Runner Buggy

CHOP SHOP · Jun 26, 2009

Bunk said:
X3:haha::haha::haha:

Links will be 2X4 3/8 wall rectangle tube.:fawkdancesmiley:

Tube is for rails and fluid. Box is structrual.

I dont think its going to bend holms.:;

82toyomud · Jun 26, 2009

CHOP SHOP said:
Links will be 2X4 3/8 wall rectangle tube.:fawkdancesmiley:

Tube is for rails and fluid. Box is structrual.

I dont think its going to bend holms.:;

As long as the forces are parallel to the faces of box, and you have no twisting at weird angles... Tube you an infinite # of directions, and twisting moments you can deal with:awesomework:

CHOP SHOP · Jun 26, 2009

82toyomud said:
As long as the forces are parallel to the faces of box, and you have no twisting at weird angles... Tube you an infinite # of directions, and twisting moments you can deal with:awesomework:

Keep smokin the crack and find me a bridge or building or trailer thats made out of tube? Round=burst square/flat structual.

Grab a stick of 2x2x.25 box tube in the middle of a 20 foot stick and note how much droop it has.
Now grab a stick of 2x.25 dom tubing in the middle of a 20 foot stick and note how much more droop it has than the box.

When looking for that bridge made of tube, you might notice most of the square/rectangle ones will have some tube also. Its usually is on one side of the bridge and full of CNG or poop or water, etc, just like it should be.

overbuilding (thickness) a round tube link is not a good engineering.

82toyomud · Jun 26, 2009

CHOP SHOP said:
Keep smokin the crack and find me a bridge or building or trailer thats made out of tube? Round=burst square/flat structual.

Grab a stick of 2x2x.25 box tube in the middle of a 20 foot stick and note how much droop it has.
Now grab a stick of 2x.25 dom tubing in the middle of a 20 foot stick and note how much more droop it has than the box.

When looking for that bridge made of tube, you might notice most of the square/rectangle ones will have some tube also. Its usually is on one side of the bridge and full of CNG or poop or water, etc, just like it should be.

overbuilding (thickness) a round tube link is not a good engineering.

Your right, bridges and structures are built out of square because 90% of the forces are coplanar, and the twisting forces are restricted by the triangulation... and the box tube isn't going to droop for this very reason... your forces are coplanar...

Now go take your box tube and apply bending/twisting forces and see what happens (like what will be seen in a link) and do the same for the tube... you'll see what I'm talking about.

CHOP SHOP · Jun 26, 2009

82toyomud said:
Your right, bridges and structures are built out of square because 90% of the forces are coplanar, and the twisting forces are restricted by the triangulation... and the box tube isn't going to droop for this very reason... your forces are coplanar...

Now go take your box tube and apply bending/twisting forces and see what happens (like what will be seen in a link) and do the same for the tube... you'll see what I'm talking about.

Good point and I agree.

But the reason links are overbuilt is because they fail due to the rig being constantly parked/landing on them. Not cuz there twisted.

Why do round tube driveshafts twist off and box tube ones dont?:corn:

82toyomud · Jun 26, 2009

CHOP SHOP said:
Good point and I agree.

But the reason links are overbuilt is because they fail due to the rig being constantly parked/landing on them. Not cuz there twisted.

Why do round tube driveshafts twist off and box tube ones dont?:corn:

Because of denting

CHOP SHOP · Jun 26, 2009

82toyomud said:
Because of denting

Wishfull thinking. Not always.

So you saying a dented round link/dshaft is weak? How would a link/dsahft get dented?:corn:

dents come from side load, again not what the tube was designed for.:;

Binder · Jun 26, 2009

Say for the sake of argument that your links are made of unobtainium and won't deflect at all. What you've done is transfer the forces to the link ends and into the tabs- chassis, etc.....In my opinion, idealy the links should flex then spring back to thier original shape.
I'm not saying that your design isn't going to work just as well as anything else but just that there isn't realy a perfect answer without just overbuilding crazy heavy ****.

Binder · Jun 26, 2009

CHOP SHOP said:
Why do round tube driveshafts twist off and box tube ones dont?:corn:

Because round tube shafts are typically made from much thinner material.

CHOP SHOP · Jun 26, 2009

Binder said:
Say for the sake of argument that your links are made of unobtainium and won't deflect at all. What you've done is transfer the forces to the link ends and into the tabs- chassis, etc.....In my opinion, idealy the links should flex then spring back to thier original shape.
I'm not saying that your design isn't going to work just as well as anything else but just that there isn't realy a perfect answer without just overbuilding crazy heavy ****.

You are correct.

Such material exists. Its 2.5 inch 7075. And I cant afford it, hence the paid for rectangle. Cost is a big factor in material choice for me.

I would definatly recomend a different route for a well off customer.

I will eventually do the 2.5 7075 lowers when this things done. Im ok with some heavy **** for a while that can be swapped out when moneys better.

CHOP SHOP · Jun 26, 2009

Binder said:
Because round tube shafts are typically made from much thinner material.

you not helpin me any here.

:haha::haha:

Look at brains round THICK shaft, twisted off in the garage. Before pointing out that it was soft steel, so is boxtube.:corn:

Binder · Jun 26, 2009

CHOP SHOP said:
Im ok with some heavy **** for a while that can be swapped out when moneys better.

I can totally relate to that.:beer:

Binder · Jun 26, 2009

CHOP SHOP said:
Look at brains round THICK shaft, twisted off in the garage. Before pointing out that it was soft steel, so is boxtube.:corn:

I can't say as I've not seen it. It's probably safe to say though that he didn't twist it off from pure torque.

82toyomud · Jun 26, 2009

CHOP SHOP said:
Wishfull thinking. Not always.

So you saying a dented round link/dshaft is weak? How would a link/dsahft get dented?:corn:

dents come from side load, again not what the tube was designed for.:;

Well nothing is going to respond well when the force is perpendicular or close to perpendicular, but the tube will respond magnitudes better compared to box because it has an infinite number of planes... So tube really is designed for these types of situations...

Plus, if you were to do an apples to apples comparison in either link or D-shaft the tube would always win... Like Binder said, when round is used, its usually a thinner wall, compared to when box is used.