Re: 2073 is looking into WCD, feedback requested
 

It looks like you are using 2 x 1 inch tubing for the frame and the "stubs" between the wheels for supporting the bumpers. If you are anticipating playing a hard hitting game like this years, the bumpers may "pivot" inward on the top edge of the stubs and the front and rear cross members when hit hard. You may want to consider stacking another piece of 2 x 1 on top of the stubs and the front and rear cross members. Some spacers may be needed where you have the gusset plates. Alternatively, use 3 x 1, or larger tubing.


It would be best to locate the battery and input breaker at the end with the PDB and the motor controllers and rotate the PDB by 180 degrees to minimize the lengths of the high current paths. Ensure that you do not cut off access to the battery with your upper structure. Use the space between the CIMs to run wires between the two halves of the chassis. Allow at least an inch of space along each side of the PDB and the Digital Sidecar to allow for the wiring in and out. I would suggest allowing the same clearance around the new RoboRio.

You may want to locate the CRio and Digital Sidecar together on one side, say where you currently have pneumatic valves and compressor. Locate the compressor where the air tanks are now. The air tanks are pretty light so they can be put in the middle or up on the upper structure. You may want to install the pneumatic gauge higher up and turned around (as Frank suggested) so it can be seen over the bumpers.

Moving the radio to the other end will put it closer to the CRio that it connects to and away from potential noise sources (motor controllers). If possible, mount the radio on a light piece of plastic in a space in the upper structure so that it is physically protected and not surround it with metal (for better reception).

Re: 2073 is looking into WCD, feedback requested
 

Thank you for the feedback. Yes the little tabs are for the bumpers. Throughout the 2014 season we used a similar fashion for mounting the bumpers. How do you suggest we support them? I felt like keeping them away from the edge would allow them from being bent by having all the force of impact be disbursed throught the 2x1. Any suggestions would appreciated.

Re: 2073 is looking into WCD, feedback requested
 

Thank you for the feedback. I will work on moving the wheels out more, it will definitely help with getting more space inside the frame. Standing the battery upright was done at first and i simply forgot about it, that will for sure be done. As far as cadding in the new electronics goes i have done that and its simply a seperate render. After putting those in there is alot more space also considering the new speed controllers are stackable. Anything more advise will be highly appreciated. Also the reason for using old electronics is this will possibly be used as a practice run for our first WCD, i dont beleive we will be buying the new control system for it.

Re: 2073 is looking into WCD, feedback requested
 

Thank you for the feedback. At first we were planning on using a single belt that ran inside the 2x1 but were promptly met with many issues. In this render we were planning on having the back to center wheel's belt on the inside of the frame and the front to the middle inside the tubing. We planned on using belts because of their minimal stretching, but after recieving all this feedback to switch to chains, we will probably be doing so. I will be cadding a cover too and will update the render with all the great suggestions. As far as the gearing block goes we have already ordered them before break and i will propose buying those to our instructor. The render issue you saw was simply a reflection issue but the transmissions still need to be editted to include a sprocket on the output shaft. I will hopefully have the updated render in by tonight.

Re: 2073 is looking into WCD, feedback requested
 

The simple things always count! Thank you for your feedback, i will edit that part.

Re: 2073 is looking into WCD, feedback requested
 

Thank you for your feedback. Yes the gearboxes are mounted on by only 2 bolts, i was wonderig of a way to fix that and R.C. has responded with a great idea. I will be editting the cad to allow better contact. If you would still lile to see the exploded view let me know and i will happily render it out with the frame's transparency changed, it just that knowing we will probably be changing to chain it we wont have that issue any longer

Re: 2073 is looking into WCD, feedback requested
 

If you are concerned about running chains inside the frame perimeter you can easily put the sprockets on the back of the wheels and run the chain system that way. It will reduce the interior available space but will eliminate the need for chain covers. The chain covers will reduce the interior space available so in reality it about the same amount of space. If you like I can send you our CAD from last year.

Here is one of our CAD models with chain runs behind the wheels. Pardon the overly large sprockets.. We ended up moving the chain to the interior for that year.

http://www.chiefdelphi.com/media/img...9ae90ccd_l.jpg


Last year we used the WCP 3CIM DS transmission with chain runs inside the frame perimeter. We installed chain covers, like on a bicycle. The chain covers worked just fine but this year we are going to run the sprocket & chains in the frame..

http://www.chiefdelphi.com/media/img...e70e30e9_l.jpg

Keep it up!!

Aloha
Mr H.

Re: 2073 is looking into WCD, feedback requested
 

I would love to see your cad from last year to reference the chain idea. Being our first time with WestCoast, anything will help!

Re: 2073 is looking into WCD, feedback requested
 

Do you have the center wheel dropped lower? If so, how much lower? I think I have seen some teams that did not drop their center wheel, how much of a difference is this? Is it beneficial or not? For those that did not drop the center wheel, would you recommend it?

Re: 2073 is looking into WCD, feedback requested
 

The current design has a .125" drop.

Many of the suggestions here have been incorporated into an updated version. I will see if I can get the improved version up soon.

Re: 2073 is looking into WCD, feedback requested
 

If there is no drop center you will run into scrubbing (robot hopping from the outer wheels having too much traction to allow smooth turning). I have seen the use of Omni wheels to resolve this on a non dropped WCD.

1/8" drop is the norm for the center wheels. If you keep the weight centered well enough, spinning around is very easy! As mentioned, even when weight is not centered, on a drop center drive the robot will rock to one end and essentially be 4wd with a short wheelbase, which will turn much easier with less scrubbing than 6wd non drop..

Yeah robot doughnuts!

Aloha!

Re: 2073 is looking into WCD, feedback requested
 

I'd recommend using colsons and then shaving down the center wheel till happy with your drop. We started out with 3/32 and ended up with 1/16 or none.

Re: 2073 is looking into WCD, feedback requested
 

Did you find 1/8" gives too much rocking of the chassis?

By intentionally shaving down the center wheel, which usually wears down fastest anyway, aren't you introducing a different effective FPS from the center wheels than the front and rear wheels? I know this is done on purpose with some 4x4 vehicles to increase traction on surfaces that will allow slippage, like sand or gravel. Are you suggesting to do this as a way to determine optimum drop, or something else.

Re: 2073 is looking into WCD, feedback requested
 

^THIS ^

We started with 1/8" and kept it. By championship it was worn close to 1/16th and ran like a champ.. Though might of been that WCP 3CIM DS transmission... :D

With the deformation of the carpet and the Colson wheels, it was ready to go at 1/8" !

I will get the CADs up over the long weekend.. like the end of it because the weather is great!

Aloha

Re: 2073 is looking into WCD, feedback requested
 

Thanks everyone who gave suggestions and comments. This is almost becoming a "Design by Community" project.
Here are two new renders. Most of the suggestions have been incorporated now. In the oblique projection, we noticed the tension cam is on the wrong side of the block. Ooops! It is corrected in the overhead render.





Full Res images here and here.