RB84 woods 3pt blade .. more welding....

[DavidVT]

Hello,
Looking for ways to beef up my RB84 rear blade.

This is used mostly for snow removal and the majority of the time I push the blade in reverse with the cutting edge facing forwards. The idea is to ride up on obstructions rather than catch them.. It usually works....

This winter the blade has not worked that hard (mild winter in Vermont), but the damages are starting to really accelerate.

Last summer the primary pivot bolt (used to angle the blade R to L) backed out of the welded nut and both the bolt and nut were a total loss. Fortunately I was able to insert a similar size bolt and fasten it with a large lock nut. I accept responsibility for not checking the bolt was getting loose.

A few months ago the tilt pivot (used to level or lower one side of the blade to cut a ditch) was completely split. No idea why but I was able to dig out the new welder and pour enough rod into it to make is stay together. (proud of that fix but it looks pretty novice). I suspect a poor weld from when it was put together. When that failed, it allowed the blade to hang off the frame by the tilt pivot pin. That is why the photos will show that rear most pin at an odd angle.

Two days ago I noticed the blade at an odd angle and thought the above weld might have failed. No such luck. The blade is bolted near the hub to a square plate. Four bolts hold the 84" blade to the plate. This plate is welded to the tilt pivot assembly. The bottom side of the plate split, allowing the plate to flex as the blade caught snow on one side or the other.

Today I inspected the area and discovered this new split. Curiously I found a repaired split on the other side in exactly the same place. Maybe this is OEM?

Anyone with a Woods RB84, please tell me if you find vertical welds between the two middle lower blade mount bolts. The welds will be below this tilt pivot tube and on the plate with the 4 mounting bolts.

SO, anyone have a good idea how I can beef this up enough to survive a few more years?

Thank you!

 

[Baby Grand]

I'd cut that 4 bolt plate completely off and weld on a similar plate that's 3/8" or 1/2" thick. Then weld the legs of a 6" section C-Channel about 4 feet long to your moldboard. But before you do that, weld nuts to sets of 4 holes spaced so you can offset the blade on the inside flat (web) of the C-Channel. 4 bolts thru the new 3/8" plate into the set of C-Channel holes of your choice and get back to doing some plowing. The C-Channel will give your moldboard additional support and add some weight where it's needed. And cut that wimpy bent up tip plate off and weld a piece of 3/8" in it's place. You must have some tough snow up there.
-jim

 

[DavidVT]

Jim,
Thank you for the input. I like your idea. I was thinking about all kinds of horrid looking fixes that would likely have removed some of the pivot points.

Let me reword your suggestion to see if I understand it.

1) replace the mounting plate with something more robust. Great idea
2) weld C channel (open side) to the back side of the blade, running parallel with the blade. These channels with captive nuts inside for bolting to the new plate in step 1

Question, where will I be accommodating the curvature of the blade in this new mount? In the new plate (step 1), or in the positioning of the C channels?

The snow is not so tough, it is the ice mounts lurking under the edges that caught this one. It was weird, as in the past such a chunk of ice would just end up causing the rear wheels to pivot away rather than breaking the blade. No chains on this year either...

I will put the monster front FEL mounted truck plow on if I get into trouble before the winter ends. The rear blade can be a counter balance in the worst case.

 

[wushaw]

Baby Grand has a great fix. Althought if you don't want to do that kind of heavy duty fix at this time you can just heat & bend the plate back flat & weld it back together, then add 45deg gussets from the plate to the frame to keep the plate from flexing.

 

[DavidVT]

Thank you for the temporary idea.
Snow coming tomorrow so hopefully the old FEL QA snow plow will break out of the ice for me tonight.....

 

[Baby Grand]

David-

Good luck with this storm - looks like some quick welding of what you have will get you thru just fine. It sounds like you understood my ramblings surprisingly well. I usually communicate ideas like that with pictures/drawings.

You can accomodate the curvature of the moldboard by welding it to the two legs of the C-Channel. Make sure you get (or fabricate) a C-Channel with long enough legs that you can accomodate the curvature + the height of the nut + lock washer + 2 bolt threads without the end of the bolt bottoming on the moldboard. You may need to get different length bolts. I really like Wushaw's idea of using gussets - they could add greatly to the strength between the 3/8" flat plate with 4 holes and the column it's to which it's welded.

I will try to sketch something up, scan it and post it here this PM for this longer term fix. The idea of using the C-Channel isn't mine, so I won't take credit for it - it's an idea I am stealing from existing designs I have seen on other equipment. That's what I do best.

-Jim

 

[DavidVT]

Baby Grand,
I tried to do this in Google Sketch but I really need to learn more about that product.

I shamelessly used another plow I found on the web and deleted all but the snowboard.

I found a C channel plug in but could not figure out how to angle the C-channel in Sketch.

So here is my best try at showing what you suggest. The plate has no depth but attempts to show what I think you are suggesting.

It is still how the channels will meet the curvature of the snowboard that puzzles me.

Thx again for your ideas.

 

[Baby Grand]

David,

That's actually a very interesting approach and could make offsetting the blade a lot simpler. Here's what I was trying to describe:

(This is a conversion from Unigraphics ---> Powerpoint ---> jpg,
so I'm crossing my fingers that something recognizable comes out the other end ...)



Jim

 

[DavidVT]

LIGHT BLINKS ON.... the AH HA moment

Baby Grand,
I was fixated on thinking I needed two Channels and that is why I could not figure out the angle vs Channel.

Your picture clears it up. THANK YOU..

This is what I came up with trying to figure out the two Channel idea... At least I learned a bit more about Google Sketch which is free........

 

[DavidVT]

A friend helped me weld this up this weekend.

We pulled the blade and found the round weld behind the blade has 3/4 pulled out of the plate. There were two concentric weld beads and these had split down the center.

He welded that back up nice and then welded those rear splits. It will work for the rest of the winter!

As to the future, I will weld gussets at the bottom of the rear assy which will be parallel to the earth and will reach out to the outer edges of the blade mounting plate.

To be fair to Woods, the only thing I can think of is that last winter (only last winter), we had chains on the rear wheels. Maybe the blade caught some ice ,and rather than sliding sideways as it did without chains, and with the extra traction the forces made that rotary weld start to fail behind the plate...

Who knows, I've never been real happy with the flex in this blade....

'your mileage may vary'