How much power, force ......

[loves80z]

One thing that has been very confusing to me is the hp ratings from manufacturers. A rotary implement using pto and shear pin is easy. Now i look at a box blade and its far from clear. A 55 hp land pride says i can use a 5 ft to 8 ft. I've read lots of threads about sizing and still walk away scratching my head. If i can use the charts like in the pdf i posted, the answer is clear. It factors in many variables and quantifies them pretty well. It tells me what information is needed and gives me a procedure.

I have never been accused of overthinking before.......well at least not in a few weeks.

 

[buickanddeere]

There is the data in the official Nebraska tractor tests which makes and apples to apples comparison and rating of tractors.

 

[loves80z]

When I posted about hp ratings from manufacturers, i should have said implement manufacturers. If there is a gearbox it is obvious that exceeding the gearbox is bad. When it is a drawn implement, it is much less clear.

 

[RedNeckRacin]

The implements are able to handle a wide range of tractors. The only major distinction I have seen with the HP rating of attachments is whether the machine is 2wd or 4wd. The ratings drop significantly for that. There is also a reason why implements have 0-3 rating on them. A cat 0 attachment pales in comparison even to a cat 2 attachment.

What implement are you looking at that you want to dissect it to this degree?

 

[loves80z]

What implement are you looking at that you want to dissect it to this degree?

I am trying to understand the capabilities of my tractor and to match them to implements I might buy, copy or design. I am trying not to be specific, but I will give an example. I will build a ripper after hunting season so that in the spring I can rip an area, then use the loader to move the dirt to a new area. I will buy the rippers and build the rest.

My standard approach is
- Ask my self some questions like: How many rippers do I use? How wide should it be? How large should the tubing be?
- Understand what my tractors capabilities are. This is useful from now on as long as I own the tractor.
- I have no ballast in my tires
- Tractor weight is 7,130 lbs without the front loader
- Front loader weighs 1,350 lbs
- I have 15.5-38 R-1 tires
- Width is 83 inches to the outside of the rear tires
- I have about 54 drawbar HP
- Understand how the soil conditions influence my tractors capabilities. My soil is clay. As I go deeper it turns from clay to clay and rock. This is useful as long as I live in this house. In the future I can quickly reasses the new soil conditions because I have done it once.
- Take a look at what I can purchase for concepts
- How are the purchased items rated. Are the ratings enough for me to know the forces involved. So far most don't give me a clear answer.
- See if there is anything in my area I can measure
- Look at material I have
- hand sketch and asses the loads and determine if my existing material is sufficient. I think in this case my material will be close enough. I calculate all the time at work and have some preset mathCAD and excel sheets that can give me answers. It does not take me long.
- If the material is not sufficient as it sits can it be reinforce well enough or do I have to buy material. It is my plan on the boxblade project to reinforce.
- Determine costs of build vs buy. I know what material I want in my purchased item because I have done the reasurch up front and can now quickly asses what the effect of a larger or smaller item would be so that if I find something used and it is a good deal I can snatch it up knowing what I am getting into. Will what I buy be as good as what I build.
- If I decide to build I can decide if the hand sketch is sufficient to build from or do I want to put it in 3D to work out some details and run FEA on it.

I posted the PDF document because it helped me to understand my tractor, the soil, and implements. Perhaps it will not be helpful to most, but I have to believe that it can be helpful to someone else. Even in my profession, people consider me to be more detailed than most. Also more successful than most. So most people would consider this approach as too much. I am OK with that. I have to understand and plan. This is both a benefit and a hinderance.

 

[SPYDERLK]

I am trying to understand the capabilities of my tractor and to match them to implements I might buy, copy or design. I am trying not to be specific, but I will give an example. I will build a ripper after hunting season so that in the spring I can rip an area, then use the loader to move the dirt to a new area. I will buy the rippers and build the rest.

My standard approach is
- Ask my self some questions like: How many rippers do I use? How wide should it be? How large should the tubing be?
- Understand what my tractors capabilities are. This is useful from now on as long as I own the tractor.
- I have no ballast in my tires
- Tractor weight is 7,130 lbs without the front loader
- Front loader weighs 1,350 lbs
- I have 15.5-38 R-1 tires
- Width is 83 inches to the outside of the rear tires
- I have about 54 drawbar HP
- Understand how the soil conditions influence my tractors capabilities. My soil is clay. As I go deeper it turns from clay to clay and rock. This is useful as long as I live in this house. In the future I can quickly reasses the new soil conditions because I have done it once.
- Take a look at what I can purchase for concepts
- How are the purchased items rated. Are the ratings enough for me to know the forces involved. So far most don't give me a clear answer.
- See if there is anything in my area I can measure
- Look at material I have
- hand sketch and asses the loads and determine if my existing material is sufficient. I think in this case my material will be close enough. I calculate all the time at work and have some preset mathCAD and excel sheets that can give me answers. It does not take me long.
- If the material is not sufficient as it sits can it be reinforce well enough or do I have to buy material. It is my plan on the boxblade project to reinforce.
- Determine costs of build vs buy. I know what material I want in my purchased item because I have done the reasurch up front and can now quickly asses what the effect of a larger or smaller item would be so that if I find something used and it is a good deal I can snatch it up knowing what I am getting into. Will what I buy be as good as what I build.
- If I decide to build I can decide if the hand sketch is sufficient to build from or do I want to put it in 3D to work out some details and run FEA on it.

I posted the PDF document because it helped me to understand my tractor, the soil, and implements. Perhaps it will not be helpful to most, but I have to believe that it can be helpful to someone else. Even in my profession, people consider me to be more detailed than most. Also more successful than most. So most people would consider this approach as too much. I am OK with that. I have to understand and plan. This is both a benefit and a hinderance.

The max steady force you can apply is very near the weight the tires carry, if AGs. Getting brought up short will spike it higher.

This is your best start point for ground engaging. The force is traction limited except in the cases where jerking occurs.

 

[BHD]

just a bit of info, many of the ratings for AG equipment is rated for more horse power, than if it was rated for industrial use, for example a gear box, may be rated for 50 hp agriculture and only 35 hp if it was commercial,

for example take a look at an agriculture loader, and a commercial loader, two different animals yet they may be mounted on basically the same tractor,

for most things I am going to suggest a implement at least the width of the tractor, just for example with my speed mover, a 40 hp tractor can be used with it, but a 90 hp tractor works well with it also, and at times the 90 hp will make the work easer, but the 40 will do it as well may be not as fast and not full loads.

it is some what using a 3/8" drill vs a 1/2 drill, capacity, they can both drill a 1/2 hole but the 1/2 does it easer, and both can drill a 3/8" hole, but the 1/2 does it easer,

most likely a 8 foot chisel maybe a 10 foot.

it will run a 7 foot mower/bush hog type,

a 7 foot blade it should handle,

I personally think your working to hard to reinvent the wheel,

 

[bigdeano]

If you want to know how hard your tractor will pull you can measure it. Just use a hyd cylinder with a gauge on the rod end and pull on it. My 2wd tractor that weighs about 6000 with FEL pulled 5250 on damp grass. It has ag tires on the back. I pointed my camcorder at the gauge and increased the pull slowly until the tires spun. The sod went out the back.

 

[RedNeckRacin]

Thas. Otherwise the only factor, a three point hitch will increase your traction and let you pull more, hence why tractors use them.

 

[Garandman]

Then its a calculator festival to calculate all the forces and strength of materials to finally arrive at some concrete numbers.

If you are old school.

Mechanical CAD systems can assign materials by part and reference a library of physical properties. You can the use an integrated FEA product with the loads and safety factors defined, and even optimize the design through multiple iterations to maximize or minimize particular properties. You can run fatigue durability limit tests to learn lifecycle as well.