Wedge Angle

Secrets, tips, tools, design considerations, materials, the "science" behind it all, and other topics related to building the cars and semi-trucks.
Post Reply
Kindintentions
Journeyman
Journeyman
Posts: 27
Joined: Mon Jan 13, 2020 10:02 am
Location: Cranford, NJ

Wedge Angle

Post by Kindintentions » Thu Jan 14, 2021 4:53 pm

Quick question:

Is there any consensus on the best angle to cut a wedge car at. I have seen all of the templates, but they all seem to leave a lot of wood in the car. I figured with a combination square my scouts and I could mark an angle on the side to cut that would give us a much sleeker profile, but not sure how much of an angle to go with if using the entire BSA block of wood.

Any guidance is appreciated.

Thank you.



Speedster
Pine Head Legend
Pine Head Legend
Posts: 1940
Joined: Sat Feb 18, 2012 2:48 pm
Location: Toledo, Ohio

Re: Wedge Angle

Post by Speedster » Fri Jan 15, 2021 6:59 am

If you are choosing the Wedge for speed then science will give you the answer. A very slim basic wedge gets rid of a lot of wood ( weight ) and that's what you need to do.

Let's choose 2 weight designs, 3/8" tungsten cylinders and 1/4" tungsten cubes or blocks.
For cylinders you will drill two 25"/64" holes at the back of the car, 1 behind the rear axle slot and 1 in front of the rear axle slot. Drill the holes before you cut the block and drill the holes as low as you can. Three 3/8" x 1/2" tungsten cylinders will fit in the rear hole for a weight of one and a half ounces. The rear holes will guide you on how you cut the block for a wedge. You can then sand the top of the block down to the top of the rear holes if you choose.

If you are using 1/4" tungsten cubes or blocks ( it now gets expensive ) you can cut and sand the block down until something stops you. Two ounce blocks are sold by the vendors which will give you 2 ounces behind the rear axle slot if you choose the 2 ounce block.

Hobby Lobby sells a 3 ounce package of 3/8" tungsten cylinders for $23.99 with 40% OFF. Their 40% Off one item seems to be always advertised.

You said "my scouts". How many is that an what is your goal?
Are you having a race where you want all the cars shaped exactly the same like a NASCAR race? That's actually a lot of Fun.
Are you building a car for speed and want to do it the simplest way?



Online
Loud2ns
Pine Head
Pine Head
Posts: 55
Joined: Thu Mar 15, 2018 7:50 pm
Location: Hudsonville, Michigan

Re: Wedge Angle

Post by Loud2ns » Sat Jan 16, 2021 7:41 am

The shape of the body is always dictated by what weight is used.
We started our first two years with lead weight cast into ingots then glued into the car. The next couple of years we moved into the 3/8 tungsten to get more aggresive with weighting. I ended up getting sick of digging out the rounds to reuse(I have the rounds still in our 3 cars that last year). When using the rounds they dictated the shape of the body.
So being faced with many years of racing ahead, we made the decision to switch to 1/4 cubes. I bought enough to weight the 4 cars we were doing that year($$$). Pulling the weight that year was a simple task. Also adjusting the weight around was easier with the 1/4's.
A unexpected benefit of the 1/4's is that my kids could do more work on their car as the process was easier. They could now cut out a ladder body on the scroll saw with some assistance. They can also move weight around themselves with instruction.

I just looked on Derby Evolution and they are selling 4 oz of 1/4's for $20. It's pricey up front, but if you have a bunch of racing ahead of you and your kids then I most definitely think its worth it. It will serve you well year after year from the earliest scout up to league racing.

Ryan

Sent from my SM-G950U using Tapatalk




Online
Loud2ns
Pine Head
Pine Head
Posts: 55
Joined: Thu Mar 15, 2018 7:50 pm
Location: Hudsonville, Michigan

Re: Wedge Angle

Post by Loud2ns » Sat Jan 16, 2021 7:45 am

Sorry, I realized I didn't really answer your question at all. Drill holes for your weight and then cut your wedge as close to them as possible. I wouldn't get closer than 1/8 inch to the weights.

Sent from my SM-G950U using Tapatalk




Kindintentions
Journeyman
Journeyman
Posts: 27
Joined: Mon Jan 13, 2020 10:02 am
Location: Cranford, NJ

Re: Wedge Angle

Post by Kindintentions » Mon Jan 18, 2021 3:21 pm

The angle we decided to use was about 85 degrees. we set the front of the car to be 1/8 inch tall and lined it up with the combination square at 85 degrees. Our line is right above the weight pockets (we are using cylinder tungsten weights from Hobby Lobby) and enough above our axles to keep their integrity.

They both wanted to maximize their display area on top of the car for their designs, and we have done well with wedge cars in the past so my attempts to convert them to a flat ladder body design failed. I hope this angle helps to gain a bit more speed. Still using the same bore and axle prep from prior years that have provided fast cars.



Speedster
Pine Head Legend
Pine Head Legend
Posts: 1940
Joined: Sat Feb 18, 2012 2:48 pm
Location: Toledo, Ohio

Re: Wedge Angle

Post by Speedster » Tue Jan 19, 2021 6:07 am

I Love the Wedge car.
I was playing with tungsten cylinders and a wedge block yesterday. Without doing anything to the wedge I find it difficult to get the COG down to 3/4" in front of the rear axle slot. 3/4" just happens to be my favorite. I realize things can be done to add more weight behind the rear axle slot without changing the shape but it takes a bit more work and the expense goes up. Buying things from the vendors always results in Shipping costs. The other thing that affects the build is the original weight of the block. I have 100 wedge blocks with 3 holes cut in them from Hodges Hobby House ( It's another story ) and they vary in weight by a lot.

I would be interested in knowing what COG's you end up with in the cars.



Post Reply

Who is online

Users browsing this forum: No registered users and 26 guests