I finished the metal ramp!!

[MikeT]

Cool Man

I worked out some numbers but my units are all wrong.... I need to further study it. I figured out from your dimensions that your ramp curve has a dimater of 37 feet. I hope I can figure out the rest. Maybe someone else can.

I knew you weren't razzin me, but I see your ramp as a good Physics problem, plus I don't want to see you get hurt. :D

 

[shift085]

metal ramp

hey what sup that ramp is off the hook can you send me some plans on that.

 

[Hondaofroyracer]

Mike T- how did you figure out that diameter? do you know how to use the dia. to get the shape you want, i used a hydrolic bender, and just bent it till i thought it looked like it worked.

Shift085- I didn't use plans, i just made it. i dunno how it turned out so bitchen.

EVERYONE ELSE WHO WANTS PLANS READ THIS!-
e-mail me at [email protected] and let me know you want some. give me your e-mail adress, phone #, and fax # if you have one. it just alot eaiser for me to draw the plans up, then copy them, and fax them or mail them to you, rahter than try and use something like CAD to do it.

Im gonna TRY and get around to doin it this weekend, but id rather ride.;)

Anyway, thanks for the feedback and interest guys, i apreciate it....keep it comin

Late

Drew

 

[CanadianRidr]

If you go to freestylemx.com (sorry I hope this is not spam) There is a guy named slider, if you post a pic of your ramp with the dimesions and the materials he used, he can tell you every inch of that ramp's safety! He's awesome, he designs all the ramps for the big freestyle comps, If I am not mistaken it was his ramp in the US OPEN:)

 

[MikeT]

Originally posted by Hondaofroyracer
Mike T- how did you figure out that diameter? do you know how to use the dia. to get the shape you want, i used a hydrolic bender, and just bent it till i thought it looked like it worked.

I just used the dimensions you gave and fit the appropriate circle into it. The formulas to figure out the force you exert on the ramp need the diameter and speed you are going to work. In my calculations (whenever I figure them all out) I will be assuming that you will hit the ramp at 25mph. It might not sound like a lot but it is. I'll try to work on them a little later today and see if I can get them to work correctly. Once I know the force you are exerting then we are into my field. I will then be able to tell you about every weld and angle on your ramp. Provided I know where they are. For now I'm just going to see If I can figure out the force first. :confused:

 

[MikeT]

I DID IT!!

OK Drew, I've got your forces. The following is provided you are going at 25mph and have your ramp on the top setting. I can recalculate if you are going at a different speed if you want.

The formula is Fc=(m *(v^2/r))/g

Fc= centripetal force
m= your mass which is 400lbs
v= your velocity which is 36.6 ft/second
r= the radius of your ramp which is 18.5ft
g= gravity 32.2

So, Fc=(400(36.6^2/18.5))/32.2
Fc= 900lbs
and that means that you are experiencing 2.25 g's on take off. Now what do we do with that number? You take that number and create whats called a force diagram, and through much trigonometry, we can come up with the force in each member and the forces in each weld. Once that is done, we can determine if the pieces of the ramp are adequately designed and if the welds are the correct size.

Sorry to bore you guys, I just love this stuff! I'd rather be riding though.
:)

MikeT

 

[Jaybird]

Lots of variable when plotting this one out, Mike. Remember hes using lattice work.

Hondaofroy, Very kewl ramp. I suggest that you sell plans and forget about selling the ramp. The liability for such a sale would be tremendous. Your best buddy in the world would sue your (or your parents) pants off if he got hurt on one.

 

[MikeT]

Originally posted by Jaybird
Lots of variable when plotting this one out, Mike. Remember hes using lattice work.

Plotting? I drew it to scale. If he gave me the right numbers and has a correctly shaped arc (and he's going 25) the numbers should be correct.

Lattice work? Are you referring to the fact that he's built an indeterminate structure? I have a nifty little program that can do that easily. Where does he have lattice? I didn't get a copy of the plans, just the length and top height..

 

[Jaybird]

Mike,
I can't get his pics to load now, but I think I remember the support structure was two lattice works with intermediate joists between holding the ramp.

You using ANSYS?

 

[MikeT]

The pics aren't coming up for me either anymore. No I'm not using that program. The calcs I posted are just using pencil and paper. If I were to figure out the indeterminate structure I'd use RAM Advance. It's a very nice program. I don't think it would do an arc, but I haven't tried that yet. I might just have to cut the arc into a few segments. It might take an arc, you never know. I won't have access to it until Monday though. Even with that, I don't know the dimensions of where his "webs" are. I think that's what you may be calling lattice work, right?

 

[Hondaofroyracer]

........LOL............this is like my Algebra 2 class. But to some extent i get it. Thats sweet how you use math to figure this stuff out, when i built it, i was just thinking strong and just what i knew from experiance, anyway. Thanks for all those equations and what not. thats sweet.

Thanks to everyone for thier help, and opinions

Drew

 

[Jaybird]

LOL...Drew, some folks just have a natural knack for building stuff. It's a feel thing that you apparently are blessed with. This natural common sense can always be proven or disproven with math, since we live in a constrained world.

Mike, lattice work would be a support structure using diagonal bracing to distribute load. A big building will have trusses supporting the roof and they will be in a lattice formation(or your house roof). Ususally a top and a bottom member joined strategically by diagonal intermidiates. The point where two diagonals meet would be considered a pick or load point, depending if the joint is at the top or bottom of the structure. When engineering a building, load of both the roof and what will be suspended below the joist are taken into consideration when sizing the lattice work, or truss, as it's refered to in that instance.

 

[MikeT]

Originally posted by Jaybird
Ususally a top and a bottom member joined strategically by diagonal intermidiates. The point where two diagonals meet would be considered a pick or load point, depending if the joint is at the top or bottom of the structure.

I think we are talking about the same thing, I just hadn't heard the termonology you were using. We just call it a truss, or truss type framing with top chords, bottom chords, and webs. You were just referring to the whole system as lattice work, which is correct. Now that I think of it, the whole ramp is lattice. I understand what you are saying now. Different companies just use different terms. I got ya. :D

Originally posted by Jaybird
When engineering a building, load of both the roof and what will be suspended below the joist are taken into consideration when sizing the lattice work, or truss, as it's refered to in that instance.

Yes, it's fun finding out which way all the loads go. I used to design light gage steel trusses that were mainly controlled by wind cases because they were so light, but now I am doing conventional type framing that is usually controlled by dead and live loads. I have to think a little differently when I design them. I think in Drew's case, even with an impact factor of 1.5 he will probably be OK. I think you said it best when you said,

"Drew, some folks just have a natural knack for building stuff. It's a feel thing that you apparently are blessed with. "

This has been a fun excercise. I would like to see a drawing with some measurements on it Drew if you get a chance. I would have a lot of fun analyzing it further if you like. I'm sure Jaybird will too. Guys like us just love this type of thing.

MikeT

 

[sleeplow]

where can I learn how to make a portable ramp

 

[MikeT]

Hmm, are you sure you want to? I forgot this thread even existed! You need to be able to weld and have a LOT of fabrication experience. Does that describe you?

 

[TP thunder]

ramp plans

i can open the pictures but are wanting plans to build a ramp can you send some through to me [email protected]
cheers

 

[sleeplow]

How

I need some plans for a good ramp and i don't have much money :think:

 

[YZ165]

I've been thinking about building a ramp for a couple years and I finally did it. It is a blast! Anyone who wants pics or measurements can e-mail me at mryance[at]hotmail.com. It cost me around $350.00 in materials, and two days to build. :aj:
BEEF706 saw it last weekend and just shook his head at me!! :laugh:

 

[SpeedyManiac]

I can't get the pictures to open. MikeT, are you a civil engineer? I'm a mechanical engineering student, and I doubt it would be hard to figure out the loading of everything. If I could get a diagram of the ramp, I would probably be able to get one of my profs to look at it in september when I'm back at school.

 

[Jamir]

I worked out some numbers but my units are all wrong.... I need to further study it. I figured out from your dimensions that your ramp curve has a dimater of 37 feet. I hope I can figure out the rest. Maybe someone else can.

I knew you weren't razzin me, but I see your ramp as a good Physics problem, plus I don't want to see you get hurt. :D

Mike T:one cat that is cooler than the other side of the pillow! :worship:

 

[MikeT]

I can't get the pictures to open. MikeT, are you a civil engineer?

I am a Structural Engineer

 

[Casper250]

I made a wooden ramp couple years ago. Got bored waiting for my part to come in. Not huge, but has a nice little kick to it.

Check it out.

http://dirtrider.net/teamdrn/showphoto.php/photo/1405/sort/1/cat/500/page/2

 

[MikeT]

Mike T:one cat that is cooler than the other side of the pillow! :worship:

Thanks for the complement thunder. :cool:

 

[Kyleb15]

Does anybody have anymore info on this ramp? I cant get the pics to work. I have the welder, grinder, band saw and everthing but no plans. Cold somebody hook me up? [email protected]
Thanks