Cubmobile starting ramp

General cubmobile related topics.
Roy Shafer
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Cubmobile starting ramp

Post by Roy Shafer »

We are looking for plans for a starting ramp for our Cubmobile race.
We have found lots of help with the car designs but very little information about the start ramp.

Thanks Roy Shafer
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rtshafer@totelcsi.net
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Da Graphite Kid
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Re: Cubmobile starting ramp

Post by Da Graphite Kid »

Roy,

First off: welcome to Derby Talk!


I have never found any plans for the starting ramp for a Cubmobile Race. Some of this may be due to the fact that everyone seems to have a different design need for their ramp. An example of this is that two different locations we were looking at using this last Summer would have needed ramps with different heights; a flat parking lot would have required a taller ramp while the inclined road would have required a shorter ramp. (Unfortunately we never did have the race…)

While looking for information on start ramps we found that many boys are loosing control of their Cubmobiles when they are leaving the ramp due to the sometimes sharp transition angle from the ramp to the road. One of our Den Leader’s designed a ramp that would not have this problem – but it also called for 10 full sized sheets of plywood! He looked on some skateboard web sites for design ideas since who else would have some smoothly curved ramps? Now if he could just accomplish the same thing with four sheets of plywood at the most; we may be in business.

For a look at what appears to be a very easy and well designed starting gate, look at KLenort’s post: Anyone else done a Cubmobile Race? ( http://derbytalk.com/viewtopic.php?t=298 ) as he shows and explains this well. If and when we build a Cubmobile Ramp we will use this same basic design.


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sporty
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Re: Cubmobile starting ramp

Post by sporty »

Yi Yi YI,

I wish I would have wrote down the specs of the ramp that the pack yses for our kids race.

But I do remember some info.

They used angle iron to make the ramp, it was a 45% angle

However, the top platform where the cubmobiles were at before the lever was pulled to release them was at a 15% angle.

The ramp was aproximately 3 to 3.5 feet tall. The platform was just long enough to hold the cubmobile and another additional 6 inches Id say.

I will do a drawing and post a linke for you to get a idea of what it looked like.

Perhaps it will help some.

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sporty
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Re: Cubmobile starting ramp

Post by sporty »

I have posted some drawings, they are ruff as I am do drawer.

But I hope they will help or give better concept or idea of a ramp.

Thre are 4 pictures in all, 3 on this link and on website, click on last remaining pic to see. double click picture to see bigure pic.

http://home.insightbb.com/~ryan.johnson ... ip-30.html


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Re: Cubmobile starting ramp

Post by Smell of pine »

We have a local company donating their services to build our ramp. For their benefit, I will do the finish work on it, to keep the cost down for them. How does this sound for a design?

It will be made in two sections that will fasten together. Each lane will be made seperately. It will be 4 feet tall, 10 feet wide, enough that the racers/volunteers can walk up the middle, and a safe margin from the sides. Then from the bottom rear corner out toward the end of the ramp, it will be 8 feet for the main angle of the ramp, then add 2 more feet to lessen the angle for the transition to the track surface. I wish I could display the drawing for you to explain it better. I will add the starting device, deck surface, and side rails, and any other minor things. I was also thinking of adding wheels to help with movement, and some trailer jacks to make it possible to adjust the ramp for the track surface, and to prevent the ramp from rolling away.

Opinions, suggestions, complaints? I'd like to have the plans to the fabricator by the end of this week.
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sporty
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Re: Cubmobile starting ramp

Post by sporty »

You mentioned 10 feet wide.

Is this like to 5 foot sections ?


Everything sounds fine buy what you described.

I'm not sure I would go more than 4 foot wide on each section or longer than 6 feet on the deck in length.

I cant recall if you said all wood or not, but angle iron works well for taking down and putting in back up. However, lag bolts for the wood work fine for assemble.

Dont nessessarily need metal frame.

Just use thick enough wood for the ramp, so no warping can happen. I recommend treated lumber.

It will however, no matter would be better than some of the pictures I have seen out there, people using back of pick up truck or milk crates.


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Re: Cubmobile starting ramp

Post by pwdarchitect »

I just did a quick layout of what you are talking about and it seems to me that you would be better off with a 7 feet (horizontal dimension) start angle of 24 degrees then to transition to a 16 degree angle for 3 feet.
If you build the 7 feet section like a wood truss then the 3 foot section could be built using a ripped down 2x10 for support and then attached to the (2) 7 foot sections using some kind of latching hardware. Also you might want to look into using M.D.O. plywood for the decking. The M.D.O. plywood takes paint very well and can last for a long time even in weathered conditions. We specify this on some of the retail projects we have done. I know of at least 6 or 7 retail centers that have the original plywood on them and they have been built for about 20 years.

J
Last edited by pwdarchitect on Wed Mar 01, 2006 11:19 am, edited 1 time in total.
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sporty
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Re: Cubmobile starting ramp

Post by sporty »

That would perhaps be better for the angle and transistion.

However- Keep in mind of lifting those, 40 - 60 pound Cubmobile's onto the ramp.

And if you are going to have the kids enter onto the ramp from the side, rear or walk up the front of the ramp to get into the Cubmobile.

Our pack, they walk up the front, even tho its 3 1/2 feet high.

The volunteers and parents help with putting the Cubmobile on the ramp.

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Re: Cubmobile starting ramp

Post by Smell of pine »

I'll have to look at the 7 foot plan. Our local vendor will fab this for us for free out of syuare metal tubing. I will probably design in some disassembly points. Our town had a skate park built for the kids. I don't remember the name off hand, but they used a special decking. I was going to check that out, but I will look for that plywood as well. Yes they will be make in two 5 foot sections, that bolt together in the middle. I liked that width, because it gives a 1 foot clearance on the outsides, and the center will be wide enough to keep the cars away from each other, and provide the walking surface to the cars. I will install plenty of grip tape. I looked at the angles, and it is not so steep as to become dangerous for walking, or starting. Since we have been priviledged to receive this ramp free (mostly), I would like it to last for years, and be sturdy and safe for anyone to use it.

Sorry, pardon my ignorance, but what does MDO stand for. Would one of the local lumber stores know what it is by MDO?
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Re: Cubmobile starting ramp

Post by pwdarchitect »

MDO = MEDIUM DENSITY OVERLAY

This plywood has applications for signage (pre-primed available), marine, bus bench, outdoor seating (bleachers) and any other interior/exterior application where a smooth surface is required.

MDO Plywood is produced with a resin-treated fiber overlay which is generally smooth and opaque. This allows for rapid, even paint and coating applications.

MDO Plywood is manufactured with 100% waterproof adhesives and has an inner ply construction of C grade veneers and B grade or better face and back veneers.

http://www.freemansupply.com/StandardPlywoods.htm
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Re: Cubmobile starting ramp

Post by pwdarchitect »

To better explain what I want talking about here is a quick sketch of what I was talking about:
Image

Hope this helps.

Jim
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Re: Cubmobile starting ramp

Post by Smell of pine »

Somewhat, yes. I still am not exactly sure how I want to make the last 3' or so. If I'll make it flexible, or rigid for a couple feet, and then make the last foot flexible. Again, our ramp will be all steel tubing. We can even put a bend into the tubing to smooth the transition even more.
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Re: Cubmobile starting ramp

Post by Smell of pine »

PWDarchitect, do you have any calculations for a curved transition? The fabricator said they can roll the tubing, to create a curve. Do you know what radius curve, and at what point the curve should start. It wouldn't have to be the last foot or two, but it shouldn't be a curve from top to bottom either. Just seeing if you have any standards or calculations to figure out an optimum figure.
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sporty
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Re: Cubmobile starting ramp

Post by sporty »

All though I do not have fine drawing ability.

here is 2 links

http://home.insightbb.com/~ryan.johnson ... 19144.html

one of a drawn ramp, the other a picture of our ramp we use.


http://home.insightbb.com/~ryan.johnson ... 19145.html

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Re: Cubmobile starting ramp

Post by pwdarchitect »

i don't have any but let me work on that later and i will get back to you and post here.

Jim
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