请高手指点椭球体和圆筒为什么不能搭接成功？谢谢！

请高手指点椭球体和圆筒为什么不能搭接成功？谢谢！
出现的错误如下：Boolean operation failled.Try adusting the tolerance value on the BTOL command to some fraction of the mininum keypoint distance.Model size(current problem)6.983637e3,current BTOL setting 1e-5,minimum kpt distance5.0000e+0000
命令流如下：
finish
/clear
/title, external pressure cylinder with single nozzal
/COM,STRUCTURAL
norad=210
norad1=200
nolength=200
rerad=500
s=10
n1=0
n2=420
CSWPLA,11,1,0.93,1,
/PREP7
ET,1,solid95
MPTEMP,1,20
mp,ex,1,2e5
mp,nuxy,1,0.3
K,1,-600,,,
K,2,600,,,
L, 1, 2
CSYS,0
LSTR, 1, 2
AL,1,2
/VIEW,1,1,1,1
VROTAT,1, , , , , ,1, 2,360, ,
VGEN, ,all, , , , ,510, , ,1
csys,4
wpro,,,90
cylind,510,500,0,2500,0,180
cylind,510,500,0,2500,180,360
cylind,510,500,0,-2500,0,180
cylind,510,500,0,-2500,180,360
cylind,510+s/2,510,-2500,2500,0,180
cylind,510+s/2,510,-2500,2500,180,360
vovlap,all