Rampage - Early's Latest Ramp

Templates up, temp bracing up. My lovely wife Jeania sitting in for scale.
Most of the joists down. Won't be long (if it weren't for the rain!)
Detail of deck beam about to be connected to template. Note pencil mark showing where to screw in the template. The excess was cut off w/ a Sawzall.
Detail of how I connected joists w/out a helper. The basic concept is simple - just put a quick-grip on the template at either end, and let those support the joist while you drive screws into the framing.
Detail of foot beneath the seam in the beam. It's very important to support at this seam, b/c at the bottom of the transition is where you get the most force.
My son says he can't wait to drop in. It brings a tear to my eye!
Most of the ply down. Coping hooked in. Rides awesome.

I'm building my 4th mini ramp now and applying lessons learned on the previous 3. It seems fitting to talk about the previous 3 now.

  1. The Double Wedge. ca. 1992
    This was really more like a plywood ditch than a mini ramp. It was completely hacked together with free material, and essentially consisted of two 4'x8' sheets of ply held up at opposing angles, and some milk crates or something as a deck. If I can find some pictures, I'll post them, but I doubt any exist, since I was pretty embarrassed by it at the time. It was pretty fun any ways, since it was basically two really shallow embankments. You couldn't really pump, so it was more of a drop-in, do-a-trick, let-somebody-else-have-a-turn.
  2. The 3-Footer. ca. 1993
    My first foray into true ramp construction. Made a lot of mistakes. The ply tore up really quickly, and I learned that 8 ft is way too much span for the joists and that if the ramp is going to be outside, it should NOT be perfectly level, so that water will run off. Especially if you're living in Alabama. Cross bracing is invaluable as well - when I first built it, it rocked side-to-side like crazy. Still, this ramp was incredibly fun, and with a gap between it and the double wedge of about 3ft, proved that ramp-to-ramp transfers are just incredibly exciting.
  3. The 2-Footer. ca. 1998
    This started off as an in-the-garage beast, but I was living in Houston at the time, and during that summer, grass fields were spontaneously combusting. My wife, Jeania (pronounced like Gina), graciously suggested that I move it to the living room. Brilliant idea. It was right beneath the AC vent and I was officially spoiled. One day I shall have an indoor ramp again. This is my solem oath.

There have of course been other little projects as well. Before the Double Wedge, I built a number of launchers and quarter pipes. Between the 3-Footer and the 2-Footer I lived in an apartment in Columbus, MS and spent a summer with Ben Gilley building a make-shift skatepark out of scrap material in the parking lot of an abandoned K-Mart. There would of course be red-necks who would come along and smash it while we weren't around, which sucked, but that little park was loads of fun.

So, on to the main attraction, my current labor of love, the Wild Rampage. It's 18' wide, 5'6" tall, with 4'+ deep decks on both ends. 2 layers of 3/8" CDX plywood for subsurface, and 1 layer 1/4" sanded ply for the riding surface. Masonite is out for the location - it's rained something like 10 out of the past 14 days!

Transitions

The transition radius is about 6'3. I broke away from the standard method for cutting the transitions. Normally, you would take a full sheet of plywood, cut out the full radius, creating a template. You would then attach joists between two templates, with screws going through the plywood and into the end of the joist. This is what all the usual manuals describe. See RampPlans.org There are a few drawbacks to this approach.

First, this method has the screws loaded in shear. A single screw can hold roughly 100 pounds in shear, and I'm a pretty big guy these days at 220 lbs. So if I land an olly just to the left of the end of a joist, pretty much all of the load goes straight to the screws holding that joist in place. I'm using 2x4's for all of the framing except the templates and posts, so that means if I used the normal method, I'd only get a whopping 2 screws into the end of the 2x4. That's considerably less than the 220 lbs I exert just by standing there, let alone landing an olly or taking the centripedal force I exert by rolling over it.

The second problem is that plywood is damned expensive. I had a few sheets laying around when I started this project and wanted to build a wide ramp without buying any more ply for transition templates. It would have been impossible if I created 1 template from each piece of plywood, especially since I wanted to build something taller than 4'.

The third problem is that cutting radiuses is fairly imperfect and I wanted something I could create a jig for in order to produce a quality transition.

My solution? I know you're curious or else you would've scrolled past this to the pictures. It was simple. I built a 4'x10' frame from scrap 2x6 and mounted a block with a screw. I then made a 2x4 with a small whitewood scrap on one end and 2 holes on the other end, the closer being 6'3 from the center of the whitewood scrap. Next, I mounted a router to the whitewood, and voila, I had a radius-cutting tool. To use it, I would slide a sheet of plywood into the frame, pass the router through it with the wide radius, switch radii, and cut the small radius. I would then slide the plywood forward and repeat the process. In this manner I could get something like 12 4' wide bits of transition from a single sheet of plywood. Glue 3 together and you've got a roughly 5'6" tall, 6'3 radius template. So now I could get 4 templates from a single sheet of plywood. In all, I made 12 templates from 3 sheets of plywood, yielding enough to construct an 18' wide ramp. Actually, I could've done 20', but decided to make the ramp a little smaller in order to save on surfacing plywood and to ensure that I could cut everything to a finished width with my circular saw at the end.

Framing

Next, I connected 10' 2x6's to the templates, with the bottom edge of the template 1' in from each end of the 2x6. This gives us 10' - 2x1'= 8' of flatbottom. I painted the templates and 2x6's at that time. Next, I laid all of this out and added an additional 10' 2x6 to each end of the bottom beam, for a total length of 30'. I rotated these items up and attached 8' tall 4x4 posts. I made sure to mount the 2x6's a few inches above grade so that I could (1) prevent them from rotting and (2) make up for the wavy pavement I'm building on. I don't want the ramp completely level, but I do want it level in the direction of the transitions. i.e., I want water to flow off the sides of the ramp and I want it to be level as a matter of perception. If I'm carving or otherwise riding side-to-side, I won't really notice the slope. If I'm constantly losing speed when heading to the "higher" transition, I'll notice it and really dislike it.

So in any event, I mounted all of the template/beams to the posts and then used some 2x4's to brace the posts. Eventually they'll get really nice, possibly mitered, cross bracing. For now, they've got 10' 2x4's on steep enough angles to keep the posts plumb. Before I put down the plywood, I plan to put a foot every 2' through the flatbottom just to keep it nicely supported.

Next, I cut a bunch of nailers. Each nailer is a 2x4 cut to a length that matches the depth of the templates. I mounted the nailers using 3 deckmate screws from each side. That's a total of 6 screws, which is probably overkill, but I learned with the 3-footer that shear is the most likely way that connections will fail. That's why the joists are mounted to these nailers by simply placing them on top and putting 2 screws through them. That connection will now be in compression during use, rather than shear. I intend to follow this same train of thought by putting squash blocks beneath all of the beam-to-post connections, thereby allowing the loads to completely bypass the post and go straight to the parking lot.

Since the transition templates do not fill in the entire space beneath them, I'm putting angles from the center of the tranny down to the corner of the post for reinforcement. From climbing around the framing, I can tell that this is overkill, but I'm going to have lots of scrap 2x4 and this is a simple thing to add.

I haven't decided on coping yet. I've got some steel fence rails recovered from the old chain-link fence that I might use. It's over 20' long, so there would be no seam in the coping at all, but its radius is way too small. I might go buy some rigid electrical conduit or check with the local plumbing supplies for some 1-1/2" conduit/pipe, but I'll have to see what my budget allows. I'm trying to figure out if I can mount the fence rails in such a way that I can upgrade later without having to replace the deck. We'll see.

Update 2006-05-29

Got a minor cash infusion from my income tax return. BTW, I'm a proponent of the FairTax, but in the meantime, I'll pretend my income taxes are a no-interest savings account rather than a no-interest loan. Anyway, with that infusion I realized I had enough cash to buy 4 2" O.D. EMC Conduit. Super Shiny. I've decided I will be going with the "Tap" method of attaching the coping, since I've never tried it before and it looks like it might be superior than my old favorite, the toggle bolt. I'll let you know how it turns out.

As I was walking around the flat bottom, I noticed it flexing a bit more than I'd like. This was likely because I had feet only at the ends of the beams, or 10 feet apart. I had actually intended to space the feet no further than 4' throughout, but somehow forgot to cut 4x4's to go beneath the flat during my enthusiastic laying down of the joists. Fortunately, there's enough room between the joists to slide a tape measure and some newly cut feet. I'm almost done putting those feet in. That would've been a nightmare had I forgotten to do it before putting the plywood on. Then I'd have to decide whether to pull all of the plywood off or try to crawl under the ramp. Neither option would be too appealing. The beams I've already reinforced aren't budging at all now. Beautiful.

Framing-wise, I'm about 80% done. I just need to screw down the joists on the decks, add some more cross-bracing here and there, and stain the frame to protect against the ridiculously wet Northern Alabama climate. Bought a 5-gallon jug of Beahr wood stain for that purpose. It's cheaper than paint, and since it is designed to really soak into the wood, I figure it'll do a better job of protecting it. I'll let you know in a few years (hopefully) if it works.

Update 2006-06-22

Well, the last bit of construction has really been dragging along. The Beahr stain went back to Home Depot. It turns out that it needs 24 hours to dry, and the weather wouldn't cooperate, so I switched to using Kilz Indoor/Outdoor primer/sealer/stainblocker. Hopefully it works as well. I've been applying it in many super-thin coats so that each coat is embedding into the pores.

I've been painting plywood inside and installing it on the ramp, which is a bit of a bottleneck since I've only got so much space inside to paint. On good days I'll go outside and paint a slew of sheets all at once. I've managed to get 2 layers of 11/32 sanded ply down for the subsurface and am now at the point where I'm saving up for the final riding surface. I haven't decided what to use yet, but I'm thinking about things like marine-grade polyurethane, epoxy garage floar coating, fiberglass and epoxy and the like.

I installed the coping. I had been planning on tapping the backside of the coping so that I could screw threaded rod into it. It turns out there is a much easier way. I saw the idea somewhere on rampplans.org, but I cannot seem to find it any more. Rather than using a toggle bolt (which they incorrectly call an anchor bolt), you use an anchor bolt, which is a bolt that is bent so that it looks like the letter "L". To attach the coping, you:

  1. Drill holes through the framing where the coping will sit.
  2. Sit the coping in its slot.
  3. Using a small paint brush, dab some paint on the back side of the coping.
  4. Remove the coping, drill through the paint spots.
  5. Insert threaded end of "L" anchor bolt through framing, point leg of L up.
  6. Slide the holes you drilled over the leg of each L.
  7. Wiggle the anchors so that the leg is pointing sideways.
  8. Push the coping into its slot.
  9. Tighten the anchors.
One thing I did to save money here was I made my own anchors. I bought an 8' section of threaded rod, normally used to install super-strut by electricians (right next to the EMC conduit at Home Depot). I then beat about 1.5" of the end into a right angle using a hammer and a parking block, and used a sawzall to cut an 8" length of the bolt out. I repeated this until I had enough anchors to install all of my coping. The single piece of rod was dirt cheap compared to buying that many pre-manufactured anchor bolts.

TODO List