Abstract: In the wild,a large number of machines can′t be repaired due to the lack of maintenance tools.The repair tools can be manufactured rapidly by Fused Deposition Modeling(FDM) process.However,the strength of direct prototyping tools are not high enough to complete the repair works.It is necessary to investigate that how to improve the tools strength produced by FDM.Research the performance influence factor of repair tools such as plum wrenches and double-headed wrench stay manufactured by FDM,the strength of maintenance tools with different internal filling units was calculated.A experiment was designed to explore the influence of filling rate,type of filling units and print direction influence on tools strength.The design and process principle of FDM tools was presented to improve the characteristics of repair tools.

Key words: rapid prototyping, repairs tools, process strength, Fused Deposition Modeling( FDM)