Part design input needed

chromehound · Post by **chromehound** » Mon May 28, 2012 10:16 pm

So I'm working on some designs for my RR and would like some input. I used square/rectangle in the designs(ease on the comp) but would like to know if round would be better. Would you add the step or not? I'm thinking of making the step a bolt on type so it could be removed for off road. I plan to use 1/4" thick HREW or DOM if $$ permits but am not sure it's heavy enough - most I've seen are 1/8" to 1/4" but those were on things like Jeeps, 1500s, Toyotas. I'm planning on grade 8 bolts as that seems to be the recommended strength (the designs have 1/2" bolts). Are the gussets needed and if so would you add a set to help with vertical movement on the plates that bolt to the frame? None of my designs are set in stone so any and all imput is welcome and I know there will be changes before they are done.

Powerwagonmark · Post by **Powerwagonmark** » Mon May 28, 2012 11:54 pm

I would definatly use square tube it's easier to work with and it's stronger than round tube. Use 1/4" wall on all the tubing. I made mine out of 1/4 but I made the mistake of making the step out 3/16ths wall and I dented it on a rock. I would put a step because it helps deflect your truck off of rocks adding more protection to the truck.You don't really need gussets on the side but definatly need the gussets on the top and I would make the 1/4 as well. I welded mine to my frame but that's up to you. Good luck on the build.

Here are some pics of my rock rail build

chromehound · Post by **chromehound** » Tue May 29, 2012 3:56 pm

My only concern with the steps was the fact that they would be angled down slightly and might cause a hang up issue; I know the chances are slim but still and that was why I thought of making them bolt on so I could pull them off when I was offroad but that requires more work to get everything just right being that the steps will probably be round or oval. I like to use all the same thickness of metal so no worries on that front and I'll probably add a set of vertical gussets to the frame plates. These are just the start of things I'll be making for the truck and hopefully I'll get some better equipment before I get far involved so the end products come out a little nicer.

Post by **Cactus Red** » Tue May 29, 2012 4:54 pm

From a structural design stand point, round tubing of the same thickness is stonger than rectangular of a similar size. (IE 2.50" x 0.250 wall round is stronger than 2.00 x 3.00 x 0.250 square).

The factory slider tube is 0.250 wall tubing, and so are the legs and flanges. When I added the nerf steps to the factory rails, I went with 0.188 wall x 2" square tube, and it has held up real well to the full weight of the truck. It's scratched and gouged on the underside, but that's OK. As far as the step angle goes, I tipped mine and BX's upward about 10 degrees so that if you do slip, it will tend be inward instead of off the step. Having it tip down will be slicker than goose grease in the mud or snow.

Gussets should be verticle vs horizontal, and if you can figure out how to do so, the mounting flange is strongest if it's got the corners rotated 45 degrees so that the points are up and down.

Mark

Powerwagonmark · Post by **Powerwagonmark** » Tue May 29, 2012 6:11 pm

Cactus Red wrote:From a structural design stand point, round tubing of the same thickness is stonger than rectangular of a similar size. (IE 2.50" x 0.250 wall round is stronger than 2.00 x 3.00 x 0.250 square).

The factory slider tube is 0.250 wall tubing, and so are the legs and flanges. When I added the nerf steps to the factory rails, I went with 0.188 wall x 2" square tube, and it has held up real well to the full weight of the truck. It's scratched and gouged on the underside, but that's OK. As far as the step angle goes, I tipped mine and BX's upward about 10 degrees so that if you do slip, it will tend be inward instead of off the step. Having it tip down will be slicker than goose grease in the mud or snow.

Gussets should be verticle vs horizontal, and if you can figure out how to do so, the mounting flange is strongest if it's got the corners rotated 45 degrees so that the points are up and down.

Mark

I have to disagree with you about round tubing being stronger than square tubing. Imagine a round tube 2"dia lets say .250 wall and 20 feet long, it will bend in the middle easily the same size square tube same wall will not bend as much. Square tube is also harder to crush then round ask me how I know

chromehound · Post by **chromehound** » Tue May 29, 2012 7:31 pm

Cactus Red wrote:From a structural design stand point, round tubing of the same thickness is stonger than rectangular of a similar size. (IE 2.50" x 0.250 wall round is stronger than 2.00 x 3.00 x 0.250 square).

The factory slider tube is 0.250 wall tubing, and so are the legs and flanges. When I added the nerf steps to the factory rails, I went with 0.188 wall x 2" square tube, and it has held up real well to the full weight of the truck. It's scratched and gouged on the underside, but that's OK. As far as the step angle goes, I tipped mine and BX's upward about 10 degrees so that if you do slip, it will tend be inward instead of off the step. Having it tip down will be slicker than goose grease in the mud or snow.

Gussets should be verticle vs horizontal, and if you can figure out how to do so, the mounting flange is strongest if it's got the corners rotated 45 degrees so that the points are up and down.

Mark

The steps themselves would be flat - I know the pic shows them angled but it was just easier to draw them that way at 3am, I'm working on revisions to the whole thing now, the down angle is just to place the step lower than the RR and since it'd be tied into the RR and made of the same material I figured it'd still hold the weight. I might just do a design with a removeable step and move my gussets. I'm glad that 1/4" thick will be heavy enough for these as everything will be made with the same thickness. Square/rectangle would be easier to work but round would look better. I've built stuff out of both round and square and have bent/crushed both types but those were on tractor loaders and heavy equipment. I'm glad I'm still in the design stage with these and my other stuff.

MSparks909 · Post by **MSparks909** » Tue May 29, 2012 8:27 pm

The factory rails have an extra mount that ties into the front leaf spring mount. Would it be possible to add that mount to your design for additional strength?

chromehound · Post by **chromehound** » Tue May 29, 2012 10:53 pm

I can add pretty much anything at this point since it's all on my computer- things will be easier when I go get measurements.

Step refinement - this shows the step flat and the bottom of the step at the same height as the main section of the RR with the ends having the same angle. The steps are now only ~2" out past the main RR vs the over 5" out that the first plan placed them. The steps are only half the height of the main RR bar so that will help with people getting in/out and not comprimise clearance. It's still all 0.25" thick metal.

twistedpw · Post by **twistedpw** » Wed May 30, 2012 9:37 pm

here is what I came up with when I did mine they are made from 2 x 4 x .188 and 2 x 2 x .250 supports and .375 x 2.5 end plates and gussets. and they have been used a bit with no damage other than the paint.