A while back I scored a fairly large quantity of laminated pine beams. I plan to turn some of these into ultra-stable/solid ramps. So the material is somewhat fixed - it's free/I have it, and it's safe/cannot collapse/bend/etc.

The main question for me is to figure out the angle, height, length, size of platform, any auxiliary features, fasteners to attach multiple pieces together, etc.

Angle of approach of the lowest longest overhang vehicle is the key number, I guess. How low is the lip on the lowest/weirdest car, and how far from the tyre centre is that lip. The flat part at the top only needs to be 200mm long, and at each end of that, a stopper, or bump. At the cliff-like-end, a highish/strongish stopper that will prevent over-driving accidents. And at the back ramp end, a little bump to let you know you're crossing the threshold. Maybe a D of brass or alloy or something, screwed to the wood.

My total height will be either 2 or 3 layers of these beams, thick. That's around 200-300mm or so.

If I use a separate piece for the stopper at the end, I can heavily screw it into all of the layers which will double to hold them all together.

Let me find a picture of the materials...








Refs: https://twitter.com/FredCookeNZ/status/ ... 7362990080 and https://twitter.com/FredCookeNZ/status/ ... 7139015680


ie, it'll need to be two pieces wide, too. Maybe 3 at the bottom, two on top? And if it needs more height after that, well, I can add more below.

Fred.

From: https://www.amazon.com/Race-Ramps-RR-TR ... UTF8&psc=1

"6 1/4" high ramps are 74" long and 14" wide, reduce angle of approach to 5.5 degrees, and can accommodate tires up to 12" wide."

From: https://www.amazon.com/Race-Ramps-RR-XT ... 3R4MNPN3W0

"Our 67 inch Race Ramps XT have a gentle, 10.75 degree angle for your low clearance vehicle -- but don't let that "gentle" stuff fool you. Our solid core design ramps are the toughest around, supporting up to 3,000 pounds and tires up to 12 inches wide."

From: https://www.amazon.com/Profile-Sports-L ... ZPBH6J7VBJ

11.5* load angle

Which looks a bit too steep IMO. I'll have a measure of the fleet and get back to this later.

I have those race ramps. You have all the specs, but let me know if I can provide anything useful.

Neat. Not 100% sure what the measurements are exactly. If you want to take some better-described metric measurements, that'd be cool. For eg:

• height of platform
• length of platform
• length of ramp section
• length of stopper section
• width

I've been thinking about it a bit today and need to draw some diagrams of my plans, minus the exact angle and dimensions, which I haven't measured, yet.

Today's measurements of the wooden stock I'll be using: https://twitter.com/FredCookeNZ/status/ ... 9664498688

Inlined:






Which likely means that my ramps will be 220 or 330 wide and 180 or 270 high.

If I made them 330x270 I doubt I could lift them by myself! So they'll probably start life as 220x180 and if I need more (unlikely?) then I'll make a base layer that's separate and can be laid down under them. If I need more width, I can laminate that on.

Off to play with LibreCAD and see what I can come up with.

5.27 degrees makes the ramp 1950 long
10 degrees makes the ramp 1020 long
8.53 degrees makes the ramp 1200 long
7.5 degrees makes the ramp 1367 long

For vertical storage I'm limited to a grand total of about 1800 long, which would be huge and heavy anyway.

CAD drawing is 1425 of ramp, meaning 7.2 degrees, and it looks reasonable in drawing form.

http://stuff.fredcooke.com/OutOfProportionRamps.dxf





Key:

little rectangle at the start of the ramp = hardwood inset, in the diagram it's 80x20mm, but I intend to use kwila decking of whatever size I have.

slither along bottom is plywood to help hold the pieces together, glue, and many many screws

vertical piece at the end as stopper filled with long screws into end grain of beams

offset top and bottom beams to provide weak interlocking of the support/platform and the ramp

separate ramp/platform to allow sill work and more access once up on top

thoughts welcome!

Vehicle measurements and reasoning AKA reality check:

Suzuki: 600x160 = ~15.0 degrees
Lantis: 700x210 = ~16.7 degrees

Both short overhang vehicles, Suzuki very short and lowered, Lantis moderately short and unlowered. I could probably drop the Lantis 50mm which would produce:

700x160 = 12.88 degrees

Let me get a few more...

Ute reality: 700x240 = 18.92 degrees
Ute with splitter as is: 700x180 = 14.42 degrees
Ute very very low with splitter: 700x100 = 8.13 degrees
Ute very low with splitter: 700x125 = 10.12 degrees
KP60 as is: 600x220 = 20.14 degrees
Lowered 70mm, till tyre top level with guard edge: 600x150 = 14.04 degrees
Back of caravan reality: 850x180 = 11.96 degrees
Back of caravan sacked: 850x160 = 10.66 degrees
Back of caravan sensible: 850x220 = 14.51 degrees

Corbon, what measurements do you get on the front of your R33? Just curious!

Johntramp, what do you get on the front of your AE85?

I shall PM/IM/SMS/SMTP/POP3 you both for responses.

So far the only thing that says a very shallow ramp is required is a 100mm clearance ute with a splitter out to the edge of the current bumper, and it needs 8 degrees. 8 makes for a ramp length of 1280 prior to the platform. A more reasonable 10 gives us a 1020mm ramp. Matching Jeff's at 10.75 yields a ramp length of 948mm. So I guess I don't want the ramp under 1000 long, and I probably don't want it over 1300 long, but we'll see what Rob and John have to say.

Fred.

R33 is about 900x140

Cheers! That's 8.84 degrees, and a ramp length for my height of 1157mm minimum. Great sample, thanks! :-)

All of these numbers definitely rule out making it three layers high as that would mean a LOA of 1800mm + platform, and they'd be uber heavy and hard to manage and hard to store, etc.

Now, where's John with some cheeky smart-arse comment? :-)

The AE85 is up on blocks. Someone must've stole the wheel, or wheel bearing, or something.

Forging ahead without that interesting but useless information:

The hardwood that I intend to use is 95x24mm section. To make it stronger and key it into the rest of the wood, I could route a step into the glue end, and to make the entry smoother, I could buzz a bevel off of the leading edge. Say 9mm of bevel, leaving a solid 15mm of kwila.

The plywood I have is actually 12mm, not 10mm, so I could route a bit into the bottom for that, too. Let me try to sketch something up on paper and then CAD it...

<some time later>

Got interrupted by a guest, and it's just gone midnight, so I'll resume this tomorrow morning, zzzz. What I will say before I go is that the 15mm end bevel, and 12mm route for the ply and 6mm route for the main meat with a small square edge, and plenty of glue for the final lamination, should work nicely. Drawing and CAD to follow. Zzzzzzz.

No CAD, yet, however I will back this up with a CAD design, as a way of giving myself a plan to work to, despite a total lack of CNC and an OS approach. I drew these, of which I'm likely to do the upper one that's simpler:

https://twitter.com/FredCookeNZ/status/ ... 0442884096