Curt-

Please see my question to John Harris below and his response.  Basically, aft rake on the lug is good.

Dave Peterson

Message: Question on mast rake on Northeaster Dory Lug Rig. I ran a plumb line from the center of square hole in the mast partner down to where the mast step will be placed. It indicates that the lug rig mast will have a
slight rake toward the stern. Is this correct or should I shave a bit off
the aft end of the mast step and get rid of the aft rake? Thanks.

Dave, that's absolutely right.  The lug rig's mast does rake aft.
With the location of the mast step and mast partner establishing the
correct rake, I hadn't felt the need for a drawing like the sloop's
mast rake diagram.  A string from the top of the Dory Lug's mast would
land about 10-1/4" aft of the base of the mast.

Cheers,
-- 
John C. Harris
Chesapeake Light Craft
"The Best Boats You Can Build"

   Thanks for the info, Dave....predicated on my best attempt to level the boat, the best I can calculate is that the math does work out to be an inch or so of aft rake, I just would feel more comfortable drilling the knees and mast partner if my calculations  came out closer to 10-1/4" (didnt know that number, thanks for advising).  I think I'll try leveling the boat again, but when I level the boat by the bottom of the skeg my marks for the waterline arent level...will try to see why that is next and recalculate the rake from the mast step to the mast partner and from that extrapolate total rake from top of mast.  I guess if it comes out as any aft rake, I'll just go ahead and drill the holes. 

Remember, he said 10 1/2 from the top of the mast so the amount at the bottom isn't much.  Bottom line, you need some aft rake.  The amount probably doesn't make that much difference.

Copy that...I re did all my measurements...the waterline hash marks are all level to the floor within a half inch, the skeg is level, and there is 3/16" "rake" between the mast step and the mast partner (sounds like you used the same measurement) which if you subtract that height from the mast and divide that height by the partner height, the 3/16" extrapolates to about 2" rake....it's not nearly 10" but at least it's not forward rake, so I'm going to go ahead and drill the knee and partner holes per the instructions in the manual...thanks for your info!

Curt

Here's the thing---unlike in the sloop rig, the lug rig's mast rake is established by the location of the mast step and mast partner.  The mast step is impossible to get wrong;  the mast partner is hard to get wrong.  No need for leveling the boat, no need for strings dangled from the masthead...

There's a bit of a dance to establish mast rake in the sloop rig because there's no mast partner---your shrouds are what hold the mast at the correct rake, so there are a lot more moving parts.  But with the lug rig, get the thwart in the right place and you will have the correct rake.

Sounds good, John, thanks!   I'm drilling for the drill, fill, drill thing on the knees and mast partner as we speak.

John (and Curt), I recalled this string from awhile ago and it has become more relevant to me now. Nothwithstanding your statement that it may be hard to get the mast rake wrong on a lug rig (Dory) I have found one way to create an issue. I think all my placements are spot on, but either due to trimming too much off the mast or making the mast thwart hole too large (I used the smaller dimension in the book and then opened it up more once I found the larger size elsewhere in the book and at that point I seem to have made it a bit too large) or a combination of the two, at both the step and the partner my holes are too big for the mast to fit in without a fair amount of play. I am less bothered by the actual rake than with that looseness. If the mast moves around in there a lot the added stress of the movement could wreck some havoc I suspect.

Fortuntely I saved all the wood I sliced off to make the mast trimmed so I have a lot of ready made shims to insert in the holes to firm it up. I once I figure out on which sides those shims should be placed and at what thickness (the rake issue), I may permanently glue them on and sand and varnish over them to make them nice and neat. If done right it may even look like it was supposed to be that way.

I think the holes are too big to just fill just by using leathers.

any thoughts would be appreciated. I should have it in the water in a couple of weeks. put the sails up yesterday in my driveway.

David  

David,

I too cut the square hole in the mast thwart a wee bit too large, allowing plenty of room for leather around the mast, or inside the thwart opening, one or the other.  I have been sailing the dory on a very narrow lake, thus lots of tacks, and have not gotten around to installing the leather so the mast has lots of freeplay back and forth on every tack that seems fine.     John would know better than I would, but to me, the slight freeplay I will have once the leather is installed is fine.  Could you just leave it as-is with no leather and sail it to see how it goes?  You could then decide what to do.

I also read comments from one builder saying that some freeplay is needed so you can pull the mast out and lay it down if you are on the water and want to switch to rowing.

Another dory builder is going to use plastic wedges, cut from the squeeges used to spread epoxy, point being that he wants some freeplay that can be shimmed, not a tight fit.

Hope that helps!  Curt

   thanks,that gives me some comfort. I will just take shims along and see how it is. hopefully it will be just fine. looking forward to sailing it soon.

David

   Mast wedges have long and storied history and work well. Word of advice - carry spares. Also , have something to knock them loose. They will swell.

I am notorious for specifying sloppy mast fits.  There is nothing worse than a mast that jams in the step.  A mast that's just a "slip fit" at rest will be rigidly locked in place as soon as there's any side-load on it at all.  So all of my masts rattle around in their steps.

(In July I had a "slip fit" mast get jammed in its step.  Took me an hour-and-a-half on the beach to get it out. I nearly sawed the thing off, I was so mad.)