Canopy - Clamp or Drill mount to ROPS??

[Tom_Veatch]

Oh, I don't know about the "doom and gloom" part, but I do know when I pay good money for something intended to save my rear when the **** hits the fan, I'm not gonna intentionally do something to it that may compromise its ability to save said rear.

 

[IslandTractor]

I agree with you Tom but I really don't see the danger in drilling a few quarter inch holes in the upper structure of the ROPS. Those things are sized as big as they are (I'm talking about the steel not the overall size) becasue there are considerable forces placed on the lower part of the rops due to the lever arm (? terminology here it's been a while since I studied physics) when a tractor rolls...am I correct? If so then the upper arch of the ROPS is way over built and could surely tolerate a few small holes (especially if there were bolts and washers) without affecting structural integrity.

 

[Tom_Veatch]

...
If so then the upper arch of the ROPS is way over built and could surely tolerate a few small holes (especially if there were bolts and washers) without affecting structural integrity.

It is quite likely, even probable, that you are right. I would not, however, put my stamp or seal on the change without a lot more investigation and analysis. I remember the collapse of the Hyatt Regency Skywalk in Kansas City on July 17, 1981. A seemingly innocuous design change by the building contractors changed the load paths enough to kill 114 people and injure another 200+.

As long as there is a satisfactory alternative to machining/drilling/etc. the installed ROPS - effectively changing the design - I would opt for that alternative and strongly recommend that course for others. Just my opinion, non-binding on anyone but me.

 

[dbdartman]

From the "for what it's worth" file:

I've built many many NHRA certified roll bars & cages, so I feel somewhat qualified to address this subject.

I would have no problem drilling a ROPS if the hole is sleeved & welded!

Simply find a piece of tube your intended bolt will fit through (not too tight!), cut it about 1/4" longer than the thickness you intend to install it in, drill your ROPS slightly larger than the OD of your tube (1/64" -1/32" works) & weld the tube in with equal over-hang on both ends. Touching the flat ends of the tube with a grinder/sander after welding, if your weld is too big, assures flat mounting surfaces. This way the structure is not compromised.

BTW, the weakest parts of a ROPS (or roll bar/cage) is at the bends & where it mounts to the chassis/frame.

And that's my 2-cents worth on this subject, take it for what it's worth!

DB

 

[Soundguy]

I was actually speaking of tractor warranty.. however.. I guess rops warranty my be a possibility. My rops have a sticker on them that says -ALL- warranties are null and voidd if the rops structure is modified. I'm sure that was added by a lawyer.. not an engineer.. but then.. it will be the lawyers who will litigate.. etc.

As for the insurance co. needing to proove that a mod tot he rops caused a problem.. well.. you can try that.. however... my bet.. is that a judge.. or a reasonable jury.. will view a non-certified modification to a safety advice as 'lending;' to the failure or accident.. i.e. reasonable doubt.. etc.

Soundguy

It's always dangerous disagreeing with Soundguy but.....

Warranty on a ROPS? How many warrranty claims are there on ROPS'?

Insurance claim is different but it would still be up to the company to show that some minor modification somehow grossly affected the strength of the product. I doubt the places that you would drill holes for a canopy are the structurally weakest areas of a ROPS. I presume the manufacturers use square tube rather than a tapering tube for economic, not engineering reasons. The top section of the ROPS must therefore be "over engineered". Common sense in using the smallest appropriate bolt (hole) near the top of the ROPS would seem prudent and not drilling anything at the more highly stressed base of the ROPS also prudent.

 

[Soundguy]

I'd say that is great advice... as long as you are willing to sign your name to the work, and offer up your insurance carriers info to cover any problems encountered.. ( that darn liability issue... )

Soundguy

From the "for what it's worth" file:

I've built many many NHRA certified roll bars & cages, so I feel somewhat qualified to address this subject.

I would have no problem drilling a ROPS if the hole is sleeved & welded!

Simply find a piece of tube your intended bolt will fit through (not too tight!), cut it about 1/4" longer than the thickness you intend to install it in, drill your ROPS slightly larger than the OD of your tube (1/64" -1/32" works) & weld the tube in with equal over-hang on both ends. Touching the flat ends of the tube with a grinder/sander after welding, if your weld is too big, assures flat mounting surfaces. This way the structure is not compromised.

BTW, the weakest parts of a ROPS (or roll bar/cage) is at the bends & where it mounts to the chassis/frame.

And that's my 2-cents worth on this subject, take it for what it's worth!

DB

 

[whitetiger]

All ROPS manufacture's will tell you not to drill or weld on the structure.
Also, it is not legal to sell or trade a tractor with modifyed ROPS.
We have had to discount trade ins the price of drilled Rops and replace them with a new one.
Our lawn and garden service drilled a hole in a grasshopper ROPS to mount a radio this summer and cost use a new ROPS to replace the new one he had just bolted on a hour before. The first one make for some very expensive powder coated scrape iron.

 

[IslandTractor]

Also, it is not legal to sell or trade a tractor with modifyed ROPS.

I'm confused by this statement. Is that a federal law?

Why are there no similar laws regarding modification of automobiles. Certainly people do all sorts of crazy things to suspensions, body, engine etc etc on automobiles (which after all travel much faster than tractors and are at much higher risk for serious "kinetic" accidents)?

I fully appreciate that the tractor company lawyers go nuts with disclaimers etc because it is cheaper to forbid doing anything at all to the tractor than it would be to defend a claim. I presume those sorts of disclaimers can be challenged.

Also, while I appreciate the concern with drilling is that you would weaken the ROPS structure, I would point out that adding anything to a ROPS whether by Ubolts or welding or bolting potentially weakens the ROPS too. A well constructed canopy could hit an object while tipping over (say a wall or tree trunk) and instantly add a shock or twisting force on the ROPS that the ROPS was not engineered or built to withstand. Does adding a canopy count as a modification to the ROPS too?

 

[Soundguy]

My sticker specificaly says drill or weld.. hard to tell if they 'imply' other reasons too.

One would think ( assuming here... ).. that if it is a dealer installed rops and a dealer installed canopy.. then it is 'compatible' equipment. Seems it would be the same issue if you added a FEL to a tractor, as you are adding weight...

I also notice many ROPS units are designed to fit multiple tractors... thus implying they have a 'range' of weight characteristics.

I'm not a lawyer.. just guessing here.

I also truly believe that the safety issue is actually the 2nd reason for the rops, and liability is the 1st reason.. even if 'safety 1st' is the best idea.. etc.

Soundguy

 

[mark1]

My Compact tractor came with Foldable ROPS and a canopy. But I have never installed the canopy. so there's these big ole 1/2" holes in the tubing.no sleeves/etc.
Remember "sometimes you have to shoot the engineers and go get the job done!"