Log Loading Ramp Size

[Pepe_Silvia]

Got the trailer kit for my mill and can no longer roll the logs onto the mill when I can't full lift them with my skidsteer.

The ramps from the factory are 2x3 tube steel that are 5' long.  I'm going to be loading logs between 4 and 5000 pounds.  I'd like a little bit more angle than 5' allow me, I was thinking more like 8'.  Is 2x3 steel going to be heavy enough?  I've got a question in to Woodmizer on what the weight capacity of their ramps is and will update when I get an answer.

I had in mind to use 2x6x0.25 as an overkill measure, but it's running $20/foot.  Not a deal breaker, but if I can get away with saving a little money and not going overkill, I'll give it a go.

Another thread mentioned using a leg halfway up the ramp to help with the load.

I figure my options are:

A) 2x3x0.25x8' - No support.
B) 2x3x0.25x8' - With support
C) 2x6x0.25x8' - No support
D) 2x6x0.25x8' - With support

I suppose 2x4 with and without support would be between B and C.  I'm leaning towards B.

[carykong]

If long beefy steel ramps becomes impractical,  you can drop your mill saw bed a few inches or raise the the ground to reduce the gradient or a combination of both.   Stage your logs on timbers to reduce the gradient. Many ways to get those big heavy logs onto your mill.

[Ljohnsaw]

You could do B but without a support leg but rather a truss.  Take a 8 to 12" piece of the 2x3 and have that hang down mid-span.  Then run a length of 3/8" or 1/2" rebar from one end to the other going under the strut and weld in place.  Make the connection at the top end such that it doesn't interfere with attaching to the mill bed.  The rebar will be in tension (what its made for!) and will significantly strengthen your "beam".  Make the 3" dimension the vertical one on the ramps.

[longtime lurker]

Go as heavy as you can afford, and truss construction both.
Even then a couple logs laid out from your ramps as a dead deck will reduce the angle and give you a space to lift one end at a time onto the "deck". From there you should be able to half lift/ half skid logs with your skid steer.

And don't forget the parbuckle trick... rope and pulleys might be a PITA but it will drag logs about.

[kelLOGg]

My ramps are 2" x 4" x 8' steel and only 1/8" wall. I parbuckle onto the mill and for heavy logs I put supports under the ramps. 

[Pepe_Silvia]

You could do B but without a support leg but rather a truss.  Take a 8 to 12" piece of the 2x3 and have that hang down mid-span.  Then run a length of 3/8" or 1/2" rebar from one end to the other going under the strut and weld in place.  Make the connection at the top end such that it doesn't interfere with attaching to the mill bed.  The rebar will be in tension (what its made for!) and will significantly strengthen your "beam".  Make the 3" dimension the vertical one on the ramps.

Is this what you mean?


 

[Ljohnsaw]

Exactly!  But (probably a quick SU drawing thing) the strap should be continuous from end to end.

[Pepe_Silvia]

Exactly!  But (probably a quick SU drawing thing) the strap should be continuous from end to end.

I was going to build it as pictured, so thanks for correcting me.

[VB-Milling]

I'm curious was your bunk height is with the mill on the trailer?  I've been contemplating a similar design.

[Pepe_Silvia]

I'm curious was your bunk height is with the mill on the trailer?  I've been contemplating a similar design.

It's about 27".

[Pepe_Silvia]

Exactly!  But (probably a quick SU drawing thing) the strap should be continuous from end to end.

For this design/weight load, will 11 gauge (about 1/8") suffice, or should I go with the 1/4"?
Cost is $5.55/ft vs $13.81/ft.

[Crusarius]

Just FYI 

2x6x.25x96 long is roughly 102 pounds
2x6x.120x96 long is roughly 50 pounds
2x3x.120x96 long is roughly 31 pounds
2x3x.25x96 long is roughly 62 pounds

My entire sawmill is built from either .120 or .188 wall material. The .120 is my mast I think everything else ended up being .188 wall. You do not need .250 wall at all. Unless you like being a body builder and lifting alot more heavy stuff than necessary.

I feel 2x3.120 with a truss would work well. Without the truss it may bow, but I doubt it will fail. 

My design when I was going to build ramps included some flat bar pinned to the side of the tube on a pivot. The reason for these was as you roll the log up it pushes the bar over and rolls over it. As soon as the log clears it pops back up and acts as a log stop. this way if you slip the log doesn't takeoff.

These weights were taken from an online calculator so I do not know how accurate they are but I would prefer not to have a single leg weigh 100 pounds and need to move it frequently.

[Ljohnsaw]

For this design/weight load, will 11 gauge (about 1/8") suffice, or should I go with the 1/4"? Cost is $5.55/ft vs $13.81/ft.

You never mentioned.  What size/species of logs?  For me, 1/4" wouldn't be strong enough to roll up the 28" dia x 33' pine logs that are probably 5,000 pounds... ;)

[Pepe_Silvia]

For this design/weight load, will 11 gauge (about 1/8") suffice, or should I go with the 1/4"? Cost is $5.55/ft vs $13.81/ft.

You never mentioned.  What size/species of logs?  For me, 1/4" wouldn't be strong enough to roll up the 28" dia x 33' pine logs that are probably 5,000 pounds... ;)

I mentioned an estimate of 4-5000 lbs in the original post.  This is the one I have to mill now.  It's a Red Oak at 30-36" diameter, 11' long.


 

[Ljohnsaw]

I mentioned an estimate of 4-5000 lbs in the original post.

Ooh, sorry, I missed that.  If it were me, I'd go with 2x4 @ .188 as a minimum.  I don't think you need to go to 2x6.  You will get more strength from the depth of the beam then the thickness of the wall.

[Pepe_Silvia]

Ok, I'll go with the 2x4 and whatever thickness my supplier has at 3/16" or more.  

I'll let you know how it goes  ;D

[Rybot]

I ran this simulation last night (8' long 2x3x.120 tubing 3/8 flat bar for the truss and 6" truss height). As you can see it is insufficient. My recommendation would be to go with a larger tubing section rather than a thicker wall. You gain more for the weight.

Good luck.

[Ljohnsaw]

I ran this simulation last night

Cool!

[Pepe_Silvia]

I ran this simulation last night (8' long 2x3x.120 tubing 3/8 flat bar for the truss and 6" truss height). As you can see it is insufficient. My recommendation would be to go with a larger tubing section rather than a thicker wall. You gain more for the weight.

Good luck.

That's awesome.  What software is this?
I tried using a couple online deflection calculators and was getting like a foot and a half for just a 8' stick of 2x3x.12 steel.  I thought maybe I was just using the tool wrong but that might be accurate based on what you're showing with a truss.

[Rybot]

Fusion 360. A bit of a learning curve but awesome once you know how. I learned on Solidworks but it is a little bit cost prohibitive for occasional/hobby use.

[kevin5055]

I ran this simulation last night (8' long 2x3x.120 tubing 3/8 flat bar for the truss and 6" truss height). As you can see it is insufficient. My recommendation would be to go with a larger tubing section rather than a thicker wall. You gain more for the weight.

Good luck.

That's awesome.  What software is this?
I tried using a couple online deflection calculators and was getting like a foot and a half for just a 8' stick of 2x3x.12 steel.  I thought maybe I was just using the tool wrong but that might be accurate based on what you're showing with a truss.

That's a little high. The formula for mid-span deflection of a simple span with a point load at the center is (PL^3)/(48EI) where P is the load (lbs), L is the span (inches), E is the modulus of elasticity (psi), and I is the section's moment of inertia (inches^4).  For steel, the modulus of elasticity is 29,000,000 psi.  An HSS3x2x1/8 section has a moment of inertia of 1.30in^4 if loaded with the 3" side vertical; it drops to 0.692in^4 if loaded "flat".  Your 5,000lb load is split between the two ramps. This results in:

Mid-span deflection = (2,500lb x 96in x 96in x 96in)/(48 x 29,000,000psi x 1.30in^4) = 1.22 inches which is a decent amount

I can give you some insight on the bending as well after lunch, but that shape doesn't have enough capacity (even assuming grade 50 steel).  With that being said, if you the option to buy a higher grade steel, that will help. You will be able to get more capacity for the same weight.

[Pepe_Silvia]

The calculator I was using did not ask for enough info to determine the Moment Of Inertia so it must have been making some (wrong) assumptions.

If I'm doing it right, I can use a 2x4 which has 2x the MOI and will give me half the deflection.  What is an allowable amount?