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

marrt · May 28, 2006

</font><font color="blue" class="small">( burned up another motor on my band saw)</font>

What's that old saying again? Something like "you get what you pay for." /forums/images/graemlins/wink.gif Just kidding. I had a similar problem with a piece of junk I bought and was able to find a cheap fan on Surplus Center. This fan looks like the 120MM 12v fans you see in some PC’s, but is 120v. I hooked it up to the motor power switch and it works fine. Could be an option.

I've bought a bunch of Harbor Freight stuff too. I think it's hit and miss with them. These days, I usually view their stuff as use once and throw away. However, I have bought some stuff there that was surprisingly good quality (a socket set for example). We don't have a store here so I have to mail order everything...without looking at it first. I just saw a 9" hand grinder the other day in their catalog for $39.95. Was tempted.

Looking forward to the next set of pics.

MossRoad · May 28, 2006

I've priced motors and they are almost 2/3 the price of the saw. /forums/images/graemlins/tongue.gif I'll make do with the air hose for now, but will consider an add/on fan later, or if I come across a good deal on a motor somewhere, I'll pick one up.

I have a 4.5" grinder from them that was probably $19.00 and it works fine. Kind of hit and miss with that stuff.

Anyhow, for once in a while use their stuff is fine, but for long term harvy use, I'll stick with brand name stuff.

No work on the backhoe today. Lots of family stuff going on. /forums/images/graemlins/wink.gif

MossRoad · May 28, 2006

I've priced motors and they are almost 2/3 the price of the saw. /forums/images/graemlins/tongue.gif I'll make do with the air hose for now, but will consider an add/on fan later, or if I come across a good deal on a motor somewhere, I'll pick one up.

I have a 4.5" grinder from them that was probably $19.00 and it works fine. Kind of hit and miss with that stuff.

Anyhow, for once in a while use their stuff is fine, but for long term harvy use, I'll stick with brand name stuff.

No work on the backhoe today. Lots of family stuff going on. /forums/images/graemlins/wink.gif

J_J · May 28, 2006

David, What is the bore and shaft size on those hyd cyl? My system calls for 2 in bore, but mine are 3.5 in . I think over kill is the word, but one has to use what one has. I have smaller ones on the out riggers. All they have to lift is about 700 lbs. the weight of the backhoe. My system is almost finished except organizing the valves that I am going to use. I have a unique seating arrangement for the fronthoe and will show pictures when I have it finished.

J_J · May 28, 2006

David, What is the bore and shaft size on those hyd cyl? My system calls for 2 in bore, but mine are 3.5 in . I think over kill is the word, but one has to use what one has. I have smaller ones on the out riggers. All they have to lift is about 700 lbs. the weight of the backhoe. My system is almost finished except organizing the valves that I am going to use. I have a unique seating arrangement for the fronthoe and will show pictures when I have it finished.

MossRoad · May 28, 2006

They appear to be 1.75" bore with 1" shaft. Stroke is 21". So my guess is they will be weak because the plans call for 3" bore X 16" stroke. I may need to get differrent cylinders anyway because of the length, but we'll see. At least I can get it going and check all the articulation to see what the actual cylinder length needed will be, since I didn't stick strictly with the plans.

MossRoad · May 28, 2006

They appear to be 1.75" bore with 1" shaft. Stroke is 21". So my guess is they will be weak because the plans call for 3" bore X 16" stroke. I may need to get differrent cylinders anyway because of the length, but we'll see. At least I can get it going and check all the articulation to see what the actual cylinder length needed will be, since I didn't stick strictly with the plans.

J_J · May 29, 2006

David, Using the hydraulic calculator, your cylinders using 2700 psi, will give a push force of 6490 lbs, and pull force of 4371 lbs.

If you use the 3 in cyl, with a 1 in shaft, the push force will be 19,075 lbs, and a push force of 16,956 lbs.

On welding the support tubes, I would suggest putting the pins in the tubes and tighten down before welding, just to keep the alignment. I had to ream out a few after welding.

Looking good , keep up the good work.

J_J · May 29, 2006

David, Using the hydraulic calculator, your cylinders using 2700 psi, will give a push force of 6490 lbs, and pull force of 4371 lbs.

If you use the 3 in cyl, with a 1 in shaft, the push force will be 19,075 lbs, and a push force of 16,956 lbs.

On welding the support tubes, I would suggest putting the pins in the tubes and tighten down before welding, just to keep the alignment. I had to ream out a few after welding.

Looking good , keep up the good work.