pic: WCD Sheet Metal Hybrid

[Joe G.]

Originally Posted by Ty Tremblay

If you're talking about the 4 flanged pieces near the outside wheels, those are bearing blocks that fit in a slot cut into the 2x1. There's a little cam that is used to change the center-to-center distance between the sprockets in order to tension the chain.

I meant the angle pieces highlighted in blue below, not the 973-style WCD bearing blocks.

[Bryce Paputa]

Originally Posted by Joe G.

I meant the angle pieces highlighted in blue below, not the 973-style WCD bearing blocks.

They're labeled "Chain Guard".

[Travis Schuh]

Originally Posted by Greg Woelki

Thanks for the supplier. I downloaded the STEP file and it is 0.0625" wall.

You might check out Admiral Metals. That was the place we would go to for metal while I was out at school near Boston. If I remember correctly, they had a pretty expansive area of ends that they would sell by the pound for a good price.

[AlecMataloni]

Oh hey, this looks familiar.

Honestly though, this is a much more thought out version of the "hybrid construction" WCD than anything I was capable of doing when I was a student.
I like this version better. Please build it one of these days and post pictures!

[rcmolloy]

Thanks for the responses everyone. I am going to go through one by one with the posts.

Austin

If you didn't take a look already, it is 5052 for the aluminum alloy with all current components being .090 thick. I know you know that sponsors don't like bending 6061 just as much as the material itself. (If anyone doesn't know, 5052 is a more pliable material than 6061 as well as less likely to fracture. It's commonly used in FRC and other applications)

As for the front and back edges of the drive, this has crossed my mind numerous amounts of times since the beginning of this drive with how our 1/16 2x1 front cross members get destroyed every year. I do think, with some thought, I will make some bent member in there to support the loading seen at the corners. Honestly though, inserting a 2.5x2 inch piece of wood wouldn't be the worst option! I'll be taking a larger look at this now that the drive is done.

James

As Adam previously mentioned, the added support of the bellypan doesn't come from different methods of webbing. It's directly correlated to the cross-sectional area of the material that is there taking the load. With what Adam referenced, the cross-sectional area taking the load is directly related to the roughly 1" side of the 2x1 on the bellypan and mostly through the 2x1's themselves. For reference, many teams have used much more flexible materials for bellypans in the past. I know we used Garolite a few times as well.

Also, riv-nuts would be a solid option as to taking apart the base. I know its your preference but drilling out a rivet might be faster in some cases then unthreading a bolt.

Greg

My mistake on the 2x1. They should be .125 thick. A quick fix in Solidworks changed that and the step file in both the topic as well as the picture have been updated.

Bryce & Joe

Typically we have an extensive amount of wires that need to be ran all along our bellypan. The angles are 3/4 x 3/4 angle that protect those wires from the chain at all costs. Also they were used for guiding and organization purposes for the wires. I honestly could have left them out but I decided to throw them in last minute.

Joe, the battery plate could possibly use more support but right now I haven't taken a closer look and also haven't went through some "light" FEA to see stresses. I can certainly take a better look and adjust where necessary. Ideally, it would only be two more bends on each side with the same thickness or smaller to help support.

Michael & Austin

From what I saw by your posts, perpendicular definitely sounds the way to go since you're not acting on only the rivets and actually on the 2x1. I have a picture below that shows off the rendition I believe you both were trying to explain.



If this is exactly what you were looking at suggesting please let me know that way I can add it in and get this guy updated.

Alec

Thanks for the words buddy. Unfortunately, there is no major sponsor that we have for sheet currently. My old team did help us out in 2012 with some sheet parts but as of now the only resource we have used was one or two teams willing to help us out. If there was ever a sponsor that showed up with sheet capabilities, I would be certainly inclined to make this!


Just also wanted to point out that the bearing blocks are not exactly what 973 is accustomed to using. The picture below shows the blocks and that they are slightly similar to the VersaBlocks by WCP/Vex. I wanted to see what other geometries could be used in this situation to support the drive shafts.



However this isn't the best solution to drive bearing block design. I can only preach to the 973 standard because of the large advantages they provide. There are great benefits to it and I can't stress that enough.

[asid61]

What's the total weight for what you have shown in the picture?

[roystur44]

Cory,

How about slotting the top of the 1 x 2 tubes so the bearing blocks drop in from the top. Once tighten the bearing block becomes integral to the frame and strengthens the tube. That would make your transmissions and wheels drop right in.

Using 6061 T-6 for your belly pan would be fine if then is no bends. Laser away.

There is a process called bump bending in which a series of small tangent bends along a radius which used to create a large radius bend in sheet metal. You can use that process to bend T6. T6 Sheet stock just requires a large inner radius or use of a wrapper while bending.

If you are worried about your front/back bending in you could attach a small hat section of sheet metal behind the front and back along the length. This also could serve to be the mounting rail for the manipulator. I think being able to mount and adjust the manipulator is very important in a design.

Here's another idea. How about making the front and back circular?



You have a good start.

[rcmolloy]

Hey Roy thanks for the reply. Sorry it took me a bit longer to get back to you. The 4th was a bit in the way this past weekend!

How about slotting the top of the 1 x 2 tubes so the bearing blocks drop in from the top. Once tighten the bearing block becomes integral to the frame and strengthens the tube. That would make your transmissions and wheels drop right in.

Hmm, didn't think about this. It's surely possible and I'll definitely toy with the idea. It would be nice to have all components "assembled" with chain and then drop right in like you mention.

Using 6061 T-6 for your belly pan would be fine if then is no bends. Laser away.

There is a process called bump bending in which a series of small tangent bends along a radius which used to create a large radius bend in sheet metal. You can use that process to bend T6. T6 Sheet stock just requires a large inner radius or use of a wrapper while bending.

This was super surprising since I didn't know that there was a method of doing so available. I would have figured a larger radius would be needed but that its characterized as bumping is certainly not jargon I know. Surprisingly, now that I think of it, I'm pretty certain I have seen this used in some applications. I didn't really think of it until now.

If you are worried about your front/back bending in you could attach a small hat section of sheet metal behind the front and back along the length. This also could serve to be the mounting rail for the manipulator. I think being able to mount and adjust the manipulator is very important in a design.

I certainly have thought about this and I do think this will be added in the near future. I just need to sit down with this guy for a bit longer until it should be solid for competitive purposes with the likelyhood of no plastic deformation.

Here's another idea. How about making the front and back circular?

Funny thing is I have been looking at doing a similar design as 971 has been doing for the past 2 years (correct me if I'm wrong) but I haven't dove into that yet since the kids are looking to do something during the off-season. They've already made headway and I'll most likely design after due to seeing flaws with it.

Thanks for all the help!