B7200 ROPS

[Paul Allwood]

The first thing I made for our "new" B7200 was a ROPS. I bought the tractor to build and fit a front loader, and thought it would be better to have the ROPS first, as if I built the loader first I would be tempted to use it without a ROPS. The mounting is based on pics of a bought one and it's fabricated from 12 mm steel plate. The square tube is 50x50x5.

I'm not sure I like the width as it is - might make it a little narrower and have a go at bending some rounded corners for the top.

I also think I'll reinforce the mounting by using the 4 threaded holes in the axle housing either side of the current mounts. May even add some bracing to the corners.

I also added a seatbelt that came out of an old 60 series Landcruiser that we still have sitting here collecting rust since we last drove it about 15 years ago.

Half the reason for buying a small tractor was to use it, the other half was to make things for it.

 

[Runs With Scissors]

Half the reason for buying a small tractor was to use it, the other half was to make things for it.

I didn't realize this until after I bought it, but that is so true.

Great job though, looks nice and the rounded corners would definitely give it a "factory look".


I think the width looks just about right though.

If you make it "skinnier" , wouldn't that allow for more rotation in the case of a roll over?

 

[Paul Allwood]

I didn't realize this until after I bought it, but that is so true.

Great job though, looks nice and the rounded corners would definitely give it a "factory look".


I think the width looks just about right though.

If you make it "skinnier" , wouldn't that allow for more rotation in the case of a roll over?

Thanks. I suspect we're not the only ones who bought a tractor so we could make things for them.

I also think rounded corners on the ROPS would look a bit better, and less chance of getting caught on low branches. Not sure yet if I'll be able to bend the corners yet though.

Skinnier would allow more rotation if I manage to lay it over sideways, but I don't think enough to worry about. Still just thoughts at this stage.

 

[Runs With Scissors]

Thanks. I suspect we're not the only ones who bought a tractor so we could make things for them.

I also think rounded corners on the ROPS would look a bit better, and less chance of getting caught on low branches. Not sure yet if I'll be able to bend the corners yet though.

Skinnier would allow more rotation if I manage to lay it over sideways, but I don't think enough to worry about. Still just thoughts at this stage.

If you put a series of triangular slices in the bar, then bent it and then welded the slices together, then ground the welds flush, it might be easier than trying to bed it "whole".

Depends on how bad you want the "rounded look" I suppose, and what type of tooling you have.

Lots of really talented people on this board, so there might be other ways to "skin this cat".

 

[D2Cat]

Looks good and will function like you want. I'd suggest a gusset on each side of the two uprights, just to make it less likely to fail in a roll over.

 

[PoTreeBoy]

I also added a seatbelt that came out of an old 60 series Landcruiser that we still have sitting here collecting rust since we last drove it about 15 years ago.

This may not apply to Australia and old Land Cruisers, but I think automotive and tractor seat belts work differently. My understanding is that auto belts have an inertial latch that only latches upon impact. The seat belt I installed on my tractor has a ratchet, once you pull it out and latch it, it can't be extended until you completely retract it. In case of rollover, I think this would hold you in the seat more securely.

Hopefully someone can confirm or debunk me here.

I understand the very newest ones are connected to the crash computer and tighten the retractors at the instant of impact.

 

[Kennyd4110]

While it 'looks' great, I'm not convinced it has enough lateral stability to really prevent a rollover since the two center uprights are so close together. If the machine tips, your top extension will likely contact the ground first and put immense force on those two uprights since they are so far away from the extended top part. Just my thoughts...

I also think the extensions will catch a lot of things (branches, limbs, structures) and risk twisting the entire ROPS easily.

Just my armchair/keyboard engineer thoughts and opinion, may be worth what you paid for it

 

[Paul Allwood]

If you put a series of triangular slices in the bar, then bent it and then welded the slices together, then ground the welds flush, it might be easier than trying to bed it "whole".

Depends on how bad you want the "rounded look" I suppose, and what type of tooling you have.

Lots of really talented people on this board, so there might be other ways to "skin this cat".

Thanks - I had seen that done but hadn't thought of it for this.

 

[Paul Allwood]

Looks good and will function like you want. I'd suggest a gusset on each side of the two uprights, just to make it less likely to fail in a roll over.

Thanks. I agree about the gussets.

 

[Paul Allwood]

This may not apply to Australia and old Land Cruisers, but I think automotive and tractor seat belts work differently. My understanding is that auto belts have an inertial latch that only latches upon impact. The seat belt I installed on my tractor has a ratchet, once you pull it out and latch it, it can't be extended until you completely retract it. In case of rollover, I think this would hold you in the seat more securely.

Hopefully someone can confirm or debunk me here.

I understand the very newest ones are connected to the crash computer and tighten the retractors at the instant of impact.

The 3 point lap/sash belts in the old Landcruiser do have inertia set ups, but this centre 2 point lap belt doesn't. Once I've set it at the length to suit me it doesn't move.

 

[Paul Allwood]

While it 'looks' great, I'm not convinced it has enough lateral stability to really prevent a rollover since the two center uprights are so close together. If the machine tips, your top extension will likely contact the ground first and put immense force on those two uprights since they are so far away from the extended top part. Just my thoughts...

I also think the extensions will catch a lot of things (branches, limbs, structures) and risk twisting the entire ROPS easily.

Just my armchair/keyboard engineer thoughts and opinion, may be worth what you paid for it

Thanks for your comments.

The design of the attachment and the 2 centre uprights is a copy of pics of commercially supplied ROPS. But after standing back and looking at it in place, I also think it could use some strengthening. There are 4 threaded M12 bolt holes facing backwards on the axle housing each side of the current mounts - I'm planning on using these to add supports up to the lower cross bar (hope that description makes sense). I'm not certain this is necessary, but it will be easy enough to do.

Also planning on making it a little narrower and changing the top to rounded corners to help prevent catching on branches.

 

[Bee-Positive]

...since the two center uprights are so close together. If the machine tips, your top extension will likely contact the ground first and put immense force on those two uprights since they are so far away from the extended top part. Just my thoughts...

My thoughts also. So I looked up pictures of other B7200's with ROPS and they are exactly the same. That's just how Kubota made them and how they are attach to the tractor. Not my first choice but it's what he's got to work with.

Nice job on the FAB by the way Paul.
FYI, my ROPS go vertical just inside the halfway point of the fenders. I'd make the outside edge of yours even with your grab handles and make the top the same way you cornered the bottom. JMTC.

 

[Paul Allwood]

My thoughts also. So I looked up pictures of other B7200's with ROPS and they are exactly the same. That's just how Kubota made them and how they are attach to the tractor. Not my first choice but it's what he's got to work with.

Nice job on the FAB by the way Paul.
FYI, my ROPS go vertical just inside the halfway point of the fenders. I'd make the outside edge of yours even with your grab handles and make the top the same way you cornered the bottom. JMTC.

Thanks again. All thoughts and comments are appreciated.