Backhoe- Build or Buy?

[wmgeorge]

If the cylinder was mounted underneath (pushing instead of pulling) like I see a lot of BH designs do, it would be fine.

Granted it seems to dig ok, but I'm considering going to a 3 inch cylinder which would give me about 49% more lift power, using the calculators on the Surplus Center website. [\quote]

If it gives 49% more pull, how much more push would it give ? would it bend the boom when trying to dig into hard soil ?
also, this will increase the required oil flow to lower the boom and decrease your cycle time.

If its possible to change the cylinder mount, that would be my first choice... just to be safe with the downforce, and to keep a quicker machine...

It would be almost impossible now to change the basic design of the boom. Since I only have a 13" bucket and my thumb is not all that large, I can't see picking up anything heavy enough to bend or damage the boom. It will slow down the boom somewhat, but all I'm asking is that it pick up a 250 lb RR tie, high enough to clear my trailer. A 2.5 inch cylinder has 7,242 pull and 9,081 push vs a 3.0 which has 10,807 pull, 13,077 push... all according to the calculators on the Surplus Center website.
This design is using the pull capacity of the cylinder.

I'd be interested in hearing from someone who has done the change out??

 

[dfkrug]

My thoughts on the Caddigger design for the 608 or perhaps in general for all Caddiggers. It would seem to me that the 2.5 inch cylinder for the boom is undersized. With my system valve set at 1850 psi I can't lift a 200 lb RR tie all the way to the highest point the boom should lift. Needs a bit more guts. If the cylinder was mounted underneath (pushing instead of pulling) like I see a lot of BH designs do, it would be fine.

Granted it seems to dig ok, but I'm considering going to a 3 inch cylinder which would give me about 49% more lift power, using the calculators on the Surplus Center website.

Bill:
If you want more force, why not just increase the relief valve setting?
Your old JD650 probably does 2000-2100psi. My 955 put out 2500psi.

That said, my CADDigger 728 had 3" cylinders and Mikulas admonished
builders to limit pressure to 1500psi. It was also designed to dig, not lift.
Unless you attach it to a tractor (as you did), it can lift very little due
to weight.

 

[wmgeorge]

Bill:
If you want more force, why not just increase the relief valve setting?
Your old JD650 probably does 2000-2100psi. My 955 put out 2500psi.

That said, my CADDigger 728 had 3" cylinders and Mikulas admonished
builders to limit pressure to 1500psi. I was also designed to dig, not lift.
Unless you attach it to a tractor (as you did), it can lift very little due
to weight.

I think the main tractor relief is set at 2,000 psi, and the Husco valve I'm using comes preset at 1,850. But thank you, you answered my question, the next size bigger Caddigger has 3" cylinders. And I can adjust this spool to cut down on the "push" side and leave the side I need a little extra on at the factory setting. The Husco valve has adjustable reliefs both in and out, and on all the spools.

I'm guessing the adjustment is IN (CW) for increase pressure and (CCW) OUT for decrease as a pressure regulator would work? The instructions tell you everything thing you need to know, except which way is Increase!!

 

[dfkrug]

I think the main tractor relief is set at 2,000 psi, and the Husco valve I'm using comes preset at 1,850. But thank you, you answered my question, the next size bigger Caddigger has 3" cylinders. And I can adjust this spool to cut down on the "push" side and leave the side I need a little extra on at the factory setting. The Husco valve has adjustable reliefs both in and out, and on all the spools.

I'm guessing the adjustment is IN (CW) for increase pressure and (CCW) OUT for decrease as a pressure regulator would work? The instructions tell you everything thing you need to know, except which way is Increase!!

Clockwise (in) is the only way I have seen on the various adjustable
reliefs. That increases the preload on the spring, increasing the hyd press
necessary to overcome it. I highly suggest getting a 3000psi guage ($10)
and testing pressures. If your valve RV is set over your tractor RV, then
you tractor RV does all the "relieving". This means if you just crank your
remote RVs in a turn or 2, you will be at 2000psi.

As for your Husco valve setup, adj RV on all work ports? That's a surprise.
Most workport RVs I have seen are not adjustable, with an adjustable single
RV on the valve center.

 

[wmgeorge]

Clockwise (in) is the only way I have seen on the various adjustable
reliefs. That increases the preload on the spring, increasing the hyd press
necessary to overcome it. I highly suggest getting a 3000psi guage ($10)
and testing pressures. If your valve RV is set over your tractor RV, then
you tractor RV does all the "relieving". This means if you just crank your
remote RVs in a turn or 2, you will be at 2000psi.

As for your Husco valve setup, adj RV on all work ports? That's a surprise.
Most workport RVs I have seen are not adjustable, with an adjustable single
RV on the valve center.

I was just thinking about putting on a gauge. Where would I install? In a "T" going to port I'm outputting too I assume or other???

Yes, This Husco valve was a buy, they only had like 160 to sell and I snapped it right up. Built in power beyond port, double acting and adjustable reliefs on all 8 ports, 4 spools. I found it listed in the 2008 catalog, Item 9-7446, page 19. It was sold without handles, so making the joysticks was a must and a time saver for a first time BH user.

 

[dfkrug]

I was just thinking about putting on a gauge. Where would I install? In a "T" going to port I'm outputting too I assume or other???

I do not use Ts cuz then the circuit you are testing must be operated to
relief. That is not always convenient. I use a JIC male adapter and put the
guage on a work port hose end. I like to cap the cyl when doing this to
avoid a mess. You may find the work ports to be more accessible at the
valve. This may mean you want to use female JICs and put the guage
right on the valve. More than one way to do this. I do not use QD couplings
as they are expensive and how often do you do this?

 

[wmgeorge]

I do not use Ts cuz then the circuit you are testing must be operated to
relief. That is not always convenient. I use a JIC male adapter and put the
guage on a work port hose end. I like to cap the cyl when doing this to
avoid a mess. You may find the work ports to be more accessible at the
valve. This may mean you want to use female JICs and put the guage
right on the valve. More than one way to do this. I do not use QD couplings
as they are expensive and how often do you do this?

So you are really "dead heading" the work port hose into a gauge? I can do that. Much simpler that trying to put in a "T", I'm hoping my local TSC has what I need. I carried home from Northern Tool a 30 lb plus new Red Lion 3" cylinder in one motorcycle saddlebag, that was interesting!!

 

[wmgeorge]

Bought a gauge and checked pressures, all where factory set @1875 psi. So mounted the new 3 inch cylinder after taking an inch off the threaded end! My old Chinese one was not at spec, so I had to adjust the new one to fit the centers of the old one. Lucky for me the new one had about 2 1/2 inches of adjustment. Needless to say the new one works like it should with more power, lifts that RR tie all the up without even a hiccup. THANK YOU for all the help!!