DTFB Racing Sloop- Scratchbuilt Sailboat

[Crawford Bros. Aeroplanes]

quick question how did you trace out the profile and get the correct profile?
@Crawford Bros. Aeroplanes

Honestly I don't remember, probably made calculations from a 3-view or just a side picture

 

[Matthewdupreez]

it's coming along.
I will be releasing plans for it.

 

[Matthewdupreez]

it's coming along.
I will be releasing plans for it.
View attachment 199895 View attachment 199896 View attachment 199897 View attachment 199898 View attachment 199899

seriously body body anybody?
@Crawford Bros. Aeroplanes
@Monte.C
@synjin

 

[Crawford Bros. Aeroplanes]

seriously body body anybody?
@Crawford Bros. Aeroplanes
@Monte.C
@synjin

It is Sunday morning so a lot of us are out, the only reason I'm not is because I'm stuck in class.

 

[Matthewdupreez]

It is Sunday morning so a lot of us are out, the only reason I'm not is because I'm stuck in class.

oops sorry.. and it's mothers day

 

[Matthewdupreez]

It is Sunday morning so a lot of us are out, the only reason I'm not is because I'm stuck in class.

class on sunday???

 

[Matthewdupreez]

finished the hull. and the runners for the controls.
now for the mast, sails, and rudder, then to plonk the servos in and i'll be done.
pics coming soon

 

[Matthewdupreez]

@Monte.C @Crawford Bros. Aeroplanes @synjin

 

[synjin]

View attachment 199967 View attachment 199968 @Monte.C @Crawford Bros. Aeroplanes @synjin

Nice progress! How long is that? It's going to need a lot of weight in the bulb at the botton of the keel. If I recall my forays into armchair sailing you'll have to figure out the center of gravity(?) for the hull and the center of effort for the sail. The center of effort goes a bit in front of the center of gravity.

If I like this and I do my own designs, I'll probably start by basing them on traditional sharpies. Their hulls and pretty much flat panels anyway, so they should work in foam board or coroplast.

I would have worked on mine this weekend, but I was doing a remodel at my mother's house. On the upside, the 20Kg, metal gear, water proof servos I ordered are being delivered today. Yay!

 

[Piotrsko]

50% mast location? Ok but you are running a big jib? Hmmm.

 

[Matthewdupreez]

Nice progress! How long is that? It's going to need a lot of weight in the bulb at the botton of the keel. If I recall my forays into armchair sailing you'll have to figure out the center of gravity(?) for the hull and the center of effort for the sail. The center of effort goes a bit in front of the center of gravity.

If I like this and I do my own designs, I'll probably start by basing them on traditional sharpies. Their hulls and pretty much flat panels anyway, so they should work in foam board or coroplast.

I would have worked on mine this weekend, but I was doing a remodel at my mother's house. On the upside, the 20Kg, metal gear, water proof servos I ordered are being delivered today. Yay!

50% mast location? Ok but you are running a big jib? Hmmm.

i am basing this design off of the T27.

 

[Matthewdupreez]

hhhmmm yea it looks like i may have to move my mast forward..
ooh great i was watching the build video for the T37, that ones jib boom is 30cm/12in, so the T27's should be 20ch / 8indang

 

[Matthewdupreez]

Nice progress! How long is that? It's going to need a lot of weight in the bulb at the botton of the keel. If I recall my forays into armchair sailing you'll have to figure out the center of gravity(?) for the hull and the center of effort for the sail. The center of effort goes a bit in front of the center of gravity.

If I like this and I do my own designs, I'll probably start by basing them on traditional sharpies. Their hulls and pretty much flat panels anyway, so they should work in foam board or coroplast.

I would have worked on mine this weekend, but I was doing a remodel at my mother's house. On the upside, the 20Kg, metal gear, water proof servos I ordered are being delivered today. Yay!

hull 70cm 27 in, mast 90cm / 3ft

 

[Hondo76251]

People mostly refer to "cutters" as any sloop with two headsails but traditionally a cutter would have the mast a bit closer to the center of the boat. This allows for larger headsails. One advantage a sloop has with its mast farther forward, however, is that you can get more tension on your forstay. This is a critical element is the ability to sail upwind and one of the reasons a sloop tends to beat a cutter to windward.

 

[FoamyDM]

Make no mistake I love this idea. I’m no sailor but I have followed The America’s Cup for a lot of my life. So I suppose if we are going here one of you brainy designers should take on this monster. By the way the sail are fabric wings with “ribs” of a sort between two layers “fabric”.
America’s Cup World Series View attachment 187106 View attachment 187106

I suppose I know what I will have on in the background...

 

[FoamyDM]

I haven't built any sails at this size, but I have made some poly-tarp sails for my sailing dinghy and done some repairs on sails for boats from 20 to 38 feet.
Most sails on anything larger than a dinghy will have some shape built into them. The sails are made up of multiple panels. These panels are cut with a little curve to the edges so that the sail will have some belly (camber) to it and create a wing shape.
Sails made from one piece of fabric, like polytarp sails or model boat sails will add that belly by either adding darts or curving the luff and foot. If you have an edge of the sail that bows outward and you pull it tight, such as along a mast or boom, it will push that extra fabric into the sail creating your camber. Many racing sailboats have an adjustable backstay which can be tensioned to curve the mast backwards. Now the curved luff is following a curved mast and some of the belly is pulled out of the sail, flattening and de-powering it. A downhaul or cunningham is used to similar effect on boats without an adjustable backstay.
When darts are used to camber the sail they are usually only sewn in at the corners and the edges of the sail are still curved to fine-tune the shape.

So they are the first shape-changing airfoil? Thank you all for the Detailed Sailing information. My closest experiences are with windsurfing.

 

[Matthewdupreez]

People mostly refer to "cutters" as any sloop with two headsails but traditionally a cutter would have the mast a bit closer to the center of the boat. This allows for larger headsails. One advantage a sloop has with its mast farther forward, however, is that you can get more tension on your forstay. This is a critical element is the ability to sail upwind and one of the reasons a sloop tends to beat a cutter to windward.

just measure my boat, and the sail is 3/7 of the way from the front of the boat... the camera angle made it look like 50%.
but anyway that may be for another build to move the mast forward...
i've already mounted the wooden support for the mast under the deck... a removable mast is a must for transport

 

[Matthewdupreez]

useful
https://www.skisafe.com/blog/Entry/11/the-funniest-boat-names-
and https://online.rapidresizer.com/make-name-patterns.php

 

[Hondo76251]

just measure my boat, and the sail is 3/7 of the way from the front of the boat... the camera angle made it look like 50%.
but anyway that may be for another build to move the mast forward...
i've already mounted the wooden support for the mast under the deck... a removable mast is a must for transport

Yeah, i was saying that i thought yours looked fine to me. What i was getting at is a single masted vessel can have its mast anywhere from 50% to right on the bow and sail just fine. (Cutter, sloop, cat)

 

[Matthewdupreez]

Yeah, i was saying that i thought yours looked fine to me. What i was getting at is a single masted vessel can have its mast anywhere from 50% to right on the bow and sail just fine. (Cutter, sloop, cat)

oh yes, i've seen some boats with the Jib boom, hangs almost completely over the bow .