This　paper　aims　to　investigate　the　effects　of　parameter　uncertainties　on　kinetostatic　behaviors　of　Exechon-like　parallel　kinematic　machines　(PKMs).　A　general　interval　kinetostatic　model　for　Exechon-like　PKMs　is　established　by　using　Chebyshev　inclusion　function.　The　prediction　accuracy　and　efficiency　of　the　interval　model　are　numerically　verified.　Based　on　the　interval　model,　two　indexes　are　formulated　to　quantify　the　effects　of　parameter　uncertainties　on　kinetostatics　of　the　PKM.　The　gravity-caused　elastic　displacements　of　the　PKM　are　computed　throughout　its　workspace　when　considering　design　parameters　as　interval　variables.　A　sensitivity　analysis　is　carried　out　to　identify　the　most　influential　design　variables　when　the　PKM　is　under　a　condition　of　parameter　uncertainties.　Based　on　this,　a　cost-effective　scheme　of　tolerance　allocation　is　designed　for　the　PKM　in　a　convenient　manner.　The　analyses　reveal　the　interval　kinetostatic　response　of　the　PKM　is　strongly　position-dependent　and　nonlinear-related　to　multiple　uncertain　parameters.　Hence,　parameter　uncertainties　need　to　be　fully　considered　during　early　design　stage　of　such　PKMs.　The　proposed　interval　model　can　be　further　applied　to　similar　over-constrained　parallel　robots　with　minor　modifications.　(C)　2020　Elsevier　Ltd.　All　rights　reserved.