus using the "middle" of the three available axle holes, and ending up with a slightly longer that square bot.

Also worth noting: The instructions produce a bot that is still 2 inches under the maximum perimeter size (either configuration)

[jblay]

Has anyone put together a CAD file of the square version of the drive? I feel like that could be useful to a lot of people that are thinking about the square option...like 694 perhaps.

[Canon reeves]

My team choose to build the long configuration because we determined that the wide base would be very tipsy, especially when driving defense, and the long chasis would be better for defense because its longer and the way we play defense. One thing about the long base is that you can not directly feed because the frame is 23 inches wide and the ball is 24, but with our strategy it worked out perfect, we are planning and doing basically the same robot as team O-RYON did for their ri3d.

[Ian Curtis]

Originally Posted by jblay

Has anyone put together a CAD file of the square version of the drive? I feel like that could be useful to a lot of people that are thinking about the square option...like 694 perhaps.

We haven't quite got it in CAD yet, but we did already build it. You just use the long belts on one side, the short belts on the other, cut off the part of the rail that sticks out, and cut the cross-braces and long churros to what you desire. We can't count and ended up at 27.5x27 though. We used a bandsaw to cut down the rails, and our manual mill to cut out one notch where the edge rail and back rail intersect, but you could use a bandsaw for that too. Went together lickety split, hopefully driving it around tomorrow.

Unfortunately I don't have a good unobscured picture of it, this is the best I can do.

[AndreaV]

This year at the 2nd annual quick build that 610 hosted a dozen AM14U chassis were up and running by 7pm on the Saturday of kickoff. Last year we had only 1, with a vast majority of them ending up at the electronics and programming stage.

The frame is LIGHT. I am a bit envious. the churro is a dream to work with, the front and back rails are super rigid. Having used direct drive last year on our custom frame, I can really appreciate what you guys have done with the center wheel/gearbox. The flanges at the bottom for the electrical panel makes drop in belly pans really easy. The belts center to center was BEAUTIFUL I drooled.

A few teams assembled it incorrectly, and it was surprisingly easy to disassemble and flip the parts around. even with all the churro contact points, I can see wheel changes and drive train maintenance being a breeze. Oh wait, belts, what maintenance?

Now the bad:
I really really really REALLY wish the inside plate (as in the ones the gearbox is mounted to) had a flange bent on the top to match the one on the outside, making the inner and outer rails the same height.. this would allow upper structure to be easily mounted across the top.

One of the rookie teams put some thin wood along the top as a sleek cover. Unfortunately, with a 1/4 wood electrical panel, the cover was right over top the victor fan. this caused them to pop a mosfet on the victor. this is not at all the fault of the chassis, they learned their lesson, but i could imagine other teams having a similar experience. with a flange on the inside this would be impossible as the fan would run into the cover/structure. The unbent flange lends itself to wood very well, but it makes attaching box tubing significantly more difficult.

So in closing really my main complaint is the lack of flanges all around. everything else is leaps and bounds better to the C-base of yesteryear. Lets never look back, EVER.

[brianbond]

We decided to go with the Versa Chassis for our rookie year this year. We built the Kit Bot also just for fun as some of our students already have experience in FIRST. It seems to be a solid bot from what I can see. The only thing I would say about the versa chassis is you need to Mill the slots and I am not sure if you have access to a Milling Machine being your first year and I have not seen any posts about that. We have CNC access and that is how we are milling our slots. If you have that access, or even a manual mill with some experience, I would say go for it. Keep us all updated as to what you decide!

[AlecS]

Originally Posted by brianbond

The only thing I would say about the versa chassis is you need to Mill the slots and I am not sure if you have access to a Milling Machine being your first year and I have not seen any posts about that.

If you are using the VersaBlocks, no machining is required. We recommend drilling a 1.25"-1.5" hole with a hole saw in the tubing. All of the location and strength is done with the VersaBlock, the hole in the tube is just clearance. During Build Blitz, Team Copioli used a 1.25" omni bit to drill the holes, this worked excellent.

[TD78]

Originally Posted by Ian Curtis

We haven't quite got it in CAD yet, but we did already build it. You just use the long belts on one side, the short belts on the other, cut off the part of the rail that sticks out, and cut the cross-braces and long churros to what you desire. We can't count and ended up at 27.5x27 though. We used a bandsaw to cut down the rails, and our manual mill to cut out one notch where the edge rail and back rail intersect, but you could use a bandsaw for that too. Went together lickety split, hopefully driving it around tomorrow.

Unfortunately I don't have a good unobscured picture of it, this is the best I can do.

How is the front-to-back rock in the chassis?

[TerryS]

I called Andy Mark this morning. If you want to make a square configuration by cutting two inches off of each end of the side plates and placing the wheels into the pre-drilled axle holes two inches in from the long configuration holes they recommend buying the 160T, am-2266 belt. This will give you equal wheel spacing.

Andy Mark hasn't tested this configuration yet, but they plan to soon as they've heard that a lot of teams want to be square this year.

[Dad1279]

Originally Posted by jblay

Has anyone put together a CAD file of the square version of the drive? I feel like that could be useful to a lot of people that are thinking about the square option...like 694 perhaps.

28", 4" vex wheels, sprockets, and Ball Shifters:

[Ian Curtis]

Originally Posted by TD78

How is the front-to-back rock in the chassis?

Not much. Guess I may have made a fool of myself assuming 1/2 of what was there in the long config would be enough. Software team spent all of today battling gremlins, so no report as to how it actually drives yet. Trying to turn it by hand on the carpet, seemed to me like there was quite a lot of scrub. May end up as an opportunity for the kids to get better at assembling and disassembling the AM14U.

[seanrobots]

We like the versatility of it

[Nick Lawrence]

All,

We here at AndyMark have been following your discussions about the AM14U chassis. We wanted to share a quick video of you demonstrating the AM14U in both long and wide configurations, showing their maneuverability under weight loads simulating a fully loaded robot, on carpet. The video is here.

Enjoy, and keep the feedback coming!

-Nick

[BrendanB]

So far I think its a very decent chassis and for our previous three years I could see us using it with a few modifications. This year we are still up in the air as to what we should do.

One portion I'm not a huge fan of is modifying the kitbot to more square and even wide configurations. It is pretty straightforward to do but making several cuts on each side rail and re-drilling several holes isn't something I'm super excited about. There are a few other issues that I'm not a huge fan of like mounting the gearboxes we want to use and same for the wheels we want. Its all possible with the AM14U just some areas require more machining work and others involve using more parts whereas I would prefer each wheel/axle be identical for fewer parts and increased reliability.

I think we will opt to have our own 1/8in. side plates CNCed to tailor to what we want along with moving from belts to chains. Plus several other changes but the DT as a whole is still in design mode.

Overall I think its a great chassis but at least for our team we feel it is harder to build/modify to our liking compared to the C-Channel systems from previous seasons.

[jeremylee]

If we had seen both the kit and VersaChassis before signing up for the kit, we'd maybe gone the VersaChassis route. However, AM14U is growing on us as we work with it and we will likely use it for this year.

I agree about making it easier to change sizes beyond long and wide. I imagine an "upgrade" available with some different belt lengths for some additional sizes from Andymark wouldn't be too hard.

I also feel a 2nd 500EX hub on each size is a good upgrade is you are going 2 speed for strength.

One other concern for us is the difficulty replacing the center wheel. Looks like the best way would be to pull the side off, but that would require a lot of work at a regional. Replacing the end wheels shouldn't be too hard. 8 wheel drive option gets around this in long config.