solid rivets

[spro]

I guess only in hindsight we can try to understand. If misery loves company, then that company shares it with you. The cutters are tied by their rivets so the most expansion occurred between the cutters...? I thought I had a bad day. I hope that someone more knowledgeable can help you in straightening it back. Sincerely.

[liveaboard]

I'll straighten it, it's just an extra job I didn't expect. I thought all would be stable and easy with riveting, not like welding.

It is indeed obvious in hindsight; when I saw the bar move after the first few teeth I started being more careful about limiting the pressure to 8 or 10 tons, but it still moved a lot.

I made jigs to hold the bar vertical in the press and a push tool.
I still need to assemble the second toothbar.

[NP317]

Unintended consequences.
They drive knowledge and innovation.
RussN

[Bill Shields]

been there, done that....true learning experience...

seem to remember something about pressure and hole diameter and before it was over with...and a specific size of chamfer in the holes (asked someone as Allis Chalmers for that tidbit....)

[liveaboard]

With a few tons on them, the 6mm rivets expand like squeezed marshmallows until stopped by the bore. With the holes being just 10mm from the edge, there is obvious bulging by the time the rivets are fully set at around 10 tons. One edge of the plate is being stretched.
I guess this wouldn't happen with hot rivets [not that I could achieve a 6mm hot rivet in a hole long enough to hit it] .
Anyway, it took an hour or two to get each bar straight enough for the hedge cutting machine. It was a bit of a challenge [aka, fun].
They fit together and slide really easily, I think it's going to work well.
I need to do some panic shopping tomorrow [if there's anything to buy in the shops] but hopefully I'll get some more work done on the machine, because the @#$%^&*() hedge keeps on growing.

[Russ Hanscom]

Very impressive trimmer!

[liveaboard]

cuts right, left, forward, backwards, any angle, 10 foot horizontal extension.

Here's the video; https://www.youtube.com/watch?v=GL5hwFOTTCY&t=15s

[Harold_V]

Pretty cool!
How hard is it to keep a straight cut? Doesn't look easy!

H

[whateg0]

Impressive design and implementation!

Dave

[liveaboard]

I haven't succeeded in cutting super straight like an ornamental hedge.
Basically, I get the tractor into the right position and sight over the hood at something off the far corner, and move along keeping in line with that point.
Sometimes it works...
Other times I'm too deep and hit something I can't cut through, or too far out and just hit the tips.
The top is dependent on the flatness of the ground I'm rolling on. I rebuilt the cylinders to minimize internal leakage, and added a ball valve to the loader cylinder line so I can lock it in position.
Otherwise leakage through the spool valves caused drop, it ends up looking like a saw tooth pattern.
The hedge is 400 yards long, 10 ft high, and 10ft wide. It takes a LOT of cutting.

When I bought the tractor and planted the blasted hedge, I thought I'd buy an attachment; then I found out what they cost. $6,000 for a used one on the edge of scrap, $22,000 new.
So I built my own.
I used a grass blade because It was available at a reasonable price. This new blade set will hopefully work better.

grinding the rivet heads;

the blade pack; top and bottom plates, 1 center strip [that was hard to find], and 2 tooth strips straightened.
10/16mm hardened rings ride on the bolts and fit in the slots in the tooth bars.

Stacked together; I still need to drill and tap the bolts for grease passages and zerk fittings.