Your plan sounds good. We have a medium sized drag at our camp that we use for "grading" the driveway in the summer. We pull it with an ATV. Not identical to your needs, but we use railroad ties, with some bracing and a chain harness. We use a piece of angle iron (which could be sharpened). Whole thing is probably 5ft wide and 5 ft long. It might be a bit heavy for a Tundra...but you probably don't need 5 ft square. Works great...super cheap.

 

Here's a more recent topic but there have been many over the years.

https://www.dootalk.com/forums/topic/1440586-ideas-for-diy-trail-groomer/

 

I think it's a recipe for disaster, i can only imagine the damage it could do to man and machine if the thing hooks in something it can't cut.

 

Here's a more recent topic but there have been many over the years.

https://www.dootalk.com/forums/topic/1440586-ideas-for-diy-trail-groomer/

Nice trail groomer, but not what I need.

suv1, only if its designed badly, Im thinking the expanded metal might be enough without a bar. The bar could absolutely end up creating the disaster yo refer to. Some of the ex-metal such as is used on stair treads, walkways etc is rough enough.

 

I saw a mechanical drag a few years ago on tube for cutting willows (alters) and small trees, it could be towed behind a sled or ATV, not sure if it was a homemade rig or not, i tried looking but can't find it now?????

 

We use "willow cutters" on our trapline all the time. Consists of a metal frame about 4' wide with a sharpened grader blade about 1" above snow level. On either side there's also a blade that's angled back and sticks out about a foot. It works best when it's pretty cold but it's amazing how well a trail can be cleaned up with one of these. This isn't a great pic but the only one I have right now.

 

I've built about a 1/2 dozen of Cutters for maintaining trail regrowth.
36" wide frame with 2 blades across, and a wing cutter one one or both sides depending what the guy wanted and how heavy a machine you have to pull it.
They will cut 2" if you are willing to put your machine to it.

 

Tundra 300, exactly the kind of thing I was thinking of. I was going down a different road design wise with the expanded ,metal bottom but like your approach. Do you add weight to the drag or is its own weight enough?

 

The top one weights about 150lbs, good for smaller regrowth.
The bottom ones about 200lbs, and will open up new trail if you can run it over with your machine.
You could add weight but i find the thing is to keep the blades sharp.
The wings are planer blades from local sawmill.
The center is cutting edge off of a dozer, ground down to a nice edge and sharpen.
I like to add a runner underneath, 1.5" flatbar on edge to keep it from sliding over when the wing hits a tree.

A trapper in my area has a heavier one that he will pull with two SWT in tandem to open up old cutlines.

 

One trick I have used is to set them up with a shear bolt, something like 1/4", so that when you hit something really tough they don't rip your sled in half.

 

A sheer bolt or something would be a good idea maybe. Would help with suv1’s concern from the earlier posts.