ROPS modification

[dlctcg]

Engineered holes = signed off by an engineer to still meet the required spec for the ROP to meet the current safety standards they have to meet.... (to save lives)... is it necessarily over-kill... maybe sometimes...

I'm in the building trade & it is the same.... an engineer needs to approve certain applications / penetration's in building materials so they meet building & safety code.... This is the norm in my world...

If your wondering what the difference is... a Degree which allows them to sign off & stamp their name on an approved specification (that they are liable for) which will hold up to a certain criteria of abuse prior to failure.... I deal with engineers all the time.... well worth our dime...

 

[bmaverick]

Skip to about the 4:05 mark in that video. I wonder what the difference is between the "engineered holes" drilled into the ROPS and someone else's holes drilled into the ROPS. Please explain what that means.

There is an OSHA CFR regulation that fully defines what the holes are engineered for. Either the holes are located where an additional wall insert is welded inside or it's at a structure location not to compromise the strength integrity of a roll over event. And engineering is done on CAD with FEA tools and DVT (Design/Validation/Test) for production intent are tested to extremes vs. a DIYer wanting holes in a location with no testing. ROPs are not cheap by any means, neither is a person's life. Testing must be done prior on models the ROPs are intended for.

1928.51 - Roll-over protective structures (ROPS) for tractors used in agricultural operations. | Occupational Safety and Health Administration

osha.gov

Home | The Kentucky ROPS Guide

rops.ca.uky.edu

Work on this project was supported by CDC/NIOSH Cooperative Agreement 3 U50OH007547-07S1,
Southeast Center for Agricultural Health and Injury Prevention, University of Kentucky.

Agricultural Safety & Health

Name First Last Email My question is

fyi.extension.wisc.edu

For our Canadian friends
California Code of Regulations, Title 8, Section 1596. Roll-Over Protective Structures (ROPS).

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Cost-effective Rollover Protective Structures (CROPS) | NIOSH | CDC

Performance Testing of NIOSH CROPS Designs​

NIOSH developed several designs through multiple iterations and tested them against the requirements of J2194 which was the accepted industry standard in 2008. NIOSH tested the tractor reference mass for these designs, and they exceeded the SAE J2194 standard by 25-32%. For example, the Ford 3000 has a suggested reference mass of 5300lbs (2404 kg); the tested reference mass was 7000lbs (3175 kg), which is 32% more than the suggested reference mass.

The Ford 3000 and 4000 model tractors’ axle housings were designed to support the installation of a ROPS by the manufacturer. The Ford 8N passed an axle strength test with a factor safety of two when evaluated by an external research study.10,11 The Massey Ferguson 135 axle is very similar to the Ford 8N axle and is considered to be of equal strength.

In 2016 a new industry testing standard, International Organization for Standardization (ISO) 570012, replaced SAE J2194. NIOSH is exploring having an external party assess if the CROPS designs are in compliance with the current ISO 5700 testing standard.

 

[bmaverick]

Skip to about the 4:05 mark in that video. I wonder what the difference is between the "engineered holes" drilled into the ROPS and someone else's holes drilled into the ROPS. Please explain what that means.

Tinback,

Here, I'll show you my ROPs engineering drawings certified to the OSHA regulations and the NIOSH Cooperative Agreement 3 U50OH007547-07S1

BTW, ROPs isn't just a roll bar on the machine. By law, it has to have seat belts too.

Manufactured ROPS has to have a certification sticker that defines several items for qualification. See the OSHA link I had posted above.

See attached.

 

[3Ts]

The way I see it is that it doesn't really matter if the modification to the ROPS is safe from an engineering standpoint. It's "if you changed it, it's now your liability". I personally would not modify a ROPS so that the liability stays with the manufacturer who has engineered and tested it to perform properly. Heating and cutting metal can do odd things when stressed in unusual ways.

 

[Tinhack]

Shoooooo! What a snow job. OSHA rules only apply if you have employees, not home owners or personal use tractors. All it says is the tractor must have seatbelts--For employees. And it only means something if the employee/driver actually wears the seatbelt. Have you actually looked at a ROPS? I mean a factory ROPS, not a CROPS or CRAPS more like it. The CROPS are full of un-backed holes. I've included a pic of one of the CROPS you note below.

My factory ROPS came with "engineered holes" and there's no internal backing. And yes, it has a label attached. Hard to tell (signs of welding) in the video if there's backing since the paint job is so bad but I'd be willing to bet there isn't. One way to tell if there's factory backing is to put a bolt through it and start tightening a washer and nut on the other side. If you see the wall(s) start to deform, STOP. There's no backing.

I'll be using "pass-through tubes" at my factory top mounts to stop the compression. Mine are factory 1/2"+ holes so I'll use a tube through each hole with the bolts passing through the tubes and the ROPS. The compression force will be applied to the tubes, not the walls of the ROPS.

Incidentally, my new lawnmower came with holes in the ROPS and it doesn't have backing behind the "engineered holes" either.

 

[Jimbo16720]

I understand the drilling part but the welding makes no sense. I'm sure they don't temper these bars they use and that's all the heat of welding would change.

 

[hiddentacocatneddih]

Im sure welding is fine as i assume its mild steel. But the weld should probably be decent and not add a bunch of burn thru holes and such.

Safety police will come in and hound you regardless. But i wonder how many of them have a rops but dont wear a seat belt everytime they sit on the tractor.....

 

[Jimbo16720]

Well my Kubota L245dt didn't come with a ROPS so I'm making my own and will weld anything I want on it.

 

[flyerdan]

The fanatical abhorrence at ROP modification is probably a blanket policy that's aimed at those who either didn't take or failed physics; the same people who are puzzled at why a trailer facing downhill will try and run away from them when they start to drive something onto it, or think that one loose strap across a skidsteer is good enough.
I don't balk at any modification; if I was drilling through a RT rollbar, I'd drill big enough to put in a piece of round tube so it wouldn't collapse, thereby making it stronger than original. Even weld on a couple of fender washers for doublers if there was a significant moment arm that could cause problems. Of course, that level of detail is better suited to a place like The Smallest Cog rather than a fabrication facility which banged out the ROPS in the first place.

 

[bmaverick]

The fanatical abhorrence at ROP modification is probably a blanket policy that's aimed at those who either didn't take or failed physics; the same people who are puzzled at why a trailer facing downhill will try and run away from them when they start to drive something onto it, or think that one loose strap across a skidsteer is good enough.
I don't balk at any modification; if I was drilling through a RT rollbar, I'd drill big enough to put in a piece of round tube so it wouldn't collapse, thereby making it stronger than original. Even weld on a couple of fender washers for doublers if there was a significant moment arm that could cause problems. Of course, that level of detail is better suited to a place like The Smallest Cog rather than a fabrication facility which banged out the ROPS in the first place.

Yes, there are the Smartest Cog ROPs makers and then there is Custom Products certified to the standards and testing. Many of the big name brands use Custom Products to manufacture their ROPs.

On the Gray Market tractor side of things, there are plenty of Smart Cogs making ROPS from Vietnam and China.