84gmcjimmy
1 ton status
I want to have a badass rockcrawler, and a good mud bogger/trail rig. its not just for rockcrawling etc. so I dont know what to do... /forums/images/graemlins/dunno.gif
CK5
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questions on boxing the frame...
- Thread starter 84gmcjimmy
- Start date
zeroz400
1/2 ton status
Seems like you just want a more rigid, tougher frame. You want the suspension to do the flexin not your frame. I say you should just add some crossmembers in and be done.
Later
Later
poorboy1
Registered Member
well if your suspension is flexable it is less likely to twist the frame. My frame only started to twist when the suspension began reaching it's limits. Might try to upgrade there first then see what the frame does /forums/images/graemlins/dunno.gif
84gmcjimmy
1 ton status
Im not trying to mess with anyones mind, as I am still young and I keep changing my mind. I sat staring at the wall for half an hour, and this is my new plan:
keep the frame how it is, just add more crossmembers where I can. then a few years down the road after I have bashed on the frame enough, I will look into getting a shop to build a tube frame... but thats after I "finish" the k5 so it can drive.
I dont have a local place that will do the custom frame, and I think if eventually I will be getting a custom frame, i wont waste time on boxing the stock frame when it will be replaced in a few years.
sorry.
keep the frame how it is, just add more crossmembers where I can. then a few years down the road after I have bashed on the frame enough, I will look into getting a shop to build a tube frame... but thats after I "finish" the k5 so it can drive.
I dont have a local place that will do the custom frame, and I think if eventually I will be getting a custom frame, i wont waste time on boxing the stock frame when it will be replaced in a few years.
sorry.
84_Chevy_K10
Banned
[ QUOTE ]
well if your suspension is flexable it is less likely to twist the frame. My frame only started to twist when the suspension began reaching it's limits. Might try to upgrade there first then see what the frame does /forums/images/graemlins/dunno.gif
[/ QUOTE ]
That's not true at all.
The more your rig flexes, the more it transmits into the frame.
well if your suspension is flexable it is less likely to twist the frame. My frame only started to twist when the suspension began reaching it's limits. Might try to upgrade there first then see what the frame does /forums/images/graemlins/dunno.gif
[/ QUOTE ]
That's not true at all.
The more your rig flexes, the more it transmits into the frame.
thebigdaddyof2
1/2 ton status
Check out the custom frame Steve Sharp put in his first gen...in his driveway! He did it in two phases.
extreme 4 wheelin
Be sure to check out the frame stretch as well.
extreme 4 wheelin
Be sure to check out the frame stretch as well.
I’ll admit right up front to having some bias, but I have to tell you that the technology in Off-Road Racing is so far ahead of the Rock Crawling/Mud Bogging world that you would be well served to look to that venue for guidance. Yes, Crawling and Bogging have come a long way in recent years, particularly since veterans of the Off-Road Racing world like Walker Evans, Jon Nelson, Wayne Cook and others have crossed over. Suspension technology (Shocks, Triangulated Links, Spherical Bearings, Rod ends and countless other innovations and improvements on existing technology) used in Off-Road Racing is at highly developed state. In Off-Road Racing a rigid chassis is crucial; we let the suspension do the work, it’s tunable. Where original stock frames are required by class rules (Class 8, 7, 7S, 3 and others) frame boxing is seldom used. Rigidity comes from a properly designed and implemented cage, which is tied to the frame and body, creating one integrated system. If you are not going to build a proper cage, opting for your typical jungle gym configuration that is bolted to the floor, boxing your frame will add some rigidity to a poor design. There are some on this forum that will tell you that tying the cage to the body will cause cracking, or tying the cage to the frame will cause cracking, or whatever will cause whatever. In their case I’m sure they are right, because they did it wrong. Boxing you frame is a waste of time and weight. You are going to need a cage, so do it right. Follow Thom’s advice and check out Race-Dezert.com and other Off-Road Racing sites.
Have I pissed anyone off yet?
Have I pissed anyone off yet?
84gmcjimmy
1 ton status
baja blazer, so your saying that I should leave my frame alone, and just build a GOOD cage, mounted to the frame properly? I went to that race-dezert.com put I dont know where to look for some information /forums/images/graemlins/confused.gif
If your talking about me, then no, you'll have to work a lot harder to piss me off...
I still maintain what I've always said. That tying to the frame the way most people do it is a mistake and can/will lead to problems just exactly like what happens with the steering box fatiguing and ripping off the frame. Furthermore, the typical “frame tie in” does not really address rigidity that well either. To do it “right”, you would need to tie the cage in at all 8 of the spring mounting points. When the front stops well behind the fire wall, and assuming you have a strong/rigid tie-in, then all your doing is working the front horns against the rigid area which will reduce the life of the frame. They fatigue there anyway, haven’t you ever seen one crack there? Do you think adding to the fatigue at the fire wall is a good thing? Same for the back, but it’s easier to tie in on top of (or near) the spring mounts if you try. But if the tie-ins are spaced too far off the mounts, same thing with localized stress and fatigue; again, assuming the cage and tie-in are relatively rigid.
In short, as I've said before, I'm not totally against tying to the frame. I just think that the vast majority of the full body "rock crawlers" evangelizing/implementing frame tie-in are doing/recommending it wrong and are missing/ignoring reasonable options that are superior to an improper implementation. Follow your own suggestion and look at the desert racers you reference. They do a lot more than stick in a 6-8 point cage and add dog legs to the frame. Most of them that I’ve looked at (depending on class) are little more than a tube space frame with body panels hung on. Even the lower class trucks are a big difference from the average Joe on a with a tight budget, full bodied, daily driver having little tolerance for down time. And lets not forget the target audience. We’re talking a potential for 100+ mph rolls vs. the typical flop or 1-2 slow rolls of a “crawler”. Big difference…
I do however agree about boxing the frame, not worth the trouble, cost, and weight, especially if the goal is rigidity.
I still maintain what I've always said. That tying to the frame the way most people do it is a mistake and can/will lead to problems just exactly like what happens with the steering box fatiguing and ripping off the frame. Furthermore, the typical “frame tie in” does not really address rigidity that well either. To do it “right”, you would need to tie the cage in at all 8 of the spring mounting points. When the front stops well behind the fire wall, and assuming you have a strong/rigid tie-in, then all your doing is working the front horns against the rigid area which will reduce the life of the frame. They fatigue there anyway, haven’t you ever seen one crack there? Do you think adding to the fatigue at the fire wall is a good thing? Same for the back, but it’s easier to tie in on top of (or near) the spring mounts if you try. But if the tie-ins are spaced too far off the mounts, same thing with localized stress and fatigue; again, assuming the cage and tie-in are relatively rigid.
In short, as I've said before, I'm not totally against tying to the frame. I just think that the vast majority of the full body "rock crawlers" evangelizing/implementing frame tie-in are doing/recommending it wrong and are missing/ignoring reasonable options that are superior to an improper implementation. Follow your own suggestion and look at the desert racers you reference. They do a lot more than stick in a 6-8 point cage and add dog legs to the frame. Most of them that I’ve looked at (depending on class) are little more than a tube space frame with body panels hung on. Even the lower class trucks are a big difference from the average Joe on a with a tight budget, full bodied, daily driver having little tolerance for down time. And lets not forget the target audience. We’re talking a potential for 100+ mph rolls vs. the typical flop or 1-2 slow rolls of a “crawler”. Big difference…
I do however agree about boxing the frame, not worth the trouble, cost, and weight, especially if the goal is rigidity.
[ QUOTE ]
[ QUOTE ]
well if your suspension is flexable it is less likely to twist the frame. My frame only started to twist when the suspension began reaching it's limits. Might try to upgrade there first then see what the frame does /forums/images/graemlins/dunno.gif
[/ QUOTE ]
That's not true at all.
The more your rig flexes, the more it transmits into the frame.
[/ QUOTE ]
The frame is a spring with a very large spring rate. The suspension in comparison to the frame has a very small spring rate. Each moves in a ratio of their rates relative to the force. The stiffer the frame, the more work the suspension does.
If this link to Race-Dezert doesn't work you want to click on the "Skunkz" at the top right of the main page. Might also try the Pics link in the same banner.
[ QUOTE ]
well if your suspension is flexable it is less likely to twist the frame. My frame only started to twist when the suspension began reaching it's limits. Might try to upgrade there first then see what the frame does /forums/images/graemlins/dunno.gif
[/ QUOTE ]
That's not true at all.
The more your rig flexes, the more it transmits into the frame.
[/ QUOTE ]
The frame is a spring with a very large spring rate. The suspension in comparison to the frame has a very small spring rate. Each moves in a ratio of their rates relative to the force. The stiffer the frame, the more work the suspension does.
If this link to Race-Dezert doesn't work you want to click on the "Skunkz" at the top right of the main page. Might also try the Pics link in the same banner.
84gmcjimmy
1 ton status
Ah I dont know what to do.
I will check out that forum later when I have time to read everything. /forums/images/graemlins/peace.gif
I will check out that forum later when I have time to read everything. /forums/images/graemlins/peace.gif
Notice how the body is tied to the cage at every point where they touch each other, and cage is attached to the frame.
Triangulation is used to create a “Truss” effect (like the trusses in your roof) and make the cage/frame rigid.
Triangulation is used to create a “Truss” effect (like the trusses in your roof) and make the cage/frame rigid.
My frame is now entirely boxed with the exception of the first 1" and the last couple inches. I've left the ends open for bolt access and as stated before these portions are outside the extremities of the suspension mounting points and do not see the same forces or resistance against them that the rest of the frame does.
Total cost approximately 100 bucks. That is just buying the sheet steel in strips. I added in some for grinding wheels and what have you. Also used some material to rebuild the front most crossmember. I left the factory engine crossmember in place for now and it is now solid to the frame and gusseted to the verticals of the frame. As for weight I'm not sure how much was added but it wasn't much. The crossmembers I built weren't any heavier than factory and the sheet itself was probably around 75 lbs.
Now the fun part to finish the project with the cage. Getting the cage to finish stiffening the frame will definitely be interesting. I have a good plan. Now its time to pull it off.
Total cost approximately 100 bucks. That is just buying the sheet steel in strips. I added in some for grinding wheels and what have you. Also used some material to rebuild the front most crossmember. I left the factory engine crossmember in place for now and it is now solid to the frame and gusseted to the verticals of the frame. As for weight I'm not sure how much was added but it wasn't much. The crossmembers I built weren't any heavier than factory and the sheet itself was probably around 75 lbs.
Now the fun part to finish the project with the cage. Getting the cage to finish stiffening the frame will definitely be interesting. I have a good plan. Now its time to pull it off.
84gmcjimmy
1 ton status
woah! that is alot of bracing... so doing things like this with my cage with strengthen it?:
and making the cage attach to the body whereever I can will strengthen it too? You said they have to just leave there frame alone?
Thanks for the pics!
and making the cage attach to the body whereever I can will strengthen it too? You said they have to just leave there frame alone?
Thanks for the pics!
84_Chevy_K10
Banned
Yes they do, and all that bracing is necessary because unlike in rock crawling, if that vehicle rolls over, it's going to roll HARD and REPEATEDLY at high speed, thus it needs that much triangulation to protect the occupants.
84gmcjimmy
1 ton status
so since in rockcrawling, when you roll you go slow... so I wont need that much bracing.
Hmmmm, yummy eye candy. Thanks for the fix Ramsey!
One situation where it would make sense to start boxing the frame is where you know you won't put an adequate cage on it. You can pick up some stiffness and though it's inefficient, it doesn't intrude into the cab area at all. Piercing the cab to put in a well braced chassis and then patching it back to weatherproof condition is a lot of work for a skilled fabricator. You can also end up with a lot more interior noise and vibration.
I think there are some reasonable gains to be made in stiffness while still keeping your body and frame separate but we're really starting to fudge toward everyday street use when this becomes a priority.
When you start talking about offroad performance, following the lead of a well build desert racer is pretty smart. It's just a challenge to get all the tubes going the right places and still have full cargo areas, easy step in heights, factory climate controls, etc.
As for NOT building your truck to take a hard roll? Chances are if you have a serious wreck it's giong to be on the highway, so think about that. Also, if you take a slow roll that bends your roll cage past the usable point, you have a lot of work into getting it to where you can even drive it again. roll it with a well braced chassis and you'll be ready for action as soon as you're back on your wheels. My brother has now rolled his buggy twice and if we felt like being anal, we could fix one tube. Otherwise it's ready to keep using. Same situation with my K5 and the class 3 we're working on now. All have seen slow to moderate speed rolls and have sustained minimal structural damage.
How hard do you want to play?
One situation where it would make sense to start boxing the frame is where you know you won't put an adequate cage on it. You can pick up some stiffness and though it's inefficient, it doesn't intrude into the cab area at all. Piercing the cab to put in a well braced chassis and then patching it back to weatherproof condition is a lot of work for a skilled fabricator. You can also end up with a lot more interior noise and vibration.
I think there are some reasonable gains to be made in stiffness while still keeping your body and frame separate but we're really starting to fudge toward everyday street use when this becomes a priority.
When you start talking about offroad performance, following the lead of a well build desert racer is pretty smart. It's just a challenge to get all the tubes going the right places and still have full cargo areas, easy step in heights, factory climate controls, etc.
As for NOT building your truck to take a hard roll? Chances are if you have a serious wreck it's giong to be on the highway, so think about that. Also, if you take a slow roll that bends your roll cage past the usable point, you have a lot of work into getting it to where you can even drive it again. roll it with a well braced chassis and you'll be ready for action as soon as you're back on your wheels. My brother has now rolled his buggy twice and if we felt like being anal, we could fix one tube. Otherwise it's ready to keep using. Same situation with my K5 and the class 3 we're working on now. All have seen slow to moderate speed rolls and have sustained minimal structural damage.
How hard do you want to play?
84gmcjimmy
1 ton status
I want it to be so if I roll it on the trail, I can get it back on all 4, and continue as if it never happened, even if it bent a little bit, just not bend ALOT like some pics i've seen of rigs rolling, and the bars caving in, etc.
This rig wont see highway speeds, it will only drive on trails, and just my driveway (for pavement).it will be trailered.
I will take more looks at those desert trucks contruction of the cage and everything built with it. anyone know of anymore good off-road racing sites to look at? I will do a google after dinner.
What about if I just got some straight square steel tubing, and used that? (same size as the frame, just thicker wall maybe) and didn't bend it. I haven't exactly seen where the body mounts-compared to where the bends are in the frame, but if I cut the floor it would probably work, and be alot cheaper than finding someone to custom build me one.
You said, "how hard do you want to play", well I want to beable to drive it threw trails, roll over a few times in a weekend, and go back home (on the trailer) with minimal structural damage. This is far in the future though, as I dont have alot of skills to wheel yet, the way I am looking at it, build the best rig I can afford, and learn to drive that, instead of keep changing it, so I have to re learn how to drive it and get used to it.
This rig wont see highway speeds, it will only drive on trails, and just my driveway (for pavement).it will be trailered.
I will take more looks at those desert trucks contruction of the cage and everything built with it. anyone know of anymore good off-road racing sites to look at? I will do a google after dinner.
What about if I just got some straight square steel tubing, and used that? (same size as the frame, just thicker wall maybe) and didn't bend it. I haven't exactly seen where the body mounts-compared to where the bends are in the frame, but if I cut the floor it would probably work, and be alot cheaper than finding someone to custom build me one.
You said, "how hard do you want to play", well I want to beable to drive it threw trails, roll over a few times in a weekend, and go back home (on the trailer) with minimal structural damage. This is far in the future though, as I dont have alot of skills to wheel yet, the way I am looking at it, build the best rig I can afford, and learn to drive that, instead of keep changing it, so I have to re learn how to drive it and get used to it.
