It's been quite a cold and snowy winter here in NH and actual work on the boat has pretty much ceased until conditions improve a bit (it won't be long now). I haven't been idle though; my office has become the official Velorum Skunk Works lab until I get back on the boat and I don't want to share everything yet because I want to get everything installed before I report back on it. The office closely mimics the messy madness that resides between my ears. For now though, I'll just say that it is lithium related and includes a bunch of monitoring/charging goodies. More on that soon.
I have been working on another project that I wasn't entirely sure I'd get to this year, but finding myself idle after the project mentioned above was finished I decided to go ahead and install the Maxwell RC8-8 windlass with capstan. By install, I really mean get ready to install because there was (and still is) a lot of planning and design work to do before I start cutting holes in the boat. After a lot of thought and careful measurements, I came up with a plan where I could build the entire mounting base for the windlass so when the weather finally does warm up I can essentially drop it in and wire it up.
After a lot of research on other Niagara 35s with windlasses, it was clear that I would need to elevate the windlass up off the deck to be able to meet the correct vertical angle (+/- 6degrees) between the windlass and the bow roller. I could have just glued a few pieces of plywood together, epoxied it up and called it a day, but I wanted something that looked like it belonged there, didn't stub toes too bad, and still allowed me to keep both hawse pipes on deck for an additional rope rode that could be hauled on the capstan.
As always I like to incorporate CAD designed parts where I can and the more I thought about it, the more I started thinking of creating a 3d printed mold that would follow the shape of the windlass. Initially, I was going to use the dimensions of the holes from the mounting template that is supplied with the installation manual and create a shape that approximated the windlass base in Autodesk Inventor, but my son (who is much better at Autodesk than I am) reminded me that you can import a scanned image of the template, scale it so the dimensions are correct in Inventor and then build the shape off that. So, that's what I did.
I ended up sizing the inside dimensions of the mold 1/2" larger all around than the actual windlass base and then extruded the shape up 1" to make a mold that I could then use to make an epoxy and 1708 biaxial fabric part that could be machined. Once I was satisfied with the dimensions, I added a bottom layer and sent it off to my 3d printer (Bambu 1PS) to make the mold. About an hour later, I had the mold in hand and went over to the shop to make a sticky mess.
Because of the size of the part, I didn't want to fill the entire mold up at once to keep the part from going exothermic and cooking itself, so I did it in 3 separate sessions allowing each layer to partially cure before proceeding with the next. During each layup I added 4 layers of 1708 biaxial cloth along with a healthy dose of West System 404 high density filler. I expect it will be plenty strong and much cheaper than 1" thick G10 plate. Once I finished the layups, I let it cure for a few days before starting the machining. The first step was to round over the top edges so there would be no sharp edges that I would invariably kick and stub my toes once installed. I used my router with a 3/8" radius roundover bit and did it in 2 passes to make sure I didn't get any tearout from trying to remove too much material at once.
Next I taped the template onto the routed out part and drilled out the three 3/8" bolt holes so the windlass could attach. For the two big holes, I needed to use a hole saw. Unfortunately, I have been using Lennox hole saws for years and have accumulated at least 12 sizes and a variety of collets over the years, but to my knowledge, they don't make metric so I had to settle on a 4" bit for the motor cutout and 2-7/8" for the chain cutout. They were both about 1mm larger than needed, but shouldn't be a problem.
With the main part completed except for sanding an paint, I took a template (actually the gasket) over to the boat and used it along with a piece of carboard to use as a template for the second part of the base. This will serve 3 purposes:
- The base plate (I have some leftover 1/2" G-10 plate) will be epoxied to the deck to spread the load across more area of the deck.
- It will cover the old hawse pipe hole. I will fill this hole with epoxy and cloth, but since it will be covered I won't have to make it pretty and paint the filled area.
- It will raise the entire assembly up another 1/2" and make the vertical angle to the bow roller more fair.
I used the carboard template to cut out the shape of the G-10 plate and then rounded over the top edges with the same 3/8" roundover bit. I gave it a rough sanding and then epoxied the molded part in the same orientation that I marked with the gasket template. After the full assembly cured, I used the drill and holesaw cuts on the molded part as the template to cut out the holes on the plate.
I was happy to find that my measurements were spot on and was able to dry fit the windlass on the part without any modifications.
After a thorough sanding with 80 -> 150 grit sandpaper I primed the assembly and followed up with a few initial coats of 1 part topside paint. I won't do the final painting until its fully epoxied onto the boat, but I wanted to get some of it done so I can just apply a few finish coats once it's on the boat.
I'm hoping we will start to get some warmer weather in the next week so I can start working on prepping the deck for install. Think spring!
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| The red are the sharpie marks I used to trace the template onto the 1708 biaxial cloth |
