[eBoyDog]

I thinking about fabricating a sleeve hitch that's lifted/lowered using a cylinder mounted behind the seat. Something like a 3 point but a sleeve hitch instead, I should also be able to get down pressure which might be useful.

Why?
I have a home made sleeve hitch that can't be easily fixed to use the normal mid lift attachment and it already has a point to attach the cylinder. My 446 already has the lines running to back for a the 3 point lift so hydro plumbing is already done. While I'm getting another sleeve hitch, it seems a waste to not use the home made frame I already have.

Problem?
Making a suitable frame to attach the top of the lift cylinder to the rear of the 446, not hard to do but rather something that will hold up well and not look bad. I'm thinking of something in triangle like frame. The 446 is better suited since there is more room as I'm planning on using a standard Case lift piston from another Case GT.

What do you think?

Rough concept looks something like this:

 

[Bart]

You can bolt a piece of heavy angle iron just behind the seat pedestal to get a secure mounting point for the cylinder. My biggest concern from your sketch is that the lift is generated when the cylinder retracts and may not have enough power to lift much weight. The standard attachment lift cylinder operates at a relatively low pressure to protect the lift mechanism and if you intend to tap into the same circuit to operate the cylinder in the sketch it will have the same pressure. You'll have to do a few calculations based on the cylinder attachment points and the cylinder dimensions to know for sure.

 

[Hydriv]

This is do-able.

I would create a mount that takes advantage of the two 1/2" bolts that bolt the trans-axle to the tractor frame and the two 1/2" bolts that bolt the triangular tow plate on. 1/4" stock would be more than adequate for whatever you hook to the hitch no matter which way you move the cylinder.

One issue will be that of "hitch travel" when you are figuring out the attachment points for the cylinder. You want the end of the sleeve hitch to come up as high as it can but just shy of making contact with the underside of the axle housing at any point. I think that you would also want it just about touch the ground in the fully lowered position.

Of a minor concern would be "float" because of the time it takes for fluid to move in and out of the cylinder through those tiny 1/4" lines. A three point is different to some degree because of the leverage factor that affects the amount of fluid displaced.

I am not as troubled as my friend Bart seems to be when it comes to the ability of this cylinder to work upside down. The standard relief setting is 575 PSI but If you should actually run into a lift problem, then the relief could be jacked up 100 PSI without any concern.

I strongly suggest the use of a selector valve if you proceed with this.

 

[Billygoat]

If you built the back plate as if building your own three point, then make the needed brackets to hold the cylinder, I don't see any problem with that. The cylinder could be mounted with the rod end up as in a three point.

 

[Hydriv]

The issue isn't whether the cylinder is mounted "rod up" or "rod down". Either way you mount the cylinder, the "lift" takes place with the cylinder retracting and that means fewer square inches of piston exposed to the oil pressure due to rod being attached to that side of the piston.

The only way to reverse that situation would be to hinge a lever at the top of the plate and hang a link off of it to lift the sleeve hitch. The cylinder would be mounted so that it could push the lever upward.

That's the same principle that is used on the 3 pt hitch.

 

[Nutcase446]

The only way to reverse that situation would be to hinge a lever at the top of the plate and hang a link off of it to lift the sleeve hitch. The cylinder would be mounted so that it could push the lever upward

And if you made that link flexable your float issue would be solved.

 

[Billygoat]

The issue isn't whether the cylinder is mounted "rod up" or "rod down".

Brain fart, my bad. Need to read slower so the brain can comprehend better. :facepalm:

 

[Hydriv]

The only way to reverse that situation would be to hinge a lever at the top of the plate and hang a link off of it to lift the sleeve hitch. The cylinder would be mounted so that it could push the lever upward

And if you made that link flexable your float issue would be solved.

But............... wouldn't a flexible link mean that he would be giving up down pressure?

 

[Nutcase446]

Yes it would. It would have to be made so you could lock it ridged for those situations that requird down pressure. It wouldn't be a major engineering feat but it is getting a little more complicated.

 

[cp7]

For all this work eBoy you need to just get the specs for the three point and do it up right. :thumbsup:

 

[akeller]

This is do-able.

I would create a mount that takes advantage of the two 1/2" bolts that bolt the trans-axle to the tractor frame and the two 1/2" bolts that bolt the triangular tow plate on. 1/4" stock would be more than adequate for whatever you hook to the hitch no matter which way you move the cylinder.

I did something very similar to Hydriv's suggestion to add a top link for when I tow over weight trailers.

Al

 

[eBoyDog]

For all this work eBoy you need to just get the specs for the three point and do it up right. :thumbsup:

That's what I starting to think too.