19-01-2010 21:20

yoshibrock

Re: pic: (RP) Team 1708 Idea #1

Very neat design, and quite visually pleasing. I take it you're not trying to make it over the hump? And what was your premise for choosing slick wheels over any other options? Just curious.

19-01-2010 21:33

1708xMr.Roboto

Re: pic: (RP) Team 1708 Idea #1

I failed to mention a few things in the drawing, The wheels were supposed to be the Traction wheels, when I drew this on my computer at school I didn't have all the drawings handy when I was making this. I was really antcy to post it. So I'll make a list of all the revisions to this drawing.

1. Andy Mark Shift-able Transmissions
2. Any Mark Traction Wheels
3. 2 Motors with the tough boxes

Sorry for the inconvenience, I'll take this one down tomorrow and re-post the one with all the real stuff.

Happy Commenting, -Eddie

19-01-2010 21:39

Travis Hoffman

Re: pic: (RP) Team 1708 Idea #1

Can you tell me more about the suspension springs/shocks?

19-01-2010 21:53

1708xMr.Roboto

Re: pic: (RP) Team 1708 Idea #1

We actually came up from a diesel truck motor, a dodge to be exact. They are Valve springs, they are about 3'' long and have about 1 1/2'' of give to them. They are good to support about 145pds.

19-01-2010 21:56

yoshibrock

Re: pic: (RP) Team 1708 Idea #1

They don't have enough give to let the frame slam into the ground, right? Because if so you might be dealing with damage to yourself/the field. Unless I'm interpreting the image wrong....which is entirely possible.

19-01-2010 22:02

waterfreak#1

Re: pic: (RP) Team 1708 Idea #1

i realize the potential of springs but the hight of your bot seems like its going under the tunnel then why do you neeed the springs?

19-01-2010 22:04

1708xMr.Roboto

Re: pic: (RP) Team 1708 Idea #1

With the 8" Andy Mark traction wheels, and the springs being capable of hold about 135 - 145 pds, and we are hoping to have to robot as close to weight this year as possible.

19-01-2010 22:06

1708xMr.Roboto

Re: pic: (RP) Team 1708 Idea #1

Quote:

Originally Posted by waterfreak#1 i realize the potential of springs but the hight of your bot seems like its going under the tunnel then why do you neeed the springs?

19-01-2010 22:08

yoshibrock

Re: pic: (RP) Team 1708 Idea #1

Quote:

Originally Posted by 1708xMr.Roboto The robot was actually planned to go over the hump, the springs are there to absorb the load of the robot when we hit the bump at speed. To keep us moving in the direction we want to, not being flipped

19-01-2010 22:10

1708xMr.Roboto

Re: pic: (RP) Team 1708 Idea #1

Quote:

Originally Posted by yoshibrock From the way the image is presented, it looks like there isn't going to be enough clearance between the frame and the bump to accomplish a 45 degree climb. The frame would contact the bump before the wheels could.

19-01-2010 22:15

yoshibrock

Re: pic: (RP) Team 1708 Idea #1

I understand that you're going to be switching the wheels out for traction wheels, but those will only add 2" to your wheel diameter. I can't really tell because of the black background, but it looks as if the framework extends in front of the wheel well and then up at an angle. I didn't do any math, but it intuitively seems that your frame is going to prevent you from climbing the bump by contacting the bump at one of those two points (the bumper zone, or right in front of the wheel).

19-01-2010 22:29

1708xMr.Roboto

Re: pic: (RP) Team 1708 Idea #1

This does appoint a possible problem in our design. Thanks a lot for the heads up, I am actually going to draw the "Bump" in Inventor tomorrow and see what happens when I take the robot to it.

Thanks, -Eddie

19-01-2010 22:44

MrForbes

Re: pic: (RP) Team 1708 Idea #1

if you make a scale side view of the bot and the bump, you can just cut the robot out of paper and play with it like a paper doll. We did this for hanging ideas...it works for bumps too.

just for fun, try an 8wd version of your robot with 6" wheels over the bump, as well as 4 and 6 wd with 8" wheels.

19-01-2010 22:46

yoshibrock

Re: pic: (RP) Team 1708 Idea #1

Quote:

Originally Posted by 1708xMr.Roboto This does appoint a possible problem in our design. Thanks a lot for the heads up, I am actually going to draw the "Bump" in Inventor tomorrow and see what happens when I take the robot to it. Thanks, -Eddie

19-01-2010 22:54

1708xMr.Roboto

Re: pic: (RP) Team 1708 Idea #1

Quote:

Originally Posted by yoshibrock No problem, I hope I wasn't coming off as too harsh. I find that playing devil's advocate is unusually helpful in many cases

19-01-2010 22:57

1708xMr.Roboto

Re: pic: (RP) Team 1708 Idea #1

Quote:

Originally Posted by squirrel if you make a scale side view of the bot and the bump, you can just cut the robot out of paper and play with it like a paper doll. We did this for hanging ideas...it works for bumps too. just for fun, try an 8wd version of your robot with 6" wheels over the bump, as well as 4 and 6 wd with 8" wheels.

19-01-2010 23:02

EricH

Re: pic: (RP) Team 1708 Idea #1

What if you switched where the front support and the front wheel are? That might help with your ramp approach. Ditto with the back wheel and back support. If that's even possible with your design, of course.

Oh, and your upper frame on the front side seems to violate <R07-M>.

19-01-2010 23:06

1708xMr.Roboto

Re: pic: (RP) Team 1708 Idea #1

Quote:

Originally Posted by EricH What if you switched where the front support and the front wheel are? That might help with your ramp approach. Ditto with the back wheel and back support. If that's even possible with your design, of course. Oh, and your upper frame on the front side seems to violate <R07-M>.

20-01-2010 01:52

GUI

Re: pic: (RP) Team 1708 Idea #1

Where do the springs mount to the frame?

Have you figured out how to rout and tension the chain/belt you're going to use to power the wheels? Also, it looks like the wheels could easily twist (one spring being compressed more than the other for the same wheel). This could easily cause it to throw a chain, or create a lot of weird stresses on the suspension.

20-01-2010 09:55

Taylor

Re: pic: (RP) Team 1708 Idea #1

Be careful with the suspension - if the frame tilts too much when the robot accelerates hard or brakes hard on flat ground, the bumpers may go beyond the bumper zone. Also, the frame may scrape carpet.
Good luck!

20-01-2010 11:06

IKE

Re: pic: (RP) Team 1708 Idea #1

A piece of constructive criticism on the original post.

While this is a pretty neat design, I would recommend add in some hoped objectives. Some years this is a bigger deal than others. This year it is especially important. Statements like "tunnel only" or "planning on going over the bump" will help critics out immensely. Essentially you are asking for a design review. Without knowing your objectives, it is tough to give valuable criticism.

20-01-2010 11:12

IKE

Re: pic: (RP) Team 1708 Idea #1

Besides Squirrels Paper idea, I have used Powerpoint to make a few models of dynamics. if you use a 1/10 scale, it is very good size for a single sheet of paper. You can then "group" the components and move them. Throw in a CG point and you can follow CG migration and approximate whether or not you will be in trouble. I may post a white paper example of how to do this.

21-01-2010 14:35

Victor_Mec

Re: pic: (RP) Team 1708 Idea #1

Is it a shock absorber or only springs?

I don't understand why use this concept.. Anyway in my opinion you must be carefully with vibrations issues that can affect chassis stability and any other system above the bot.

27-01-2010 12:01

MadeinRussia

Re: pic: (RP) Team 1708 Idea #1

can you guys let use know where you got your shocks at? we would like to find shocks that are that small.