Steel tubing strong enough to support plow without bending?

[RockyNY]

Looks like the concern would be tearing the SS plate off. You have a 90 degree angle between the horizontal tubes and the SS plate that is vertical. And you are pushing pretty high up on the SS plate. With no gussets or diagonal bracing, I can see that angle becoming more than 90 degrees.

IF it was me, I would mount it up to the tractor, then find a place to add some type of brace that works around the loader frame.

Another suggestion. IT appears that the fittings at the angle cylinders are not high pressure fittings. Rather they look like galvanized water pipe fittings. They are not rated for hydraulic pressures. If that is the case, I would remedy that ASAP

I did forget to mention, what you can't see in the picture is another 3x2 steel tube welded horizontally across the bottom on the front of the quick attach plate. The tubes holding the plow's A frame are extended out to the edge of this other tube (so 3" past the front of the QA plate) and welded all the way around as well. So from the point you can see in the pictures, where the bottom angled part of the QA plate slopes down and makes contact with the 3x2" tubes, the tubes extend 6" forward of that point and are welded in any place there is metal-to-metal contact. That's why I'm not much worried about the tubes breaking off the QA plate, but rather the tubes bending. I think the tubes are pretty much as strong or stronger than the A-frame, so there might not be any cause for worry. But I think I figured out a way to run some bracing, it won't be as ideal as what I had on there before, but better than nothing. Also, good eye on the fittings and yes you are correct about them. At the time I built it I didn't consider that the fittings weren't rated for hydraulic pressure. I do plan to re-do that part before next season though, it's held up through (almost) 4 winters, so hopefully it will hold up for a couple more plowouts.

 

[LD1]

I did forget to mention, what you can't see in the picture is another 3x2 steel tube welded horizontally across the bottom on the front of the quick attach plate. The tubes holding the plow's A frame are extended out to the edge of this other tube (so 3" past the front of the QA plate) and welded all the way around as well. So from the point you can see in the pictures, where the bottom angled part of the QA plate slopes down and makes contact with the 3x2" tubes, the tubes extend 6" forward of that point and are welded in any place there is metal-to-metal contact. That's why I'm not much worried about the tubes breaking off the QA plate, but rather the tubes bending. I think the tubes are pretty much as strong or stronger than the A-frame, so there might not be any cause for worry. But I think I figured out a way to run some bracing, it won't be as ideal as what I had on there before, but better than nothing. Also, good eye on the fittings and yes you are correct about them. At the time I built it I didn't consider that the fittings weren't rated for hydraulic pressure. I do plan to re-do that part before next season though, it's held up through (almost) 4 winters, so hopefully it will hold up for a couple more plowouts.

The tubes are likely stronger than the angle a-frame, but the angles in which you are applying force is totally different. The angles on the a-frame are pretty much seeing force in a straight line from the hitch pins, trying to compress them.

With a ~12" tall SS plate attached ON TOP of the 2x3 tubes, the forces arent in a straight line.

 

[Brad_Blazer]

The tubes are likely stronger than the angle a-frame, but the angles in which you are applying force is totally different. The angles on the a-frame are pretty much seeing force in a straight line from the hitch pins, trying to compress them.

With a ~12" tall SS plate attached ON TOP of the 2x3 tubes, the forces arent in a straight line.

The pushing force of the tractor should come from the bottom of the QA plate. I don't see where the height of the plate matters. The curl cylinders hold the plate rigid and the A-frame is free floating in operation. Only when floating very low does it look like the blade could achieve much of a bending moment on the lower tubes in the event of the edge catching a curb. Hopefully the trip springs protect in that situation. If the top of the blade hits something the A-frame will see the bigger bending moment.

 

[SPYDERLK]

No, the forces are the same. The plow's A frame hooks to the back of those tubes (at the bolt you can see in the right side of the picture). All the force is right at that bolt.

Seems you could put the braces in a little differently and clear the loader torque tube.

 

[RockyNY]

Seems you could put the braces in a little differently and clear the loader torque tube.

If I drop them very low (2-3" above the bottom of the QA plate) I could fit them under the torque tube. This is probably what I'll end up doing.

 

[SPYDERLK]

If I drop them very low (2-3" above the bottom of the QA plate) I could fit them under the torque tube. This is probably what I'll end up doing.

What about a bolt on arrangement for the brace ... after coupling?

 

[RockyNY]

What about a bolt on arrangement for the brace ... after coupling?

I still need to be able to easily change attachments. I thought about a pin-on brace, that might actually work.

 

[SPYDERLK]

OK... So, I read, its possible. What about an electric impact to set bolts tight into a ~taper socket? ... The little free play in pins can degrade the effect of a brace more than an intuitive assessment might alert.