Summary

Basic end cap for 25.4mm tube with 1.2mm wall thickness.
I designed this in blender, printed and test fitted in some 25.4mm tube that i have bought to make an MPCNC.
Fits well, nice and snug once i deburred end of tube.
I may design a new once once i build the mpcnc with holes to poke cabling through

Thanks to the MPCNC guys for giving me something to make

end dimension is 25.4mm
length dimension is 17.25mm
inner plug is 23mm