907 4 inch IFI Sheet Metal Drivetrain Feedback

Needs more Colson....(Talk to Gregor about that. He'll tell you what I told him)

[ttldomination]

I've often wondered this, but what's the benefit of having the outer rail face flange outwards?

From my understanding, it would only complicate bumper mounting and other minor things, but the benefit is lost to me.

- Sunny G.

[Matthew.Mc]

Originally Posted by ttldomination

I've often wondered this, but what's the benefit of having the outer rail face flange outwards?

From my understanding, it would only complicate bumper mounting and other minor things, but the benefit is lost to me.

- Sunny G.

I believe that having this flange face outwards, makes it easier to access the wheel assembly. If anything were to go wrong out on the field, it would be faster to fix. From what I have researched it may also have a benefit strength wise compared to bending the flange inwards. But don't quote me on that. Perhaps someone could shed some light on this?

[BJC]

Originally Posted by Gregor

What if the inner flange faced outward, and the gearbox was mounted to the flat face?
That would work perfectly well. You could also make your chassis 5” tall to accommodate the gearbox between the upper and lower flanges. I’ve also designed a couple of drivetrains with the gearbox actually inside the wheel well and only the motors sticking out into the machine. There are lots of ways to mount a gearbox without cutting through any flanges.


What do you recommend to be the optimum rock?

This directly relates to how torsionally stiff your chassis is. The older Andymark kitbots were very flexible which in turn meant that more rock was needed to turn (so opposite outside wheels couldn’t touch the ground.) In general, the more tortionally stiff you can make your chassis the less drop you can safely have. 1/8” is a general rule of thumb although if you’re using wide wheels 3/16th may be a better choice. There are also ways to design in methods to change your drop so you can best adjust it to what you need in season. If you’re interested in something like this let me know and I’ll try to explain what we do more in depth.

Originally Posted by Dr Theta

Looks pretty solid. I don't know how much I can add to what has been stated above. I do have a general question though about drivetrains designed in this manner that I've been hoping to get answered. How do you guys attach your bumpers to the sides of the robot? We have only ever used bolts and T nuts set into the wood, and I have been hoping we can take our drivetrains more in the direction of one like this.

The fun and cool thing about bumpers is that they are free weight! If you do your bumper mounts right you can significantly strengthen your chassis for essentially no weight. A really strong way to do this is to mount two 1/8” think 1” L angle along the length of your bumpers. Then you can pick up that angle along the top and side of your chassis. To really strengthen your chassis though, it’s best to make one or two really solid bumper pieces that just fit around your robot. Making the corners of the bumpers strong is the key here. Again, there are many ways to do this, it’s more a team preference thing.

Originally Posted by ttldomination

I've often wondered this, but what's the benefit of having the outer rail face flange outwards?
From my understanding, it would only complicate bumper mounting and other minor things, but the benefit is lost to me.

- Sunny G.

I guess another question you could ask is what is the benefit of having it face inwards? Having the rail face outwards allows for us to put stuff including dead axle mounts, decorative body panels, and our lower bumper mounts within that outer 1” cavity without worrying about being outside the bumper zone. Additionally you decrease the length of your axles by one inch reducing the chance of it being bent by a hard impact. All in all though, it comes down to preference and the way your team like to do things.

Regards, Bryan

[roystur44]

Looks good.

Keep in mind you need to get your chain breaker in there if you go the chain route.

Needs a battery holder which can be made integrated to the rear panel. Keep in mind you want a short cable run to the PDB

Needs mounting points for your bumpers. We have had success with using locking compression latches.

You could make the chassis thinner to save weight.

Looking at the drive train from the top you could improve access to the front and back wheels by removing some material in the corners.

Think of a cool way to mount your encoders to the drive train away from the motors.

Check with your sheet metal sponsor and ask about using csk head rivets on the bottom to make your bottom smooth. They may have a tool that can csk the holes.

Keep in mind with your squared profile on the front and back of the chassis if there is a ramp the chassis gets lifted and the wheels could come off the ground and free spin.

Lastly access to electronics, cables and pneumatics can come via the bottom of the robot via a removable panel or access cut outs.