CRP Group

Via Cesare Della Chiesa 21 - 41126 Modena, Italy Tel./Phone +39-059-330544/821135/826025

Fax +39-059-822071/381148 www.crp.eu

CRP Motorsport Case study

Direct Digital Manufacturing on 250cc road racing motorbike

From several years, CRP Technology is involved in the production of components with the

Rapid Prototyping Technology.

These rapid prototypes are made by Laser Sintering Technology and WINDFORM® materials,

developed by CRP starting from 1998.

There are several different fields of application for WINDFORM® XT (carbon filled material) and

WINDFORM® GF (aluminium and glass filled), largely used by CRP Technology.

One of the most representative example of Direct Digital Manufacturing with Windform®

material is the development of the 250 cc Fantic Motorbike, that took part at the MotoGP 2005.

In 2005, the company began the great challenge of the racing motorbikes, facing the

worldwide market with a MotoGP 250 cc class bike, completely built by the CRP technical staff

and that has lined up at the World Road Championship 2 bikes with the Fantic Motor brand.

Picture 1 – R250GP. On the right the R250GP that has attended the ’05 World Championship. On the left the frame(chassis) prototype made of Windform and used for the first assembling tests in January 2005. Airbox

The project

Thanks to the top-level materials such as WINDFORM® GF and XT, it is now possible to use

laser sintering for reliable and high performance parts ready to race.

Everything has been focused on the case study of a new air box configuration made of

WINDFORM® XT for the CRP R250 Engine, combined with a special carburettor insulator

made of WINDFORM® GF; a new Cowling for the CRP R250 made of WINDFORM® XT; a

special Front Mudguard for the CRP R250, with integrated air ducts, made of

WINDFORM®XT and a rear Mudguard and Rider Seat for the CRP R250 made of

WINDFORM® XT.

CRP Group

Via Cesare Della Chiesa 21 - 41126 Modena, Italy Tel./Phone +39-059-330544/821135/826025

Fax +39-059-822071/381148 www.crp.eu

In F1, everything is about time, from reducing the time on the racing track, to reducing the

time to deliver as many design iterations as possible.

“In wind tunnel a half-scale car is continuously tested in as many aerodynamic configurations

as time permits. And then, the inevitable question — can you make parts that go on the actual

car? The advantages would be immense, if we could take that precious next step.” (Steve

Nevey, Red Bull Racing)

WINDFORM® XT suits exactly these requirements: perfect for wind tunnel, it can be used to

make master models for carbon lamination (also in autoclave) and can be sintered for race car

parts of course.

CRP used it in order to bring a completely new bike on the MotoGP race tracks within 6

months and is still using it for next seasons business.

It was the beginning of a great new challenge. During the 2005 season, the most evident gap

consisted in the power output of the engine and that’s why most of the job has been focused

on it in 2006.

CRP Technology worked on the development of the engine exploiting the Rapid Prototyping

technology and the Windform® materials.

The 2005 250cc engine set up was a 90° 2 cylinders, with reed valve and two 40mm

carburettors.

Picture 2 – R250GP engine. It is possible to see the 90° configuration of the engine.

The Air Box

There were two air intakes on the side of the cowling, bringing fresh air to the two separated

air boxes. After several tests made to study the configuration of the two separated air boxes,

in order to obtain a similar functionality of the two cylinders, it hasn’t been possible to have 2

air boxes of the same dimensions, due to the overall dimensions.

CRP Group

Via Cesare Della Chiesa 21 - 41126 Modena, Italy Tel./Phone +39-059-330544/821135/826025

Fax +39-059-822071/381148 www.crp.eu

Picture 3- CRP Technology’s dyno. Torque and power curves obtained for the 2005 R250GP.

Looking at the curves, you can see quite a regular output of power. In particular, a worsening

of the power and torque curve is noticed due to the research of higher power in a lower range

of use.

Picture 4 – CRP Technology’s dyno. A comparison between two 2005 configurations. Working on the electronics you can reach higher power but in a smaller range of use.

For this reason, during the 2006 season, a one-piece air box in Windform® has been realized in

order to exploit in the better way the space inside the frame with the front air intake under the

lower triple clamp.

This allowed to reach a similar behaviour of the two cylinders, therefore making the set up of

the engine easier. The engine has immediately improved and the setting of the two

carburettors was similar.

A big success as there were no more difficulties with the fuel supply, different from cylinder to

cylinder. The lower cylinder’s carburettor was very critical because the venturi first was too

close to the side of the air box. The carburettor has therefore been rotated respecting the

limits of the fuel level. Realizing a new structural (it means it supports the carburettor)

CRP Group

Via Cesare Della Chiesa 21 - 41126 Modena, Italy Tel./Phone +39-059-330544/821135/826025

Fax +39-059-822071/381148 www.crp.eu

induction insulator in Windform® XT, it has been possible to improve the functionality of the

cylinder n° 2.

Picture 5 – Particular of the R250GP carburettor. On the left, the CAD image of the air box and lower carburettor, on the right, the completely assembled system. The air box has been realized in Windform and used for the test.

With an increase in volume, a better geometry of the air box and a better positioning of the

lower carburettor, a higher power and torque curve has been achieved, allowing the rider to

exploit the engine already from low rpms.

Picture 6 – R250GP’s air box. In light and dark green the elements of the new air box. Beneath the triple clamp there is the air intake. To be noticed how all the space has been exploited.

CRP Group

Via Cesare Della Chiesa 21 - 41126 Modena, Italy Tel./Phone +39-059-330544/821135/826025

Fax +39-059-822071/381148 www.crp.eu

Thanks to the mechanical wear resistance of CRP’s SLS material, it has been possible to realize

the air box and over all the insulator directly in Windform shortening a lot the development

and realization timing.

Diverse kind of insulators have been made and have been directly tested on the dyno until the

best geometry was found. Holding the files, the “story” of the component can be preserved.

Picture 7 – CRP’s dyno. In green the 2005 configuration, in red the result achieved with the described modifications.

Cooling and Front Fender

Using an air box that exploits the whole space inside the frame, a big increase of power has

been achieved. This increase is ruined by the engine’s temperature that reaches in a while 65-

75°C with peaks of 75-80°C in the worse climatic conditions. These temperatures penalize the

efficiency of the engine frustrating the job done on the air box.

To resolve this problem, a new front fender, whose function was also of an air conveyor, was

created, exploiting the potentialities of the Rapid Prototyping.

Picture 8 – R250GP front fender. CAD image of the front fender with air intakes. It’s possible to see the air flux pushed to the radiator.

CRP Group

Via Cesare Della Chiesa 21 - 41126 Modena, Italy Tel./Phone +39-059-330544/821135/826025

Fax +39-059-822071/381148 www.crp.eu

It was realized in Windform®

XT and the idea was to bring fresh air to those “hidden” parts of

the radiator to increase the engine’s cooling.

Exploiting the SLS technology and the Windform®

XT material it has been possible to realize

the fender in a very short time and its use permitted to lower the temperature of 2°C and had

absolutely no side effect for assembling and dynamics.

Picture 9 - R250GP front fender. The front fender realized in Windform®

XT, painted and assembled

directly on the bike

Rear Fender

In order to optimise the air flux in the rear part of the bike, thus avoiding turbulences, a rear

fender with two lateral fins to protect the swing arm was realized in Windform® XT in a very

short time. This part is really important to help the extraction of the hot air flux from the front

and it has inside a duct for the rear braking oil pipe

CRP Group

Via Cesare Della Chiesa 21 - 41126 Modena, Italy Tel./Phone +39-059-330544/821135/826025

Fax +39-059-822071/381148 www.crp.eu

Picture 10 – R250GP rear fender. Realized in Windform®

XT and then painted and used on track. To be

noticed, on the right of the figure the passage for the rear brake hose.

Fairing

The next step is to improve the cooling and the aerodynamics, in the penetration and the hot

air extraction.

The air’s front entry of the R250GP fairings has increased in order to exploit the whole radiator

and to facilitate the air’s entry.

Picture 11 – R250GP fairings. In white the 2005 fairing and in purple the 2006 fairing. To be noticed how the air’s front entry has increased in order to exploit the whole radiator.

CRP Group

Via Cesare Della Chiesa 21 - 41126 Modena, Italy Tel./Phone +39-059-330544/821135/826025

Fax +39-059-822071/381148 www.crp.eu

Conclusion

In motor sport and automotive high performance, high quality and short time make the

difference.

CRP worked hard to improve properties not only for functional testing models, but also for

high-end prototypes and small lot production parts.

WINDFORM® family was born in 1998 with WINDFORM® GF (aluminium and glass filled), a

compound later developed by other manufacturers too, and continued with WINDFORM® PRO

and PRO B (aluminium and glass flakes filled; graphite filled). The carbon fibre filled material

branded WINDFORM® XT was launched in December 2004, and is the laser sintering powder

with the higher mechanical and thermal properties compared to all powders for this

technology. Then, in 2007 it has been launched the WINDFORM® FX, a new generation

polyamide based material, in which mechanical and repeatable characteristics make it

particularly suited for Rapid Manufacturing applications, that need of flexibility (e.i.: flexible

components, functional parts with clicks or zips. In addition, ducts of a complex shape, with

thin walls, particularly suited for aerospace and motorsport, dashboards and grids, fenders,

fans and connectors).