Hi

Going to be a quiet winter for the boat. I am bulding two seats from aluminum tubing and open mesh. The frames are complete and painted, the covers are cut and sewn, now I just need to make one more fibreglass seat platform and I can put them together. I'm going to make a few changes to the frame as well to streamline things a bit.
I had the whole boat assembled in the driveway and was running control lines through plastic housing to main control centre between the seats (or beside the seat if I am going solo). I made blocks to attach to the deck that were the correct size for the tubing, and I used tie wraps on either side of the block to stop the tube from sliding under load. This worked when things were dry but slipped when they got wet.  Steering was easy and moved smoothly but the force required to raise and lower the rudder was much higher than I expected. About this time I decided to pull the plug for the year........Get back at it in March I guess!

There has been a pause in the testing of the new cat because of a gearbox failure. I am happy to report that the box was returned Friday and the ratio has been changed from 1:2 to 1:1. This gearing is less desirable but should be much more robust. The diameter of the output shaft is only about 7 mm and I think that while this is may be fine for a lighter craft with less drag, it isn't enough for this application. They were great to deal with and I may buy another drive from them shortly.
In the mean time I added some graphics to the hulls and changed the mounting methods for the drive line tubes, built a couple cedar decks to cover both single user and double user configurations.
I am going to be away for a few weeks so nothing will happen on this front for a while. First results were very encouraging so I am looking forward to the evolution of this craft!

 

Some not-so-good quality video

The on-board videos was taken with 430 pounds of man and spruce and I really don't know what the speed was. We were not trying to go fast but just keep up a decent speed. Cadence was well below ideal.

Hi,
I've had 3 test sessions so far and we are getting the bugs out slowly. First, the hulls are dry inside, and they seems to move easily through the water. On Saturday Kevin and I were both on the boat and we took turns pedaling while the other tended to some issue. Then while I was pedaling Kevin took pictures and video of the wake at various speeds. Unfortunately I couldn't seem to get the GPS on my phone to cooperate so we don't know the speed although folks along the shore were complaining that the wake was making it unsafe to swim......
We tried several props and it does make a big difference how much the boat and cargo weigh. The 16x14 APC pattern prop was just too aggressive with two people on board. The boat seemed to move right along but I could not reach a cadence I liked and still keep that up for an hour with two people on board. Now if there were two drive units we would be going faster and that might have worked. In the end we were using a 16x12 prop that had been previously cut down to about 13 inches. It was a bit light for a single rider but good for two. I bought a few larger props but I won't use them unless I back off on the gearing. At some point I would like to tow the boat through the water and see what the drag is at different speeds.

I dropped the frame down about 5 inches and could go a bit lower but I don't think I will. It's great for flat water but too low for white caps I expect. I will keep the original frame extensions and make 4 more so that I can switch if I have to.

On Sunday Jane and I went back to the lake and did a bit of a tour. The issue of dragging the prop prompted me to take another stab at supporting the shaft which seems to work quite well. Basically I changed the support so that the only restriction was to keep the prop tips from falling more than 6 inches below the surface. Other than that the shaft and prop came move where ever it likes. At the shore I got Jane to pedal while I held the boat and the drive shaft bowed out enough that the prop moves ahead almost a foot! But it seems to be okay at this.......... We went out around some islands and back with the only issue being that I forgot to tighten up one of the bolts on the rudder bar and the forward end came off so it bent the tie rod at the back to about 90 degrees. But we borrowed  a bolt from something else and wade it back fine.

Pictures to follow and maybe video if I figure out how to upload it.

First wet test

So.......first wet test on Saturday morning. Jane, myself and Kevin went to Cox Lake near Tantallon where we met Bill who had paddled over to help. We put the hulls and frame parts together without incident and then clamped on the boom with all the drive train, the seat, and the support tube that held the steady bearing bar for the prop shaft. We had the center of the main frame marked and positioned the assembly with the center of mass where we thought it should be. Right on the money, because when it was thrown in the water it was about 1 inch out of the water on the bow and stern. This was installed with duct tape, c-clamps, retchet straps etc!
I kept one rudder dry and installed a telescoping tent pole to the other with a ball style tie rod end. Since this was still not long enough we duct taped a paddle to the end of the handle.. Nothing but the best.....

The prop was an APC plastic model airplane prop ( 16 x 12) and I should have taken a picture of it before it went in the water. It is on the end of an 11 foot aluminum shaft, 3/8 in diameter, or just under 10mm.
52 tooth crank sprocket, to a 14 tooth sprocket on a 2:1 Miterpak right angle gear box.

The prop is installed on a stainless steel stub shaft which goes through a Delrin block. This is bolted to a 1.5 x .125 aluminum flat bar going up to the frame. This is what I wanted to use to set the maximum depth of the prop. All the joints used 1/4-20 bolts with self-locking nuts so they could all move without falling out.

The first thing I noticed was how easily the boat moved through the water. A very light effort with a canoe paddle would move it right allong. I started to pedal gingerly and everything worked great. However, when I used just slightly more effort I could hear the prop hitting so I went back to shore. Turns out that when pedalling, the bow in the shaft is very much exagerated and this effectively shortens the shaft which changes the angle on the aluminum flat bar. So we experimented with woving the hinge point forward but eventually ended up taking the guide off altogether. This worked great for about 10 minutes and while I was starting to push just a little, one blade snapped off the prop!! On examination we could see that the other blade was white and soft at the same location and it broke a few minutes later. by this time we were just using a loop of rope to lift the prop for shallow water. I really don't want the prop dragging on the bottom when I stop pedalling....

I think maybe the gearbox is just too far above the surface and the blades are working too hard to try and straighten shaft when pedalling. There was more flopping of the drive shaft than I expected but this could be due to not enough of the shaft in the water.

Over all I was extremely happy with the first outing and now will start the refinements!

Summer is getting close and I am not on the water yet, but getting closer.......

The woodwork on the hulls is almost done, and once I scrape some of the runs off the bottom it will be ready for paint. The tops need one more coat and they will be ready also. The holes are cut for the access ports but I will need to install them as the last step because I have to reach as far as I can (and a bit further) to place the nuts for the main frame mount on the inside. Can't reach far enough with the ring in place. I am going to paint the hulls white and add some graphics over that.

I had these frame mounts water jet cut from 2 x 2 x 1/4 alumium angle and they are bolted though the deck and the stringers (still don't know the right word for this) which is doubled for 12 inches at these points. Using four #10-24 SS screws per mount with 1/8 stainless steel backing plates and locking nuts on the inside.

I had planned to make the rudders myself but the equipment is not available at this time so I bought two rudder kits from Seaward Kayaks, very close to my home town on Vancouver Island. And, since I bought two they gave me a break on the price thank you very much!!! These are the larger model from the double kayaks. I will probably use just one 90% of the time but when the water gets rough I will be more concerned about handling than speed. Most of the time I will need very little turning input so I will only lower the one rudder as much as I need to. I have made two rudder mounts out of fibreglass and will drill the holes and mount them temporarily to check fit and alignment.

Nice boots...!

I have the frame  under way now. I ordered 3" x .120 wall aluminum square tube but they delivered
2 1/2 instead and then informed me that they couldn't get the other, don't believe but.....So I made the main frame out of that. Since the hulls will be at least 6 feet apart the frame would be pretty awkward to manage and transport in one piece. So I made the ends removable and built them from 2" x  .120   square tube. They will be pinned in place with 1/2" round aluminum pins, both to the main frame and to the frame mounts on the hull. I will use 80 duro rubber to take up the space between the frame and the ends. This will allow a small amount of movement without torquing the mounts too much. I hope.

For now the boat will be set up with one rider although all the drive line and seat components will be on one bar which can be moved or doubled at any time. This is shown with the seat off one of my home built recumbents. I had planned to use a lowracer seat but but found this to be more comfortable. I have lots of bike parts laying about so I am using a Tiagra triple crank and one sprocket on the Mitrpac 2:1 gearbox up front. And a front derailler. This will be a 3 speed machine at first anyway. One speed for cruising, one for going up the face of really big waves, and one for going down the back side....... Plus, if I make the spread between gearing smaller that a normal bike I can do more testing with less wrenching. I will use the derailler underneath and a chain tensioner up top. This will do two things, allow me to have some capacity to span gear ranges, but could also be calibrated to indicate torque. That way I will be able to read speed from a GPS, torque from this apparatus, and rpm from the input shaft on the gearbox. There will also be the capacity to lock the tensioner to allow reverse. I am going to use a long curved shaft but it will be supported close to the prop. I am going to use a thin aliminum or plastic blade down to an impregnated bushing for the shaft. A lever will raise the prop until it just clears the water so I can avoid rocks, beach pull ups, get it out of the way when using a kite or sail,  and clean off weeds, baby seals, and other stuff. So with 4 lines to control the rudders, 4 more to raise and lower, 1 more to raise the prop, 1 cable to the derailler, 1 to raise the beach umbrella, 1 to raise the pirate flag, and I plan to use a kite with more lines, and probably a sail with more lines...................if I used an electric trolling motor all this fuss would be eliminated........



 

Still sanding........

The tops are on and trimmed. I used a router with a straight bit and I have included a photo of what happens when the bearing falls off the bottom as you are trimming. Good thing the 1 x 1 was there.......Just a little more minor filling to do and then I can start fibreglassing. One layer of cloth on the bottom, just epoxy on the top. They are starting to look like they might float!!!

Filling cracks

I used epoxy thickened with micro balloons to fill the cracks between the cedar strips on the hull. I found that when I had the consistancy I wanted, the mixture would not stick to the wood. Also, the strips are so narrow that by the time I had forced the mixture into one crack, the two strips on either side were covered as well. So I decided to put a coat of clear epoxy on the hull first and then do the filling. This worked quite well. I tried to use a syringe (various sizes) to inject the mixture into the crack but this did not work so I ended up forcing it in with popsicle sticks. I didn't clean the hull off as well as I should have and so there was more sanding than I expected. The other undesirable result was that the mixture sunk into the cracks as it cured and so now I have to fill many of them over again! You can see some of the dark spots in the pictures. When I did the second hull I was much more careful about scraping the hull after the mixture was partially set.

I used short pieces of cedar strip to make a wider landing area on two of the formers (bulkheads) for the top which is in 3 parts. The under side of the top sections were coated with epoxy as was the top of the strip used to attach the top and sides, and the tops of each former. Then I spread thickened epoxy on the top of the attachment strip and the tops of the formers before installing the top. I used nails at each end to locate the top before I started so I used these to set the top down in the right spot. I flipped the boat over and set it on top of one of the eight foot sections of 3/4 plywood I used for the original lay out (I put the top on in 2 eight foot sections, and 1 two foot section) , then I used metal strip and screwed into the plywood. SInce teh mixture sometimes gets runny before it sets I thought this action would stop it running away from the surfaces I was hoping to join. The epoxy seemed to extrude from the outside joint in a fairly consistant manner and when I took the 3/4 plywood off the following day the results were promising.
It is supposed to be sunny here on Sunday so I will take the boats out and use a router to trim off the tops flush with the sides. I will also start to sand the epoxy mixture on the strips again, hopefully for the last time!

This is not much of a picture, I will take better ones outside this weekend. I tried standing on the deck and it did deflect when I was not over a former but there were no cracking or snapping noises! I expect that just putting a heel in the center would break something but.......just don't do that.

First sanding

I now have two hulls with the bottom wood in place. The insides are all covered with epoxy although I may have to go back and address some of the larger voids since this East Systems epoxy does not flow well at all. This weekend I sanded (with Kevin's help) the outside of both hulls and now I am going to attempt to fill all the joints from the outside. I will be wetting down the surfaces with epoxy and then filling with a mixture of epoxy and micro-balloons. Very tedious of course but has to be done. I will also finish the ends where the two plywood sheets on the side come together. While I am waiting for these applications to cure, I will lay out and cut the tops. I am going to put a small opening (hatch cover) on each end so that I can remove any water that gets in, plus I can force air in one end and out the other to make sure the hulls get stored dry. I am wondering about putting any more hatch access closer to the mid section for storing small things....but I am worried about compromising the strength of the hull at the point where bending stresses will be the highest....
We used a combination of belt sander, palm sander, sanding belts cut to make a long 3-4 inch strip, and a frame that looked similar to a bow saw to hold belts. I'll put a picture of that in later.

Nice boots eh?

Hull step 2

So the boat project putts along…. I have two hulls ready for cedar strips now. I started the stripping process by tapering enough strips for one hull. I started 5 feet from the end of the strip and cut a straight line to the end on the opposite side. I knew this was not the ideal shape but I didn’t think it would make that much difference…it does! You can see from this picture (1 and 2) that the strips are not following the hull properly and that is after just 4 rows on each side. Since the hulls require 17 rows in total, Kevin cut 18 strips of MDF on the router table at the proper dimensions ( the tapered part plus one foot) and I used the other hull to do a test fitting, big improvement. I traced the new shape on enough strips to finish the first hull and used a jigsaw to cut them. This worked okay but they still took quite a bit of time and the results were ……less than perfect. When the strips were all on there was still a thin slice where the two different strip shapes met so we shaped and installed an insert for the four places. I epoxied the ends on the hull where the strips land but used Gorilla Glue to glue the strips on to the bulkheads, holding them in place with masking tape.  I did not glue the strips together. That hull is now hanging from the ceiling and I am working on the next one. The first set of strips we cut were not very uniform in thickness so there will be lots of sanding and shaping to come.

The second set of strips are much better quality. We used two sided tape to stick an MDF pattern right to the top of the strip and used that as a cutting guide for the band saw. It worked great and I don’t expect to have to do much planing etc to get them to fit. This hull should go much quicker (these things are all relative) and will need less work in the end.

The third picture shows the added width of one of two bulkheads to anchor the strips at the 7 foot mark from each end. Strips are alternated 7 and 11 feet The tight radius of the curve will mean more filling later on but I couldn't imagine beveling every strip and fitting each one, not for a trial boat anyway.

Once the hulls are stripped, I will check the fit of the strips on the inside and then coat the entire inside with a layer of epoxy.  I may have to use masking tape on the outside in a few places where the gaps are larger than I would like. When that dries the hull will be one solid unit and I can start shaping the outside. I am not sure how I will do this yet, but I might make an aluminum frame, cut a belt from a belt sander in half, holding it at the ends only.

My decision to have rounded hull cross sections was based on information in posts to the Boat Design forum but I am not sure yet if the extra work involved will pay off. Stitch and glue would be MUCH faster and less work but not quite as nice…depending on how good the shaping job is! These hulls will definitely be painted, I won’t be showing off this handiwork under clear epoxy……!