Log splitter question

[cwarrix]

I hope this is the right forum, my splitter is not really a tractor attachment, but my question is related to hydraulics, so here goes...

I found a home made log splitter for a decent price, $250 over the summer. It is mounted on an old truck axel and has a hitch to tow it with. They used an 18HP lawn tractor (at least the front half) as a power unit. The pump is under the motor and connects directly to the shaft with no belts, etc. I mounted a different (safer and larger) fuel tank that I had left over from an old pontoon boat and was able to get it running in short time. Oh, had to add a new battery as well for the electric start.

I was able to split about 1.5 cords of wood, over a couple of days, and it started spitting hydraulic fluid out of the fill hole in the tank. The guy told me there was supposed to be a vent cap there? Anyway, I didn't seal it up and just stuck a plastic cup over the hole to prevent water from entering the tank. Any ideas why it would be doing this? It sprayed fluid out hard enough to knock the cup off and shoot about 10 feet in the air! One other thing... the hyd tank is about 2 gallons, does it need to be bigger to allow the fluid to cool more? I'm not very good with hydraulics so any ideas would be appreciated.

I'll try to snap a couple of pics of this beast tomorrow.

Thanks in advance!

[MarlandS]

It does sound like the tank is too small, I've got one set up virtually the same way but I have a 10 gallon tank with about 5 gallons of oil in it.

The only other thing I can think of is maybe the oil is getting saturated with air causing expansion. And if the cup was snug on the fill pipe, it caused pressure to build then when it finally blew , suction caused the oil to evacuate with the air. Is the suction line good or are there cracks that could be letting air into an otherwise full system?

Was the tank clear full and how much oil did you lose?

[cwarrix]

Thanks for the reply MarlandS, I have been watching eBay for a used tank that I could use for this. The plastic cup I stuck on there was actually the top off a spray can, it was just laying there to keep rain out, don't think it was tight enough to cause a seal. I think I lost quite a bit of fluid before I got it shut down. I didn't notice any bad cracks in the lines, none of them leak.

I'd like to get this in the barn and tear it down, clean it up, add a filter (has no filter now) and get it ready for next year. Oh, and add a bigger tank.

Thanks again for the help and ideas!
Chuck

[cwarrix]

One more question on the tank size... Is there a rule of thumb for sizing that I can use? I found a couple on eBay but not sure what size to use. Is bigger better, or is too big a problem? Also, do I need a filter on this type of setup?

Thanks again for the help.
Chuck

[gizmo]

Another thing that you can do is use a large diameter return line to the tank. This will reduce the velocity of the returning fluid.

[rswyan]

</font><font color="blue" class="small">( Is there a rule of thumb for sizing that I can use? I found a couple on eBay but not sure what size to use. )</font>
One gallon of reservoir capacity for each gallon of flow. With a two stage pump (dual flow rates) you'd probably be safe using the average of your flow rates.

</font><font color="blue" class="small">( or is too big a problem? )</font>
Nope - other than the expense of having to fill it [img]/forums/images/graemlins/grin.gif[/img]

</font><font color="blue" class="small">( lso, do I need a filter on this type of setup? )</font>
Absolutely - if you want your components to last.

[cwarrix]

Thanks gizmo, my neighbor mentioned the same thing last night while we were talking. Sounds like I need a much bigger tank as well. I'll probably use the bigger return line when I replace the tank.

[cwarrix]

Thanks for the info rswyan. So, what I need to do first is figure out what flow rate the pump is and if it is a dual stage. Hopefully that info is on the pump under all the grease and grime. Sounds like a good Winter project to me. I need to get it in the barn where I can tear into it, replace the tank, maybe the lines, add a filter, maybe some paint to make it look pretty [img]/forums/images/graemlins/smile.gif[/img]

I was also thinking about a pressure gauge somewhere in the system just to make sure I'm not exceeding any limits. I guess I could figure it out the hard way by finding the RPM of the motor, then checking the specs on the pump.... hmmm, a ten dollar gauge sounds easier [img]/forums/images/graemlins/smile.gif[/img]

[cwarrix]

One more question about the tank... will an air compressor tank work? I'm assuming it should be metal, but didn't know if there were any other requirements. Since it is vented, I'm assumin there is no pressure either, right? I just need to draw the fluid from the bottom and return it to the top, sound right?

Thanks!
Chuck

[turnkey4099]

</font><font color="blue" class="small">( One more question about the tank... will an air compressor tank work? I'm assuming it should be metal, but didn't know if there were any other requirements. Since it is vented, I'm assumin there is no pressure either, right? I just need to draw the fluid from the bottom and return it to the top, sound right?

Thanks!
Chuck )</font>

Yes, any good mechanically sound tank will work. It must have a vent cap. It must also not be filled full, leave room for expansion.

I noticed one thing. YOu say you bought it used and had some rehab to do on it. Did you change the hydraulic oil? If it was sitting with a an open vent or even a vented cap, it oculd have absorbed a considerable amount of water. If so, coupled with a small tank, the splitting activity could have heated it to the point of the water boiling.

I wouldn't run any used hydraulic equipment without a total replacement of all fluids first.

Harry K