Shade Tree Jacks, Stands, & Cribbing --or--"Lift and Support"
>>>>>>PRACTICE SAFE LIFTING AND SUPPORT!<<<<<<
At some point, when working on your Cub, you will be forced to raise one or more of the feet off the ground. There are 2 parts to jacking up your Cub. The first is jacking it up and the second is keeping it up. Jacks are designed to lift but NOT
to keep the item in place. Although modern hydraulic jacks are pretty good and pretty cheap, they are not designed to maintain support. Maintaining support is the job of jackstands or other items with high compressive strength. In addition whatever you use for a jackstand MUST
be secure and stable. Because of the open nature of the Cub's design, you won't be forced to crawl under the tractor to work on the steering or change the oil. In fact, there are not many reasons to crawl under the tractor. But you will have to raise the wheels off the ground for things like splitting the tractor, working on the transmission, brake bands, and final drives.
Here are some things I have found to be helpful for lifting the Cub and holding it off the ground. These tools and techniques work for me and have made working on my Cub easier and safer. Remember, the Cub is cast iron and steel, if it falls on you, the best you can hope for is a crushed hand or foot. The worst is loss of the Cub and your life.
>>>>>>PRACTICE SAFE LIFTING AND SUPPORT!<<<<<<
I would appreciate any feedback you have. This link will take you to the Feedback thread: Shade Tree Feedback
- Elevator Shoes for the Bottle Jack
While modern hydraulic bottle jacks are a good value, they tend to be designed for lifting modern vehicles. The latest econobox has a ground clearance of 12" to 14". And a 2 ton bottle jack starts at about 10" closed and maybe as much as 16" fully extended. This is a long way from jacking up a Cub. The clearance on a Cub is measured in feet rather than inches. To fill the gap between the base of the jack and the ground, I've welded together a couple of jack bases. The bottle jack sits on the base and the top of the jack is within a reasonable distance of the Cub.
Since I wanted as stable a platform as possible, it seemed like a good idea to bolt the bottle jack onto the base. I've done this 2 different ways. The first was more work but the bottle jack remains unmolested. I drilled and tapped the top plate for 5/16" bolts and used flanged bolts that were sitting idle. I slip the jack into position and gently tighten down the 3 bolts. That base is shown below both with and without jack mounted.
On the second base, I decided to try something different. Instead of drilling and tapping 3 holes, I drilled a clearance hole in the top plate and mounted a 5/16" bolt on the bottom side with the bolt sticking up through the top plate. This mounting bolt was brazed to the top plate. Next I drilled a 5/16" clearance hole in the base of the bottle jack. To use the bottle jack on the jack base, just slide the jack over the mounting bolt and secure with a 5/16" nut.
I believe the jack mounted using the 3 tapped holes is probably stronger. These mounting methods are meant to combat side loads which would shift the jack. Any side load strong enough to break the bottle jack on either base would probably be serious enough that the loss of a $10 bottle jack is insignificant.
- Front End Wedges
When you do ANY jacking on the back end of the Cub, have your front end wedges handy and use them. Because of the front axle pivot and the offset due to Culti-vision, it is easy to tip your Cub over on its side. You will not only damage that great paint job, the tractor, and anything that was on the low side. Getting the tractor back up on its wheels becomes a major chore.
Here is a link to an article by Spaceghost on how to split a cultivision tractor. Good pictures, clear instructions, read it and believe it.
Just in case you think I'm foolin' take a look at a fallen Cub. It can happen in a moment.
- Swamp Footed Jackstands
Let me introduce "Swamp Footed Jackstands" Not to be confused with "your web footed friends". I bought a pair of jackstands from Harbor Freight to support the Cub's front end while I was working on the "adjustable axle*". When I got them home and looked at the foot of the jackstand, I knew I had to do something. (My Cub workspace is the area around the Cub when she last stopped. Currently, this workspace is paved in Texas clay and this is a great surface when it is dry. But here in Western East Texas, it ain't dry much of the time. And when it is wet, the ground turns kinda' swampy.) The jackstand foot is essentially angle iron on edge. In the image below, you can see the red dots showing where the weld line is around the jackstand foot.
This means that these jackstands are useless in my workspace as delivered. Any weight at all and they will slowly sink out of sight. In order to decrease the ground pressure, I welded a couple of pieces of channel on the jackstand feet. These jackstands, as modified, are much less likely to bury themselves in my backyard. An additional benefit is that these jackstands are less likely to tip than they were before. By putting the channel on the bottom, I moved the pivot point for the jackstand. In the drawing below, there are 3 jackstands. At rest shows the basic stable position. Let's assume that center of mass is right at the top center of the jackstand in all 3 cases. The "As Delivered" shows the distance the center of mass would have to move for the jackstand to fall over. The center of mass on the Swamp Footed jackstand has to farther in order to fall over. It can still fall over, but it will take more lateral movement before it does.
*See George Willer's entry on using hydraulic jacks to adjust the adjustable front axle
- Custom Jackstands
When I was working on the right band brake, I had to pull the final drive housing. To support the rear end while I messing about, I put this jackstand together.
It is made out of angle iron verticals, 1 1/4" pipe for the base, and a piece of 2 1/4" pipe at the top. Total cost for the stand, other than my time and a couple feet of MIG wire was $0. All the iron is scrap. I'm about to let you in on a little secret. (If you promise not to tell anyone else)Cribbing If you are looking for angle iron to have on hand various projects, start looking for discarded bed frames. Yep, that's what I said. Apparently a lot of people discard the old bed frame when they buy a new mattress. If you have a Furniture Row or other place in town that sells a lot of beds/mattersses talk to the guys that work in the back. If the buyer wants to discard the old frame, the delivery guys will usually load it up and put it in their dumpster back at the store. If you ask nicely, they may set them aside for you. In a typical frame there are 2 pieces about 6' long and 4 pieces about 40" long. All of the jack bases and stands that I have made are built out of bed frames.
Some people call it cribbing, others call it lagging, and some of us just call it a pile of wood. But a well-designed pile of dimensional lumber is a great support. Don't let the "well-designed" or "dimensional lumber" scare you off. The design part says that the finished pile should look like a pyramid. Each layer of wood should have a footprint that is no larger than the layer immediately below. The drawing below shows a crib from the side and the top. Notice that each layer from the bottom up is smaller in area than the one before it. This causes the familiar pyramid shape. The reason the pyramids are shaped the way they are is for the stability.
Notice also that the 1st and 2nd layers have 3 members and the 3rd and 4th layer have 2 members. The 3rd or middle member of the first 2 layers is optional depending on the span, the material, and the weight to be supported. Looking at the arrows on the drawing, the weight (force) is downward in the red arrows and lateral for the gold arrows. If the optional members are not used, then the timber has to be able to support the load without bending or breaking.
It is obvious that larger timbers mean that there are fewer layers. The downside is that it can be difficult to find large timbers of the appropriate length and they can be heavy to move and lift into place. Smaller timbers such as 4x4s and 2x4s are readily available and are a lot easier to move. When figuring out how much and what kind of dimensional lumber to use, remember that a 4x4 is only 3 1/2" x 3 1/2" square. For dimensional lumber subtract 1/2" from each dimension. To build a support 24" tall, I would use 6 layers of 4x4s (6*3.5 = 21) and 2 layers of 2x4s (2*1.5 = 3). If you find that your pile is just a hair shy, get some cedar shakes or shingles. By sliding the wedges in or out you can precisely adjust the thickness and this may get you the height you need.
If the shingles are still too thick, get some thin non-compressible material. For instance, paper or sheet metal. For a really high-end setup, put an air mattress between a couple of layers of plywood. Inflate the air cushion to get exactly what you need. Or pump the air mattress full of water. There are lots of possibilities, but think about everything that you do because the cost of a falling tractor can be very high.
- Legs for the Cub
There are a couple of reasons to put legs on your Cub. If you want to
To work on the pieces forward of the engine, these legs work fine. They will also work if you intend to split the tractor, moving the motor and other pieces, but not move the clutch housing/differential/final drives/rear wheels. Jim Becker makes an excellent point in the Feedback thread.
- Work on or remove the parts forward of the engine including the radiator casting and/or the steering.
- Split the tractor to work on one end or the other. In this case you are separating the engine from the clutch housing.
Jim said wrote:
"I have found it is almost always easier to block the front in place and move the back. About the only exception is when you split it in front of the engine and wheel the front axle away."
Since I've not yet actually split my Cub, I'll address the 1st part here since I was working on the radiator and steering. The motivation for supporting the main portion of the tractor was to allow me to work on the front end without worrying about jacks and jackstands. After examining the tractor I decided that the implement lugs on the tunnel provided a stout and safe mounting point for the support. The following drawing shows the pieces of the Cub's legs. And the photos that follow show the implementation of the legs.
Having identified the bolt on location, I turned to materials. I had picked up several pieces of 2x2 3/16" thick angle iron 32" long at the scrap yard. Since they were all about the same length, I assume they were drops from a machine shop or something similar. Anyway, I drilled 2 holes, 11/16" dia., in each leg for the 5/8" bolts. The holes were drilled along the long axis of the angle iron. I wanted to take advantage of the angle on the implement lugs to increase the length of the support base. Using the angle this way increases the support base about 20% in length. Here you can see the forward angle of the legs as well as the bolts holding the leg to tractor's implement lug.
Since I needed a jacking point and something to tie the legs together, I welded an angle iron cross piece to one leg. On the other leg I welded a piece od angle iron as a stop. As soon as I get around to it, I intend to drill a hole through the cross piece and the stop so I can bolt them together. Here is a shot to the legs from the rear showing the stop on the left side and the 2 ton bottle jack that is used to raise the front end of the tractor.
And here is a detail shot of the cross piece stop and the planned bolt hole location.
I hope this gets you thinking about ways to get your Cub up in the air so you can get it back on its feet. Jim's comment about moving the rear portion makes sense since the rear wheels don't turn. Imagine that you've split the tractor and are attempting to move the front assembly. Not only do you have to support and move this mass, you also have to either steer it or lock the front wheels in place. By moving the rear portion, you don't have to deal with floppy front wheels. The Mark II version of these legs will have large casters mounted. When the time comes to move the rear end, it will be just like pushing a LARGE teacart.
Whatever you do, DO IT SAFELY! Life is too short to make it any shorter!