my home made hydraulic hedge cutter

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liveaboard
Posts: 1971
Joined: Sun Dec 08, 2013 1:40 pm
Location: southern Portugal
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Re: my home made hydraulic hedge cutter

Post by liveaboard »

Another update;
I cut the hedge a few times, then the swing linkage broke.
This is the big right to left swing powered be the large vertical hydraulic cylinder.
The linkages were all twisted and the pivot post tore away.
As you can see, the 30mm post is visibly bent.
bent post.jpg
It was a poor design.
First thing was to replace it with a bored rod, and mount a matching one over it so the pivot pin will be held on either end.
The "right" way to do this would be to dismantle the machine, lift the center plate onto the mill, and bore through both parts.
Instead, I made 2 parts and welded them. then made a little cut and welded again, then welded a couple of beads here and there to warp the parts into position.
The pin slides in dry with no noticeable play, so getting the two parts aligned close enough to work was a big achievement.
linkage base 2021.jpg

The 2 link plates are pretty basic, but one had a clearance cut that weakened it too much.
Before this picture was taken, I straightened them out with a press so I could measure the hole distance accurately.
old links and pins.jpg
Now that I have a mill, I can make a better one.
I torch cut from 20mm plate I had.
Actually, I could have just torch cut it and bored the holes; but where would the fun be in that?
I made a cardboard template and measured the angle I needed, actually the only critical measurement is the distance between the holes.
On the rotary table for the edge cuts; I rand the table across, then rotated 58 degrees, then continued across.
Then cranked out the head 60mm and did the other side the same way.
elbow link first cut.jpg
Cutting the ends half round is pure vanity.
cutting halfround end on link.jpg
cutting halfround with rotary table2.jpg
Last edited by liveaboard on Sun Sep 26, 2021 2:22 pm, edited 1 time in total.
User avatar
liveaboard
Posts: 1971
Joined: Sun Dec 08, 2013 1:40 pm
Location: southern Portugal
Contact:

Re: my home made hydraulic hedge cutter

Post by liveaboard »

And facing the flats makes no sense at all, it will be painted anyway. but I did it just for experience.
There is some slight cross hatching, but I need to improve my traming.
elbow link finished.jpg
Here are the finished links and pins; I bored grease passages in the pins instead of having zerks in the link plates like before.
new links and pins 2021.jpg
I have fitted them to the machine but I didn't take a picture yet. It's in a weird position, because I can't move the cylinder until I mount it on the tractor again.
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