B6000 brush hog

[Changnam 59]

I am a relative novice to the world of tractors.

I own a Kubota B6000 4WD in Thailand. The intention was that it would do relatively light work running around our fairly large garden pulling a trailer. In that application its small size and tight turning circle were an advantage as it could weave in and out of the numerous decorative palms in the garden. Its light weight meant that little damage would be done to the garden using my improvised version of turf tyres.

Things have moved on and I now own a palm oil farm. The land area is around three hectares (just over seven acres) and the likelihood is that we will expand the property by buying up adjacent or nearby land.

There is a need to knock down the weeds that grow in between the palm trees. In the past this was done either using hand held brush cutters which was a long winded process or by a contractor with a Ford 6 series tractor using a brush hog. Particularly in the wet season the heavy Ford would cut up the soil to the point where it made vehicular access to the palm trees for harvesting more difficult. The Ford is now banned from the property.

So I bought a brush hog for the B6000. The overall width is one metre and the diameter of the blades is 80cm. According to the manufacturers the brush hog weights 156 kg. It was the smallest I could get here. I have an adaptor for the PTO so that the 18 spline Kubota shaft will work with the 6 spline brush hog shaft.

At the moment the tractor and brush hog are at a machine shop with experience with tractors. They are in the process of putting together a three point hitch working from photographs and other information which I put together from the internet. I doubt it will be an exact replica of the Kubota original but I think it will be good enough.

My question is simple. Do you think I will need to add weight to the front of the tractor and, if so, how much?

Any other advice on this combination of tractor and brush hog will be appreciated.

I guess a bigger tractor would be a good idea but, for now, a B6000 is what I have got.

 

[Forge]

Most probably. Your are putting a 350 lb implement on the back of a 1000 lb tractor. If I put a 500 lb bush hog on the back of my 1700 lb B7800 I'm using front weights. You might just get away without on level ground but weights are the safe way to go.

 

[Eric McCarthy]

I'd put a few weights on the front for stability sake.

 

[Changnam 59]

Thank you very much for your advice.

I never doubted the B6000's ability to handle the workload. It pulls like a train. It was the light weight that troubled me.

I will investigate an appropriate way to add mass to the front.

 

[Stubbyie]

I can't offer at the moment any specific Internet links but I know that in the past I've looked up specifics related to 'size' (arm and top link spacing) and geometric configuration of standard Society of Automotive Engineers (SAE) 3-point lifts in Categories 0-1-2-3-4. I think yours would probably be Cat-0 or Cat-1. If you do this you'll have a higher probability that your fabricated 3-point would fit a variety of implements all designed within one Category type.

Please post back your experiences so we may all learn. In this case, photos of the end product would be greatly appreciated.

 

[kubotasam]

Hopefully you and your shop know that a B6000 has a pto that turns in the opposite direction from most other tractors. You will need a PTO reverser or change the bush hog so the blades cut on the other side.

 

[Changnam 59]

OK. Here's a couple of work in progress photos.

The first pic shows the workshop in all its glory. In rural Thailand this workshop is the cream of the crop. While I know a very good machine shop in Bangkok that is an 1100 km round trip and I don't have time for that.

You can see the brush hog in the foreground. It cost 900 bucks and is the most expensive and best quality I could get. You can buy a brush hog for less than half that but the quality is pretty grim.

You can see that this workshop adhere pretty rigidly to standards of cleanliness and safety!

The second pic shows the three point linkage as of today after two days work. On and off presumably.


On the positive side.

1. It's cheap at around 150 bucks total.

2. It looks robust.

3. It looks like it should work.

4. It's cheap enough that I can get the guy to revise the bits that I don't like or don't work properly once it is up and running.


On the negative side:

1. It isn't going to be quickly removable.

2. I very much doubt it complies with standards.

3. The guy building it doesn't seem to fully appreciate in which directions the loads are working.


It looks to me like the lower links are cranked outwards too much. Bear in mind that the guy building the hitch is working from photographs only in deciding how much bend to put in the links.

The pivot bar for the lower links is stepped where it meets the plates bolted to the transmission. I hope he has got the step just right so that it is not stressing the transmission casing. Outside the plates bolted to the transmission you have a spacer, then the lower link, then a castellated nut.

The vertical lift bars are parts I had hanging around from the rear suspension of a race car. They may look insubstantial but they are very high quality and I am confident they will take any load a B6000 can throw at them. The bars are billet stainless steel gun drilled. The rod ends are top spec parts from Fluro in Germany. If the length is wrong we can cut them down.

I don't like the way the threaded part of the top link bolt sits in the bracket. A simple pin with R clips or whatever would be better.

I think the guy is doing a decent job with the resources available to him. I speak only very limited Thai and he was given his brief using interpretation in a mobile phone conference call.

 

[North Idaho Wolfman]

That is the best pair of home/shop build 3 point arms that I've ever seen.
The guy looks like he knows what he's doing!

 

[ptsg]

I have a homemade brush hog for my B7000 , i think the tractors are almost the same, if you want pics to help somehow, just ask.

 

[Changnam 59]

The two key dimensions I am lacking are:

1. The length of the original Kubota B6000 vertical lift links (minimum and maximum)

2. The offset of the original Kubota B6000 lower arms

I think what the guy building the 3PT has done is crank the lower links so that the parts that run on the fore/aft axis of the tractor are parallel when attached to this particular brush hog.

If any of you are wondering why I didn't simply go for something off the shelf such as Yenibiz make the reason is cost. Their price is, I think, reasonable but I would have to add freight and import tax to it. These days freight is the real killer.

My guess is that the Yenibiz 3PT would cost 4 to 5 times this solution once delivered.

 

[Changnam 59]

These pictures are after two and a half days work on the 3PT.

A super robust looking top link has been added. The driveshaft for the brush hog has been cut to length and the whole thing is up and running. At least in a static position.

The hydraulics work fine and the tool lifts smoothly. The blades were sharpened on the opposite side to the original cutting edge as the blade could not be flipped over. The brush hog rotates and there are no strange noises or vibrations.

In the detail picture you can see the PTO adapter which was sourced from the UK. It also looks like the upper rod ends on the lift arms are operating at, or close to, their angular limit. I didn’t spot that when I was looking at the tractor today. If there is an issue there it can probably be sorted by putting a conical spacer inboard of each upper rod end.

What stopped me going beyond static testing is that the tractor is clearly too light at the front end. I tried three different tractor shops today including a Kubota dealer and none had weights of any kind in stock. It would not be reasonable for me to leave the guy with an unfinished tractor job completely filling his tiny workshop for days while I order in parts so I am going with the man’s proposed solution which seems to be some sort of bumper come ballast box arrangement nailed to the front. It will be interesting to see what goes in the box because I could not understand what he was proposing. I got the impression that Thai tractor drivers like to crash into things a lot hence the front bumper.

The tractor has car tyres on the front as a legacy from its light duty days as a lawn tractor. Whereas turf tyres in the USA are readily available and affordable in Thailand a set of turf tyres for the B6000 would have cost more than my brother paid for a set of tyres for his 2007 Porsche 911 in the UK.

No way was I going to pay that so I spent ages number crunching tyre sizes in Excel to get the rolling circumferences right for 4WD and ended up using car tyres on the front and pick up truck tyres on the back. It worked fine except for pulling loads in muddy conditions.

I have new ag tyres for the front but I have not got round to fitting them because the wheels need respraying and therein lies another tale which I will save for another day.

 

[olthumpa]

Nice work and nice tractor.