deuce frame reinforcement

[BFR]

I am thinking of using 1"x3"x14' DOM as a spacer under the boom & bed (and under the rear 2' of the cab) with the thought that it will reinforce the frame. this will replace the wood strips found under the cargo bed. Any thoughts or observations?

 

[pa.rich]

You may have to drill holes where the rivets are and the oak would be able to work easier.

 

[BFR]

I know about the rivets/need for holes... my main concern is frame reinforcement

 

[andyindy]

If I understand you correctly, the plate must be on "edge" to have any stregnth. I've seen trucks stretched at professional shops and they weld in the piece of donor frame and then "plate" the outside of the rail, top to bottom, or the depth or the rail. They use flat plate and bolt or rivet it to the frame. Again, this plate is on edge or side of rail.
On your project, I would go under cab as far as practical and back to the bogie mounts. I've thought about this very project also, but haven't come up with a knuckle boom yet. Just my worth, I'm sure others will offer thier views also Keep us posted Andy.............

 

[cranetruck]

Joel, you may want to read up on structural engineering...
One reference I have is chassis requirements for "Auto Crane Co" cranes and one K-boom weighing 4,755 lb requires a section modulus of 21 cubic inches which results in a frame resistance to bending of 1,000,000 in lb.
One way to achieve a higher section modulus is to add a C-channel, which was done on the International truck that originally had my HIAB mounted. It was about 6 inches high.

For comparison, my 8x8 truck frame is made from 9 inch channel with 3 inch flanges and it has a section modulus of about 9 cubic inches...

On my deuce, I have a 3x3 inch solid steel spacer and don't know what that translates into, but have no problems after 13 years of service. I do , however, leave the boom extended over the bed 99% of the time to reduce front axle and frame loading....

Edit: When crane is used, the load is taken up by the outriggers.

 

[Srjeeper]

BFR,

Perhaps you should consider talking with your local truck 'frame shop' or 'truck body' dealership about your idea. I know for a fact that too much reinforcement is just as bad if not worse, than too little. The wood needs to be there to prevent wear when the frame flexes, and they do need to flex or things will break.

 

[pa.rich]

Yes ,i thought you meant the choice of spacer material between the reinforcement and the chassis. sorry.

 

[Stretch44875]

The deuce wreckers(and I think dumps, maybe tankers) Have a plate riveted to the side of the frame rail, from the spring hanger for the front axle, to the rear axle. Also have overload bars for the rear springs. There is a truss welded under the cab, to the bottom of the frame also.

 

[Jakob]

Holy dirty Deuces Batman!

Is that your personal truck or just some pictures you found? I can see the plate in the first pic, but can't make out what you're referring to in the second one.

 

[BFR]

anyone know what the specs on deuce frame material?

 

[Rolling_Eudaimonia]

Double frame the chassis, it is simple and works.

 

[Stretch44875]

Yep, my truck( M108 It's dirty alright, came to me that way). In the second pic it is showing the i-beam across the top of the springs, same as 5-ton wreckers. Has about 2-3 inches of travel in the spring, then hits the i-beam to keep from overloading the spring.
Dennis

 

[grounded]

 

[yeager1]

I am thinking of using 1"x3"x14' DOM as a spacer under the boom & bed

Do you mean 1"x3" solid steel bar or rectangular tubing? And if rectangular, what wall thickness?

 

[supermechanic]

Do you mean 1"x3" solid steel bar or rectangular tubing? And if rectangular, what wall thickness?

DOM means drawn over mandrel, it is a tube, in this case it has a rectangular cross section.

To address the frame stiffening question, the DOM, if just attached to the frame with a few connections through the top flange, will have little effect.

The frame needs a second member sandwiched to the web.

Any major truck shop can get you pointed in the right direction.

 

[yeager1]

DOM means drawn over mandrel, it is a tube, in this case it has a rectangular cross section.

I'm familiar with DOM, but since rectangular DOM in fairly uncommon (but it is out there) and no wall thickness is listed I wanted a little clarification.

Adding material to the top of the frame will help spread a vertical load, like a knucleboom or top mounted winch, and dissipate the stress points from were the boom attaches to the web, keeping the web from cracking. But once you get a small distance away from the unit, it does little to help with overall strength because its vertical cross section is too small. I have a 14k capacity knucleboom and a 30k winch truck (top mount-behind the cab), if anyone is interested, I can take some pictures of the attachment points.

 

[BFR]

I used a poor choice of words in the original question.
Think of this as an attempt to spread the load over a greater area of the frame.

The thickest wall 1.5"x3" tube I have found is 3/16

I am not opposed to using solid stock if it will do a better job spreading the load.

edit: pics of what I am thinking...

 

[BFR]

if anyone is interested, I can take some pictures of the attachment points.

I would like to see them

 

[Jones]

You might want to look into structural shapes and their characteristics.
With sufficient wall thickness, tubing- round or box, is often stronger than solid.
DOM tubing is usually more expensive and only used if a very specific inside or outside dimension is required.
Steel comes in all levels of carbon content but the higher strength alloys often require special welding practices. It's a balancing act to get adequete strength and still be workable.
If bolting it together I'd tend to go with fine thread bolts with a flat washer on either side and locking nuts. A lock washer isn't a good choice as it only locks the nut against the washer, not against the parent metal.
Fish plating the frame web will add to the strength as will "boxing" the frame (making a piece of channel that will just slide into the open side of the existing frame, forming a box) it's the best if fitting the inner channel isn't a monumental project.
Above all you want to try and keep the flexibility of the frame somewhere close to original as a section that's too stiff will present problems of it's own in rough terrain or after some time in service.
I'm not condoning doing a poor job but does practically fit into the equation? If a fish plate re-enforcing job will give you ten years of service but you only plan on keeping the truck in it's present configuration three or four, then is overkill worth it?
Riveting is the best means of re-enforcing attachment as the rivets swell into the drilled holes and will allow for a certain amount of flex, unlike a weld; and don't tend to loosen up, like a bolt.
Unfortunately, hot riveting isn't for the home shop as it requires a forge or heat source to get the rivet red-hot, a riveting gun (not an air hammer) with the proper "sets or snaps", and "bucking" bars to hold the rivet in place while it's being set.
We do hot riveting at work but it isn't something I'd try at home-- even given the time I've managed to acquire as an ironworker.

 

[tm america]

it would help just a little you'd be better off putting a piece of plate steel down the inside or outside of the frame and riveting it to the frame or bolting it on through any factory hloes that are there try not to drill or weld to the frame it is tempered steel and is made to flex without cracking putting a tube on top of the frame and only attaching it to the top could cause stress cracks by letting the sides flex and not the top .remember the sides hold the vertical load the sides just keep it straight