Backhoe Build A Backhoe For PT425... It Could Happen

[J_J]

David, This picture shows an under boom cylinder. Customers had damaged this cylinder in the past and they changed their plans by adding a plate to protect the cylinder.

 

[J_J]

Check this out. Would you work under this? Chain is hooked to bucket.

 

[MossRoad]

I think I hear what you are saying. If the geometry of the unit allows the bucket to curl up far enough and the dipper to swing back far enough, I could end up hitting the lift cylinder with the bucket if it is mounted underneath. Even if it isn't, large debris in the bucket could still hit it.

Since a hydraulic cylinder is stronger on the push than the pull:

If the cylinder is on top of the boom I will be able to push it down into things easier, but have less lift strength.

If the clylinder is under the boom, I will have less power when pushing down into things, but more lift strength.

I think I'd like more power digging than lifting, so I think I'll alter the plan to put the cylinder on the top. I can always switch it if I don't like it. It will change the total lift height or digging depth by a few inches, maybe a foot, but that is the fun of experimenting. /forums/images/graemlins/grin.gif

I saw that picture of the lawn tractor with FEL chained down lifting itself. Pretty neat. That whole website had lots of good pictures.

 

[SnowRidge]

J.J., that is one scary picture.

It's hard to tell exactly what size (or grade) that chain is, but if it is proof coil, it sure looks like it might be near or over its WLL. /forums/images/graemlins/crazy.gif /forums/images/graemlins/crazy.gif /forums/images/graemlins/crazy.gif

 

[MossRoad]

Well, I stayed home today due to a nasty sore throat and one of my kids was sick, too. They both had the day off from school, but I wasn't going to make the older one watch her sick sister and I didn't want to spread it around the office. About mid afternoon the sun came out and the tylenol kicked in. I felt a bit better and puttered out to get the mail. I looked at the garage and just had to see what kind of dent I could make in the square tubing with the sawzall. Oh, man, that is going to be too slow. Took about five minutes to go an inch and I was getting dizzy. /forums/images/graemlins/tongue.gif Went back to the house and took a shower. I'll be weaseling my way into a band saw for sure before I go any further. A friend of mine has the same Harbor Freight saw that they still sell. He's had it for quite a few years and it still works. It is usually $200. It is on sale for $179 in the store. I have a 20% off coupon that expires in November, so I'll watch for it to go off sale and pick it up for about $160, I hope.

 

[J_J]

David, There is a new metal cutting saw out now by several manufacturers. It is called a cold cut or dry cut saw, that uses carbide teeth set at a shallow angle. It runs at a lower rpm than the abrasive saws. 1500 rpm verses 3800 rpm . I have used the Dewalt DW872 which has a 14 in blade, and it gives a very good cut. It is 4 times faster, and very little sparks. It is more expensive than other saws. I bought this saw at a flea market at a super deal. Pure luck. I also have the plasma cutter, and oxy-fuel burners. The above chop saw gives the best cut.

 

[J_J]

David, Do you have a way to cut perfect 1 1/2 in holes in your tubing for the pin supports? At the time I was doing my backhoe, I cut mine out with a home made circle cutter using a plasma cutter. Wasn't perfect, but once I aligned the tubing for the pins, it all worked out. If you have a big enough drill press, this annular cutter should do a nice job. Next best thing would be to have some one cut out all the circles with a computerized plasma or laser cutter. Then, all you have to do, is assemble and weld.

 

[Spiffy]

I saw an industrial cold saw at a trade show a few years ago; they are neat! That one was probably only a couple hundred RPM (but a larger wheel, so I'm guessing 1/3 the cutting ft/min as the bench-top models); no sparks and beautiful cut! /forums/images/graemlins/cool.gif

 

[Spiffy]

Would a hole saw give a clean enough cut?

 

[J_J]

That 14 in blade has about 70 carbide teeth on it and the metal comes out in chips. I cut three in angle i/2 in thick in 30 sec. It is fast and gives a smooth cut. The edges look polished.