Questus Radar Mount, Update and Service

[SVQuestOfPaget]

This is posted as a followup/update to an earlier thread I posted in the classifieds section, where I was looking for some spare parts for the Questus radar mount:
https://www.cruisersforum.com/forums...ts-279750.html

Several people chimed in with good information, and I was finally able to track down the parts I needed. THANK YOU!

A bit of an update I learned: Questus is now owned by "Tannin Corp" in Peabody, MA, which oversees several product lines. They still sell complete Questus gimballing units, and they have an assortment of spare parts available for purchase as well.

I was told that they do not refurbish or work on older units, so I was out of luck with my seized piece of equipment. I have some modest machining experience, so with nothing to lose and well out of any warranty, I disassembled, cleaned, and rebuilt the whole unit.

I quickly learned the reason that my unit was seized; the stainless steel shaft is a tight fit through the 1" thick aluminum face plate (with needle bearings and a oil lip seal on the inside). The aluminum had corroded around the stainless shaft, so I removed the entire face plate from the damper housing, then was able to safely break the shaft free from the aluminum, without damaging the bearings or internal damper components.

The shaft came out clean, and the bearing plate had a thin layer of white aluminum oxide around the shaft. I think the initial corrosion tightened things up so quickly that no further salt could get in and cause pitting on either surface. The lip seal was toast, but the bearings were tight and smooth. With a new lip seal now and general cleanup, it's working smoothly and ready for installation in the spring. I even gave it a new paint job with leftover Alexseal topside paint.

I think some liberal greasing or spray with boeshield during maintenance would go a long way to preventing this - see the circled area in the photo. If you use one of these and it's not as smooth as it used to be, I'd look there first. Likewise, make sure your stainless bolts have tefgel or other corrosion inhibitor - I had to drill out several of the original fasteners. I might start to offer rebuild services on these if there is interest, but that'll be another post.

For what its worth, I had intended to use a fixed mast mount for radar, but this was offered to me off a friend's boat, so I figured it was worth it to try making it work again.
-Eric

[hlev00]

Nicely done and thanks for the follow up!

I might give ours another go this winter after I get it down. There is one point where it just doesn't quite rotate smoothly and so gets stuck about 5 degrees off of vertical until the boat heal enough to overcome the friction.

Did you get to where you had to empty and refill the oil that I believe is part of the dampening mechanism? Is that set screw left of the circle the fill point?

It just occurred to me that likely there was a patent filed on this, and sure enough
https://image-ppubs.uspto.gov/dirsea...oadPdf/5111212
It looks a bit different that the final product but the basics are there.

I too am in the Boston area. If I get stuck this winter, maybe I could stop by with the unit and a 6-pack of your favorite beverage for some some brief consulting?

Harry