-High cutting speed machining processes have been used for about 10 years for metals. This technology presents many advantages related to output and surface quality. For timber machining, commonly used velocities are already high. However, literature about cutting velocity function during a machining process is rare. Nevertheless, some published results have shown the effect of speed on chip formation. In order to perform experiments at high cutting speeds, we used a prototype model of a CN routing machine, which allowed us to conduct machining from 3 m s -1 to 62 m s -1 . Surface analysis was carried out by an optical roughness measurement device. The wood species studied is beech. Tests have been performed with constant chip thickness value.wood / milling / cutting speed / surface quality Résumé -Utilisation des grandes vitesses de coupe dans le fraisage du bois. Depuis une dizaine d'années, l'industrie des métaux a recours au procédé d'usinage à grande vitesse. Ses principaux avantages résident dans l'augmentation du débit matière ainsi que l'amélioration des surfaces usinées. Dans le domaine de l'usinage du bois, les vitesses de coupe sont déjà très élevées de telle sorte que les limites techniques sont pratiquement atteintes. Concernant la vitesse de coupe, peu d'informations existent sur son effet au cours du procédé d'usinage. Cependant, certains travaux traitent de l'effet de la vitesse sur le mode de formation du copeau. Afin d'analyser ce rôle de la vitesse, nous avons acquis une défonceuse à commande numérique permettant une gamme de vitesses de coupe de 3 m s -1 à 62 m s -1 . Une première série d'essais de contournage sur du hêtre, parallèlement et perpendiculairement au sens des fibres est présentée ici. Les surfaces obtenues sont analysées à l'aide d'un rugosimètre à capteur optique.bois / défonçage / vitesse de coupe / état de surface

-Nowadays, to measure cutting forces involved during routing, systems with piezo-electric sensors are generally used. This study began with the following observation: two species with the same density can induce completely different cutting forces. But two species with completely different densities can also show closed cutting forces. Current formulations used to calculate cutting forces can not explain such phenomenon. That is why some new research has been done to establish relationship between cutting forces and mechanical parameters [8]. In this work, we decided to present a very simple, quick and accurate method to obtain similar results and good cutting forces approximation using a dynamometric pendulum. With this method, we can take into account the machining parameters, wood characteristics, cutting speed, and impact resistance into just one test. It is possible to quickly know wood behaviour during machining, particularly when new species or new conditions are used in industries.cutting forces prediction / dynamometric pendulum / routing / tropical woods Résumé -Utilisation d'un pendule dynamométrique pour estimer les efforts de coupe en défonçage, comparaison avec les valeurs actuellement calculées. De nos jours, pour mesurer les efforts de coupe en défonçage, on utilise généralement des capteurs piézo-électriques. Cette étude a été lancée suite à certaines observations : deux essences avec la même densité peuvent demander des efforts de coupe complètement différents. Mais deux essences avec des densités complètement différentes peuvent également demander des efforts de coupe identiques. Les formulations actuellement utilisées ne permettent pas d'expliquer ces phénomènes. C'est pourquoi des travaux de recherche ont été réalisés pour établir des relations entre les efforts de coupe et les propriétés mécaniques du bois [8]. Dans ce travail, nous avons décidé de présenter une méthode simple, rapide et précise pour obtenir de bons résultats et de bonnes approximations des efforts de coupe en utilisant un pendule dynamométrique. Grâce à cette méthode, il est possible de tenir compte des paramètres de coupe, des caractéristiques du bois, de la vitesse de coupe et de la résistance aux chocs avec seulement un essai. Il est possible de connaître rapidement le comportement du bois pendant l'usinage, en particulier quand de nouvelles essences ou de nouvelles conditions de coupe sont utilisées dans les entreprises. prédiction d'efforts de coupe / pendule dynamométrique / défonçage / bois tropicaux

Abstract& Key message Wood machining is compulsory both for timber separation and the surfacing of wooden objects. The anisotropy, cellular nature and multi-scale level organisation of wood make its cutting complicated to study. During the last 50 years, most of the wood machining subjects were covered by French teams. & Context Woodcutting is a very old technology but scientific research is scarce on the subject. In the last 50 years, much work on basic mechanisms as well as on industrial processes has been done in France. In primary conversion such as sawing, veneer cutting or green wood chipping, huge progress comes from automation and the possibility of linking the process to log and product quality through new sensors. In secondary processing, much has been done on the links between the cutting process, surface qualification and the properties of these surfaces for further processing, such as gluing or coating. Tool wear depends on the cutting process, timber quality and species. Tradeoffs are required in tool technology and coating technologies may improve tool life. & Conclusion A large amount of knowledge and innovation has come from 50 years of worldwide research effort, with France being particularly active in this period. The transfer of skills from metals cutting industry was often a key, but much is needed to move closer to both metal cutting sector and woodcutting skills among craftsmen.

The objective measurement and subjective estimation of the surface quality by the consumers are important issues for furniture production and marketing. The objective of the present study is to find suitable (objective) roughness parameters that are linked to human sensation. Maritime pinewood and medium-density fiberboard (MDF) made from the same species are in focus. The roughness was measured by means of a 3D confocal profilometer and 13 independent 3D roughness parameters were computed. The quality of surfaces was modified through sanding, whereas the grit size of sand papers ranged between P60 and P320. The applied pressure and sanding time were controlled. The subjective estimation of the surface aspects was performed by several individuals through sensorial analysis. Biplots of several roughness parameters versus tactile rank revealed in the case of MDF a significant correlation to arithmetical average roughness S a and valley material component S r2 . For pinewood, the parameters arithmetical average roughness S a and texture aspect ratio S tr correlated best to tactile rank.

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