scrapyard box blade...first fabrication project

ovrszd · Dec 24, 2013

Yep, like Spiker's drawing. The angle iron is in place like this ^

stormpetrel · Dec 24, 2013

Ok....I get it. That should be an interesting welding situation! I'll have to grind the upward-facing point of the angle flat to mate that surface to the bottom edge of the BB.....?

It'll also be fun cutting away the bottom edge, 1/2". On 110 V house current. :/

ovrszd · Dec 24, 2013

No actually the angle usually goes inside the box. But then, the rear panel of a box is usually rolled a bit and mates to the top of the angle ^. Let's see,,,,, how you gonna do this?? Maybe use flat iron to bolt the cutter to? Weld in a piece of flat at a 30 degrees angle tipping forward to bolt the front blade to? Then add a similar piece on the back side to bolt the rear blade to??? You could then weld in some braces between your existing back panel and those flats to give it more strength? The bottoms of the flats would be flush with the bottom of the box. Then your cutters would bolt on with them hanging down 1/2" or so??

petes · Dec 24, 2013

Looks good. Definitely add the angle on the bottom. It provides a lot of stiffness to the bottom edge, and also is perfect for bolting a cutting edge onto. I'd replace the flatbar rear support on your 3pt with square tube, or at a minimum, weld another piece of flat on it to make it a "T" shape. The flat will bend in compression. Also consider stiffening the top edge of the back of the box by welding a piece of angle (or flat) to it, too, like this:
_
|
|
^

You don't need to grind the "point" off the angle... after you cut the rear plate off up higher (have fun!), butt the angle to it and fill the gap with weld fillet. When butt welding, you always want a notch to fill so you get good penetration into each piece rather than just on the surface.

It's surprising how heavy these things get after adding all the bit together, isn't it!

stormpetrel · Dec 24, 2013

I'm liking the idea of welding flat steel at the bottom of the BB front and back. And NOT cutting the 1/2" steel. I could weld little triangles into the empty space and get a very strong bottom edge. I could also weld a 1/4" flat strip onto the bottom edge, then weld my 30 degree flat steel (that the blade would get bolted to) to that, then hang the blade 3/4" or so below that? Thoughts?

I was gonna get the cutting blades from Agri-supply. I don't see thickness and width dimensions on their site. Is there a standard thickness & width for a 60" cutting edge?

ovrszd · Dec 24, 2013

stormpetrel said:
I'm liking the idea of welding flat steel at the bottom of the BB front and back. And NOT cutting the 1/2" steel. I could weld little triangles into the empty space and get a very strong bottom edge. I could also weld a 1/4" flat strip onto the bottom edge, then weld my 30 degree flat steel (that the blade would get bolted to) to that, then hang the blade 3/4" or so below that? Thoughts?

I was gonna get the cutting blades from Agri-supply. I don't see thickness and width dimensions on their site. Is there a standard thickness & width for a 60" cutting edge?

The triangles is what I was thinking. You can't run the 1/4" Flat Strip all the way across the bottom edge of the box back panel because then you wouldn't be able to get in there to bolt on the cutters. Just use the triangle idea maybe every foot or so. Also for the rear you can cut and weld in a triangle on each end to close that gap and add strength. As for the triangles, don't weld them in until you've drilled your blade holes. Otherwise, if your luck is like mine, you'd weld one exactly where a cutter bolt goes!!!!

I'm not sure about the cutter dimensions. I'd want cutters with the bolt holes in the middle so they can be reversed. I think you should purchase the cutters before you build the brackets we are talking about to mount them to. That way you can make up and down adjustments to those brackets to place your cutters where you want them before you weld the brackets on. If you don't have the cutters you won't know for sure where the best placement is.

SPIKER · Dec 24, 2013

Hey Guys:

It can be fixed with the small triangle cut out hunks and 1/4" flat bar with holes drilled and some Nuts welded into that so you can bolt the cutter edges onto it.

I modified the drawing from page one and showed end and back view w colors to show different parts welded/bolted together.

CLICK PIC FOR FULL SIZE LOOK

BLACK is 1/2" existing back plate
Orange is the 1/4" flat bar
Red is the Cutter Edge
Pink Bolts
Grey is the 1/4" cut triangles to fit and support the 1/2" to the two 1/4" & Cutting edges so all of it ties together supporting itself all as one part.

I would add some 2x2 or 3x3 angle to the TOP Edge too, and that down drag can be replaced with channel OR modify with some 1x1/4 bar welded in to keep it from collapsing when pushing and the thing wants to roll/twist up on ya.

I pushed my factory built box back into my tire almost it bent so bad when I hit a stump backing up...

Like someone mentioned bolt that cutter edge to the 1/4" and weld the nuts on back then tack weld the 1/4" to the box blade so that the cutter edge is 1/4" below the side plates, (set it on floor on some 1/4 shims then set the edge and 1/4" against the back 1/2" & tack it good same goes for inside, you MAY have to cut down the hardened cutting edge for the inside cutter (forward pulling cut).

Mark

stormpetrel · Dec 24, 2013

SPIKER said:
Hey Guys:

It can be fixed with the small triangle cut out hunks and 1/4" flat bar with holes drilled and some Nuts welded into that so you can bolt the cutter edges onto it.

I modified the drawing from page one and showed end and back view w colors to show different parts welded/bolted together.

CLICK PIC FOR FULL SIZE LOOK

BLACK is 1/2" existing back plate
Orange is the 1/4" flat bar
Red is the Cutter Edge
Pink Bolts
Grey is the 1/4" cut triangles to fit and support the 1/2" to the two 1/4" & Cutting edges so all of it ties together supporting itself all as one part.

I would add some 2x2 or 3x3 angle to the TOP Edge too, and that down drag can be replaced with channel OR modify with some 1x1/4 bar welded in to keep it from collapsing when pushing and the thing wants to roll/twist up on ya.

I pushed my factory built box back into my tire almost it bent so bad when I hit a stump backing up...

Like someone mentioned bolt that cutter edge to the 1/4" and weld the nuts on back then tack weld the 1/4" to the box blade so that the cutter edge is 1/4" below the side plates, (set it on floor on some 1/4 shims then set the edge and 1/4" against the back 1/2" & tack it good same goes for inside, you MAY have to cut down the hardened cutting edge for the inside cutter (forward pulling cut).

Mark

Oh yeah, that'll do it! Should add a bunch of weight to the whole thing too! Thanks!

ovrszd · Dec 25, 2013

I'm with Mark on everything except welding the nuts. I don't recommend that for long term use.

It will take you quite a while to wear out your cutters. So when, not if, when the day comes that they need flipped or replaced the bolts/nuts may be rusted to the point that the bolts twist off or eat the threads out of the nuts on the way out. Usually caused by a couple threads of the bolts sticking thru the nuts and exposed. If you've welded the nuts, this will be a disaster to fix and will probably require cutting your flats loose so you can get at the welded nuts.

Additionally cutters usually have square holes in them for the bolts. Designed to use carriage or plow shear type bolts which require the nuts be turned to remove them.

I suggest using triangle braces between the cutter bolts and leaving the bottom open so you can access the nuts. Then when it's time to change the cutters, if needed, you can cut the nuts off with a torch and replace them without having to disassemble the cutter holder assembly.