X-Drive Tips

You can drill holes in the metal to get it to work; assuming everything else is lined up and centered, all the distances will be right.

what softwear do you use to make this image? hope to get an anwser from you lol

AutoCAD. Not Inventor or Fusion, the og. You can do this in both of those though too through sketches.

thanks! I’m an Inventor user,seems like I should get an auto cad now

It’s good for first drafts imo. It’s available for free with a student license

I spent some time this year designing an x-drive in Fusion 360 to make sure everything lines up perfectly, and I’m pretty happy with the result. It is quite strong, and a change up ball fits in between the motors in the front. Here are some pictures of my design

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This is actually really nice. Love the use of standoffs to make braces to maintain the frames stiffness. I assume you used the shaft collars to make the right angles there? Did you tap them to be 8-32 as opposed to 6-32?

Just wondering, is there a reasoning behind not having like an c-channel on the outer sides of the bot?

Yeah I used shaft collars there. I wasn’t aware the threads are different, regular screws always seem to work fine for me. Maybe it’s close enough?

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I didn’t also use c-channel on the outside because it’s not really necessary, just adds more weight and makes it more complicated. Also it’s a little annoying trying to get everything to line up perfectly when you do it that way.

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The shaft collars are already 8-32. The only screw that is not 8-32 in V5 now is the rack gears.

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The main purpose of adding an outer support channel is to help prevent twisting in the pod itself when there is added weight to the base. without them, the pods will start flaring up as it is used more given there isn’t anything supporting the outer flange except standoffs.

An easy way around this is to either design and fabricate custom lexan gussets to help sandwich the outer and inner channels of a pod or to drill holes in the bracing c-channels in order to allow holes to line up. Examples of both are provided below:

Full Model Snail 1X-Drive Back

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With my design (I also used a similar x-drive last year) I haven’t had any issues with flexing or twisting. In fact, it’s a lot more rigid than the robots I have built with normal drives. I am actually having a problem where if any of the wheel pods are higher, even if only a small amount, they lose traction. I think this is because the frame is so rigid that there is no flex allowing the wheel pods to better contact the foam tiles.

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The new racks use 8 32 screws and lock nuts

idk what ur doing bro but you do not want flex in a drive

unless it’s a bendy drive of course

And besides, foam tiles deform so much already

If your drive’s pod alignment is off by however much the foam tiles deform, there are some serious build quality issues to deal with lol

Oh cool. Maybe we’ll buy some; then again they’re not that useful. I do really hate having two sizes of screws though.

Obviously having a flexible drive is not a good thing, but I do think that a tiny bit of flex in some cases does help with traction. The better solution is to try to make all 4 wheels perfectly aligned vertically, but you can never get it perfect. In a normal drive that’s usually not a problem, but I have found that with x drives, even the tiniest amount of difference can have a noticeable affect in the way it drives. Because for an x drive to drive straight, all four wheels need to have almost exactly the same traction. Even when all four wheels are visibly contacting the foam tiles, you can still have one wheel that isn’t pushing against the tiles with quite the same force. If that’s the case, it can cause the x drive to drift left or right, especially when accelerating from a stop.

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the squish of the tiles as well as the weight of the robot should counter minor variances I would think.

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Have shaft collars always been 8-32? I have found that on some of the older shaft collars in my teams supplies don’t fit screws while the new ones always do. For the old ones I can sometimes forcibly tap it by violently screwing the screws, digging it intothe inner surface while for others it’s just plain impossible and the screw gets stuck. I don’t know shaft collars have changed sizes or if it is just vex’s bad tolerances.