1114 Inspired Chasis

[Cash4587]

I have been working on this chassis a few weeks now and I think I have finally gotten it to where I am ready to show you guys. I tried to base this chassis completely off of 1114's 2013 chassis. All my work was done by research of pictures and videos . I have not actually seen the chassis in person so keep that in mind. Well the only thing I haven't really figured out how to implement into this design is the chain tensioners. They basically are a bolt with a nylon tube around it inside a slot pushing down on the chain. Everything is kept simple just like on 1114's actual chassis. Well, without further adieu enjoy!
P.S. I also I have a sorta remake of their climbing arm in the works. I am trying to model it but it is not as easy to do as the chassis.

[Akash Rastogi]

Originally Posted by Cash4587

I have been working on this chassis a few weeks now and I think I have finally gotten it to where I am ready to show you guys. I tried to base this chassis completely off of 1114's 2013 chassis. All my work was done by research of pictures and videos . I have not actually seen the chassis in person so keep that in mind. Well the only thing I haven't really figured out how to implement into this design is the chain tensioners. They basically are a bolt with a nylon tube around it inside a slot pushing down on the chain. Everything is kept simple just like on 1114's actual chassis. Well, without further adieu enjoy!
P.S. I also I have a sorta remake of their climbing arm in the works. I am trying to model it but it is not as easy to do as the chassis.

Just remember, if you need more pictures or information for reference, never hesitate to PM Karthik or another team member for help. On several occasions they've provided CAD files and screenshots of CAD as well.

[apalrd]

From what I can see, that is the least rigid sheet metal chassis I have ever seen.

The front is open without any stiffener across, and the back had a nice flanged back plate but you cut the flange out.

Something has to bridge the two sides and provide stiffness, or the chassis dynamic performance will be quite bad.

[Cash4587]

Originally Posted by apalrd

From what I can see, that is the least rigid sheet metal chassis I have ever seen.

The front is open without any stiffener across, and the back had a nice flanged back plate but you cut the flange out.

Something has to bridge the two sides and provide stiffness, or the chassis dynamic performance will be quite bad.

I'm sorry? Did I forget to mention it is unfinished?

[apalrd]

You posted an image of a chassis design on Chief Delphi. The Chief Delphi community has seen many chassis designs, and helps many designers such as yourself improve their designs and methods.

It's generally frowned upon to copy a design without understanding the engineering behind it. You can understand the engineering behind it by designing, building, and testing a chassis and learning what is right and wrong, and improving it for the next design iteration. Frequently, by doing this, you will learn why they did something a specific way by not doing it on your own design and wishing you had, or finding that the solution works fine in testing and accepting it as good enough. It's perfectly fine (and highly encouraged) to use another teams design as a starting point when designing something new, but to gain anything you have to make it your own. Short of actually building and testing a physical chassis, you can ask experts and teammates for advice during the design process to iterate to a final design, before possibly building and testing the final product. Chief Delphi includes many long-term FRC members who have designed many drivetrains, and some engineers who have learned the common design pitfalls and are willing to help you.

As someone who has built and tested many sheet metal and other types of drivetrains, your design needs more torsional stiffness. This is most easily provided by adding cross bracing.

[ablatner]

Originally Posted by Cash4587

I'm sorry? Did I forget to mention it is unfinished?

You did forget, and if you post a design or CAD on Chief Delphi that is "ready to show", expect critique whether it's finished or not.

[Cash4587]

Thanks for all the support guys! (no pun intended) I appreciate the help, I updated it so it should withstand anything now. Built like a tank #win #sostrong #support #yolo #chassis #aluminum ##

[tickspe15]

is that a solid metal block. If so you may run into some weight problems.

[cj3958]

Let me preface this with the fact that I think that it is coming along great.... But(thus letting you know that everything else will be critical of your work)

Have you put any thought into how you would build this chassis if that was going to be an offseason project or something? To me, it seems pointless to design a robot that is impossible for YOUR team to build. Not just a hall of fame team, or a world champion team, but your team. What you have right now looks like it is un-manufacturable to me, but maybe it is just the way that I am looking at it.

If I were you, I would try and figure out what it is that you are trying to learn from this experience, is it just to learn the concept of CAD? Or is it to get practice for the build season? Or Is it to learn how the world champion and hall of fame teams build robots and why they do certain things to their robot?

Once you establish what it is that you might try to learn from the experience, it will guide you as to how you would proceed from here. I did a similar thing last fall. I was eventually just told by our lead mentor to stop doing that and make a robot that we could build, (given only a spec, and a general construction technique) and because I gained more of the experience of how to make a robot that my team could build it helped A LOT more in the build season.

[Cash4587]

Originally Posted by cj3958

Let me preface this with the fact that I think that it is coming along great.... But(thus letting you know that everything else will be critical of your work)

Have you put any thought into how you would build this chassis if that was going to be an offseason project or something? To me, it seems pointless to design a robot that is impossible for YOUR team to build. Not just a hall of fame team, or a world champion team, but your team. What you have right now looks like it is un-manufacturable to me, but maybe it is just the way that I am looking at it.

If I were you, I would try and figure out what it is that you are trying to learn from this experience, is it just to learn the concept of CAD? Or is it to get practice for the build season? Or Is it to learn how the world champion and hall of fame teams build robots and why they do certain things to their robot?

Once you establish what it is that you might try to learn from the experience, it will guide you as to how you would proceed from here. I did a similar thing last fall. I was eventually just told by our lead mentor to stop doing that and make a robot that we could build, (given only a spec, and a general construction technique) and because I gained more of the experience of how to make a robot that my team could build it helped A LOT more in the build season.

Oh no this is something that I am doing for practice and also for a chassis for a team potential standard go to chassis, (Minus the cut in the front) I built this all using the sheet metal tool so idk how it would be not build-able? care to explain how it wouldn't?

[J_Miles]

Originally Posted by Cash4587

I built this all using the sheet metal tool so idk how it would be not build-able? care to explain how it wouldn't?

Just because you can make it in CAD doesn't mean it can be manufactured (or that it would be sensible/economical to do. (i.e. Would building this chassis require an insane amount of wasted metal?))

[EricH]

Originally Posted by J_Miles

Just because you can make it in CAD doesn't mean it can be manufactured (or that it would be sensible/economical to do. (i.e. Would building this chassis require an insane amount of wasted metal?))

Exactly. I have seen parts in CAD that would be impossible to build without one particular piece of equipment.

Here is what I'm seeing that is probably a waste of material, and what I'd do about it:

--Those two solid (endcapped?) cross-beams. You don't need the ends on there; go ahead and remove them (they'll be a REAL pain, even with sheet metal). Better yet, replace them with a bellypan and some much lighter angled upper crossmembers. If you do need only upper crossmembers, then make them as small and light as you can get away with--and probably not a full tube, unless that were to make some other aspect of the design easier.

--It looks like you have a solid sheet area below the rear cross-beam; that could probably be removed. Ditto for part of the front that looks quite similar.

--No light-weighting. Yes, this is sheet metal--but you can still remove quite a bit of material on the sides of the robot. Triangles are your friend.

Essentially, what I'm seeing is that you could use some studying in the direction of how to effectively use sheet metal. I don't have a lot of experience myself, but the one thing that I keep hearing is "flanges" are what give sheet metal its strength--you've got flanges, all right, but you also have a lot of material that probably isn't contributing a whole lot to the structural integrity of the drivebase.

[Adrian Clark]

Is there a purpose to front gap other than copying it from 1114's chassis? If you took out the front gap and made it like you did in the back minus the cutout in the flange you'd have a pretty solid frame.

Side note: because of your cim cutouts in the bellypan and the flanges on your frame it will be impossible to either install or remove the gearboxes once the frame is assembled. I suggest elongating the slot for the cim to allow space for the gearbox to slide out from under the flange. Details like this are often missed in cad, make sure you put some thought in how this thing will be built and assembled.

edit: EricH is right, triangles are your friend, quoted for truth.

[lemiant]

You would need some good sheet metal breaks to be able produce all the bends on the side plates with them being so close together.

[Cash4587]

Update:
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-Thanks for all the feedback