Anybody using a backhoe attachment on their CUT?

   / Anybody using a backhoe attachment on their CUT?
  • Thread Starter
#71  
Your neighbor likely had a 3 pth model, which does put a lot of strain on the rear housing. A subframe is bolted to the bottom and distributes the weight to different points on the tractor.

It's a much lighter weight machine and you would be stressing it beyond the limits. I know what you are talking about with your Case and have seen it before. I've even seen guys load it onto a trailer using the bucket and hoe.
Yeah, I have moved my machine with the bucket and the hoe. It's kinda weird to have the tractor suspended by both the bucket and the hoe at the same time.
I don't understand why I would be stressing my lighter machine if the hoe is affixed to a proper sub frame. Am I missing something?
Thanks,
Eric
 
   / Anybody using a backhoe attachment on their CUT? #72  
Greetings All,
I just can't seem to get this out of my mind. I have a Yanmar YM2310 with an FEL and a Case 580CK backhoe. I no longer need the big backhoe. It digs well but the bucket is 2 feet wide. And the machine is huge compared to my Yanmar. Now the only digging I need to do is ditches for water lines and a few power lines. I could really use a small backhoe with a thumb.
I move a lot of rocks because we have so many and every time I dig I get more. My back is slowly fusing itself, some sort of genetic thing, and this makes it particularly hard on my back when moving heavy things. Being able to pick and place rocks with a thumb would save me a lot of trouble and pain.
I would love to have a small excavator but I can't justify the expense. I have been looking to trade my big hoe for a smaller one but haven't had any luck with that. So I'm wondering if a subframe mounted backhoe on my Yanmar would be useful. Maybe something like this: 5\' Dig Self Contained Backhoe, VL-BHM5 | Betstco Sales, Parts, and Service:
I can build the subframe myself, I have a complete machine shop and welders and the expertise. Since I'm retired the shop is free for me to play in. The hoe would be powered with a PTO pump.
Anybody with a good amount of experience that wants to chime in I would greatly appreciate anything you would have to say.
Thanks,
Eric
I've been running a Bradco 408 sub-frame mounted backhoe on my Mahinra 3510 4WD since new in 2002, with great success. Unfortunately Bradco ceased their small backhoe line years ago, so you'd have to find an old one someplace. I've got almost 1900 hours on it, and have dug many hundreds of feet of drain and utility lines, plus a 35'x42' foundation for my garage. I just recently had a 10" trench bucket built for it at a local welding/bucket manufacturing shop (Manco Thumbs in New Milford, Ct). Can't wait to try it out.
 
   / Anybody using a backhoe attachment on their CUT?
  • Thread Starter
#73  
I've been running a Bradco 408 sub-frame mounted backhoe on my Mahinra 3510 4WD since new in 2002, with great success. Unfortunately Bradco ceased their small backhoe line years ago, so you'd have to find an old one someplace. I've got almost 1900 hours on it, and have dug many hundreds of feet of drain and utility lines, plus a 35'x42' foundation for my garage. I just recently had a 10" trench bucket built for it at a local welding/bucket manufacturing shop (Manco Thumbs in New Milford, Ct). Can't wait to try it out.
Your tractor weighs about 1000 lbs more than mine so I'm sure it has an easier time digging. What size bucket are you using? I will be using a 9 inch max wide bucket.
Eric
 
   / Anybody using a backhoe attachment on their CUT? #74  
I use the 16"bucket which came with it. Just this year I replaced all 4 digging teeth. It has plenty of digging power, and will dig a max 8' flat bottom trench.
 
   / Anybody using a backhoe attachment on their CUT? #75  
Yeah, I have moved my machine with the bucket and the hoe. It's kinda weird to have the tractor suspended by both the bucket and the hoe at the same time.
I don't understand why I would be stressing my lighter machine if the hoe is affixed to a proper sub frame. Am I missing something?
Thanks,
Eric
I would say that you are missing the strength to weight ratio. Yes, these small units can do a lot. But your TLB is designed for that purpose. It is a lot more robust.
 
   / Anybody using a backhoe attachment on their CUT?
  • Thread Starter
#77  
I would say that you are missing the strength to weight ratio. Yes, these small units can do a lot. But your TLB is designed for that purpose. It is a lot more robust.
The purpose of the subframe (dammit! my computer doesn't recognize subframe but I'm gonna continue to use it anyway), is to take away stress from whatever it is supporting. The subframe must be able to carry the weight of the tractor. So the subframe, being connected at the front and rear of the tractor, should support the tractor's weight the same way that the wheels do. The problem I see is that if the rear of the tractor is lifted then the tractor's weight will be suspended from the rear axle and as the rear is raised more weight will be transferred to the front axle. Like going downhill. More weight on the front of the tractor.
So, if the subframe is strong enough to keep it from flexing enough to stress the tractor beyond acceptable limits it should be OK. Fortunately the tractor is not that heavy and the stiffness of a beam increases to the cube of the height. So I don't really need a really tall beam to support the tractor.
Though I'm not a mechanical engineer I am a machinist who has had to build stuff that involved beams. From small and very delicate inspection tools to shop cranes. And I used Machinery's Handbook to help me with the design process. All the formulas and drawings that tell you how to apply the formulas are in the book. So designing a proper subframe won't be that hard. I feel sorry for anybody who was using the formulas back when my 1918 edition of Machinery's Handbook was published. I did some calculations years ago longhand, without using a calculator, but instead using charts to cheat a little bit, and it took a looong time. And then checking my work took that much longer. I REALLY respect the folks who used to figure out and do all the math without even mechanical calculators.
Eric
 
   / Anybody using a backhoe attachment on their CUT? #78  
I have a 1960’s International 404 with a loader. I bought a Bush Hog BH with a NH subframe, modified the mounts to fit my tractor and built a 3 pt power pack. I dug a 32’ x 50’ foundation for my new house. Later I trenched and backfilled over 120’ of sewer and electric conduit from 36” to 54” deep in an afternoon. Mostly it runs at idle and has all the power I’ve needed. I have a 20” bucket but a 9” is the standard issue size with options to 36”?? (I bought it sitting beside the road for $2500 and about $1000 for power pack.) Don’t like not having 3pt access but wouldn’t give up BH! Just haven’t taken time to unhook it and replace 3pt arms.
 

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   / Anybody using a backhoe attachment on their CUT? #79  
Sorry about the SP in spelling class I spent to much time watching the gal with the BB
No need to apologize, I've committed countless spelling errors. I initially thought it was a new tractor attachment Ive never heard of. Lol
 
   / Anybody using a backhoe attachment on their CUT? #80  
The purpose of the subframe (dammit! my computer doesn't recognize subframe but I'm gonna continue to use it anyway), is to take away stress from whatever it is supporting. The subframe must be able to carry the weight of the tractor. So the subframe, being connected at the front and rear of the tractor, should support the tractor's weight the same way that the wheels do. The problem I see is that if the rear of the tractor is lifted then the tractor's weight will be suspended from the rear axle and as the rear is raised more weight will be transferred to the front axle. Like going downhill. More weight on the front of the tractor.
So, if the subframe is strong enough to keep it from flexing enough to stress the tractor beyond acceptable limits it should be OK. Fortunately the tractor is not that heavy and the stiffness of a beam increases to the cube of the height. So I don't really need a really tall beam to support the tractor.
Though I'm not a mechanical engineer I am a machinist who has had to build stuff that involved beams. From small and very delicate inspection tools to shop cranes. And I used Machinery's Handbook to help me with the design process. All the formulas and drawings that tell you how to apply the formulas are in the book. So designing a proper subframe won't be that hard. I feel sorry for anybody who was using the formulas back when my 1918 edition of Machinery's Handbook was published. I did some calculations years ago longhand, without using a calculator, but instead using charts to cheat a little bit, and it took a looong time. And then checking my work took that much longer. I REALLY respect the folks who used to figure out and do all the math without even mechanical calculators.
Eric
Really interesting viewpoint of this from a purely analytical standpoint.
The purpose of the subframe (dammit! my computer doesn't recognize subframe but I'm gonna continue to use it anyway), is to take away stress from whatever it is supporting. The subframe must be able to carry the weight of the tractor. So the subframe, being connected at the front and rear of the tractor, should support the tractor's weight the same way that the wheels do. The problem I see is that if the rear of the tractor is lifted then the tractor's weight will be suspended from the rear axle and as the rear is raised more weight will be transferred to the front axle. Like going downhill. More weight on the front of the tractor.
So, if the subframe is strong enough to keep it from flexing enough to stress the tractor beyond acceptable limits it should be OK. Fortunately the tractor is not that heavy and the stiffness of a beam increases to the cube of the height. So I don't really need a really tall beam to support the tractor.
Though I'm not a mechanical engineer I am a machinist who has had to build stuff that involved beams. From small and very delicate inspection tools to shop cranes. And I used Machinery's Handbook to help me with the design process. All the formulas and drawings that tell you how to apply the formulas are in the book. So designing a proper subframe won't be that hard. I feel sorry for anybody who was using the formulas back when my 1918 edition of Machinery's Handbook was published. I did some calculations years ago longhand, without using a calculator, but instead using charts to cheat a little bit, and it took a looong time. And then checking my work took that much longer. I REALLY respect the folks who used to figure out and do all the math without even mechanical calculators.
Eric
Great feedback from a purely analytical perspective. Thank you!!

From looking at my Kubota subframe it appears that wherever they could build in a solid straight frame assembly they did. But there are areas where they needed to cut away material to clear other areas that were not something that could be redesigned such as the transmission/engine/ rear-end components. So I'm cutting away material, they had to increase the overall "beam" size, or height of the subframe basis. That is, if you have a 3/4" thick beam that's 8" high and let's say it supports 3000lbs over a 8' length, then if you take a 4" x 4" square out of the beam let's say from the top (compression side), than you would need to compensate for that cutout by adding another 4" to the beam width...? So you would need to start with a 12" high beam instead of an 8" high, because you would be cutting 4" away at some distance that would actually weaken the structure of the beam by about 4"...

So I'm just saying that if there are 4 to 6 areas that need cutouts for various things, that you would need to figure all of that into the design.

THEN if you have the beam bent off the x/y axis so that it gets wider as it moves toward the front, or narrower depending on what you need to attach the front of the frame to... well then you add additional weakness due to a moment about the original axis... so it starts to get complicated quickly with every bend or cutout necessary.
 
 
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