When you are out in the field or you are not near a splitter with a lifter, sometimes you need to get rounds up in the air (truck bed, on a stack of pallets, etc.). This manual firewood lifter gives you about 4:1 mechanical advantage allowing you to lift rounds you normally could not budge yourself. When constructing this lifter, you want to choose very light and dry wood. Dry Cedar 4x4's would be a good choice so that you don't add any excess weight to the round that you are lifting.
When I first came up with this idea I was watching a show where a team of people were trying to lift a pickup. They had put some blocks under the back of a small pickup truck probably a Datsun or a Mazda - well, maybe even a Toyota, and created a 36 (roughly) foot long (what looked a like a ladder rotated 90° from west to east with support 2x4's along the center. There was a significant amount of bend in their structure but with a large number of people pressing down on the end of the 36 foot length, the pickup was raised into the air and I thought to myself, I bet I could adapt this philosophy to lift heavy firewood rounds - and behold, the manual lifter was born. I built 3 of these: 1x 8' for a trailer and 1x 12' for a trailer, and 2x 12' with the support plank at a different height on my F350.
The interesting part was the responses I would get when picking up firewood. People would walk by and say, what's is that! Some tree services guys thought it was awesome so all in all, it has turned out to be pretty good invention. Maybe you can get some benefit out of it as well. When you build a manual lifter, go out of your way to make sure you are using very light dry wood (preferably cedar, although I understand its expensive).
Physical Usage Instructions
Place the lifter flat on the ground behind your truck with the tailgate taken off if possible. Roll your firewood round in front of the 2x12 plank sticking up. Walk to the end of the lifter that is away from your truck. Pick up the end of the lifter and walk slowly towards the truck repositioning your hand holds one at a time. Make sure the round is balanced, especially if it's odd shaped so you don't lose it on the way up.
Your lifter should now be straight up in the air and the 2x12 plank should be on the bed of your truck. Roll the round off of the plank and move it to its final destination for the ride home.
Depending on the size and variety of trucks and trailers you have, making 3 or 4 of these for various heights would be beneficial.
For a truck - I recommend 12' in length and about 16-20" for width. The firewood round support plank should be about 30 - 36 inches depending on the height of the truck. Some flatbeds are much higher than box trucks.
For a trailer - there are lower beds and higher beds if you have the double doors.
ManualLifter-V1-0-6 - The technical Stuff - using MathCompiler3D
In version 1-0-6, the lifter has gone from a static 3D drawing to a parametric 3D drawing.
In the project tree of MathCompiler3D for the ManualLifter project:
- 3D Models - This is the 3D worlds node
- Manual Lifter - This is the 3D model of the manual lifter
- Equations - This is the Slate / Virtual "White" board section
- Lumber - Contains equations with standard units of lumber like 1x2, 2x4, 4x4...etc.
- Standard Lengths - Contains equations for #'s 0-12, which is useful when using the right click context menu on those equations to make changes to the 3D object using the selected value
- Control Panel - The Control Panel contains the 4 main equations that set the primary values that make up the shape of the lifter
- The rest of the project tree has features that are not relevant to this project at this time
The Control Panel Project Node
When using the ManualLifter formula - only change the value of the equations on the control panel to achieve the parametric attributes of the lifter. Select the green values shown in the image of the equations below where you see 2, 12, 3, 2. Select the 12 in lifter depth
The anatomy of an equation
Symbol #1: Variable Name - In math we have variables like A,B,C,D1 and similar values. The MathCompiler3D uses a hybrid of math & C# creating a super-math so it allows you to have longer variable names. When creating your own equation you can use whichever syntax is more comfortable to you.
Symbol #2: Equals - This symbol is an = sign. It means the variable on the left is set to the value on the right
Symbol #3: In this case, looking at LifterWidth, 2 is a number. This symbol does not have a requirement of what symbol type it has to be, as long as its valid syntax.
Symbol #4: The answer - still looking at LifterWidth, the value of this equation is 2 (Black with Yellow text) since the equation to the right of the equals only has 1 symbol
Symbol #5: Unit of measure - This symbol is a manual entry so that you and your equation consumer known what unit of measure your equation results in
- LifterWidth - controls the distance between the 2 long side 2x4's. This is what controls the size of firewood rounds that you will lift.
- LifterDepth - How long the lifter is
- ShelfPosition - The # of feet from the base of the lifter that the 2x12 shelf will be placed
- BraceDistance - The # of feet apart that braces #4 - #6 will be placed apart on the end that is opposite of the base
The Positions Project Node
Looking at the slate view after having selected the Positions project node, you will see 11 equations that are used to set targets and sizes of the 3D objects.
CenterBraceWidth - this equation sets the width of the 7 cross braces of the lifter and is calculated based on the LifterWidth from the Control Panel.
LeftLifterX - when standing at the base of the lifter, this if the X position of the 2x4 on the left side
RightLifterX - when standing at the base of the lifter, this is the X position of the 2x4 on the right side
ShelfPositionY - This value is the Y position for the support plank that the round is put against - the distance in feet from the base of the
BraceY₁ - BraceY₇: These variables are read as "Brace Y Sub 1" - the small ₁ is a subscript and is thus part of the variable name. These variable pertain to the Y position of the center 4x4 braces starting at the end of the lifter that the shelf is closest too, going up to the end where you pick up the lifter to get the firewood round off of the ground (in the picture on the left, the green 4x4's numbered from right to left).
Control Panel Variations - using the same parametric formula
The nice thing about a parametric formula is that you can keep adjusting until you get the fit that works best for your application.
This version of the lifter is only 8 feet long and I decreased the Y spacing on the braces on the opposite end of the base (braces #4,#5,#6) because of having less spacing moving from 12' to 8'. I wouldn't recommend going any lower than 8' - the shorter the lifter, the less mechanical advantage you have - so only use the 8' if you have hauling constraint or loading space constraints of which you can find yourself in from time to time.
For lifting 30" diameter rounds and larger I increased the LifterWidth to 2'. Although on some of these, even if you are quite strong, you may still need 2 people on the lifter. The brace distance from the opposite of the brace has moved to 2', you want to leave enough room for you round especially if you are lifting from 18" length to 24".
How could we improve this parametric formula?
- New Variables
- Make the sides sizes adjustable allowing you to use 4x4's instead of 2x4's - but you may say wait, 4x4's would be way to heavy, not if you are using your wench and a pully system, there will be another article in a future edition covering that scenario.
- Make the brace size adjustable to change size from 4x4 to 2x4 to lessen the weight of the lifter.
- Change the length of the support plank
- New Features
- Add new lumber to raise the lifting end (where you put your hands) off of the ground so you can easily get your hands under it
- Adapt the lifter to work with a B & W 8 or 10 drop trailer hitch
If you would like to share your modifications to the manual lifter formula - zip your DataModel Folder and send it to - contact@mathcompiler3d.com. After reviewing your submission the Data Model may be added to the public projects or featured in an upcoming issue of Conceptual Design 3D Magazine.