Inqism-01: 3 Guesses. First 2 don't count.

[Inquisitor]

Also, I wanted something without bearings. It would likely see salt water most of the time in the down position. I was figuring on something crude like the upper sheave.

[Highlander]

Rudder Mod 2-1 pull







D/B Mod

[Highlander]

D/B Mod 4-1
This is what Tom was talking about


This is what I did


new d/b line
















Hope this helps u out

J

[Highlander]

something u should know if u don,t already know is that the D/B trunk is tapered so it gets narrower as u go down from top to bottom so make sure u use the bottom measurement of the D/B trunk as the top is wider otherwise ur new d/b will only go down inside the d/b trunk halfway

J

[Inquisitor]

something u should know if u don,t already know is that the D/B trunk is tapered so it gets narrower as u go down from top to bottom so make sure u use the bottom measurement of the D/B trunk as the top is wider otherwise ur new d/b will only go down inside the d/b trunk halfway

J

I appreciate the heads-up, but I did note that in earlier researching here. I did take it seriously as I measured at the top and bottom and then printed a test foil to slide up and down using the strings to make sure of no surprises in between. The parts above are based on this test, minus wall thicknesses for the fiberglass work.

[Inquisitor]

Rudder Mod 2-1 pull
D/B Mod

I got cha.

My plan is for just a 2:1 since it'll only be ~36 lbs. My thought was to just tie the line off at backup hole, run it down the trunk to the D/B and have a single sheave down, return over the upper pulley as normal... 2:1 and don't need the block and tackle up top...

... unless someone sees a problem with that idea.

I appreciate stone throwing.

[Tomfoolery]

My plan is for just a 2:1 since it'll only be ~36 lbs. My thought was to just tie the line off at backup hole, run it down the trunk to the D/B and have a single sheave down, return over the upper pulley as normal... 2:1 and don't need the block and tackle up top...

... unless someone sees a problem with that idea.

I appreciate stone throwing.

No stone throwing, but you have to encase the line around the sheave in some fashion so it can't jump off and get jammed. If it's in a narrow pocket so it's enclosed on both sides, it's probably fine. But if it's on the side in a recess or something like that, you need some sort of rope guide or fairlead to keep the line in the groove when slack.

[Inquisitor]

My boat is in the shop far away and I've lost the pictures I made. I'm at a standstill on my project until I get it back. If you have an image or if your boat is handy and you're on it anyway, could someone take a picture looking strait down on the lifting hinge pulley? Please include the full 16" length of the daggerboard so I can take measurements and scale the results.

I seem to recall it was placed far back from the center of mass to clear the mast and the configuration was something like this


I'm needing both the position of the hinge, distance and angle of the down line relative to the safety line hole. A picture can give me all that accurate enough for government work.

Thanks.

[Jimmyt]

Let me know if you need anything else.

[Inquisitor]

Its a rainy, boring, COVID cooped, cabin fever weekend and I have nothing better to do than jaw-jack on my favorite forum.
Now, I have something else to do.

I owe you a beer (or other favorite poison)

[Jimmyt]

Its a rainy, boring, COVID cooped, cabin fever weekend and I have nothing better to do than jaw-jack on my favorite forum.
Now, I have something else to do.

I owe you a beer (or other favorite poison)

Same here. Going to try to get more plumbing done. Should be around most of the day if you need any other info.

[finding41]

I took a mold off my DB on my Mac 26D. It's not too hard to copy the DB even if you don't have all of it. It's symmetrical. Just do part and when it's cured flip it over and do the other end. I use modeling clay to fill any voids or holed. Clear packing tape works great for holes too. Fiberglass doesn't stick to it.
Check our Boatworkstoday on YouTube.
There are other tutorials on YouTube for making molds for almost anything.

Marty

[Inquisitor]

I took a mold off my DB on my Mac 26D. It's not too hard to copy the DB even if you don't have all of it. It's symmetrical. Just do part and when it's cured flip it over and do the other end. I use modeling clay to fill any voids or holed. Clear packing tape works great for holes too. Fiberglass doesn't stick to it.
Check our Boatworkstoday on YouTube.
There are other tutorials on YouTube for making molds for almost anything.

Marty

Yes, that would certainly work and is far easier and I would also recommend that method to those that just want to simply replace their D/B and go sailing. I'm wanting to try something different than the stock daggerboard. I'm using the male mold technique since its a one-off. I have no desires to go into business and mass-produce these. BWY does a fine job.

I'm using a slightly different NACA foil. I'm also using techniques that should be near 2 decimal places accurate in relation to that shape. The factory one as described in other threads is an approximate NACA0012, but is not even 1 decimal place accurate. The primary goal is to have deeper and better stall characteristics. Although there should be significantly less drag, I do not expect to notice a speed improvement. Hull speed controls that. Besides I have no way to do a before and after.

VBR

[Inquisitor]

Let me know if you need anything else.

... but you have to encase the line around the sheave in some fashion so it can't jump off and get jammed. If it's in a narrow pocket so it's enclosed on both sides, it's probably fine. But if it's on the side in a recess or something like that, you need some sort of rope guide or fairlead to keep the line in the groove when slack.

Here is the model for the pulley housing. I've used your photo to get a good location and orientation of the pulley. Works great with easy access of the bolt shaft for replacement of the sheave. I'll be 3D printing the sheave in nylon and press fit a bronze bushing inside and then mount with SS bolt. Tomfoolery, I've incorporated your suggestion about trapping the line so it can't pop off the sheave. Clearances are 1mm... no way it has anyplace to go.

Another piece is on the printer now, and then the nylon sheave, then this housing last.

[finding41]

Nice design. I may have to copy that for my 26D. It is pretty heavy coming up.
The biggest problem I have when raising the DB is the safety rope getting caught between the DB and the trunk. I'm not sure there is a quick fix for that.
One thing I've noticed with my DB is that it changes position when ever I tack. One tack it's / in the trunk, the other tack it's \.
I wonder if that takes away from the pointing ability. I think I could design a set of rollers that would go inside the DB to keep it strait and still allow it to be raised and lowered. (That seems like a lot of work...)

Marty