Looking for design ideas on tapered front jack leveling blocks

[brianharrison]

For the angle, I have used a cedar shingle or premium shake as a wedge on the top of the block, between the foot and the block. I routed through the discard pile at the shake store. In compression the soft cedar still stands up.

Brian

 

[porthole]

Duane,

Thanks for the wheel chock link. I do need a much better pair for this driveway. Rather than getting a pair from U-Line, I got a similar pair via Amazon.com. Saved $22 on shipping

Here's what I got.

I will admit that I did not search, I already knew of U-line. I probably would have gotten them from the same place you did. Can't beat free 2nd day shipping on most items.

You and another person suggested using 4x4 and even 6x6 treated posts and then 5/4 decking on top/bottom to tie that sandwich together.
I get all that, but, what to do about the slope. It's significant. I don't feel there's enough flex in the jack pad to tilt as much as needed. I really want a flat top.

I suppose I could have the bottom course of posts cut to the angle required to match the driveway slope. Then make a second set with no slope and stack them.

Maybe 18"x18" by the height of material used. If I used 4x4s and 5/4 decking top and bottom, I come close to 6" thick. Two of those get me a foot or close to it. I don't have a good enough or big enough table saw to rip 4x4s at an angle for the length needed. My flimsy miter would laugh at that on my $100 table saw. But I'll bet there are several guys here in the Gardens with full wood shops

You don't need 6x6's. We have lifted and supported just about any vehicle you can imagine using 4x4's. And we don't have them tied together. Just lay them out, next row perpendicular to the first and so on. Called cribbing.

Personally, if I was doing this for myself I would use 3/4" plywood. The deck board is a bit unstable as far as shrinkage and sizing. And I would only use the ply on one side, just my preference.

That said. Since you have a slope that seems fairly - well slopey, and you want angled pieces, you are left with the band saw option. That is the only way to safely cut the 4x4's. Figure out your angle, get a piece of plywood or any 1/2" to 3/4" wood, rip it to 3.5" (4x4 size) and cut your angle with a jig saw. When you get what you want find a band saw buddy.

My driveway is steep also. There are times I have it set the trailer on the slope a bit. I'm sure you know this, but I would suggest anyway.

What I do is:

• chocks in front of tires, both axles (4)
• pull forward slightly to load the chocks
• chocks behind rear axle tires
• un-load the hitch (back up a hair to take of the load off the pin) and disconnect.

This essentially sets your tires in the chocks "cupped".
I have never had an issue doing this. I use 6 of the smaller rubber chocks, But i would use what I suggested to you if I was leaving the trailer like that for any length of time.

 

[JohnDar]

I use 4x4 cribbing pads with 5/4 decking for the tops to tie it together. Making them into a pad, rather than loose pieces of lumber, makes them more convenient to use. When I replaced the front jacks, I used a stack of 3 under the frame on each side to support the front of the rig as I sat in the front compartment doing the work. You could also make flat bottomed cribbing sets, similar to mine and use wooden wedges under them to bring the tops level. Same way we crib angled objects when shoring them. 4x4's will be more than adequate to support the trailer and a lot less expensive than 6x6's.

View attachment 18122

 

[jbeletti]

Okay, I measured the drop of my driveway today over a distance of 4 feet in order to calculate the slope angle.

Results:
@18": 2-1/8"
@24": 2-13/16
@36": 4-1/16"
@48": 5-1/4"

After measuring, I determined I wanted to build 18" square leveling blocks. However, doing so with 5 4x4s (3.5" wide) across will be 17.5", so that's what I'll use - 17.5" blocks.

I used an online calculator (link) and it computed my slope at 6.7562 degrees (at 18" out).

So if I use a 4x4, which is 3.5" wide/high, and if I start at zero at the front edge, I guess we'll be cutting it to taper back to 1-3/8 (a difference of 2-1/8") at the back edge. <- Am I on the right track with my thought here?

If I am, then I'd cut 10 ea 4x4s to this same dimension. That's 5 each for the bottom course of 2 blocks (left and right). I like Duane's idea of using 3/4" treated plywood for the top and bottom to tie everything together and have a flat/smooth. This also gives me a finished block (at the front edge) of 5" in height (.75 + 3.5 + .75). Two if these stacked gives me 10"

My coach is leveled out in my garage, so I can't confirm hitch height. Assuming a level tow, I measured/estimated what I think would be the max height from ground to raised bottom of jack pad. I'm thinking this is about 11". With 10" of rise with my 2 courses of blocks, I think I'm going to be good. Plus, I don't know what any of my RV visitors will have for clearance, so 10" will be better. I think what I'll do is cut another 4 ea, 17.5" squares of 3/4" plywood to have ready in case more height is needed and doable.

If I consistently need more height, then I can always attach 1 or more plywood squares to my blocks with screws. When doing so, I'll rotate the orientation of the plywood squares 90 degrees (if I can figure out any direction in it)

Thoughts y'all?

Also - what if I used untreated lumber and painted it? Just as good?

Jim



Oops on the ruler not being level - could change my figure by an 1/8". Not worth setting up and remeasuring though

 

[Ray LeTourneau]

I think you'll be fine with plain ol' pine, untreated lumber. If you didn't want to paint them you could just use some waterproofing stuff or deck stain. I'm guessing they'll be stored indoors.

 

[jbeletti]

Yes Ray - they would be stored indoors. When in use, they'd be used for 2 day intervals. It's unlikely they'll see much rain, but I would still want to paint or treat the exterior.

Jim

 

[dieselengineer]

Hey, Jim
I have a 24 inch industrial bandsaw that would cut the 4 x 4 with no problem. I made all my wheel chocks etc. I am in Delaware now, so come over and we will cut twice and measure .....

 

[jbeletti]

I like it Jim. Gotta find a neighbor here with one of those!

Jim

 

[porthole]

That's a heck of a slope you got there.

Given any thought to the loads on the rear axle versus the front once the trailer is leveled? or are you going to keep your visitors limited to a 1 or 2 day stay?

 

[jbeletti]

Good point on axle loading Duane. But yeah, it's a 2-day max stay in the driveway per HOA rules.

Jim

 

[Ray LeTourneau]

That's a heck of a slope you got there.

Given any thought to the loads on the rear axle versus the front once the trailer is leveled? or are you going to keep your visitors limited to a 1 or 2 day stay?

Believe it or not, I was thinking of the exact same thing very early this morning. Another thing to ponder, will the tail end of the trailer or the spare tire possibly contact the driveway prior to getting up to the point of being level? Just thinking out loud...

 

[jbeletti]

I feel I have the clearance needed Ray. I'm committed to trying this, so we'll find out

 

[FoxHunt]

I'm not familiar with your trailer's setup, and whether or not the jacks can support the trailer weight entirely, but if rear bumper clearance is an issue, simply crib the rear jacks and/or axles a few inches to raise the trailer slightly (before leveling if pulling up on the 2X6 etc). Sure this will add to the height of the blocks in the front, but it will also get the unit off the ground in the rear enough that you won't be digging in while jacking up. I was the duty driver on a 95' Ladder Truck in a not-so-level city, so I can appreciate the concern over one end being jacked up in the sky and the other end touching the ground!

 

[Ray LeTourneau]

So Jim, how is this project coming along?

 

[rick_debbie_gallant]

How about using a HEAVY duty hinge on the up side and an acme thread on the bottom side. Then you could adjust the angle to level. I would also include in the design some way to "PIN" the block to the ground. In your drive way because it so steep I would bore a couple of holes to accommodate pins that are welded to the "block" on the bottom.

 

[jbeletti]

Rick,

I can't wrap my head around your design - sorry.

Ray,

I have been traveling too much to get to this, so nothing done yet. But we're hoping to host our first RV visitors in July after we return from Gillette, so I'll tackle this when we get home.

I did measure the space from my level garage floor to the bottom of the jack pads on the front of the coach. Based on that, I think my total height on the front edge of the tapered block can be 8". So maybe make a tapered bottom course at 3.5" and a flat top course at 3.5" for a total lift in front of 7" Then hope that 7" plus the full travel of most front jacks is enough to get a coach in the driveway level or very close to it.

 

[Squatty]

Hey Jim,
Out of the box thinking, but could you just cut a hole(s) in the new driveway for the KL wheels to drop into? Then, build cover(s) for the hole(s) so you can get to the garage with your car or to sled down the driveway? Ha ha!

 

[TexAndLinda]

I came across this during search

found at http://www.northerntool.com/shop/tools/product_200426744_200426744

 

[evolvingpowercat]

At a six degree slope the # of pounds of force in the horizontal direction, that how hard you would have to push to keep the trailer from rolling down the drive way if it were free to roll is 10.1 percent of the weight of the RV -- weight * sin (10 degrees).

So, you are trying to hold back perhaps a thousand pounds of force on a 10,000 pound 5th wheel !

So to keep it from sliding down the drive way:

- use large wood blocks under the pads - more contact area = more friction to the sliding down. Perhaps pieces cut out of 2 x 12 joist material cut to be at least a square foot in area.

- use serious wheel chocks certainly not the little Trailer Life ones. Perhaps some X-chocks too.

- If your pads have 6 degrees freedom of swivel on the pads I would not mess with wedge shaped blocks.

 

[evolvingpowercat]

Just a caution - when applying weight downward on a slope the horizontal force is Weight * sin ( angle ). At 6 degrees the horizontal force is slightly over 10 %. So on a Bighorn you are trying to hold back 1,000 pounds of force wanting to roll rig down the six degree slope.

The more surface area under the areas contacting the ground and using items contacting the ground with large friction coefficents advised. Locking the wheels so they can't roll is also a good idea using X-chocks and very large size wheel chocks also a good idea.