V-17 connection.. must be on topic here. We didnt make it this year (just got back from Denver) but did hang out there last year.
The Official "What Did You Do To Your Mac Today" Thread!
- Thread starter Sock Puppet
- Start date
Wow way cool! Gives some great ideas. Can you tell me what you used to replace the liner where you cut it out? Did you just cover with wood or find some other substitute?
Sorry my reply was to ghochgraf for his cabin mods. I mistakenly thought it would be tied to his post.
The pooches are a pleasure to bring along - and they are always very excited to go. The smaller dog likes to be out in the cockpit (not allowed up on top like in the picture below except when we are motoring slow). The brown dog goes way back in the aft berth.. just loves that spot. These pictures were also taken in the last week.
Today I got the boat washed, all the teak oiled and started waxing the exterior. Hopefully tomorrow I will test run the new( to me) electric start 9.9 engine ( already installed new impeller). Been sailing my hobie 16 , but am looking forward to getting out in the mac.
Today I helped get Sovereign's new owners familiarized with the boat, setting sails and dropping the mast to prep for trailering to her new digs in Marana, AZ.
Nice family whom I'm sure will be good for the boat.
(sniff)
Nice family whom I'm sure will be good for the boat.
(sniff)
Ok, so, I went out and sat in the boat. It’s in the driveway. I got depressed at all I want to do, and will likely fix any safety issues and go sailing come April. It’s been to cold to do much, but that is starting to change.
However, I did add up the volume of the foam blocks I have pulled out, and am considering leaving out so I can reclaim the space. It looks like they used 1 cubic foot blocks and cut them down. This has made the calculations somewhat easier. A conservative estimate is 7 cubic feet. For example, the block in the lower left of the first picture is 12x12x6 (aka 1x1x.5).
I started running some numbers and at 60lbs per cubic foot, this is only 420 lbs of floatation! I haven’t removed what’s under the cockpit benches, but ... if there is 10 cubic feet under each bench that’s only 1620 lbs of flotation for a boat, that when loaded will likely be twice that heavy.
The boat has an unloaded weight of 2550.
Ok, I have to be missing something. Someone, please educate me.
However, I did add up the volume of the foam blocks I have pulled out, and am considering leaving out so I can reclaim the space. It looks like they used 1 cubic foot blocks and cut them down. This has made the calculations somewhat easier. A conservative estimate is 7 cubic feet. For example, the block in the lower left of the first picture is 12x12x6 (aka 1x1x.5).
I started running some numbers and at 60lbs per cubic foot, this is only 420 lbs of floatation! I haven’t removed what’s under the cockpit benches, but ... if there is 10 cubic feet under each bench that’s only 1620 lbs of flotation for a boat, that when loaded will likely be twice that heavy.
The boat has an unloaded weight of 2550.
Ok, I have to be missing something. Someone, please educate me.
Pictures from today trying out a change. Stopped here for a dog potty break. I cut the stern rail above the ladder like others have done to make it easier to get on and off the boat from the rear ladder. I also lowered the solar panel by about 5 inches made possible by the easier access.
FYI, I got the method for that rear rail opening from Chris Holderness who used to own a 26S. Sumner did something similar also.
The 26C is nicely set up for aft beaching where you can pretty much walk from the back of the boat to land on the ladder. Or if you are moored or anchored, that aft ladder is the best place also to get on the boat. We are not getting any younger and climbing over the rail in the original setup was just getting to be a little more difficult than we liked. Especially true now with mondo solar panel back there (and like Sumner, we are really liking having the fridge). When you are getting back on the boat using the ladder, you are typically going to pull yourself up using the stern rail so particularly the new post in the center needs to handle a fair amount of torque.
What I did for the torque issue.. My stern rail is about 17 inches off the deck. I bought a six foot 1 inch OD .049 wall stainless steel tube and used most of it. The two pictures show how the torque on the new tubes is handled. The new tube on the outside gets strength from rail structure on the side but the new center tube is the one that has to handle torque when boarding by itself.
So the new tube in the center extends fairly far down inside the Laz and forms a lever arm with the fulcrum being where it enters the Laz. The longer the pole inside the Laz, the lower the force is where the pole is bolted to the fiberglass. Im not completely done with this yet but I think I have a lot of margin in the strength of the railing for boarding from the ladder.
Top picture shows the "backing plates" for the new tubes on the transom outside. Lower picture shows where the tubes are bolted on inside the Laz.
The 26C is nicely set up for aft beaching where you can pretty much walk from the back of the boat to land on the ladder. Or if you are moored or anchored, that aft ladder is the best place also to get on the boat. We are not getting any younger and climbing over the rail in the original setup was just getting to be a little more difficult than we liked. Especially true now with mondo solar panel back there (and like Sumner, we are really liking having the fridge). When you are getting back on the boat using the ladder, you are typically going to pull yourself up using the stern rail so particularly the new post in the center needs to handle a fair amount of torque.
What I did for the torque issue.. My stern rail is about 17 inches off the deck. I bought a six foot 1 inch OD .049 wall stainless steel tube and used most of it. The two pictures show how the torque on the new tubes is handled. The new tube on the outside gets strength from rail structure on the side but the new center tube is the one that has to handle torque when boarding by itself.
So the new tube in the center extends fairly far down inside the Laz and forms a lever arm with the fulcrum being where it enters the Laz. The longer the pole inside the Laz, the lower the force is where the pole is bolted to the fiberglass. Im not completely done with this yet but I think I have a lot of margin in the strength of the railing for boarding from the ladder.
Top picture shows the "backing plates" for the new tubes on the transom outside. Lower picture shows where the tubes are bolted on inside the Laz.
Walt wins for the most stuff, (plates, beams. angle, plastic pieces) on the stern of a boat. What sealant are you going to use around the tubes?
Hi Walt. Nice work but I’m a bit confused with your use of the term torque.
One definition is :
Torque, moment, or moment of force is rotational force. Just as a linear force is a push or a pull, a torque can be thought of as a twist to an object.Wikipedia
Don’t get the rotational force in this instance. Except to tighten up the bolts that is. Sorry if I’m being petty.
One definition is :
Torque, moment, or moment of force is rotational force. Just as a linear force is a push or a pull, a torque can be thought of as a twist to an object.Wikipedia
Don’t get the rotational force in this instance. Except to tighten up the bolts that is. Sorry if I’m being petty.
Im not sure if this is just about defining terms or understanding the problem.
When you grab that center post when boarding from the ladder, you are going to pull mostly backwards as you pull yourself up. If you are boarding from a dingy and there is some swell (like at Two Harbors on Catalina Island).. you may even pull with your total body weight. This puts a force vector where you grabbed the post and with the post attached at the hull, that force would want to rotate the post backwards around the fulcrum point where the post exits the fiberglass. If the post were simply bolted to the glass surface like all of the other rail hardware, it would create a rotational force that in my estimation, might rip the fiberglass. By extending the pole inside the Laz and bolting it at the end of the pole, the resulting force where the pole is bolted is diminished. Torque is force X distance.. The longer the distance, the less the force. I did have to slightly bend that 1 inch OD SS tube for the outside tube so know what it takes and am fairly confident that I wont bend anything and it also feels stiff.
That center post is also tied to the original horizontal rail with a 90 degree T but that existing horizontal rail after having a section cut out can flex a fair amount.. not stiff enough by itself.
Rick, Im going to epoxy/ glass reinforce that area inside the Laz just where the poles poke through. This is partly for strength, partly to seal things as the pole will of course aid water getting into the Laz. I may then additionally seal the hole from the top side with one of the 3M sealants. Also, since this is not cored glass in that area, a little water getting in there just really doesn't matter that much but I want it sealed regardless.
I have used that ladder opening with the mod a few times and it makes getting in and out of the boat from the rear WAY nicer than when we had to climb over the rail. We are in our early 60's now and that easy access is really nice.. keeps the wife going on outings like to Catalina Island next summer where you have to moor and access the boat by dingy.
When you grab that center post when boarding from the ladder, you are going to pull mostly backwards as you pull yourself up. If you are boarding from a dingy and there is some swell (like at Two Harbors on Catalina Island).. you may even pull with your total body weight. This puts a force vector where you grabbed the post and with the post attached at the hull, that force would want to rotate the post backwards around the fulcrum point where the post exits the fiberglass. If the post were simply bolted to the glass surface like all of the other rail hardware, it would create a rotational force that in my estimation, might rip the fiberglass. By extending the pole inside the Laz and bolting it at the end of the pole, the resulting force where the pole is bolted is diminished. Torque is force X distance.. The longer the distance, the less the force. I did have to slightly bend that 1 inch OD SS tube for the outside tube so know what it takes and am fairly confident that I wont bend anything and it also feels stiff.
That center post is also tied to the original horizontal rail with a 90 degree T but that existing horizontal rail after having a section cut out can flex a fair amount.. not stiff enough by itself.
Rick, Im going to epoxy/ glass reinforce that area inside the Laz just where the poles poke through. This is partly for strength, partly to seal things as the pole will of course aid water getting into the Laz. I may then additionally seal the hole from the top side with one of the 3M sealants. Also, since this is not cored glass in that area, a little water getting in there just really doesn't matter that much but I want it sealed regardless.
I have used that ladder opening with the mod a few times and it makes getting in and out of the boat from the rear WAY nicer than when we had to climb over the rail. We are in our early 60's now and that easy access is really nice.. keeps the wife going on outings like to Catalina Island next summer where you have to moor and access the boat by dingy.
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FYI, that "other" bracket under the ladder is for an emergency outboard motor mount bracket that stays stored in Laz. I put this on when the family was doing Lake Powell trips where we got up to near 90 miles from any sort of civilization and VHF and land based cell communication just did not work. For those trips, I had a spare 4 hp outboard also stored in the Laz. Well.. I have fortunately never needed to use that spare outboard bracket except when I tested it.
The rotational force is around the point Walt marked fulcrum point on his drawing. This rotational force happens due to a hand grabbing the top of the tube. Think of a side view of his drawing (athwartship) and you will see this rotation. Being a mechanical engineer I've always used the term the way Walt did. If you really want to have some fun figure out the moment of inertia of the tubing Walt used lets say it's 25.4mm diameter X 3mm wall thickness 43cm long ( I saw you were Canadian
) 304 stainless steel. Then we can tell if it will bend or not when he is trying to pull himself up from the beach while hanging on to the dog. Of course we would have to know the force Walt would apply. If Walt is right handed the additional strength of the support from the original railing will help offset some of the torque Walt can apply to the new tube.
He he.. I will just have to see what happens after a few years of using it including getting back on the boat via inflatable kayak after a beach party at Two Harbors (no dogs but possibly extra weight of a few beers in the belly).
Maybe one trip I will come back with only that piece of steel tube because it was in my hand when the rest of the boat sank from a big hole.
Maybe one trip I will come back with only that piece of steel tube because it was in my hand when the rest of the boat sank from a big hole.
Yup. See it now. A lever on a fulcrum exerts torque. As far as calculating moment of inertia I think I’d to know need a few more details. So Walt, how much mass and velocity can you and your dog produce??