John’s Thoughts & Photos—November

img_0106

The Vendee Globe started last week. For the next three months or so I will be following the race every day, as I did four years ago, and four years before that.

And this from a guy who has exactly zero interest in being a sports spectator…no, not even hockey, my adopted country’s favourite. As for baseball and cricket, they put me into a coma. Even watching “the beautiful game” is a total snore to me.

But there’s just something about the Vendee Globe that reels me in.

Maybe it’s because I think that completing a Vendee Globe, never mind winning it, is the toughest challenge that any person can take on in any sport or discipline. Yea, tougher than Everest, tougher than man-hauling a sled to the North Pole…well, maybe that comes close…if you do it alone and unsupported.

By the way, the Vendee iPad app is a great way to follow along.

Cutless Bearings

jhhrx100-0599

I do this a lot these days: When I need measurements, instead of taking them and writing it down, I get a couple of people to hold a tape and I take a photo.

jhhrx100-0599-2

You can do this with a phone, but it works even better with a higher res camera. This came from my Sony RX-100 Mk4 and is a crop of the one above, quite legible down to 1mm on my screen.

Now, if I had just had them hold the tape the right way up, I would be really smart.

jhhrx100-0609

I needed the measurements to build this cutless bearing extraction tool. There’s a disk of 1/2″ G10 on the inside end (up inside the stern tube) of the 5/8″ fine thread rod. Just wind on the wrench and out she comes…except it didn’t work, much to my amazement.

Tightened as much as I dared…no movement. Think about how much load that is! I’m sure the engineers around here could calculate it, but I suspect the answer is one $%#@!! of a lot.

jhhrx100-0627

Back to the drawing board to design and build this tool. The long handle required because the bearing had managed to wind itself way up inside the shaft log—that’s a story for another day.

Nearly burst a blood vessel putting two cuts in the bearing at full reach. But then it just dropped out—go figure. If it was easy, everybody would be doing it.

Prime Lenses

Those of you who hate it when I go off topic should stop reading now. Not to worry, this post is in addition to our normal content, so you are not missing out.

Still here? Cool.

A couple of years ago I sold both my prime (no zoom) lenses. One because it was a bad example of a good design—happens in boats and lenses—and the other because it focused slowly on my OMD-EM1.

And generally I have been pretty happy with three fast 2.8 zooms covering 24 mm to waaay out to 420 mm. But every so often I get a serious jones on for a fast prime…or maybe two—there is simply no way to get “that special look”, particularly in people photography, other than a fast prime.

Yesterday I had to drive to Halifax. By the time I finished my errands it was rush hour. So what could I do but go and visit my pusher…er, favourite camera photo store, while the traffic died down. Cue the eye roll from Phyllis.

So I spent a happy hour, at least it was happy for me, making the sales people open boxes…lots of boxes…while I tried out lenses on my Olympus body.

I shot all wide open and used the long-suffering sales staff as models. This is not a lens review…I do have a life. But I thought the different looks that focal lengths produce would be of interest…well, I’m interested anyway.

Let’s start wide. The numbers in brackets are 35 mm equivalent. Click on the images to see them bigger.

None of this is great art, or scientific, and the light in the store is for shit, but still…

I like the 17 mm (34) Oly for environmental portraits and the 45 mm (90) Oly for emphasizing the person over everything else. I expected to like the Leica/Panasonic 15 mm, but turns out it’s just a bit wide for me, and the 25 mm (50) Oly did not grab me, although I thought it would. Maybe I should try it again…cut to shot of camera sales people screaming and running for the hills.

The Pany 20 mm is really nice, but like its predecessor, which I owned and loved, it focuses slow on my Oly body, so that’s out.

To me a test like this is a heck of a lot more useful than spending hours on the forums and reviews reading tech specs. Bottom line, a lens must give you images that please you, and that pleasure can’t be completely quantified—bit like boats.

So what did I buy? Nothing…yet.

What about you? What focal length(s) just work for you?

Let’s finish with the obligatory oversaturated evening shot. This one of Mahone Bay. Shot at 1/4-second hand heldjust amazing what modern in-body image stabilization can do and Oly are the masters at it.

jhhomd1-072410

Like what you just read? Get lots more:

Learn About Membership

Subscribe
Notify of
33 Comments
Oldest
Newest
Inline Feedbacks
View all comments
Bill Hoyne

Hi John,
I was wondering if the Sony RX-100 MK4 would be a suitable camera on a boat. Is is weatherproof enough to be outside while sailing, obviously not getting dunked in the water, but can it take the splashes and rain? It looks like a great portable camera with great resolution.

On a side note, winter is finally settling in here out here in the Bragg Creek and Canmore. We should be skiing full time here in a few weeks. Let me know if you are planing a trip out here 🙂
Cheers,
Bill

pedr turner

John
I shot the Oly 45 f1.8 on Pany GX7 body in a small town in the mountains of Costa Rica with a very dim incandescent bulb illuminating my partner’s favorite carnival activity, BUMPER CARS! The look of glee in her eyes and cheeks was very crisp as she bashed her way around the floor
( TWICE)!
Seasons Greetings

Kristen Berry

The new Oly 25 1.2 in intriguing – flies in the face of the small/light prime concept – but it is fast and super sharp.

Marc Dacey

John, was that MC’s cutlass bearing you were replacing? What’s the story behind what appears to be a detachable rudder?

Marc Dacey

If the rudder is aluminum like the rest of the boat, I would be interested to know how top half fastens to the bottom half, and whether bushings are involved. Metal boat owners have an interest in such details! It’s a nice feature to have, however; our rudder’s transom-hung, so off she comes in under half an hour!

Marc Dacey

It might be worth it given how often rudders sustain damage. Ours is well-supported by a skeg, but most these days are not…presumably yours represents both the middle ground (no pun intended) not only in terms of making shaft work easier, but by way of repair, should damage be sustained. If you chose to, you could probably carry the lower half of that rudder as a bolt-on spare.

Jean Jutras

Concerning the Vendée Globe, have a look to the virtual regatta and consider joining. You will have a boat and you will need to select your route, your sails, etc. You have real time information (wind, waves, pressure, etc) and there is a spectacular 3D view showing your boat in various angles. Amaizing.

Dave Gustafson

I switched to a full frame Sony about a year and a half ago. My favorite lenses were a 35 year old OM Zuiko 50mm f1.8 and an old Canon EF-85/1.2L, both with adapters. The Sony gear was stolen in San Francisco last summer, and I switched to shooting primarily B&W film. An old OM-1n w/50mm when my primary purpose is taking photos, and an almost equally old XA w/35mm f2.8 rangefinder that is always in my pocket. I think the prime lens selection is based on what I’m shooting. 28mm iphone for landscapes, 35 mm rangefinder for street and urban, 50mm for nature and things, 85mm for portraits. A scan through tens of thousands of shots in Lightroom grouped by focal length from when I was using a zoom seems to support that. The lens I will probably pick up next will be a 50mm macro for those flowers and close up “small world” shots. Of course it’s all subjective!

Dave Gustafson

Yes, that 40mm focal length has a lot of appeal. If I understand correctly, on a full frame 35mm format, 42mm focal length is equal to the diagonal of the frame, and some call it a “perfect” prime. Apparently it is easier to make a very sharp lens in that configuration. It is also nicely in the middle between 35 which many say is similar to our typical field of veiw (or attention) and 50 which is similar to many paintings. That 20mm Lumix has been on my list for a long time. Though I don’t have a m43 camera myself, Janna has a Lumix GH3 that I get to play with occasionally.

Tom

Cutlass Bearing question – you mention that it had worked it’s way up the shaft log – i have a cutlass bearing in the strut, but none in the log – and i experience some shaft whip at higher RPM’s, maybe because there is no bearing between the strut and engine. – what is your experience for common practice? Do most boats have bearings in both strut and the log? I can put one in, but the opening on the hull end is very small (just over shaft size) and flush with the outside of the hull. Or would i be better off with a pillow bearing inside between the shaft log an the engine? It’s a 2nd hand boat for me, all Aluminum, with no access to the original designer or building plans to reference. MCYachts BlueOcean 42.

Thanks,
Tom & Ingrid
S/V Moin

Eric Klem

Hi Tom,

As a general rule, you should try not to ever overconstrain anything and 3 radial bearings on a shaft (the first being your transmission one) is generally considered an overconstraint. It works when you have a very flexible shaft but if your shaft is properly designed with appropriate stiffness, then 2 bearings fully defines that shaft. A 3rd bearing would necessarily put a bend in the shaft even with a very good alignment and as the shaft rotates, this would mean that the shaft would have to keep flexing. The end result from this resistance and the associated heat is usually bearing or shaft failure.

The proper way to fix shaft whip is to look at the reasons for it. Things I would look at are: balance of prop, shaft straightness, alignment, number of prop blades, prop overhang, shaft diameter. Our boat had a minor shaft whip problem which we cured by switching from a 2 to 3 blade prop but we could have also upped the shaft size although that would have been a lot harder. Other owners of the same model have reported issues with props with long overhangs and 2 bladed props.

Eric

Eric Klem

Hi John,

In your application, it obviously works (although concerning that it moved axially) and you shouldn’t change something that works. I believe that there are a few key differences in your application compared to many boats that allow it to work. For one, I suspect you have a very carefully set of machined bores for the bearings to go in which is something that very few yards are really setup to do. Also, you have a boat with sufficient stiffness to make this work, many boats would flex too much and cause significant issues. In general, boats are more tolerant of multiple bearings than other applications as the bearings used tend to have play allowing an imperfect alignment to not cause large bending loads.

To be honest, I am not that surprised that you needed a third bearing, 1.5″ is not that heavy of a shaft when there is a big prop hanging off of it.

Eric

Tom

Eric, would you be willing to discuss directly (e-mail or phone), I’d love to give you more install details & symptoms, and hear some pros/cons about my considered next steps, but don’t want to bore the group here. (I can post the final results when cured).

John, if you’ve got professional resources who you think would be helpful, that’d be appreciated as well.

Thanks,
Tom

Tom

Thanks John,

I’m in the Annapolis area, but i’m a die-hard DIY owner, so haven’t reached out yet other than to seek advice and explore options like I’ve done here. I understand and agree with your comment on Eric’s time – I didn’t know if this discussion was his line of work, and if so, I’d compensate him appropriately for his advice/time.

Tom

Eric Klem

Hi Tom,

As John has nicely stated, I don’t do one on one consulting. I enjoy participating in this website as it is very informative, civilized and tends to have very knowledgeable and thoughtful people commenting in addition to the expertise in the writing. My day job is as a mechanical engineer developing robotic systems although I used to do air compressors and steam expanders. This means that I have designed tons of shafts and know good design practices for them but occasionally I will have an issue and then am forced to call the true experts in this who are far more knowledgeable than I on things like vibration, balance, etc.

John has given you a good idea of where you should start your search with a good machinist. Good luck.

Eric

Taras

Hi John!

How do you determine when is the time to check / replace cutlass bearing?
Is there a way to check this if the boat is in the water in the slip?

The PO of my 30 year old aluminum boat did replaced it 5 years ago…
I’m planning to hull out this year to replace thru holes, so thinking what else should I put on my list, as hull out here in Amsterdam is not the cheapest thing to do.

Taras

Thank you!

Would you carry a cutlass bearing as a spare part if going on for circumnavigation?