Saw Ramp geometry question.

[Gregg Feldstone]

I am having a small concrete ramp made in my garage to allow me to roll my tablesaw down from the raised section of the garage slab to the more spacious main area.
The raised area is 3 1/4" higher. The distance from the front wheels of the mobile base to the extension table legs is 45". The distance between the front and back wheels of the mobile base is 35". The extension table leveling feet can be raised 1.5" if necessary (leaving them 2.5" off the ground when the saw is jacked up on the mobile base.) "Front" and "back" refers to the uphill and downhill side of the saw (not the usual front and back used when using the saw.)
What I am trying to figure out is how long the ramp needs to be to keep one end of the saw (most likely the extension table legs) from bottoming out before the rest of the saw gets down. I could roll it down heavy end first but I think it will be easier to bring the table end first.
I know this is a simple geometry question but I'm not a math whiz. Any help will be appreciated!!
Bye the way, it is a SawStop cabinet saw on SawStops mobile base. Thanks!!

[Chip Lindley]

Let's not get a headache involving geometry in a thing like this! Make the ramp 8 feet long, using two *green-treated* (if this is outside) 8' 2x4s. Rip them to 2-3/4" for starters. Then rip them at an angle from opposite corners, lengthwise to make 4 runners tapering from 2-3/4" to 0" beneath your ramp. Using 1/2" exterior ply for the surface will bring your ramp to the 3-1/4" height you desire. There will be a 1/2" *bump* at the low end (thickness of plywood) Nothings' Perfect is it?

[Scott Schwake]

or model it in Sketchup if you're so inclined.

[richard poitras]

I worked with handicap people for a lot of projects and the wheelchair ramps are a 12-to 1 slope that I used/ installed that would give you a nice gential slope

[Anthony Whitesell]

Unfortunately, you/we need one more piece of information. What is the clearance between the floor and the mobile base in between the base wheels?

Without taking into account the base clearance I have two numbers for you.

I started by working backwards, if you wanted to drive the table saw up the ramp extension table first, how long would the ramp need to be?

The extension table leg raises (worst case) 1 1/2" 45" from the wheels then the distance 45" in front of the wheels cannot be higher than 1 1/2". Those numbers become your rise and run (1 1/2" every 45") Since you need to go up 3 1/4, then the ramp needs to be 3 1/4 divided by 1 1/2 times 45, or 97.5 inches long. If you go best case and raise the extension table leg up, then it becomes 3 1/4 divided by 2 1/2 times 45, or 58.5 inches long.

The question is still with the wheels 35 inches apart, will the mobile base catch on the top of the ramp and hence why you/we need to know what the clearance between the mobile base and the floor is.

[Steve Rozmiarek]

The longer you make the ramp, the easier the saw will be to roll up the hill. Unless there are length constraints, longer is better.

[Fred Belknap]

I would make something out of plywood and treated lumber. If you use concrete sloped to nothing the edge is very week and will break under any load. Make a template using the height of the saw in the middle and the spacing of the wheels and give yourself a ¼" clearance in the middle. You can bevel the back of plywood to fit the floor, use a grinder or make a beveled strip to fit at the end.

[Doug Shepard]

Here's another thought. Could you get by with a pallet jack to fork it off the raised plarform and lower it down?

[Gregg Feldstone]

Thanks for the response, especially Anthony.

The mobile base is only 1/4" of the ground. Unfortunately, the parts of the base that go up and down are internal steel straps, while the outside frame is a fixed height.

I may end up making something out of wood because I got prices between $300--$750 to do this. The pros that gave me a bid all said that they would have to "saw cut" my garage at the bottom (thin) end of the ramp and than use a hammer drill to carve out a 2" recess for the narrow end to attach to. The high bid was for a 5' ramp by a reputable local company. The low bid was by a "migrant" contractor who lives 3 hours away.
I'm thinking a longer, more gradual ramp may cost me $1000. I don't want to use wood because the garage floods sometimes and I plan to leave the ramp in place and not take up space storing it. I suppose a good finish of marine varish would work.

[Anthony Whitesell]

Unfortunately, if you had the shallower grade (1 1/2" scenerio) you'll only make it over the hump about 7 1/2" before the mobile base hangs up on the edge of the ramp. Less if you opt for the 2 1/2" option. You could try to get fancy and make the ramp curved like those camel-back pick-up truck ramps (like these http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=96513) But I don't think I'll be able to help with the math on those.

If you can do something (larger wheels or base modifications) to raise the mobile base up to 1.16" then you'll just clear the hump at the edge of the ramp. But you'll still be stuck with the 105" long ramp.

I'm sorry I can't find a way to make the numbers work out better.