Bristol Pilot Cutter by michael mott - 1/8 scale - POF

[archjofo]

Very impressive Work!

[hook]

Hi!

"dorade wents"  -  Olin Stephens designed the yacht Dorade in 1930. Here are the first such vents. Ingenious, nice work!

[Piet]

I just love watching your work Michael and wish you and your family a very good and healthy 2019.

 

Cheers,

[KeithAug]

Michael - I hadn't looked for a while - so much to catch up on. Very interesting techniques and everything up to the usual extremely high standard.

[Bob Cleek]

On ‎12‎/‎30‎/‎2018 at 2:44 PM, hook said:

Hi!

"dorade wents"  -  Olin Stephens designed the yacht Dorade in 1930. Here are the first such vents. Ingenious, nice work!

Well, yes and no. Just to put a finer point on it, the ventilator cowl was around long before Stephens designed Dorade. What was added to Dorade was a box, properly called a "Dorade box," upon which the ventilator cowl is mounted. The box has a hole on the top for the ventilator, a half-height baffle in the middle, and a hole offset on the other side of the baffle. This permits water to enter the cowl vent, run down into the box on one side of the baffle and out drain holes, while permitting the air to move over the baffle and down the hole through the deck on the other side of the baffle.

 

The boxes weren't original to Sephens' Dorade design. They were added shortly after her launch to solve the problem of water running into the accommodation below. "Boxes like on Dorade" became "Dorade boxes," and, it seems, over the years, many have come to incorrectly call ordinary cowl vents "Dorade boxes," but the cowl vents preceded the boxes by quite some time.

 

 

Dorade's boxes on a model of her.

 

Edited January 7, 2019 by Bob Cleek

[wefalck]

I have seen this arrangement before, but didn’t know that name. I can see very well spray being kept out, albeit at a reduced efficiency of the ventilator due to some air bleeding out of the drainage holes. However, a serious wave would flood the hole system anyway.

[michael mott]

This should give me some Ideas. l received this in the post today.

 

 

I know I only have one mast but this will expand my knowledge.

 

Michael

Edited January 7, 2019 by michael mott
grammar

[wefalck]

Still one of the Bibels and nice drawings anyway.

[SJSoane]

Hi Michael,

 

Just catching up. Everything is looking wonderful, and I am particularly impressed with your machining and metal working. It all seems impossibly difficult until you demonstrate it, which makes it even more magical!

 

Mark

[michael mott]

Thanks to all for your complimentary comments and for the additional info on the dorade vents.

 

When i made the first set of "screws" for attaching the vents to the side of the cabin I used a commercial pin vice that is the traditional one that allows very small diameters down to basically 0 the way it works is a bit hit and miss being a shaft with a couple of cross cuts. This took a few tries each time to get the pin properly centered. I also used a file to reduce the diameter of the pin head and basically did the work by eye. Knowing that when they were assembled in the vents the slight variations in diameter would become obvious. So I decided to make a small pin chuck specifically for these pins.  I used a bit of 1/4 inch brass rod and using the collet chuck on the lathe turned down the shaft to fit the new micro drill which is 3/32. Keeping some of the shaft at the 1/4 inch in order to thread the opposite end for the locking collar. This was then reduced  and threaded 8x36. The threaded end was then tapered about 1/8 so that the locking nut could work to clamp the threaded end.

The threaded end was drilled with a hole the same diameter as the pin to a depth of 5/32  then slit lengthwise with a .010" slitting blade. The shaft end was drilled to the pin hole with a #50 drill as a relief and to allow the pin end to close.

 

First picture shows the chuck with the locking nut off. the lock nut was easier to work with the flats filed which allowed a wrench to tighten it instead of my finger and thumb (which got cut on the sharp edges hence the flats) 

 

 

The cross cut is more visible in the next picture. I cut enough pins to complete both sides. By using the collet chuck and the new pin vice it enables me to complete a single operation on all the pins knowing that they will be concentric for the next operation.

 

 

The pins stayed concentric in the new chuck.

 

 

 

 

The heads were turned down to .93mm which turns out to be just under 5/16 actually closer to 19/64ths in diameter which is very close to the diameter of a #8 round head wood screw at 1:1

 

 

 

The next operation I will shape the round and then slot them using a different pin vice and a block of wood to position the jewelers saw blade as in the next picture.

 

 

I will set up the boxes with a slot on the bottom and by bringing the vents up it looks better than having them cross the panel reveal.

 

 

That's all for now.

 

Michael

 

 

 

[Bob Cleek]

9 hours ago, michael mott said:

This should give me some Ideas. l received this in the post today.

I'm surprised you didn't have "Masting and Rigging," and everything else Underhill has written. They are encyclopedic in scope and detail and, as Welfalk says, "one of the Bibles." You might also consider, if you don't have them already,

https://www.amazon.com/Gaff-Rig-John-Leather/dp/B00RDCFUJO

 

There's also a Second Edition written thirty years later with some added material,

https://www.amazon.com/Gaff-Rig-Handbook-Techniques-Developments/dp/0937822671

 

and

 

 

https://www.amazon.com/Pilot-Cutters-Under-Sail-Pilotage/dp/1848321546/ref=pd_sim_14_2/135-1756572-5309355?_encoding=UTF8&pd_rd_i=1848321546&pd_rd_r=96476c2c-1308-11e9-94cc-233ded4a07d6&pd_rd_w=4UMc8&pd_rd_wg=ChJAF&pf_rd_p=18bb0b78-4200-49b9-ac91-f141d61a1780&pf_rd_r=S2GQYZV5MCQ02DN5HPWA&psc=1&refRID=S2GQYZV5MCQ02DN5HPWA

 

Cunliffe's book is fairly new, coming out in 2013. He wrote the two volume set, Pilot Schooners, the definitive tome on American and British pilot schooners and brigs. I'd love to have them, but they are decidedly pricey, so I'll have to wait until I have a sufficiently motivating excuse to buy them!  Cunliffe's Pilot Cutters Under Sail , which is in somewhat different format from Pilot Schooners, was to be the third volume in the "Pilot" set, but he lost his publisher and it took some time to find another one. Pilot Cutters addresses the English pilot cutters in great detail.  I don't have any of Cunliffe's books, but have seen the schooner and brig volumes and presume from the "preview" on Amazon that the cutter volume is every bit as encompassing and wonderful. Regrettably, they aren't cheap, or weren't when they came out. Perhaps there are some less expensive used volumes round and about now.

[BANYAN]

Great ideas and technique Michael,  the support for the saw blade is one that I will definitely file away.

 

cheers

 

Pat

[Bob Cleek]

11 hours ago, wefalck said:

I have seen this arrangement before, but didn’t know that name. I can see very well spray being kept out, albeit at a reduced efficiency of the ventilator due to some air bleeding out of the drainage holes. However, a serious wave would flood the hole system anyway.

Actually, cowl ventilators on smaller craft (as opposed to large ships) were never intended to be shipped except at anchor or in a berth in port. They weren't for use when exposed to rain, spray, and breaking waves. (And they always posed the hazard of a loose sheet taking a flying half-hitch around one on a tack.) They had plates which screwed into the base mount when the cowl was stowed. The Dorade box was actually something of a compromise. (The loss of air flow through the drainage holes is minimal.) I don't believe they were intended for use in really heavy weather, either. Below, Dorade was relatively Spartan and dark, giving something of a claustrophobic experience. She was designed as a "ocean racing machine" in which speed was paramount and cruising accommodations secondary. (Although, at the time, standards being what they were, she is finished quite nicely, unlike today's bare-bones "racing machines.") When sailing, particularly in warm weather, it was found that there was a great need for ventilation below decks. The "boxes" permitted the cowl ventilators to be shipped in all but really heavy weather and carried their closing plates for use when needed.

 

(If anybody's wondering, my limited familiarity with Dorade was the result of having the good fortune to have a friend who had her under charter for a time many years ago.)

Edited January 8, 2019 by Bob Cleek

[Bob Cleek]

 

I really like the look of this installation with the box!  Might I suggest that you consider making another set of those cowl vents to wear as cuff-links?. 

 

I'm sure it's a variation I simply have never seen here in the US, but I've never seen two half-cowls mounted together. It makes sense if one wants the same air flow as would be realized from one whole cowl, though, obviously.  What seems to have been common here was simply the half-cowl on each side, or even more commonly, a "clamshell" cowl on each side. The "clamshell" cowl was the same as the half-cowl, except that it had no base and just the top section alone (which was sometimes shaped a bit flatter.) There was simply a hole cut in the cabin side to accommodate the air intake on the side mount half-cowls and clamshell ventilators I've seen here in the US. I've never seen a Dorade box on a half cowl, though. These side mounted cowls seem to have been far more common on early power yachts than on sailing vessels. I'm not saying there's anything improper about the pictured installation, but only that in my experience (which includes working in a classic yacht brokerage decades ago,) we didn't seem to have similar arrangements here in America. That said, as the long-time owner of a Giles Vertue sloop, I can attest that there are many such ingenious fittings which are decidedly "British" and yet rarely seen in the US. Cruciform cleats and Highfield levers are prime examples of "better mousetraps" that inexplicably never made it across the pond very often.

Edited January 8, 2019 by Bob Cleek

[michael mott]

Bob Polly Agatha was my inspiration This shot particulary.

 

Michael

[Bedford]

Yet another master class Michael

[wefalck]

Michael, not sure I grasped the purpose of the sub-chuck. Was it that you didn't have a small enough collet for your lathe ?

 

I found small brass pins a better starting material for making screws and bolts than just brass wire. That is probably because the stamping process in making the pins hardens the material, which then turns better than plain drawn wire. The problem is that one has to do all the machining in one set-up, as the rough pins cannot be re-centred. Hence, one has to make the pins long enough for holding during secondary operations.

 

The watchmakers use for slotting screws a square collet holder in a special small table with a V-groove that is typically inserted into the holder for the hand-turning T-rest. A small circular saw is mounted in the lathe for that purpose. For slotting by hand, there are also special extra-thin slotting files.

 

Nevertheless, I like the idea of the saw-guide with a noth that is held against the screw 👍

[SJSoane]

Michael,

 

Your closeup photos look as much like a full scale vessel as any I have ever seen. Spectacular craftsmanship!

 

Mark

[Chasseur]

I have Masting and Rigging the Clipper Ship & Ocean Carrier. Wefalck is correct it's an amazing book as you will soon find out. Another one on my radar is Deep-Water Sail by Underhill.

Enjoying the posts and masterful work!

[michael mott]

7 hours ago, wefalck said:

Michael, not sure I grasped the purpose of the sub-chuck. Was it that you didn't have a small enough collet for your lathe ?

Eberhard, yes you are correct. If I had a watchmakers lathe with the full set of collets I would not need a chuck like the one I made. My Myford is quite big compared to the watchmakers. I only have the course set of collets 1/16, 1/8th 1/4 in the original Myford collets, and then a set of aftermarket #2 morse taper ones in the same fractional sizes up to 1/2 inch.  Initially I was going to put the new collet chuck into the micro drill but decided to try it in the Myford  because I had machined it using the 1/4 inch collet anyway. At first I was concerned that I did not have a high enough speed, but it was not a problem. By making the hole in this collet the same as the pin they centered and re-centered perfectly with no problem. today I will round off the heads. I will use a file because it is pretty small for a form tool, although i might give a form tool a try.

 

Thanks Steve Mark and Jeff for you kind remarks.

 

Michael

[wefalck]

Thanks ! For those, who think they don't have Michael's machining capabilities: one can actually buy small insert-chucks or buy (e.g. from Chinese sources) a small brass drill-chuck with collets and fit it with a stem to go into a larger lathe-collet.

 

P.S. On Underhill: one should remember that he focused on the last three decades or so of commercial sailing ships, so one has to be cautious to back-extrapolate his descriptions into the time say before the 1880s.

Edited January 8, 2019 by wefalck

[michael mott]

Yes to follow up on Eberhard's comment this page gives a good sampling of micro chucks.

 

Michael

[Bob Cleek]

14 hours ago, michael mott said:

Bob Polly Agatha was my inspiration This shot particulary.

 

Michael

What beautiful joinerwork there! And the double half-cowls. Now I can say I've seen them on at least one boat!  

 

I can't figure out what the "Dorade" boxes look like inside. The drain holes leave me scratching my head, but no matter. I'm sure they are as well thought out as the rest of this lovely boat. My own favorite of the pilot cutter type, though originally designed as yacht, not a pilot cutter, is J. Laurent Giles' masterpiece, Dyarchy. I have her plans and a license to build one model. Perhaps one day I'll get around to it.

 

 

 

[KORTES]

Dear Michael.

Your mastery of the instruments as well as your work performance culture fascinates and are the highest standard. I'm very happy to have the opportunity to observe Your work.

My best regards, Alexander.

 

[rwiederrich]

9 hours ago, Chasseur said:

I have Masting and Rigging the Clipper Ship & Ocean Carrier. Wefalck is correct it's an amazing book as you will soon find out. Another one on my radar is Deep-Water Sail by Underhill.

Enjoying the posts and masterful work!

I have an extensive library...and I just added *Deep Water Sail* to it.....Thanks.

 

Rob

[rwiederrich]

Michael...your work is absolutely wonderful.

 

Rob

[druxey]

I can echo the other responses above!

 

A really useful pin chuck is the old Eclipse 160, which comes with three collets. I have two, one dedicated for the mill, the other as a hand-held chuck. ebay is one source for these useful items.

[Sailor1234567890]

Those Dorade Vents would not flood because the ventilator would be removed and the hole plugged in nasty weather. They are fine weather ventilators.

[Bob Cleek]

17 minutes ago, Sailor1234567890 said:

Those Dorade Vents would not flood because the ventilator would be removed and the hole plugged in nasty weather. They are fine weather ventilators.

Correct. Some Dorade boxes also have two identical cowl bases, one next to the other. This permits shipping the cowl in the base directly over the air inlet hole in fair weather so that the air flow goes directly below, rather than having to go "up and over" the baffle.

[michael mott]

Thanks Kortes Rob and Druxey for you kind comments. Bob yes I can see why you like that boat very nice lines indeed.

 

Druxey funny you should mention he eclipse 160 I have 2 of them plus an assortment of others. the upper right ones are the 160 one hac been slightlu modified to fit the third hand.

Just to be clear none of these worked the way I needed them to work for me.

 

 

I decided that using the very fine watchmakers file and burnisher is the best way to round the heads.

 

The first two pictures taken with the old camera which I still prefer the way it operates and focuses, it get closer than the new camera.

 

 

 

Trying to get a professional looking picture with amateurish practices and lighting 😉

 

 

Of course cleaning the burs off the holes in the vent would help. I am pleased with how the screw are turning out though. only 44 to go.

 

Michael