Convert trail mower to boom mower with hydraulic motor?

[JimS]

I see a few small (about 48") brush hog mowers intended to be pulled with ATV on craigs list for around $200 - $400. Thinking this would be a good start for a boom mower. These are the type with swinging blades so hitting the occasional stump, etc wouldn't be a problem. Ones I am currently seeing are Swisher brand. Would be nice to have a mower for some steep banks along a drive. Banks slope up at nearly 45 degrees. If I could mow up about 5 ft that would be great. Higher would be a plus. Need to figure out what hydraulic motor would be suitable to replace gas engine - think they are typically 10 to 15 hp. Decks are belt drive. I am guessing I would need extra support for motor shaft due to side load of belt. Tractor is Kubota L3600 and wondering if I can use on board hydraulics or need a PTO pump. The vegetation is not heavy so a slightly less powerful motor may be ok.

I looked up a similar mower and saw it weighs about 500 lbs. I expected less. Is this too much to expect for this tractor, with or without counterweight? It has wheel weights and loaded tires. Maybe I should shoot for something smaller to make the frame easier - I would likely have to have someone else make the frame and looking to keep the cost down. I don't have a huge area to cover so making several passes would be reasonable.

Some of these units only have 2 wheels. I would think 4 would be much better but that could be changed fairly easily. Some swing links or some other way to prevent down pressure on the mower seems needed also to allow the mower to ride over high spots without stressing the frame.

 

[Densleigh]

I do not post very often but this is something I started on a few years back. I have some pics but not handy at the moment but will post up in a day or so.
Briefly I built a side arm are with a hydraulic rise (single acting so it floats a little). this in turn has an extending arm (again hydraulic cylinder) all out of box section. All this is mounted on a pivot with a hydraulic positioning ram. thus I can position it to the side, raise it and extend/ retract it.
By using this idea you can get the whole lot behind you for narrow access points.

I have this driven via a pto pump which drives some gang mowers (reel type) I have the parts to fabricate the rotary (swisher) head and mine is planned to be anout a 30inch cut.
Yes you will need some extra support of the Hyd motor shaft as most are not designed for side loads, a belt drive to the cutter spindle is best as it removes shock loads from the hyd motor which can be mounted nearer the main machine both for some protection and to keep the weight in from the head when extended.

I designed the whole thing such that I can swap the side arm for a full boom hedge cutter flail head. This got built first as the hedges needed cutting before I lost control of them.
It does weigh quite a bit - side arm described with tank and mounting frame I would guess is about 150kgs the flail assembly version is pushing 300kgs.
i mount this on a std cat 1 3pt system which I lock into place with additional top links used as sway bars.

My machine is a 26hp Italian 4wd BCS tractor and it is possible to bog down the engine when using the flail to cut grass and trying to cut it to short!!

It has kept me busy designing this lot but means I get kit at a sensible price all built from s/hand hydro parts (except pump) and reasonable priced steel
Flail head and gang mowers from scrap yard (most expensive bits).

As above I will find the pics and post for you - it might give you a clue as to what I have done which works ok

 

[JimS]

Densleigh,

Would like to see some pictures of your setup. I have been looking at lots of peoples creations and getting ideas.

I am thinking 4' may be too big for reasonable weight and to use the tractor hydraulics. I could go with a PTO pump but I would still have the weight issues. So am thinking about a 30 - 42" riding mower deck with a hydraulic motor. I won't be chopping any trees over 1", at least not intentionally... Most is much less - some grass, weeds, and small limbs. I have seen a top of the line DR brush mower in operation and it was impressive. More than up to the task of what I want but was not boom mounted. It has a rigid blade of 30" that is heavier than a typical mower blade. I have seen some older, single spindle mower decks of around 30" or slightly larger but they were quite old. Seems like the two blade version would be better - a bit more width and more available used. Belt drive would protect the motor. These are quite a bit lighter than a brush hog.

Considered a two cycle engine like a lawn boy and almost bought a used one but I would like to trim vertically which is out without a carb change. And if it ever gets overloaded you have to get off and restart it.

 

[jenkinsph]

For a small tractor having a mower off to the side it would need to be as light as possible without a counter weight. You have the weight of the mower deck and hydraulics motor plus the boom weight and length it extends outward to consider. I would think about a much smaller deck which could use a lighter boom to handle it, maybe a 22" single blade deck with a smaller hydraulic motor to operate it. I suspect that is all the hydraulics you will have anyway.