09-09-2012 20:05

Andrew Remmers

Re: pic: First attempt at Sheet Metal Chasis please give advice to help me improve

I would make the front braces with a little bit more "meat" Remember you can always remove material, but once its gone its difficult to put back.

Looking good, keep up the good work!

- Andrew

09-09-2012 20:13

Re: pic: First attempt at Sheet Metal Chasis please give advice to help me improve

Put some braces between your transmissions, or something to stiffen the frame. It looks like I can warp it in any which way I'd like with a little impact.

Any reason for using FIRST wheels? Plaction, Colson, etc are all really nice wheels, and provide a ton more grip than the FIRST wheels.

Other than that, nice design. Keep up the good work.

09-09-2012 21:27

tickspe15

Re: pic: First attempt at Sheet Metal Chasis please give advice to help me improve

thanks i will put braces in for the transmissions and i used first wheels in the model because that is what i have in my cad library already will most likley end up using plaction wheels and mabey omni wheels

09-09-2012 21:35

protoserge

Re: pic: First attempt at Sheet Metal Chasis please give advice to help me improve

How will you mount other components to that chassis? There doesn't appear to be a lot of room to affix any additional structure? Have you considered a standard mounting hole pattern?

Additionally, are you familiar with the SuperShifter as a whole (maintenance, accessibility, access of internals)? The transmissions should be removable in a few minutes. I can speak from experience here: it takes The RoboBees over 20 minutes to remove the transmissions at a moderate pace (that is really not good).

To your above mention of omni wheels, I'm curious why you would consider them in a 6WD drivetrain (from a design perspective). In my experience, the 6WD is built for robust pushing power and stability, I would think that omniwheels would discount pushing power and ability to hold ground in a pushing match.

Not a bad first design. It's definitely a good start. Keep iterating.

Depending on the design of the superstructure, a lot of bracing may not be required for this drive platform. You can gain significant stiffness from a structure that mounts to this chassis.

I definitely agree with the bracing from one of the transmissions to the other, however.

09-09-2012 21:53

EricH

Re: pic: First attempt at Sheet Metal Chasis please give advice to help me improve

It depends on the 6WD. If it's a flat 6WD, and you don't have omnis on one end or the other, you'll probably end up not being able to turn well. (You might also be able to get the turning by using different stickinesses of wheels, but that's what omnis do side-to-side.)

If it's a 6WD with a dropped center wheel, then you probably don't want omnis on there. It'll be able to turn a little too well, especially under defense.

09-09-2012 22:00

Redo91

Re: pic: First attempt at Sheet Metal Chasis please give advice to help me improve

It definitely looks good.

Like Joyride said, you may want to leave a bit more material in the front and back pieces. I would also suggest replacing the cool curves with straight edges. It makes bending the pieces easier. You could also have a smaller bend radius. I believe our sponsor uses .09 inch on the things they do for us.

I recommend sitting down with your sponsor(or whoever is going to be fabricating the pieces) and going through your design with them. They will be able to tell you what they are capable of doing.

Also, examine other team's CAD and see what they have done.

10-09-2012 11:58

roystur44

Re: pic: First attempt at Sheet Metal Chasis please give advice to help me improve

Needs some bracing in between the wheels, stand offs or bracketry will work. This will help to prevent twisting of the left and right wheel modules. Adding a sturdy belly pan will stiffen the frame. Make sure you can get to the chain with a chain breaker. The curved arc on your front and back panels looks cool but you can add a straight bend instead of the arc and this will strengthen the frame. The guys bending the part will appreciate the flat surface to bend from instead of the arc. Design in a tension method for the chain. You will find the chain stretches and will need maintenance. I'm a fan of round perforation patterns for lightening. Instead of triangles or rectangles try a round 60 deg staggered perforation pattern.


So far you are on the right track.

10-09-2012 12:26

protoserge

Re: pic: First attempt at Sheet Metal Chasis please give advice to help me improve

Your fabricator will also thank you. Round holes can be punched much faster than a waterjet can cut (saves time and money). The pattern is a great suggestion; additionally, use a common hole diameter. Even better is to use a dimple die to add a flange to the hole, which adds strenth back to the structure.