Archive for the 'Chassis Design' Category

SolidWorks CAD Drawing of a Tony Kart Chassis

ABout Tony Kart

Tony Kart produces high quality racing kart chassis. A catalogue of their kart chassis can be found on their website. A particular chassis model, a Tony Kart Extreme ’97, was modelled using SolidWorks, and is available for download. Below is an overview of the chassis, in isometric and in a plan view.

Overview of Chassis in SolidWorks

This chassis is modelled perfectly in SolidWorks, with each member as an individual part and fully in-context. With the complete assembly and part files, it would be very easy to create 2d drawings of the chassis. The chassis is full size, so no scaling would have to be carried out.
Perhaps in the future the author will complete a fully dimensioned chassis using SolidWorks. Please contact the author if you have any queries etc. regarding this.

Download SolidWorks Files

The SolidWorks assembly file can be downloaded from its original location here, along with some other CAD drawings also. A backup local copy of the SolidWorks chassis is also available.

eDrawings Download of the Chassis

In case you don’t have a copy of SolidWorks to open and measure the components, the eDrawings viewer can be used to open the chassis, measure each component, and create a section view through the chassis. The chassis opened in eDrawings can be seen below:

Tony Kart Chassis in eDrawings

Download the Tony Kart Chassis ’97 eDrawing
Note: the eDrawings download of the chassis contains a self executable viewer application.

Conclusion

Hopefully the detailed professional chassis design will give you ideas on how to design and create your own chassis. An idea of the size of the chassis design can also be obtained using the eDrawing. Best of Luck!
If you have any queries or comments, please email them to the author at:

Edit: A few people emailed me asking for the above Tony Kart in AutoCAD DWG Forma: PDF Format of Tony Kart | DWG Format of Tony Kart (in a Zip File) | STEP Format (in a Zip File)

Vintage Go-Karts: A Website Review

The following website (http://www.vintagekarts.com/karts.htm) has some excellent photos and articles on old vintage go-karts. These karts were made using the basic necessities, and still achieved high speeds with excellent cornering and handling. Several ideas can be taken from these vintage karts where there were “no frills” to building gokarts. Ideas which can be combed from the gallery of photos include:

  • Twin Engines
  • Simple friction brakes
  • Types of Seats
  • Keeping Chassis Designs Simple

Thumbnail Previews of VintageKarts.com’s Gallery: 

      

View more photos here: http://www.vintagekarts.com/gallery.htm

Preview of VintageKarts.com’s Articles:

There are also some excellent in-depth articles about the history of karting, right up to the current day! Some of the topics discussed include:

  • Karting Grand Nationals, from 1960 to 2005
  • Transportation of GoKarts
  • Women Gokart Racers
  • Rocket Powered Karts
  • McCulloch’s Entry into Karting

Hopefully this website will provide further insight and details as to how simple engine powered gokarts were and can be made. If you would like your karting website reviewed and mentioned here, or if you have any comments on this or any other article, please contact the author by email at

Free Technical Kart Drawings (FIA)

CIA LogoThe CIA (Commission Internationale de Karting) is the specialised Karting commission of the FIA, the governing body of world Motor Sport. The CIA oversees Karting safety in conjunction with the FIA and with a Research Group exclusively dedicated to Karting.

The CIA publish Technical Regulations for Karting, which includes detailed Drawings and specifications. In their most recent publication (2007), detailed drawings showing measurements and designs for Kart chassis are included.

CIA Sample Kart Chassis Technical Drawing

The drawing above shows actual sizes (metric also!!) of Karts and provide an excellent guide to building a Kart complete to regulation!! Many people, including myself develop free kart plans, and overlook the wealth of information and diagrams offered by Karting Authorities such as the CIA.

Original Reference Hyperlink to CIA’s 2007 Technical Regulations
Saved local copy of the CIA_2007_Technical_Kart_Regulations

Some more Drawings from the above Technical Regulations can be seen below:

CIA_Sample_Technical_Chassis_Drawing_Front_Elevation

CIA Technical Kart Drawing

Safety Factors for Designing and Building Go-Karts

Introduction to Factor of Safety

Recently, a person emailed me (kartbuilding[at]gmail.com) asking about the “factor of safety” (FoS) required when undertaking calculations to design and make a go-kart. The “factor of safety” is the maximum force and stress a kart can possibly undergo, multiplied by a suitable factor/multiplier. Ideally if the maximum force and stress a kart can endure is calculated, then this factor gets multiplied by the factor of safety.
Having a FoS of 1, means that a Go-Kart is not “overengineered”, and nothing extraordinary will occur. It is when the “extraordinary” or unthinkable happens, that the FoS comes into effect.

Quantifying the Factor of Safety

Quantifying the FoS for a Go-Kart is not an easy task! It certainly cannot be applied to the entire Go-Kart, but parts of it, e.g. the chassis, transmission, brakes, etc. The same FoS cannot be applied to the chassis in every Go-Kart. The purpose and category of Go-Kart must be firstly determined. I.E. is it a racing kart and in what category of racing kart? Once the category and type of Go-Kart is determined, then a FoS can be obtained.

NatSKA – Classes of Racing Karts, and Safety Regulations

NatSKA LogoNatSKA (The National Association for School and Youth Group Karting) governs the sport and activity of karting in schools throughout the United Kingdom. The association holds race meetings run under strict regulations of its governing body (Motor Sports Association), and periodically publishes a Handbook and Regulations. The most recent Handbook and Regulations (2007) outlines the various “classes” of karts, and range from Class 1 (50cc Single Ratio Open) to Class 16 (Honda C70, C90 and C90 Cub Gearbox). Specific specifications (including safety) are outlined for areas of the kart. The following is an edited exerpt from the NatSKA Kart Regulations on chassis design:
The chassis in general shall be of safe, sound and adequately strong construction and shall not include any components of a temporary nature. Specifically, the wheel base is to be a minimum of 101cm and maximum of 127cm. The maximum length of the kart, including bodywork shall not exceed 210cm. No kart is to weigh more than 100kg without the driver.

I highly recommend that the NatSKA handbook and regulations are read and followed, especially if other people are driving and racing your Go-Kart. At the very least, excellent safety guidelines are outlined.

More Technical “Factor of Safety” etc. - Formula Racing

CAD Stress Tests on a ChassisIf you are designing your own Kart on a CAD system etc. some software will allow you to carry out “Stress Analysis” of components. Some examples of CAD software packages are: Solidworks and Cosmos, Pro-Engineer and Pro-Mechanica. These software packages will allow you to carry out simulation of kart components, allowing you to place particular loads throughout, and calculate a FoS automatically! If you are heavily involved in design and analysis of karts, this CAD software will speed things up, and provide a wealth of information.

Stress Test and Factor of Safety Analysis of a Front Stub Axle from a Go-Kart

Stress Test Result Image on a Front Stub AxleAs an example of the amount of information and the ease at which CAD software can calculate the FOS, a stress test was carried out on a Front Stub Axle from a Go-Kart, as can be seen in the image on the left. The entire CAD HTML Stress Analysis is also available. The plans for this “Front Stub Axle” are contained in the Complete Set of Racing Kart Plans.
This test, taking a total of 10 minutes to model and analyse, found that, if a loading of 50 kilograms were placed onto the steering arm, that the resulting Factor of Safety would be 1.466. Therefore, this Front Stub axle is slightly overdesigned. An in-depth knowledge of the individual forces involved in a Go-Kart would be required for an entire Stress Analysis.

Factors of Safety for Go-Karts in Amusements and Funparks

In doing some research on Factor of Safety for Go-Karts, I came across an “Amusements Devices Act” which makes specific references to Go-Karts and the required Factor of Safety! Although the act (legally binding),  has been superseded by a later document, the numbers and references are interesting to see. Part IV of the above act, pertains specifically to Kart Design! An excerpt of its legal requirements are:

  • The speed of an adult kart shall be limited or governed so as not to exceed 45 kilometres per hour.  R.R.O. 1990, Reg. 20, s. 40 (2).
  • The seat, back rest and leg area of every kart shall be so designed as to retain the driver inside the kart in the event of a collision at the front, rear or side of the kart.  R.R.O. 1990, Reg. 20, s. 41.
  • Rotating, moving or hot engine parts of a kart that may constitute a hazard to an occupant of the kart shall be shielded to prevent burns to the occupant or the entanglement of the occupant’s hair, hands or clothing.  R.R.O. 1990, Reg. 20, s. 42.
  • The wheels of a kart shall be so enclosed or guarded that the wheel of one kart cannot interlock with or ride over the wheels of another kart.

Factor of Safety on Formula Racing Cars

Various universities are taking part in “Formula Student” lots of readily available information about building advanced racing Cars is available. Two excellent reports on designing formula racing cars can be found here and here. The latter document has a section on “Factor of Safety Development”.

Conclusion to Factor of Safety when Designing Karts

The materials used, and the forces involved make the calculations for FOS quite difficult. CAD software makes things much easier, allowing you to select the materials from a drop-down menu, and allowing you to apply forces wherever you require. CAD software will also allow you to change material thicknesses to achieve an optimum FOS, and weight balance.
Using your common sense, and reinforcing areas which would potentially fail in a collision will go a long way in having a robust Go-Kart.
If you have any queries or questions, drop me an email or leave a comment below.