3D Spiral ramp

Cad a career is pretty new to me… I did autocad at college got a btec in mech eng. Went to uni studied motorsport. quit that after to yours for various reasons and then took a job in a cycle shop and was there 4 years….left to a friends company that’s sells fruit and present is were I am now. I was very fortunate a company took me on as a trainee and have been here 7 months or so. I am really enjoying cad as a job.

In terms of Autocad experience I have used it I would say a fare amount and I am competent. At college I did it as a module and since then it is something I have always enjoyed I have always have a form of it on my computer and would draw random things like rc cars or measure a paintball marker and try and draw it in 3d. at college we did 2d and 3d modules. Then at uni used solidworks.

The company I work for is a transport planning consultancy so id say 99% of there work is two dimensional my job consist of allot of vehicle tracking…well a new job come in and is a spiral car park ramp.one of the top bods said they would love to do it in 3d.i was approached/mentioned to me and they would now like to do it in 3d.

I have had a good crack at it and its there or there about. the problem I am having is getting the ramp revole/extrude at he the right gradient.

I drew the ramps minimum radius in 2d then divided that by 10 (1:10 ramp) then took likes up every 10m getting a meter longer each time. After this I struggles to get a line/spline in with there 3 points at the correct radius. As Ideally that is what I would like it to follow.

In the end I did it by drawing a spiral/helix setting the diameter parameters and the then just dragging in up to the point were it “looked” like the spirals touched/intersected with the gradient lines I drew up from the divide circle.

I have draw this as “roughly” 1:10 the ramp I will draw hopefully with your help will be 1:12 I have attached ramp dimensions and a floors levels and a dwg of my attempt.

The ramp will go from ground floor to basement then latter this ramp will go onto lower basement.

i have attached 4 files

floor levels

ramp dimensions

ramp.dwg is some of the process i went over to try and get to a final ramp

then 3d ramp.dwg was what i finally achieved

I am new be kind  all help appreciated.

L

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update cant get the 3d model to upload.heres an image

ramp dim.dwg

ramp.dwg

FLoor levels.dwg

The top of slab of distance between floors is 3000mm. You worked the spiral out initially using a grade of 1:10 but now you want to do it at a grade of 1:12?

yes this correct.

my initial/first attempt were done @ 1:10ish gradient how ever "guidance" says its now must be 1:12

Seant - really appreciate your help with the drawing.

for future reference for my self how did you achieve this?

The 1:12 requirement forces a 36000 mm Run for the 3000 mm Rise. We know that the circumference of a circle is:

C = 2 * Radius * PI

So, via algebraic manipulation we can say:

Radius = C/(2*PI)

Which, in your case will be:

Radius = 36000/(2 * PI)

So, the radius at top and bottom of the Helix should be 5729.578

seant - if i am honest this will take a little while for me to digest however i will get my head around it.only 10am here...

so next how did you go about drawing the helix?

AutoCAD actually has a Helix command. Essentially, you select a Center point, input Bottom radius, input the same Top radius, input Turn Height (3000), input Turns (I used just one, you could enter more to accommodate all the required levels).

SO i have had a go at getting the ramps draw which i have achieved i think.

i am now struggling with grasping. how to make the ramps so that can come on and off.

so the top ramp needs to drop from road level to basement the ramp will next to allow cars to exit then get back on again next to it to go down to basement level 1.

i had initially rotated one of the ramp sections so its still in line with the sections above if looking down on it but starting adjacent to it.the ramp from basement 1 to basement collides with the ramp above.

so a nudge in the right direction would be appreciated would the helix change?or the direction of it or the gradient?

cant seem to get the dwg to upload so i tried this

https://drive.google.com/file/d/0B63WJhkrzDolWFdsQmVYTThZems/view?usp=sharing

it would seem my post didnt post.think i have managed to get the ramps correct now i am having trouble with allow. on and off ramps i want the ramp from basement 1 to exit enter on basement then restart at basement and go up from there.when i rotate the basement 1 ramp it seems to collide with the ramp above?

why would it do this is this due to gradient or the helix?

cant get the file to upload so had to try and use google drive

https://drive.google.com/file/d/0B63WJhkrzDolWFdsQmVYTThZems/view?usp=sharing

You have to wait for any posts with attachments to be approved by a Moderator until you have 10 valid posts.

To allow on/off, would you need some setup like this?

RampTest.dwg