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 | BillMullens
Join Date: Jun 2000 Posts: 649 Central West Virginia 
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2001-11-25 33405
It seems I've seen this mentioned before in passing, and would like more details. Is it possible and safe to lock down the 3 point hitch arms somehow when attaching a 3ph backhoe? I'm looking for something that will work with a Cadplans hoe which doesn't have hydraulic stabilizers.
Thanks,
Bill
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 | Roger L.
Join Date: Jun 1999 Posts: 0 
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2001-11-25 33408
I've never seen a tractor that allowed the 3pt to be locked solid with some onboard control. Maybe you could do it with the hydraulic rate valve, but I wouldn't recommend it. All of the 3pt hoes that I have seen so far have some sort of heavily built extra struts or clamps that lock the 3pt arms from moving.
I guess I don't understand the question on not having hydraulic stabilizers. All the backhoes I've ever seen have some sort of hydraulic stabilizer. A hoe would not work very well at all without them, and the potential for damaging the 3pt mounts would be high. Plus you are always adjusting the stabilizers because the downforces on them cause them to slide around and sink. Without hydraulics this would be tedious. Having said that, I'll confess that I sometimes use my little 3pt backhoe without the stabilizers or even hold downs on the the 3pt. But this is a special case when I happen to have the 3pt on the big category II farm tractor and am only doing a little bit of light work. The big tractor has a heavy 3pt assembly and also has the ability to turn off the hydraulic flow to the 3pt so that you don't accidentally trigger the draft control valve and cause the backhoe to rise up. 3pt hoes are VERY dangerous if you cannot disconnect draft control somehow. If you have any doubt about the tractor's draft control I'd sure figure that out completely before even thinking about a 3pt hoe. I speak from experience about that. I forgot to turn off my draft control one day and will never forget that experience. Terrifying and potentially expensive, too.
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 | lsheaffer
Join Date: Jun 1999 Posts: 1082 Northern Illinois 
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2001-11-25 33411
What you can do to lock down the hoe from lifting is to make a bracket for the tractor drawbar to fasten 2 toplinks to & on iether side of the hoes toplink bracket make a bracket for the other end of the top links to fasten to. When attached this will create a solid triangle that will keep the arms from lifting ....
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| BillMullens
Join Date: Jun 2000 Posts: 649 Central West Virginia
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2001-11-25 33413
Thanks for the replies. Roger, the Cadplans hoes don't have hydraulic stabilizers; they have manually adjusted ones; you use the tractors 3 ph to raise and lower the whole hoe. You are then limited in downforce by the backhoe's attachment weight. I figured if I don't devise an actual mechanism of some kind (such as Leonard is talking about) to keep the 3ph from lifting, I'd at least make some sort of lock to keep the 3ph from being accidentally raised. Leonard, is what you are describing what is used in factory 3ph hoes? What happens if you accidentally raise the 3ph with the lock in place; wouldn't that tend to break the drawbar and/or attachment points? Or, am I over-estimating how much force the 3ph has in comparison to the drawbar strength.
I'm interested in locking down the 3ph for safety, and perhaps to enhance the performance of the hoe. The main complaint I've seen about these hoes is that (because they don't have the weight of the tractor on them) they tend to bounce around a lot when in use.
Thanks,
Bill ....
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| Roger L.
Join Date: Jun 1999 Posts: 0
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2001-11-26 33416
No hydraulic stabilizers?! I haven't looked at any of those plans, but that seems to be an unusual design. Not all bad though.... at least it is a situation that anyone who is clever enough to weld up their own backhoe should be able to remedy with a couple of hours of work. I think you will be much more pleased with the results of the project if you add workable stabilizers.
When you design the hydraulic stabilizers be sure that they swing out sideways as far as is reasonable for your clearance. About 20 or 30 years ago there were some backhoes marketed with hydraulic stabilizers that dropped straight down from the corners of the backhoe instead of swinging wide. The result was that the tool had a narrow support. They worked.....but had problems with swing stability. That design wasn't what I'd call a no-brainer; just a newbie mistake.
As far as sizing the upper limiting struts and the strength of the drawbar connection it would vary depending on your particular tractor. To give you an idea of how to think about it, consider this: On tractors that have draft control, it is actuated when the top link is put into compression. And since that normally happens when the lower arms are being forced up, it means that you will have to add the appropriate forces that the backhoe can put into the lift arms together with the normal lifting force of the 3pt in order to figure the strength of the restraint that you are going to build.
It does sound like a great project! I hope you go for it....
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 | Art White
Join Date: Jan 2000 Posts: 6898 Waterville New York 
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2001-11-26 33419
Years ago Long built a backhoe that when connected to the tractor it was not locked down. They stopped years ago from building this design do to liability. Your best bet is to fasten a chain around the drawbar so the three point will only lift so high and then the drawbar will catch it. With nearly all tractors having rollbars that unit sure will be a major case for a headache. ....
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| BillMullens
Join Date: Jun 2000 Posts: 649 Central West Virginia
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2001-11-26 33425
Roger, follow this link or go to cadplans.com to help me clarify how these little hoes work. Probably the best picture is the "tractor and frame 1".
As I've been discussing in another topic, I believe that these machines are similar to backhoes, in that they are hydraulically actuated buckets, but really not identical in operation details and what they will do. I suspect that anybody that has used a traditional backhoe wouldn't think too highly of the Cadplans hoes, but anybody whose alternative is a shovel and pick would love them.
I appreciate the suggestions and positive comments. I'm 18-1/2 hours into this project and have only to weld together the boom, boom extension, and bucket before fitting the hydraulics and painting.
Thanks,
Bill ....
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| Art White
Join Date: Jan 2000 Posts: 6898 Waterville New York
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2001-11-26 33428
Bill if thats your welding you are doing excellent. The design differences of these style hoe's is you have no down pressure to dig in with. The stabalizers by being fixed and the three point not being locked as in the other makes and kinds makes it difficult to start digging down. When you dig pulling towards you and you donot need down pressure to dig you can do fine. That is why I suggested a loose chain around the drawbar just as the updated Long used till they changed there design. ....
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| BillMullens
Join Date: Jun 2000 Posts: 649 Central West Virginia
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2001-11-26 33440
Art, I like the chain suggestion. I'd been thinking along the lines of solid links (such as Leonard is talking about); the problem being the solid links wouldn't let the hoe sink into the ground any more than when you first set-up. Thanks for the idea!
Some of my flat position butt welds are suffering from porosity; not present in the fillet welds. This is the first time I've used 7018 rods and am just learning the ins and outs. I think that base metal contamination (oil) is the culprit.
Bill ....
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