Why not drill ROPS?

[penokee]

Warranty aside, what's wrong with drilling a few holes in your ROPS to support an overhead Falling Object protector? My pickup frame has numerous holes drilled at the factory. doesn't make it any weaker far as I know.

Have to install something over my head to protect from falling brances, etc. Seems that a couple of holes in the ROPS vs catching a branch on the head is a good tradeoff. Comments?
penokee /forums/images/graemlins/smile.gif

 

[JerryG]

Nothing if your family wants to take a chance on weaking the structure. Just use U-bolts.

 

[Bird]

Penokee, I suppose any time you remove some metal from that ROPS you weaken it to some extent. Now what that extent is, I don't know. But I'm sure liability issues are the reason for the manuals saying to not do it. So if you turn the tractor over, and the ROPS should collapse, your heirs will want to sue the manufacturer. They'll have a harder case to win if it has any holes drilled in it. /forums/images/graemlins/wink.gif

 

[frank_f15]

IN my estimation there is nothing wrong with drilling a few holes in the rops, BUT i am sure that if something happened and you got hurt ,they will say that you voided the intergerity of the ROPS by drilling holes..

 

[GEB]

I guess it all depends on where and if you have a clue
about stress points....
I have even cut mine down a few inches to fit in
my storage building.
I also build roll-cages as a 2nd income so I do have a
bit of a clue, even though the height is a factor in safty also.
I'd say if ya have to ask, your not sure, then maybe dont drill.
As said u-bolts or maybe weld some studs...?
Better yet cut the branches /forums/images/graemlins/smirk.gif
Gene

 

[RobS]

I'll give you the engineering answer but I'm sure you'll find many other answers as this has been a hot topic in the past.

Your ROPS is a structural member and is designed/tested to meet specific strength criteria. It is designed/tested without additional holes. Holes can be "stress risers" in structural members. In the wrong place they can greatly magnify the stresses, to the point of failure.

Your truck frame is also a structural member and is designed/tested to meet specific strength criteria. It however, is designed and tested with many additional holes for many intended purposes. You pay for that flexibility in additional steel, weight and cost but trucks are intended to be flexible vehicles so that cost is generally acceptable.

With as many ROPS drilling posts as there are on TBN you'd think the manufacturers would catch on and incorporate some holes and/or accessory brackets. If designed/tested from the beginning the ROPS could be made to meet the specific strength criteria and us users would probably pay a little more for the convenience.

A side note and a research project for someone: Compare the frame of your typical big three pickup truck to the new Honda Ridgeline. I'll bet the Honda has fewer "additional" holes allowing it to be thinner, lighter, less expensive. Typical Japanese design optimization.

Also take a look at the front of your truck frame, around the bumper mounting area. Sometimes holes are added specifically to weaken a structural member. The front ends of most modern vehicles are loaded with holes, ripples and other features designed to crush very predictably and absorb energy during a collision. The energy absorbed by the frame crumpling is energy NOT going into your body upon impact and that's a good thing.

So there is the generic engineering answer to your question. Only the ROPS designers, or others who have done structural analysis on your ROPS can tell for sure if a hole will be detrimental. Lawyers are not generally engineers and will work hard to convince a jury of non-engineers in the event of a mishap /forums/images/graemlins/smile.gif

 

[GEB]

BTW my ROPS has a hole on each side near the top, with a
threaded nut welded to it.
I would think if ya drilled a hole no bigger than needed
then welded a nut on top of the hole you would maybe
not loose any strenght with a good weld?
This keeps you from drilling all the way though, and the
nut provides added strenght.
Gene

 

[VA_Joe]

Well said.

 

[penokee]

Appreciate all the replies. The attched picture shows the situation I'm frequently in. Tractor may bump a dead tree or tree being skidded may. Plan on thinning a 10 acre plantation, and just don't have time to remove all hazard trees ahead of time.
penokee

 

[penokee]

Typical skidding situation.
penokee /forums/images/graemlins/smile.gif

 

[sassafraspete]

I read the title of this thread and before looking at it....thought Henro must be back from his walkabout.....

 

[RoyJackson]

I would think if ya drilled a hole no bigger than needed
then welded a nut on top of the hole you would maybe
not loose any strength with a good weld

Actually, welding can create stress risers too, in certain harder steels.

If I was going to drill a ROPS, I'd drill the hole (just big enough to accomplish the task) and chamfer inside and out. That would distribute the stresses since there would be no sharp corners.

I doubt if I'd ever have to on my Deere 790. The ROPS is a bolted structure using two vertical members, two cast or forged elbows, and a top section. If one adds a backhoe to a 790, the ROPS is modified by adding two extensions on the vertical members, then the elbows are bolted to that.
So, I could use the existing bolt holes, if necessary. I may have to use longer bolts of the same grade, however.

Unlike a truck chassis, the ROPS isn't being subjected to the constant twisting and vibration resulting from driving. My opinion is drilling (and chamfering) a ROPS isn't near the risk it would be on a truck chassis.

However, I'd still prefer to go with the U-bolt idea.

 

[have_blue]

The ROPS, in an actual roll over prevention event, takes most of the force down near the attachment point. (because of leverage.) There is relitavely little force near the top of the ROPS bar. I would say avoid drilling down below the seat back, period. Near the top of the bar where there is relitavely little force, judicious drilling is probably harmless. The top of the bar (cross member) is also subjected to relitavely little force in a rollover.

I would worry less about a single, small, clean bolt hole than an overly tightened bolt or U bolt. Wherever you bend or crush the bar, that's where the weakest point will be.

 

[shepherd]

all we did was bolted a bracket to through
the original holes then wielded onto that for the canapy

 

[Slamfire]

Skidding like that won't leave many trees after you've thinned the plantation. You wouldn't damage as many trees if the landing was on one edge and you started thinning from that point. /forums/images/graemlins/crazy.gif

 

[1bush2hog]

Does your tractor mfg. offer a FOPS? If so, maybe this is the way to go since it would be designed specifically for your tractor.

I just ordered a steel FOPS canopy from NH for my TN75 - not cheap, but I figured if it was designed for my tractor and installed by dealer, then maybe it is worth the extra cash - maybe not.

The other option would be to have someone design and build a 'cage' type protection system incorporating FOPS and ROPS into the design.

I considered this also, but thought I would try the steel canopy first, figuring it would be the least expensive of the two options.

Hopefully I will never get to test it /forums/images/graemlins/grin.gif

 

[RedRocker]

I'm in the same boat with my land, my solution was to build a FOPS. I welded 4 tabs on my ROPS and have absolutely no qualms about strength issues, I too build roll cages. Here's a pic.

 

[1bush2hog]

Nice Job Red!!!

I would have preferred this type of FOPS. I could not tell from your pic whether or not you have a metal mesh over top of the metal bars to prevent any smaller pieces from hittin' the ol' noggin'?

Wish I had that talent, time, and skill to do the same on mine-

Do you make 'tractor calls'? /forums/images/graemlins/grin.gif

 

[RedRocker]

I've been using a tarp for shade and small stuff, I'll be making an aluminum top when time allows. If you were just a little closer. /forums/images/graemlins/smile.gif

 

[penokee]

Red - Nice. If you don't have any objections plan to take some of your ideas along with Henro's and have the local Welding Shop make something up.
penokee /forums/images/graemlins/smile.gif
Ps: Many good coments and ideas as usual - thanks all.