Weak links in the macgregor

[whgoffrn]

Yes the big hole is for picking it up ...thats where the rope goes through.....it has a small hole (hard to see) that's for holding it down....that is where I'm going to have 300 or 400 lb braid go through which attaches to the rope so it will break in the event I ground it...... as far as it breaking with the grain it won't do that because it's quarter sawn wood.... I have no idea how mich stronger it is all I know if I was demonstrating how it's stronger to a friend by stepping on it on a step and the same on the fiberglass and accidentally cracked my fiberglass one ..... the fiberglass ones from what I've seen when they failed broke up top where the oem ones are more solid so thay may not be a fair comparison because I was stepping in the very middle .... but even with that said these are not as thick in the middle either and still little flex... so nothing scientific but I'm fairly sure it's considerably stronger and looking at wood characteristics it still will bend before it breaks ....i think it's listed as "moderate" on ability to bend before snapping....and when standing on the center and bouncing it barely moved.....ill take more pics so you can see this guys work .....he can do foil shape just fine ....thats what he specializes in is boat rudders for all boats ...and he is a previous macgregor owner

[whgoffrn]

I see what you are saying that with those vice grips on and clamped down no you are right I can't....they are just vice grip style clamps and can easily get removed.... I wanted vice grips rather than a regular vice for quickness of removal where a vice would have me hanging over the edge untwisting it....these one snap and it's off ....so I guess it's one additional step but it takes maybe 10 seconds per rudder and I honestly doubt I would use those clamps often unless I knew I was in for a long crossing with multiple hours of abuse on the brackets..... from all I've read and my own experience in our boats they are capable of fairly significant wave heights for a short duration but after several hours of it the rudders and or brackets start to fatigue and break down so these would only be used very infrequently

[whgoffrn]

I'll post a couple pics of the rudder it has a pretty good foil shape but I requested it not to have more as performance wasn't my motive as any less wood (or fiberglass) takes away from strength .....the thicker the wood or glass is obviously the stronger it will be..... I'm sure he can make it however u want ....i told him almost duplicate of oem but I want the thickness of the board to come down a couple more inches for added strength ..... I chose white oak as my wood but he said most choose mohaganny as it's still fairly strong but looks better but white oak is stronger

[Ponaldpe]

This is the one I made for my other sailboat not a Macgregor.

[whgoffrn]

Nice work what kind of wood is it

[Ponaldpe]

3 /4 inch marine plywood glued together and glassed over with 2
pounds of steel glassed inside, but it still needed a haul down line. Cost about $ 40 .

[whgoffrn]

$45 to have stainless lip welded onto the brackets so I can clamp some vice style vice grips on the lower edge to brace iy.... last step may not get done this season as spring is coming and exumas isn't till next year but the plan is to have stainless plate that extends in several inches welded to the back of the grudgeons , drilled out and bolted to the transom .... exumas isn't on the agenda for this year I'm doing 2 weeks in the keys so don't feel the rudders upgrade is necessary for the keys ..... i guess it depends if I have enough time as spring is closing in on me and I may save the welding fab job on the grudgeons for next winter..... for now I'm plenty happy with my new rudders and welded up brackets as i in my guestimates am fairly confident in the added strength the oak rudders and brackets with vices on them would add



Plan eventually and maybe this season if i have time is stainless plate that extends 6 or 8 inches or so towards outboard welded to the back of the grudgeons drilled out and then bolted on with another bolt or two thrown in closer towards outboard to displace any added stress thrown on the grudgeon or fiberglass under the 5 bolts holding it on

[BOAT]

That peice that you welded to the bottom - that thing that looks like a long C shape:




Seems to me that thing should do fine all by itself to prevent the rudder tangs from bending outward - actually, from a design standpoint that little welded C form thing is a great idea because it's profile to the water will not add a lot of drag.

That welded mod you created there deserves some more thought an reflection by X AND M owners - it might be a solution to a problem.

[whgoffrn]

It was just a cheap way to stiffen up the bracket with the vice grips ....i considered a thick bottom brace permanently welded into it but knew it would prob add 100 or 200 in welding per bracket so this mod was $45 for both and found the vice grips on sale also ..... all in all so far all I have invested is $380 for rudders $45 for weld job $30 for vice grips

I estimate the welded grudgeons to be another 50 bux or so with plates being another $25-$50 .... and several hours of drilling and sealing and bolting it all together so for a grand total of around $550 for what I THINK is a cheap reasonable solution to the weak rudder design

[Seapup]

That peice that you welded to the bottom - that thing that looks like a long C shape:

Seems to me that thing should do fine all by itself to prevent the rudder tangs from bending outward - actually, from a design standpoint that little welded C form thing is a great idea because it's profile to the water will not add a lot of drag.

That welded mod you created there deserves some more thought an reflection by X AND M owners - it might be a solution to a problem

That C piece is stock on the newer stainless brackets. They still bend open if stressed. A little flare is not going to stop sailing, just add slop.




A drilled hole for a bolt & nut to squeeze the flange back down in an emergency would be another approach.

[whgoffrn]

Right as u can see mine were already the newer stainless brackets but as u said even though they are stronger they still do bend and flare out which eventually makes more slop and play which breaks the bolt ...you could drill through the bottom but that means also through the rudder which is where the rudder fails often ....a hole through it would further weaken it which is why I'm using a vice....plus they can't kick up with a bolt through it my way will have 300lb braid fishing line holding it in the down position so it can still break away if grounded

[BOAT]

What if that bottom C shaped thing was just a LOT thicker? Would that fix it??

[whgoffrn]

I considered doing something like that but I'm cheap and went with a quick cheap fix that would do the same .... welder would prob want 100 or more per bracket to weld thicker plate of stainless into it then it would need drilled out etc etc but I'm sure it would work if you tripled up the size of the "c" shaped bracket at the bottom and welded it all together

[BOAT]

my biggest regret - i never learned how to weld and there is no one around to teach me seems like it would work if you had the spare 100 bucks to thow at a welder - Darn! If I could weld you could try it for free!

Why oh why did I not learn to weld? I should have joined the sub mariners in my youth, at least then i would know how to do the boilerplate.

[sailboatmike]

You can teach yourself to weld with a bit of time, effort and watching YouTube videos, Im sure a $180 Harbour Freight Gasless Mig would be a great start to learning

https://www.harborfreight.com/170-amp-d ... 61888.html