Monitor W series mast pipes

[CTXmiller]

Two of the last four W-series windmills I encountered had worn out mast pipes at the storm stay. One was a long neck WC, so I sort of expected that. I got to wondering, how hard is it to replace the mast pipe on a WB/WC? Are the mast pipes threaded into the cast iron gearbox? Or are they cast into the gearbox? There might be a thread on this, but my searches failed to locate such a thread. Thanks

[windybob]

they are screw in. Hambones are cast-in-case. The thread on W series mills is NPS from the factory. I have always used NPT because finding a straight threaded 1 1/2 or 2 inch pipe die is really hard, and not really needed. They can be very tight. be careful how you hook the mill to steady it. We use a couple of 36 inch pipe wrenches, and put one under the truck and try to turn the other. there is just enough room right at the neckpipe to get a grip, anyplace else makes me nervous. One note.....the bottom of the head is thin in one particular spot right where the neckpipe top ends, in the case. Don't thread it too far, or the top of the neckpipe can run up too far and crack the thin casting there. I have never broken one. You can use locktight for making sure it stays tight. What I usually do is to put a heavy tack weld on the spot that does not wear on the turntable, where the chain goes thru. Other than that, get the measurements right on a tower-top turntable because the bottom of it takes the bushing that goes under the stay, and the SHORT bolt over the stay. . Longnecks really don't matter that much.

[CTXmiller]

Thank you