Log Splitter Build

[JakefromCharlotte]

Did some research on the truck springs. Looks like their rate is 600 LBS per inch. To measure the drop, I hitched the splitter to the trailer ball and put the two springs under the beam where the axle will be. The springs compressed 1.75", so that puts the splitter 2100 LBS. I thought it was 1900 LBS, but I guess there might be some error in my math.

I was planning to cut coils out of the springs to get the right height, but I read that cutting the coils actually increases the spring rate.
So, a higher spring rate = rougher ride?

Since cost springs are mounted perpendicular to the axle and I plan to mount them parallel, will the axle act more like a lever since the pivot point is so close together? Will this increase the load on the spring? Tying to figure this out so I don't have to cut the springs.

I also got the rear truck shocks out of the deal, would it be worth integrating them into the setup?

 

[Wood Hound]

You could always add the shocks later, if they are needed, i would try to do without them...

 

[Ted Jenkins]

Did some research on the truck springs. Looks like their rate is 600 LBS per inch. To measure the drop, I hitched the splitter to the trailer ball and put the two springs under the beam where the axle will be. The springs compressed 1.75", so that puts the splitter 2100 LBS. I thought it was 1900 LBS, but I guess there might be some error in my math.

I was planning to cut coils out of the springs to get the right height, but I read that cutting the coils actually increases the spring rate.
So, a higher spring rate = rougher ride?

Since cost springs are mounted perpendicular to the axle and I plan to mount them parallel, will the axle act more like a lever since the pivot point is so close together? Will this increase the load on the spring? Tying to figure this out so I don't have to cut the springs.

I also got the rear truck shocks out of the deal, would it be worth integrating them into the setup?

I do not believe this is as complicated as you think. You are caught up in leverage ratios. The closer you put your springs to the pivot point the more leverage there will be or the farther you attach springs from pivot point less leverage. Do you have no self service wrecking yards around. A pair of springs cost me $25. One time springs we too stiff not a problem just got the hand grinder out and shaved about 25% off ran very plush. My projects always take more time away from what I need to get done so I plan on ways to achieve results fast as possible. My thought was double them up as it will take no space than one alone. A short section of round tubing is all that is needed to put each end it and start splitting. Thanks

 

[kevin j]

Moments about the pivot point of the axle will all balance out. The weight of the splitter on the tire times the perpendicular distance to the pivot point is a moment in one direction. The perpendicular distance to the center of the spring times the spring force is the opposing moment. so if you take tire distance times weight and divide by distance up to the Spring center line that’ll give you a force at the spring. the further you go out with the spring the lower the force in the spring, so it will effectively get stiffer the further out you put the spring. The closer you bring the spring to the pivot point the more leverage it has on the spring. Cutting coils off the spring and shortening will make it stiffer in lbf per inch of deflection because there is less effective length of the steel wire to deflect

 

[sean donato]

I think you're over thinking I as well. I'll put it in perspective, they hold up the front of a 5k+lb pickup truck, that has about 70% (+or-) hung over the front, that's the springs you have are responsible for holding up. They are pretty over kill for you situation, but will still give you a dampening effect. Yes cutting the coil increases the spring rate. I'm also going to toss out there, your current axle design has too small of a pivot, and lots of leverage for the wheel to put tremendous side load and twist to the pivot point. Hence why you see an upper and lower control arms in side hinge set ups. You would be better off keeping a solid axle and doing some sort of 3 link set up with the springs. Would keep it simple, and allow for full use of the strut/spring assembly.

 

[JakefromCharlotte]

Mounting the wheels is kicking my butt....
I feel like I spent all weekend making the spring keepers that I saw on a Jeep forum.

 

[Ted Jenkins]

Very beautiful fabrication from my point of view. However when I am putting something together that I am not sure how it is ending up I do not measure just start welding. Your only positive point is that being well made all that you will have to do is maybe change springs a little or shave them down a bit. I do not think it is under engineered so with some tuning you will not have to address it again. Thanks

 

[Wood Hound]

A lot of work, right there..

 

[JakefromCharlotte]

The Titanic made it further on her maiden voyage......

 

[Wood Hound]

Well sorry about that-looks really green down there..

 

[Ted Jenkins]

The Titanic made it further on her maiden voyage......

View attachment 904660

It still looks good but just a little fine tuning might be in order. Thanks

 

[JakefromCharlotte]

This is the what I was afraid of in post #81. Funny thing was, it was sitting really high before I hitched it up. Obviously there is more force on the spring in this configuration.

The plan: Use a Harbor Freight 20 Ton Hydraulic Short Body Ram and a hydraulic pressure gauge to measure how much force we are dealing with, and then measure the spring. Hopefully, I can then cut the spring down and move the mount closer to the I-Beam to get the right balance. One thing I did notice was, there is a lot move weight on the tank side.

 

[Wood Hound]

Me again, instead of springs how about truck bump stops???

 

[Ted Jenkins]

This is the what I was afraid of in post #81. Funny thing was, it was sitting really high before I hitched it up. Obviously there is more force on the spring in this configuration.

The plan: Use a Harbor Freight 20 Ton Hydraulic Short Body Ram and a hydraulic pressure gauge to measure how much force we are dealing with, and then measure the spring. Hopefully, I can then cut the spring down and move the mount closer to the I-Beam to get the right balance. One thing I did notice was, there is a lot move weight on the tank side.
View attachment 904786

View attachment 904787


View attachment 904788

View attachment 904789

I found this to be hilarious not because you made a miscalculation but because Most of us have been there. We could spend plenty of time debating my blunders but it would only give us all chuckle. One thing you did not expect was your linkage has quite a bit of leverage so it will take a fairly stiff spring to compensate. I would think an automotive coil spring would meet your needs. Most springs are in the range of 1500 lbs after the first inch. If you want to experiment and you have materials available. Take a spring and cut it to fit your mounting which appears to be 30 to 50% shorter than the original length which will be in the neighborhood of 3,000 lbs the first inch. Likely that will work but probably too stiff. This will give you and idea of what you need. You can always grind the out side of the spring to make it softer but that probably will not make you happy. You are almost in the final stages of taking on a new challenge. Thanks

 

[JakefromCharlotte]

Me again, instead of springs how about truck bump stops???

Thats a good idea. Maybe semi trailer kind?

I found this to be hilarious not because you made a miscalculation but because Most of us have been there. We could spend plenty of time debating my blunders but it would only give us all chuckle. One thing you did not expect was your linkage has quite a bit of leverage so it will take a fairly stiff spring to compensate. I would think an automotive coil spring would meet your needs. Most springs are in the range of 1500 lbs after the first inch. If you want to experiment and you have materials available. Take a spring and cut it to fit your mounting which appears to be 30 to 50% shorter than the original length which will be in the neighborhood of 3,000 lbs the first inch. Likely that will work but probably too stiff. This will give you and idea of what you need. You can always grind the out side of the spring to make it softer but that probably will not make you happy. You are almost in the final stages of taking on a new challenge. Thanks

There a many ways to learn and mistakes happen. I really wondered if having the spring that close to the pivot would cause problems, and now I know for sure.

Bought a ram from Harbor Freight and I have a couple hydraulic gauges to experiment with. Apparently getting the air out of the ram is a struggle. I plan to use a T and put a vacuum on it, somehow. Then plug the hole.

Force Gauge

1, Measure the force on each side of the splitter at the axles.
2, Experiment with cutting the springs down to get the right pressure.
3, Make new mouthing plate for spring on axles.
4, Test
5, Give up and weld it solid

 

[Wood Hound]

You got to look into these bumps stops- put them on my truck and springs are no match...

https://videos.etrailer.com/static/images/video/Demo-Timbren-Vehicle-Suspension-TABSTOFLC1A.webm

 

[kevin j]

It’s all part of the R&D process. As the saying goes, if we knew what we were doing it wouldn’t be research. I think part of the issue is that the force point against the spring is not a pivot. It is tilting which causes the spring to bind and buckle. it’s not truly acting as a compression spring at that point so the normal spring calculations don’t apply.

 

[JakefromCharlotte]

It’s all part of the R&D process. As the saying goes, if we knew what we were doing it wouldn’t be research. I think part of the issue is that the force point against the spring is not a pivot. It is tilting which causes the spring to bind and buckle. it’s not truly acting as a compression spring at that point so the normal spring calculations don’t apply.

True, the spring is bending a lot in the picture, but that is the extreme limit. I was hoping for 6" of travel total, this is more like 20". I thought the spring would compress about 2" total at a static load. This will be an easy problem to solve with the gauge. Figuring out a way to mount the spring and gauge to the shop press will be the hardest part. If I had a CNC mill I could crank out a sloped bracket to follow the contour of the spring. But, sadly I'm the CNC....

 

[Backyard Lumberjack]

5, Give up and weld it solid

have to admit... i was wondering why it wasn't solid in the first place? good tires with a little less air pressure seems to me would be suspension enuff! air up for work bleed for hiway running or off road access... if i was pulling a splitter on roadway... i'd slow down for sure.

in any event, other than the boilerplate shipyard approach... nice job! i like seeing your craftsmanship over all!

what will it be? a 100T splitter?

 

[JakefromCharlotte]

The splitter should be a 24 ton, according to the math. A solid axle is defiantly on the radar.