deuce frame reinforcement

[cranetruck]

Joel, going back to my post about section modulus, it should be made clear that the number is for each rail.

Did you find a formula for the C-channel?

Edit: Call HIAB and ask for actual requirements.

 

[m16ty]

remember the sides hold the vertical load the sides just keep it straight

If I get what you're trying to say " the flanges don't hold any vertical load" I'd have to disagree. For the frame to bend down the bottom flange has to get longer and the top flange has to get shorter. On a "C" channel it's not as much but on a "I" or "H" beam it gives the beam most of it's strength.

 

[BFR]

Joel, going back to my post about section modulus, it should be made clear that the number is for each rail.

Did you find a formula for the C-channel?

Edit: Call HIAB and ask for actual requirements.

everything I have found to determine section modulus requires that I know what type/ grade steel the frame is made out of. (I don't, anyone know????)

Here is my thinking...

Based on the fact that you have been satisfied with your mounting method I am planning on replicating it, but there are some issues with this...
-First, to the best of my knowledge, my boom weighs 300-400 pounds more than yours... an increase of roughly 10%.
-Second, my boom spreads the load over 8" more frame space than yours ... an increase of roughly 33% more.

My first thought was to make a spacer like yours, but to extend it out a little to spread the load (now I am leaning towards towards a 7' piece [a little more than 2' further than the crane]), but a 3" piece will not fit w/o lifting the cab/bed, so two pieces stacked (on piece 7' and one rougly 3' stacked on top directly under the crane.

 

[cranetruck]

Okay, the yield strength is probably 110,000 psi, since that's what my 8x8 is made of (frame) and also what I have noted for the new MTVR trucks.

As far as the load on the truck, the short wheel base is a plus, but folded behind the cab, my crane adds about 1,000 lb to the front axle load (measured on truck scale). That's the reason I switched to 1100-20 tires way back when and also keep the boom over the bed whenever possible....the winch was removed as well to lighten the front axle loading.

 

[tm america]

it is the sides that give it the load capacity .just think of it like this a 8 ft 2x4 has has about a 250pd rating on its side but a almost a 1000 pd capacity on its side. a piece of 1/4 inch plate that is 3inches wide will bend with a couple hundred pounds force but will hold a thousand pounds on end it works as a system. it works like a floor in a house the sub floor doesnt carry the load the floor joists do the sub floor only holds everthing straight .when they brace the frame on chevy trucks they put a plate on the side of the frame .yes adding another frame rail inside the rail that is there is best but is alot of work and every costly doubling the top and bottom plates does almost nothaing to help €carry the load look at how they braced the frame where the rear suspension attaches to the frame they put a big plate of steel on the side of the frame with no reinforcement of the top or bottom

 

[wdbtchr]

Question: what exactly is the difference between and air hammer and a rivet gun? We used to hammer rivets with a sledge hammer way back out of lack of experience and youthful exuberance. ie: young and dumb and full of .... (what ever).

I think before I went to all that work, I'd just get a 5 ton.

 

[yeager1]

BFR, here are the pics. This knuckle boom is rated at 14,500 lbs and has a max length of 32', so the mount is a little beefier then what you'll need. The boom transfers 100% of the load to the sides of the frame and has no hole through the top web. Each side is held on by 12- 3/4" bolts (grade which are actually stronger then the rivets WHEN torqued properly (over torque stretches the bolts past their elastic point). The second picture shows both the front and rear mounts. This is definitely the best way to mount it, without doing a full double frame. Let me know if you need more pics of info.

 

[Wolf.Dose]

Nice to hear somebody is pointing out overtorquing of bolts. May be he heared of the Hexagon program. Anyway, overtorquing is the death of any bolt (AND NUTS AS WELL).
Guys, allways stay to the recomended torques of the Manufacturer, thei can not be that wrong. May be with todays knowledge the result might vary, however, the tendency is the same!
Wolf

 

[tm america]

great mounting job .it braces the frame the way its mounted rather than creating stress points. although i do see some atvantages with smash rivets cuz they expand in the hole and stop things from walking in the hole we use to use them to assemble the frames when i worked at monon trailer build semi trailers.bolts allow rust to form in the hole where rivets seal the hole . have you ever cut the head off of smash rivets and then still had a hard time with a air hammer getting them to pop out the hole.but i think bolts are best for that app.since you would need alot of rivets and the proper tools to smash them uniformly but you cant over torque a rivet

 

[yeager1]

Nice to hear somebody is pointing out overtorquing of bolts. May be he heared of the Hexagon program. Anyway, overtorquing is the death of any bolt (AND NUTS AS WELL).
Guys, allways stay to the recomended torques of the Manufacturer, thei can not be that wrong. May be with todays knowledge the result might vary, however, the tendency is the same!
Wolf

Couldn't agree more! Without trying to get over technical, when torqued properly, bolts actually stretch slightly and remain elastic like a spring- so they are constantly pulling the bolted member together with massive force, just like a compressed spring does. When you over-torque a bolt, you go past its spring point (called it's modulus of elasticity). At this point it not only looses it's spring tension- which makes WAY more force then if you make it "tighter", but since it's not preloaded with tension anymore, it will also loosen easier. Failure strength is also compromised. So you get a looser fit, weaker bolt that will back off and come loose quicker... use a torque wrench.

 

[hndrsonj]

BFR, SECO has a parts 108 that has a bent frame. You could always remove the frame doubler from that one to use as a template for yours. As long as they know it is bent and going to be used as a template it would probably be pretty reasonably priced.

 

[scooter01922]

parts 108 you say???? hmm, thanks for the tip. Good to know all the parts sources.

 

[hndrsonj]

Actually 3, plus one at Hawthorne tractor. Oh, think I saw 2 at Barstow Equipment also.

 

[cranetruck]

Nice to hear somebody is pointing out overtorquing of bolts. May be he heared of the Hexagon program. Anyway, overtorquing is the death of any bolt (AND NUTS AS WELL).
Guys, allways stay to the recomended torques of the Manufacturer, thei can not be that wrong. May be with todays knowledge the result might vary, however, the tendency is the same!
Wolf

Yes, proper torque is important.
Posted a number of pertinent PS mag articles (old site) over the years on this, for example:
Steel Soldiers :: Military Vehicles Supersite

Edit: added image (right click and open link in new window for good resolution).

 

[rmgill]

Hey Joel, what did you use to actually attach the crane to your bed? Large U-Bolts? Got any photos of the attachment area?