Vaculík's first international competitions were a series of jumping competitions in the Ski Jumping Continental Cup 2001/02 , where he got only a few points with a 27th place as the best place and was finally 248th in the overall ranking. One season later he took part in the Nordic Junior Ski World Championship for the first time, where he managed at least a seventh place in the team. After he did not achieve good results in the individual competitions in the near future, the association did not nominate him for a Continental Cup competition until the end of 2005. It was not until the 2005/06 season that he started again in that lower class racing series and improved his top result to 14th place. Then he was used in the same season in the World Cup , where he collected his first World Cup points in the second competition as 28th. After another good performance in the team, with which he finished seventh at the World Cup in Willingen , he started as one of five Czech ski jumpers at the 2006 Winter Olympics in Turin . While he only barely qualified for the competition as 45th in the individual, he achieved ninth place with the team.
In the 2006/07 season Vaculík achieved successful results in the Continental Cup competitions in Engelberg and Planica , including a second and two fourth places. Overall, he placed in the overall standings on the 27th place, he also achieved further World Cup appearances, but he missed the second rounds and thus points. In March 2007 the Czech competed at the Nordic World Ski Championships in Sapporo , where he finished 50th in the individual. In the winter of 2007/08 Vaculík took second place in two FIS Cup competitions, plus another top 10 results in the Continental Cup. In summer 2008 he also achieved some good results at the FIS Grand Prix , including a third place with the team. The Ski Jumping World Cup 2008/2009 started successfully for him with further points and his best individual placement so far, a 25th place in jumping in Engelberg.