3pt lawn dethatcher

[MadReferee]

Here are some pics of a 3pt lawn dethatcher that I just finished building for another TBNer. The unit is 2 parts: the 3pt hitch and the dethatcher platform. This allows for future additional attachments to be used without building another 3pt hitch.

The dimensions of the dethatcher are 68" by 12". It will accommodate 16 tine pairs, 8 pairs in each row with each row being offset by 1/2 a tine pair. There are 3 adjustable parking stands. The platform was designed to hold 12" x 12" cement patio blocks for additional weight. The hitch is standard duty and not designed for pulling heavy duty implements.

It took be about 18 hours over a 2 week period to design and build, working a couple of hours each night. Total cost for materials was around $200.

The first picture shows the completed unit, missing 5 tine pairs.

 

[MadReferee]

Here is another of the completed unit.

 

[MadReferee]

And another.

 

[MadReferee]

One more.

 

[MadReferee]

This one shows the tine pairs.

 

[MadReferee]

This one shows how the 3pt and dethatcher platform are connected using 5/8" grade 8 bolts.

 

[MadReferee]

Here is the platform just afer welding and assembly.

 

[MadReferee]

Here is the 3pt being fabricated.

 

[MadReferee]

Final picture. This shows how the tine pairs are attached. Notice the 2 hex head screws. These are placed to prevent the tine from twisting.

All holes for the tines were drilled on my milling machine except for hex head screw holes. They were done freehand.

All welding was done with a Millermatic 175 MIG welder using C25 shielding gas and .030 wire.

 

[Casimir]

Nice Job! I gotta take a welding class. /forums/images/graemlins/crazy.gif

 

[B7510]

Mad,

I have been pondering a multi-purpose 3-point similar to the one you built here. I'm curious about the diagonal bracing on your hitch design. The drawbar between the lower links takes the load, both horizontal and vertical, and the top link basically just keeps the whole rig from rotating, true? Why the diagonals off each side of the vertical?

 

[B7510]

Mad,

I've got another question for you?

How did you attach the pins for the bottom links to the end of the tubes? Looks kinda like you bolted them to the end plates then welded the end plates to the tube. Also, what size & thickness tube did you use?

Used ta be that 3x3x.25 was standard for this sort of thing, but with the price of steel going into orbit I figure I should try to build it stout enough to last, but no need just to add more weight for traction, if you know what I mean.

 

[MadReferee]

The diagonals are there to assist in lateral stability, ie. twisting, since there is play in the 3pt linkage on a tractor. It also adds some strength. BTW, the 3 diagonals are only 2" C-channel.

 

[MadReferee]

The nuts for the lift pins are welded to the back of the end cap which is then welded to the drawbar tube. If I had used a wider tube then I would have cut an opening in the bottom so that a socket or box wrench could be used to tighten the nut instead of welding it.

For this project I used 2" x 1/4" square tubing. It is more than adequate for lighter weight implements. In fact, you probably could use 2" tubing for almost anything. Implement manufacturers tend to use 2" x 3/8" flat bar for most of their hitch components. I built a very heavy duty 72" landscape rake last year and used 4" x 3" x 1/4" tubing and I thought that was overkill (and expensive). In my opinion, 3" is overkill, 2.5" (used for trailer receivers) the best, and 2" adequate.

The dethatcher frame is made from 2.5" x 1/4" angle and worked very well. It added weight, will support additional cement patio blocks for weight, and was the right width for the tines.

 

[jrlichina]

I see the Harbor Freight metal cutting band saw in the background of one of your pictures. I bought that one 4 years ago for like $100 bucks and the thing still works great. I thought the motor would have burnt out by now but it just keeps on cutting. One of my better $100 purchases.

 

[Bowhunter]

Very nice job Mad!

 

[MadReferee]

I paid $150 for my HF bandsaw. I have literally beat it to death and it still keeps on running. Still cuts straight. I do use a good Starrett bi-metal blade. One of these days I will get around to making a better stand.

 

[NJBill]

Very professional, and as you remarked the black finish gave it a good upgrade.
Did you specify any particlar model when you were purchasing the tines, and if you don't mind, where are they available??
Athough I do not weld, I'd like to give this a shot. thanks for the pictorial story.
Bill.

 

[MadReferee]

I believe that MikeD got the tines he supplied me from Agri-fab. You might want to ask him in his finished picture thread Here .

 

[MadReferee]

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