Need Help With Sheet Metal Designing

[AllenGregoryIV]

JT, We just started using sheet metal last season. We have a laser cutter sponsor so it's easier for us than it will be with you and the mill (remember to fillet your corners to the size of your end mills).

Here is the presentation I put together for the team last season when we decided to start doing this. It's definitely not complete and I was learning at the same time so I don't make any promises that is all correct but it will get you started.

https://www.dropbox.com/s/63ke4hzitw...t%20Metal.pptx

I would also recommend looking at the CAD files and robots from teams that do sheet metal well, 33, 148, 228, 1114, etc.

My favorite is still 148's 2011 Robot Raptor. I have a whole presentation that I go over with the team that is just on this robot.

Here is an interesting read on doing different types of 2D manufacturing (sheet metal, CNC routing, etc) for building things . http://www.instructables.com/id/How-...y-Really-Fast/.

Also go back through and read the threads on other people's designs. Some really smart people, give really helpful advice. Here are a few of the recent threads. 1114 Inspired Chasssis, 488 Fall Project 1 and 2, Sheet Metal Drivetrain Prototype and there are many more like it.

[sanddrag]

Originally Posted by AllenGregoryIV

(remember to fillet your corners to the size of your end mills).

I'd recommend filleting the corners to larger than the size of the end mills, even if just by a little.

[MetalJacket]

Originally Posted by AllenGregoryIV

Here is the presentation I put together for the team last season when we decided to start doing this. It's definitely not complete and I was learning at the same time so I don't make any promises that is all correct but it will get you started.

https://www.dropbox.com/s/63ke4hzitw...t%20Metal.pptx

Do you mind if I use this presentation with some modifications to help with training our members? (I will give you guys credit at the end of the presentation)

[BBray_T1296]

Our team uses aluminum 1" box tubing for our frame, which we temporarily attach somehow (I dont remember?) before having our sponsor (one of their employee's who does nothing but weld aluminum all day) weld it all up nice. This year's frame was far too complex, but it came in at just 13lbs and is stupidly strong (could probably withstand 1,000s of lbs of force in any direction). It also is easy to work with, has nearly infinite practical durability and is very rugged. We subsidize this tubing with sheetmetal for more robot subsystems (shooter, drivetrain assemblies, ramp lowerers, innertube grabbers).

We typically use 1/8" alum (powder-coated of course) for heavy systems like drive train and climbing brackets, and 1/16"-.0404" for shooters and such. We used .0202" (basically IS paper) in 2011 on our gripper because if it got banged up, it was super easy to hand-bend back into shape.

Originally Posted by BBray_T1296

Our team uses aluminum 1" box tubing for our frame, which we temporarily attach somehow (I dont remember?) before having our sponsor (one of their employee's who does nothing but weld aluminum all day) weld it all up nice. This year's frame was far too complex, but it came in at just 13lbs and is stupidly strong (could probably withstand 1,000s of lbs of force in any direction). It also is easy to work with, has nearly infinite practical durability and is very rugged. We subsidize this tubing with sheetmetal for more robot subsystems (shooter, drivetrain assemblies, ramp lowerers, innertube grabbers).

We typically use 1/8" alum (powder-coated of course) for heavy systems like drive train and climbing brackets, and 1/16"-.0404" for shooters and such. We used .0202" (basically IS paper) in 2011 on our gripper because if it got banged up, it was super easy to hand-bend back into shape.

You should try working with 1/2"-3/4" 1/6" wall steel. It's strong, light, and easy to weld!

[topgun]

Originally Posted by Andrew Lawrence

You should try working with 1/2"-3/4" 1/6" wall steel. It's strong, light, and easy to weld!

Do you mean 1/2" square tubing (or 3/4" square tubing) 16 gauge steel? Or do you mean a different gauge steel?

- T

[BBray_T1296]

Originally Posted by topgun

Do you mean 1/2" square tubing (or 3/4" square tubing) 16 gauge steel? Or do you mean a different gauge steel?

I think he means 1/2"x3/4" rectangular tubing with (im guessing 1/16" not 1/6"?) 1/16" wall thickness

[JTN]

Aaaand the results:

[BBray_T1296]

Cool stuff! how much does all this weigh?

[JTN]

I'm not sure yet, but I'll keep you posted.

[MetalJacket]

Looks pretty awesome so far, although I do have one question/concern. Had you planned to add a belly pan? Though I will be the first to admit that my knowledge of sheet metal design is still very much a work-in-progress, it would seem that without one there would be issues with rigidity so if you hadn't planned to add one, I would recommend it.

[JTN]

This drawing is to show the frame itself. There will be a belly pan on the actual robot.

[roystur44]

JTN,

Think when you get to the assembly stage how hard to get your frame square with the current design. Think about the process to get the frame built and how to adjust/replace the swerve pods. Which parts are put together first and assembly to each other?

A example would be to built 2 each of two mirrored swerve modules. Test the swerve modules motors and steering independently of the frame. Assemble to frame.

The frame is what holds the swerve modules nice and square. It looks like there are a lot of pieces that have to mate together and be square and strong, lightweight. Consider using one piece of metal for the frame and bending it into a box structure. The hole to hole tolerances with be higher than multiple pieces assembled together and you will find that bending the piece will make the frame stiff and square.

[MetalJacket]

Originally Posted by JTN

This drawing is to show the frame itself. There will be a belly pan on the actual robot.

That's what I figured, just wanted to double check

[AllenGregoryIV]

Originally Posted by MetalJacket

Do you mind if I use this presentation with some modifications to help with training our members? (I will give you guys credit at the end of the presentation)

Feel free, I hope it helps.