pic: 6CIM WCD

Originally Posted by Gregor

Sufficient to what standard?

1" of ground clearance is sufficient for most flat games.

[KrazyCarl92]

Originally Posted by Andrew Lawrence

1" of ground clearance is sufficient for most flat games.

Andrew, If you are using 2" tall tube with 1/8th" of wall and live axles in a WCD setup, then you don't have an extra half inch to drop the wheels.

The height of the tube that is actually usable in this case is 1.75" because you do not want to machine away the top or bottom walls of the tube for the bearing to fit. Then if you are using 1/2" hex like this design calls for, the bearings would be 1.125" diameter. This means that the lowest you can drop down the bearings from center without taking away top or bottom wall material is 0.3125". Assuming you already had a 0.125" drop center to begin with, this means that you would only actually be dropping the bearings (and therefore the shafts) by 0.1875". That means you have 0.6875" ground clearance with 3" wheels, not 1".

[Chinmay]

Maybe he's using steel

[Sh1ine]

Originally Posted by DampRobot

I was less thinking of rigidity after the rivets are installed, and more before. When a rivet is first placed in a hole (but not installed) the two pieces being joined together can still move in respect to each other a small amount. 3/16" nominal rivets are designed to go into #10 (.194") holes. While the OD of the rivet is probably larger than .1875" exactly, there is still some play between the rivet and the hole when it hasn't been crushed yet.

Rivets are rigid enough to hold drivetrains together, no problem, just as you said. We riveted (and didn't weld) parts of our drivetrain together this year and the year before. After the rivets were installed, the drive was quite rigid. However, I definitely noticed a significant amount of play before the rivets were installed. I do wish I had taken more care to make sure the drive was square, as rivets aren't perfect for locating frame members together. A bellypan certainly would have helped with getting everything square before the rivets were installed.

Riveting with a bellypan is probably perfectly square, strong and rigid. But, if the OP has TIG and MIG welders in house, why not learn to use them in the offseason?

Just like I said before, it's perfectly fine to completely disregard my (or anyone else's) advice on CD. Personal experience and experimenting in the offseason should always trump what someone says on this forum.

I agree, personal experience does trump the forum, I do just want to expand on what Chris said a little bit. When we rivet our chassis together all of the parts including our rivet holes are machined on our HAAS Mill. We use a #11 drill (.191) for a slightly tighter fit. We rivet the gusset plates and chassis rails together. We then use clamps and a tape measure and compare the length from corner to corner in a X pattern and adjust the clamps as necessary to square the chassis (similar to woodworking). At that point we attach the belly pan (which is not pre-drilled.) When using rivets for structural members use High Strength Blind Rivets such as McMaster part number 98778A501 they have a much high shear strength than standard rivets.

[AdamHeard]

Originally Posted by Sh1ine

I agree, personal experience does trump the forum, I do just want to expand on what Chris said a little bit. When we rivet our chassis together all of the parts including our rivet holes are machined on our HAAS Mill. We use a #11 drill (.191) for a slightly tighter fit. We rivet the gusset plates and chassis rails together. We then use clamps and a tape measure and compare the length from corner to corner in a X pattern and adjust the clamps as necessary to square the chassis (similar to woodworking). At that point we attach the belly pan (which is not pre-drilled.) When using rivets for structural members use High Strength Blind Rivets such as McMaster part number 98778A501 they have a much high shear strength than standard rivets.

We used to use the high strength rivets, but switched to regular a few years ago. The high strength isn't worth the extra $$$.

Originally Posted by Chinmay

Maybe he's using steel

Not anymore.

Originally Posted by KrazyCarl92

Andrew, If you are using 2" tall tube with 1/8th" of wall and live axles in a WCD setup, then you don't have an extra half inch to drop the wheels.

The height of the tube that is actually usable in this case is 1.75" because you do not want to machine away the top or bottom walls of the tube for the bearing to fit. Then if you are using 1/2" hex like this design calls for, the bearings would be 1.125" diameter. This means that the lowest you can drop down the bearings from center without taking away top or bottom wall material is 0.3125". Assuming you already had a 0.125" drop center to begin with, this means that you would only actually be dropping the bearings (and therefore the shafts) by 0.1875". That means you have 0.6875" ground clearance with 3" wheels, not 1".

My model uses 3/8" ID round bearings with .875" diameter.