pic: WCD Sheet Metal Hybrid

[AdamHeard]

Originally Posted by Greg Woelki

Do you think that the frame is really strong enough for using 1/16" wall 2x1? Also, what is your source for that 2x1?

I don't think Cory specified thickness, I assume he did .125" but do not know.

Both thicknesses we get from Coast Aluminum, who is a full metal supplier. We buy 20' lengths and pay by the pound. IMO this is the best way to buy metal for FRC.

[Greg Woelki]

Originally Posted by AdamHeard

I don't think Cory specified thickness, I assume he did .125" but do not know.

Both thicknesses we get from Coast Aluminum, who is a full metal supplier. We buy 20' lengths and pay by the pound. IMO this is the best way to buy metal for FRC.

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

[AdamHeard]

Originally Posted by Greg Woelki

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

Since you're in MA, I doubt they would shop that for (nor would it be logical).

However, I'm certain there is someone filling an equivalent role out there. Figure out where machine shops buy their aluminum and ask them.

[KrazyCarl92]

Originally Posted by AdamHeard

Since you're in MA, I doubt they would shop that for (nor would it be logical).

However, I'm certain there is someone filling an equivalent role out there. Figure out where machine shops buy their aluminum and ask them.

We inquired about an order through Coast Aluminum last year for that material specifically and it didn't work out because shipping to New York was prohibitive for them. However, we were able to find 0.080" wall 2 x 1 6061 aluminum rectangular tube through Alro Metals. It arrived with a kink in the middle, likely from shipping, but we were able to use the material on either side of the kink anyway with little waste. We used this for our rear rail and bumper supports on our WCD. We used 0.125" wall on our front rail due to concerns about the stresses on the frame in that area from our 4 large torsion springs, but I would venture to say we would use 0.080" on that front rail in most years moving forward.

[Akash Rastogi]

Originally Posted by KrazyCarl92

We inquired about an order through Coast Aluminum last year for that material specifically and it didn't work out because shipping to New York was prohibitive for them. However, we were able to find 0.080" wall 2 x 1 6061 aluminum rectangular tube through Alro Metals. It arrived with a kink in the middle, likely from shipping, but we were able to use the material on either side of the kink anyway with little waste. We used this for our rear rail and bumper supports on our WCD. We used 0.125" wall on our front rail due to concerns about the stresses on the frame in that area from our 4 large torsion springs, but I would venture to say we would use 0.080" on that front rail in most years moving forward.

I looked into Alro a while ago for .062" wall, and they had it. 1251 showed it to me as I think it's still where they order from.

Check out page 10-52 http://www.alro.com/datacatalog/010-...um.pdf#Page=52

[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!

[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?