pic: my version of a wooden chassis

[gorrilla]

loading photo ...

[Cory]

31.2 lbs???

We've never used the kitbot frame, but it just seems entirely implausible that the bare kitbot chassis could weigh more than that. Maybe with gearboxes, chains, motors, and wheels?

[MrForbes]

I think that's right Cory, the kitbot chassis with transmissions, wheels, and motors would weigh about 30 lbs.

gorilla, I'm curious why you made it of such thick wood?

[gorrilla]

Originally Posted by squirrel

I think that's right Cory, the kitbot chassis with transmissions, wheels, and motors would weigh about 30 lbs.

gorilla, I'm curious why you made it of such thick wood?

its supposed to be 21.2 (i did my math wrong)


i used the 2x6's because 3/4inch plywood in florida is $32

and I was thinking about using a bearing block as well as a ball bearing in the wood itself for the canitleverd wheels
also i wanted to be able to use screws as well as the liquid nails.......

i figured the extra weight was worth it

and i wanted to be able to just bolt our supershifters to the wood also

[MrForbes]

We found precut 1/4 sheets (2 feet x 4 feet) of 3/4" birch (cabinet) plywood at 3 different building supply places for about $14-$18. Sutherlands, Lowes and Home Depot have it in stock.

[gorrilla]

Originally Posted by squirrel

We found precut 1/4 sheets (2 feet x 4 feet) of 3/4" birch (cabinet) plywood at 3 different building supply places for about $14-$18. Sutherlands, Lowes and Home Depot have it in stock.

thats what i used for the bottom...

i had a discussion about that with my team, and we thought it would be better to have thicker sides if we were going to use cantileverd axles

what i could have done, is just had the 2x6's for the sides, and the plywood for the ends and bottom.....

[Cory]

If your frame right there weighs 21.2 lbs, you're going to have a significantly heavier base than if you used the kitbot, not lighter.

[gorrilla]

Originally Posted by Cory

If your frame right there weighs 21.2 lbs, you're going to have a significantly heavier base than if you used the kitbot, not lighter.

not really, the kitbot after we put the four cims and two supershifters and all the electronics and chains and (IFI)wheels was just about 36 pounds,


with the wooden frame, im planning on using directely driven (AM)wheels and only two chains, the BB transmission should work nicely,

im still deciding weather we should use the supershifters or the banebots(i think this is were the weight could be made up ot lost), its really all a matter of what we want to use if for(probobly just for testing and demos)

i still think it will be lighter(even if its only by a pound ill be happy)

[Rick TYler]

That's going to be a seriously strong chassis. Once you get all your components mounted, get yourself a 2" spade bit and whack some speed holes down the center line of those 2x6s. Remember, the stiffness of a beam goes up as the fourth power of its cross-section. 2x6 studs are really, really stiff on edge -- and the breaking point is also very high. You can easily remove material without compromising strength below a danger point. That 3/4 ply is heavy, too. Do you have a piece of 1/2" you can use? You really don't need that 3/4.

On the other hand, a cheap, strong chassis. Have fun!

[gorrilla]

Originally Posted by Rick TYler

That's going to be a seriously strong chassis. Once you get all your components mounted, get yourself a 2" spade bit and whack some speed holes down the center line of those 2x6s. Remember, the stiffness of a beam goes up as the fourth power of its cross-section. 2x6 studs are really, really stiff on edge -- and the breaking point is also very high. You can easily remove material without compromising strength below a danger point. That 3/4 ply is heavy, too. Do you have a piece of 1/2" you can use? You really don't need that 3/4.

On the other hand, a cheap, strong chassis. Have fun!

total cost for the wood was $26.79 and most teams have should have everything else i used

Home-depot was out of 1/2 inch 1/4 sheets.......(would probobly save a pound or two without compromising strength)

thats really what i was going for with the wood,

its going to be 6wd if we have enough of the AM wheels left

it is really strong, i dropped it, kicked it, jumped on it , stood on it, and hit it with a hammer repetedly(and im not a small person) the only thing im concerned about is taking an hit on the side, and cracking the 2x6(but there will be bupers so it shouldent be that big of a problem)......


oh and interestingly, i think the bottom panel added a lot of stiffness, before i had it on, it would kinda flex out a litle bit

[Vikesrock]

Originally Posted by gorrilla

not really, the kitbot after we put the four cims and two supershifters and all the electronics and chains and (IFI)wheels was just about 36 pounds,


with the wooden frame, im planning on using directely driven (AM)wheels and only two chains, the BB transmission should work nicely,

im still deciding weather we should use the supershifters or the banebots(i think this is were the weight could be made up ot lost), its really all a matter of what we want to use if for(probobly just for testing and demos)

i still think it will be lighter(even if its only by a pound ill be happy)

If electronics are included in that 36 lbs than this base should be significantly heavier than your base from last year.

21.2 lbs chassis
+ 9.2 lbs Supershifters (as is, without any lightening)
+11.0 lbs CIMs
+ 4.0 lbs 6 AM Plaction wheels
= 45.4 lbs

That is with no electronics, and no chains. You'd have to remove a ton of material for that to come in anywhere near 36 lbs.

[gorrilla]

Originally Posted by Vikesrock

If electronics are included in that 36 lbs than this base should be significantly heavier than your base from last year.

21.2 lbs chassis
+ 9.2 lbs Supershifters (as is, without any lightening)
+11.0 lbs CIMs
+ 4.0 lbs 6 AM Plaction wheels
= 45.4 lbs

That is with no electronics, and no chains. You'd have to remove a ton of material for that to come in anywhere near 36 lbs.

I meant the AM kit wheels, and I might use BB transmissions, and we only have two cims extra currently so it might be just 4wd for now....

the electronics shouldent be more than 8 pounds for it

[Cory]

Originally Posted by gorrilla

I meant the AM kit wheels, and I might use BB transmissions, and we only have two cims extra currently so it might be just 4wd for now....

the electronics shouldent be more than 8 pounds for it

The cRIO alone is nearly 5 lbs. I would definitely budget more than 8 lbs.

[Vikesrock]

Originally Posted by gorrilla

I meant the AM kit wheels, and I might use BB transmissions, and we only have two cims extra currently so it might be just 4wd for now....

the electronics shouldent be more than 8 pounds for it

A Banebots 12:1 2 CIM gearbox is 3.75 lbs so that's still 7.5 lbs.

I can't imagine the kit wheels are a whole lot lighter than the Plaction wheels, they are probably heavier.

Of course the base will be lighter if you start removing functionality. comparing this base as a 4WD with 2 CIMS to your base last year is not an apples to apples comparison.

[gorrilla]

Originally Posted by Vikesrock

A Banebots 12:1 2 CIM gearbox is 3.75 lbs so that's still 7.5 lbs.

I can't imagine the kit wheels are a whole lot lighter than the Plaction wheels, they are probably heavier.

Of course the base will be lighter if you start removing functionality. comparing this base as a 4WD with 2 CIMS to your base last year is not an apples to apples comparison.

no, have one, single cim gearbox on each side..... with a single chain to the other

our base last year was 2wd with 4 cims


if im only using two victors, and the main block, and the power distribution panel, it should be around 8 or 9 pounds. weight isent really a concern for this, i just wanted to make it strong enough and still be lighter than the kit chassis with everything on it, just wanted to prove a concept to myself and my team