log splitter project

[vince smith]

Hello All, I'm building a conical screw log splitter for tough Australian hardwoods.I'm still working on the gear reductions.I had the screw made at an engineering shop but it was not successfull, I believe this is because they used a live centre and could not get close enough to give me a small enough entry point.

I have a small chinese lathe and used a butchered $49.00 chain saw sharpener to cut the thread. This was very slow but I got there in the end.
I will try and post a short video.

Regards Vince

 

[vince smith]

Hello all, Sorry I didn't get the video to work so I'll try and post a photo,
unfortunatly its pretty ordinary.

regards Vince.

 

[VTsteader]

Looks sweet, Vince!

Is the idea behind it to turn that into a log until it splits?

-rob

 

[yomax4]

I just wonder if it's aggressive enough?

 

[vince smith]

Hello paul, Yes, thats it. There are some good examples on the net, one being hydrocut. I must say there are some really scary ones as well.

Hello youmax4, If you mean the depth of cut, I dont think that was the finished item. If you mean angle, thats 15 deg ( x 2 ) and I think I would try something closer to 10 deg. If I was to do another. I have a 10 hp honda
gas engine with pulleys 100 mm to 250 mm then chain reduction 17 th to 57 th and it still grinds to a screaming halt. I intend to put in another lay shaft with 2 more sprockets 17 th and 57 th. when time allows and I reckon that
should do it.

regards vince.

 

[jimmysisson]

Honda at 3600 rpm, x 2.5:1 belt = 1440 rpm, x 17/57 = 429. I think that's a bit faster than when I ran one on a truck axle at idle. Next stepdown, 429 x 17/57 = 128, your planned rpm unless I missed something. I think that's slower than you'll want it to run, and that would be lower if the Honda is turning slower. Sounds like you may need more power???
Jim

 

[J_J]

If you reduce the engine rpm down to say 600, which is a 6 : 1 ratio, the torque increases 6 times. 540 is the rpm of the tractor PTO conical log splitters, but then again, HP on a tractor is greater. Although you may start to screw the unit into a log/tree, at some point, resistance goes way up and the HP necessary to complete the split, goes way up.

If you get it half way in a really tough stump, and run out of HP, what are you going to do. Do you have a plan to back it out.

 

[vince smith]

Hello fellas,
Jim, You haven't missed anything. I figured I'd rather it be a bit slow and have plenty of grunt and also something I'm not scared to use.

J.J. In trials with the higher gearing I did get some stuck fast but was able to
wind it out by hand.

My choice of gearing was from stuff I mostly had. The motor cost me $125.00

Regards Vince.

 

[jimmysisson]

I recall the most power required was just as the lead started to split the bolt. Kind of the same with a piston-wedge splitter. Once the split starts, the power requirement goes down. That doesn't mean you can't get stuck in a gnarly piece most of the way in though! I wonder if a big flywheel would get you past the hard early push?
Jim

 

[vince smith]

Hello Jim, strangely enough a heavy machine mechanic (friend) also suggested I considered a flywheel. I will try everything else first because when/if I hit the kill switch I want to be confident it stops quickly.

I'm still fairly confident It will work because the "thread" is about 8 threads per inch. and this in itself is a form of gearing, so it should make the 10 hp more workable.( he hopes) I work it out at 30 sec + for a 12" log as I expect not to have bore in much more than half way.

I cannot get to it yet as we are still cutting and collecting trees courtesy of cyclone yasi.

regards vince.