4 gpm @2,500 psi is about 5 hp. The breakdown torque on that motor must be right at 5hp. Try dropping the pressure to 2,000 and see what happens. If it works, check the amp draw. Adjust until max amps match the rated draw. I did the math when I converted mine to electric and a regular 16 gpm 2 stage pump needed a real 5hp electric motor to run a 600 psi kick down and 2500+psi relief.
My pump says 4.2 GPM in low gear, so at 2500 PSI that works out to 6.1 HP...that's where my mistake was, I was not doing the math on 2500PSI, just at 4-500, where the hi to lo flow shift should occur. So even at the 22-2300 PSI that the motor actually seems to pull, that's still 5.6 HP...still more than this 15 FLA motor is supposed to make (I'm sure it wouldn't do it for long...but then it wouldn't need to either) I'll have to get an ammeter on it and do some checking. I'm sure this motor will split 99% (+) of the wood that I throw at it, since the pressure seems to stay under 500 most of the time, 1000 for sure, but I'm still half tempted to pick up the cheap 24FLA (grain dryer) motor that I found...wish I could find one that was about 20 FLA...closest that I've seen is 22A.
Man, I had the math all bass ackwards...I was using 4.2 GPM x hi/lo shift pressure /1714, instead of 16GPM x hi/lo shift pressure / 1714 like I should have been...doing the maths correctly works out to me needing to adjust the shift point to about 425-450 PSI (4-4.2HP) and have the relief set to the 22-2300 PSI, which I already found out seems to work ok.
I dont understand anything that's being discussed here as far as pressures and such but this is an excellent thread! Well done brenndatomu
Ha ha...well, I got sucked pretty far down the rabbit hole on this build Thank you sir If you care to learn about any of this jibber jabber, this is a great place to start...I've used this site quite a lot to sort out details. Log Splitter Hydraulic Pump Horsepower Calculator
A log splitter pump has two pumps that work together. A big one and a little one. The bigger one unloads at higher pressures to reduce the hp requirement. A log splitter is "open center", meaning the fluid circulates freely when the lever is in the neutral position and there is not really any pressure. It takes more hp to make more pressure, you can calculate how much hp is required at a specific flow and pressure.
I appreciate the link. I will check it out. I'll have to be careful though. This is something I could definitely get in to myself.
Hydraulics are a pile of fun, but it's also a rabbit hole, as you can see from this thread. You can't always "just upsize one part". You can only go so big on the pump before you need bigger hoses, fittings, tank, valve, etc... A bigger rod only speeds up the return stroke, but it can increase the flow from the other end of the cylinder exponentially, which can be a real pain because then you need bigger fittings, hoses, and a dump valve. A bigger cylinder slows everything down but gives more tonnage, and a smaller cylinder goes much faster but develops less tonnage. There is no free lunch, but you can find a sweet spot. A 3-4" cylinder and 14-16 gpm pump will make a respectable combo with little to no need to upgrade hoses, fittings, or valve. Size the cylinder based on the wood you expect to split. I am using a standard 4" cylinder (1.5" rod and a 14 gpm pump. I also have a 4 way wedge that stays on for 99% of the wood I split. I get tree service wood, dead wood, fresh wood, gnarly wood, knotty wood, crotches, etc... and the 4" cylinder does it all without trouble. I have been tempted to go to a 3.5" cylinder to cut 2 seconds off my cycle time (8 seconds down to 6), but I can't justify the cost. A sharp, skinny wedge requires a fraction of the tonnage compared to a big, fat wedge. Wedges should be sharp, very sharp, or they will grab cross grain and bind up.
Was able to work up a partial load of logs yesterday...everything is working good, only had one small leak that needed 1 more revolution of the fitting to solve...started wearing the "new splitter smell" off 'er too. Played around a lil bit with placing some foam board around the pump to absorb some of the pump whine...helped some...I think I might try some rockwool next though. The results, somewhere between 1/3 and 1/2 cord overall...a mix of ash and cherry.
Looks good, Dave. At work, we have some kind of sound deadening blankets hanging around some blowers that are close to work areas. Seems to help a good bit.
Hydraulic pump noise travels through the lines and body of the machine. I have thought about mounting my pump on rubber bushings, but I don't know if it would be rigid enough to keep alignment.
Yeah the pump is on its own steel mount so that I can easily swap the engine for the motor, and vice versa, so I think there is some sound transfer through the pump mounting for sure. Its still quieter than a gas splitter by a mile, so even if it can't be improved upon, its all good!
I might try putting some thin rubber or gasket material between the pump and mount and a layer between the bolts and pump. I wonder if it would help? It's high frequency noise, so it should help reduce noise transfer anyway. Maybe wrap the pump in butyl tape? That is the same stuff as dynamat
Hey walt (hope this link works for ya) https://www.facebook.com/share/r/Xn4r4wxuy5Wee3ZL/?mibextid=D5vuiz
Price looks good I wonder what shipping would be . Split- Fire makes a small vertical splitter 1165 V that is reasonably priced. I like being able to stand up and split vertical.
