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

[CTXmiller]

Posting a few photos as I haven’t seen or can’t recall a thread on a W-series mast pipe replacement.

I had soaked the threads with penetrating oil for a few months, spraying it a couple times a week.

Vise:

IMG_1563.jpeg

Rosebud and a 36” pipe wrench w/ cheater bar got it off.

IMG_1564.jpeg

Old/new. The old one was worn down at the storm stay.

IMG_1572.jpeg

[PaulV]

Thanks for posting Michael. This thread will be handy when I start on our WB.

[windybob]

All W series Monitors mills had threaded neckpipes. It was a NPS thread, not NPT. However NPS dies are about as scarce as funds in my bank account.

Right there in picture 2 you can see the bottom of the case on the inside where the neckpipe screws into. That is a thin casting. You should use caution when threading and installing the new pipe, as any undue pressure here from a long threaded pipe is likely to crack this thin area.

On a longneck, it doesn't matter, but on a regular neck, I usually put a spot weld on the area where the turntable top's hole is for insurance against unscrewing of the neckpipe.

[CTXmiller]

Thank you. I tried to thread the pipe the same length. I’ll spot weld it once I’m confident everything lines up.