Seeking a few dimensions of tractor attachable backhoes of Woods 1050, or Bradco 3511B

[Randalthor]

Hi,

I recently purchased a Bradco 509b backhoe, which I am currently in the process of fabricating a 3 point adapter for a tractor, since there are absolutely none to purchase. I've looked extensively at internet pictures of 3 point adapters for heavy duty backhoes, like Woods 1050 "Saf-T-Lok", or pics of a Bradco 3511b, to assist in my fabrication.

So far, I'm fairly comfortable with the design of the adapter plate I've come up with. I more or less copied the design of the Woods 1050 3-point hookup, or the Bradco 3511b 3-point hook up. They seem to be very similar.

One question I have is the height of the fabricated top link of these 3 point adapters. As far as I can tell the top link is made from one bar of 3/4" flat steel, encased by two flat bars of 3/8" thick steel. But I'm unsure how tall these bars are. From pictures, it looks like the bars are 3" or 4" tall? I'm not sure which.

Anyone own one of these machines and can offer some clarification.

Here is the Saf-T-Lok system which shows the design for the Woods 1050. How tall is Ref part number 1 and the mate, number 2? Also wondering how long are these individual bars? Thanks.

 

[MTGreen]

I think your bar height should be contingent on your tractor top link bracket pin spacing. You want 2 pins engaged with enough steel around the pins to keep it solid under load. I would use the largest one I could that will fit between the ears of that bracket and allow for 2 holes for full thickness through pins.

Mine is a 7.5' digging capacity bh and my strap is 3" tall

 

[Randalthor]

Thank you.

 

[Randalthor]

I think your bar height should be contingent on your tractor top link bracket pin spacing. You want 2 pins engaged with enough steel around the pins to keep it solid under load. I would use the largest one I could that will fit between the ears of that bracket and allow for 2 holes for full thickness through pins.

Mine is a 7.5' digging capacity bh and my strap is 3" tall

Can I ask the distance between the drilled/punched holes in your two top brackets? Also can you tell me what make/model backhoe you have?

 

[MTGreen]

I have a old Kubota branded B4690 backhoe made by Woods that's mounted on a 5000 series John Deere with a cat2 hitch. The backhoe was made for a smaller tractor with a cat 1 hitch and the two holes in the top strap from the factory did not match with my cat2 top link bracket. To complicate it further it has hydraulic draft control. So I'm afraid those numbers wouldn't help you. Again, I think you need to measure the holes in the tractor that you intend to put this backhoe on.
Also, the bh was made to fit a number of cat 1 Kubota models and the top strap, braces, and holes for the bottom hitch arms have a tremendous amount of adjustability with 10 or 15 different hole pattern combo configurations creating different geometry for the various models.
A suggestion: I don't know how you're going about this or what your plans are but I think you may be asking for trouble if you are building this off of a print without the measurements from the intended tractor, especially if there's not a substantial amount of adjustability designed in. I would think before you weld everything up you may want to hold the backhoe up with a cherry picker behind the tractor and make sure everything connects correctly with the geometry that you want first

 

[kneedeep]

I have a 509 on factory subframe for the 3510. I will be back to farm after Thanksgiving.
May be able to provide info to help your project then.

 

[Randalthor]

Again, I think you need to measure the holes in the tractor that you intend to put this backhoe on.

Thanks MT, but I'm not sure we are talking about the same thing? Or, somehow I'm missing what you mean by the holes on the tractor?

Please allow me to clarify my description.

The top link bracket which is part of the tractor has three holes. Those are all Cat 2 holes, (1" in diameter) which provide some height/leveling adjustment for any 3 point implement. As I'm sure you know, a typical screw in/out top link, pins into one of those holes on the tractor, which provides for more leveling adjustment for a 3 point implement.

The 3 point adapter I am building for the backhoe has Cat 2 pins for the two lower arms on the tractor, and it's own top link arm which will pin to one of the three holes in the top link bracket on the tractor. As you mention, the top link arm needs lots of adjustment to account for different geometries of different tractors. I intend to accomplish this by drilling lots of holes in the two piece top link arm, as most of the 3 point backhoes do.

Here's a rough picture off the internet of what I'd like to do.

You'll notice the fabricated top link has a flat bar connected to a double weldment by way of numerous holes to allow for lots of length adjustment. I was seeking info on how tall to make the bars, but that was a poor way to ask the question. What I really wanted to know was dimension of the bars themselves (length, width/thickness and height) more specifically the height. I think yours is 3" in height?

I'd also be interested to know the amount of space between all the holes in the fabricated top link (the holes which provide for the overall length adjustment of the top link). In the photo I got off the internet, it looks like the holes are spaced about 3/4" apart? In my mind, that spacing is fairly important. Spacing too far apart compromises adjustability of the length of the top link which will result in the backhoe unit not being vertical when attached to the tractor. However, if the bolt hole spacing is too close, it will compromise the structural integrity of the fabricated top link bars.

 

[MTGreen]

I see, I thought you were talking about the hole spacing in the tractor top link bracket which differs cat1 to cat2 and may differ by tractor as well. My bh top link has 2 holes in the top link which connect with 2 holes in the tractor top link bracket using 2 pins rather than a single hole/pin as shown in the pic. Here is a Messicks link to a bl4690 which is very similar:

Kubota B4672A AND BL4690B (BACKHOE) Parts

Kubota B4672A AND BL4690B (BACKHOE) Parts

www.messicks.com

The top link is a 3 piece horizontal sandwich. The central top link piece that connects to the tractor top link bracket is about 3/4x3". The way this is set up with putting the diagonal bracers into different holes gives some vertical adjustability as well. You can see that central top link piece top hole and the additional bottom u-shaped hole for the second pin.

Regarding the adjustment hole spacing, a rule of thumb that I was taught for strength is to leave at least half of the hole diameter of steel in between the holes. For example, if you are drilling 1-in holes, you would put them on 1.5 inch centers so that there is at minimum 0.5" of steel (1/2 hole diam) in between the holes at the narrowest point. And again you would also want at least one half hole diameter of steel between the hole and any edge as well