how to build your own custom backhoe subframe

[electrycmonk]

Your Cub Cadet is a DaeDong CUT, correct? Equiv to Kioti DK35, first gen?

Anyway, those B-series Kubotas are much lighter duty tractors. I would do a custom subframe that wrapped around the rear axle housings, and avoid using the 3-pt lift arm pivots. You can also mount the hoe much closer to the tractor than what the Woods subframe allows.

DK35Vince said what everything I have run across. The Mitzi platform not Daedong.

So, you wouldn't recommend using this setup a a starting point to modify for the Cub?

I don't have a "shop" or even garage yet to use as a building site. So that's why I asked specifically about going at this from a Mcgyver POV and modifying it.

I will admit to not liking the fact they designed it to mount to the 3 point lower bolt spots on those smaller Kubota models.

I just don't have a functional work bench - driveway only. And very little of it currently too.
Yes I have a metal chop saw, MIG & Stock welder units. Even have oxy-Ac.however I am quite rusty and without a realistic bench & vice I'm hesitant to go full Monty and start from scratch?

I may just stay 3-point till I finally get a shop built.... Later this year or next?

Night night y'all. Tha ks for the fast replies.

 

[dfkrug]

So that's why I asked specifically about going at this from a Mcgyver POV and modifying it.

You might think it will be easier to modify an existing subframe, rather than starting from scratch. But that may still amount to a lot of cutting, drilling, and welding. Perhaps more than starting with new steel. Hard to say without having the subframe under the tractor, and a design worked out.

I have modified the hoe-side subframes that I got with my Woods 7500 clones, and also started from scratch. The latter was easier, and the results, better.

(Thanks, Vince, for the clarification on CC tractors.)

 

[electrycmonk]

You might think it will be easier to modify an existing subframe, rather than starting from scratch. But that may still amount to a lot of cutting, drilling, and welding. Perhaps more than starting with new steel. Hard to say without having the subframe under the tractor, and a design worked out.

I have modified the hoe-side subframes that I got with my Woods 7500 clones, and also started from scratch. The latter was easier, and the results, better.

(Thanks, Vince, for the clarification on CC tractors.)

So, all things being equal - in a way..... If I were to go see the subframe and offer the seller "x" with the total transparency from the gwt-go.... How low would you think is a realistic off knowing it was to get cut, spliced; morphed & welded onto?

The current "asking price is, I believe still about $750-800. I'm preparing to drive up that ways in the coming week or so for some other stuff that's forsake about an hour away from the subframe seller.

 

[dfkrug]

How low would you think is a realistic off knowing it was to get cut, spliced; morphed & welded onto?

0-$50. And if you buy it, be prepared to scrap it and start over with new steel.

 

[chatwithtom]

I am new this forum Thanks to Bob R. for moving over here from the CTOA forum. Sunday my top link broke on my 3-point attached LW6 Backhoe on my Jinma 354 Tractor. This sent the backhoe falling backwards and me falling onto the controls. this put both the dipper and boom in the downward position forcing the backhoe back up and crushing into the tractor. I somehow managed to stand up at the time as I looked down and watched the seat fold in half as it crushed against the tractor. No more 3 point hitch for this backhoe.

THis is what I am considering. see diagram. I would appreciate comments. I have a plasma cutter and a couple of stick and mig welders so I think I can do this safely.

The point is that it is almost a straight line i.e. no bends necessary for a ladder type subframe.
1. I am planning on 2x3x1/4 steel rectangular tub but I might up that to 2x4x1/4 tube. I need opinions.
2. should I just drill out 3/4 holes for the cat 1 pins our or should I attempt to sleave them?
3. how thick should I make the plates that attach to the Backhoe and on and low arm hitch points on tractor. I am currently planning on doubling up 1/4 plate steel.
4. are we confident that the lower arm support pins will support this BH? It seams that the swing arms held all the weight previously and these lower arm pins only had upward and outward forces. There really isn't any room for an over the axle type bracket.

Lastly None of this will avoid a future broken top link sending me to a possible worse demise. While it is not shown in the diagram I actually can configure the Backhoe with two top links. both the Backhoe seat bracket and the tractor have 3 mounting points for top links. while there is some play in the tractor mount because its has this silly drag control flex point, it should still avoid a single top link failure causing catastrophy.


Thoughts?

Thanks,
Tom W.

 

[dfkrug]

Lastly None of this will avoid a future broken top link sending me to a possible worse demise.

Why not go with a rigid connection between the hoe and subframe? You can weld them together, with plenty of bracing, AND use the toplink holes as well. You have already seen what can happen if you crush or collapse a regular-duty toplink. Even with 3-pt hoes, the toplink is enhanced, plus triangulated with a very strong brace to minimize this hazard. Permanently attaching subframe to hoe is perfectly OK.

As for steel thicknesses, it is hard to say. You can do a LOT of welding with 1/4" steel and it may be strong enough. You can do less welding with 1/2" plates. It depends on the design. If you use tubing, then weldments that attach to them should wrap around them.

 

[chatwithtom]

Why not go with a rigid connection between the hoe and subframe?

Thanks dfkrug, I was afraid of adding too much torque component to the subframe. Hence the lower connections with pins and the upper with a couple of top links. As I had it there would only be torque on the frame based on the weight of the BH and some of the digging pulling forces would be split between all the 3 point attach points of tractor. By NOT using the tractor top link connection. all pulling forces would be transferred as torque to the sub frame and extra force on the lower 3-point tractor pins.

None the less, I will investigate. If it works out I will move to 2x4x1/4 rectungular tubing and build the triangulated brace.

Thanks again.

 

[dfkrug]

I was afraid of adding too much torque component to the subframe.

Transferring bending moments to the subframe is exactly what you want.

If you are planning to hang your subframe from the inboard 3-pt arm pivots, then you should also consider a more secure and rigid mount to the axle and rear end housings. There are often existing threaded holes there, plus the ROPS mounting can be used.

I have not seen the Jinma tractors up close, but I hear they are built fairly stout in the rear axle dept.

 

[ericm979]

Wow, close call there!


The factory Branson subframe is similar to what you're considering. It's got two long sections of tubing that go up to a frame tube across the bottom of the tractor between the loader mounts. There's a couple toggle latches there that get flipped up to grab the tube. At the rear, there are two ears that hook over the 3pt arm bolts (after removing the arms and putting the bolts back in). The BH itself is a model that can also be used as a 3pt BH. The subframe has braces that trangulate the BH so it can't pivot on the subframe. I use a heavy duty top link on advice from the dealer, but its more for taking out play and flex than fully taking all the force. The tractor's rear axle is sturdy and the 3pt arm bolts go into a weldment that is bolted on the axle.

getting the subframe to line up so you can insert bolts through the 3pt mounts seems like it could be a lot of work.

 

[dfkrug]

I use a heavy duty top link on advice from the dealer, but its more for taking out play and flex than fully taking all the force.

That is good advice from the dealer. Many Kioti dealers have done the opposite: tell the user not to use the toplink hole on the hoe. Since Kiotis mostly use the old-fashioned undermount ladder-style subframes with triangulation braces, there is flex. Using the toplink connection reduces that flex. Those who choose not to use a toplink eventually experience metal fatigue at the braces, even after welding them.