CNC Plans not Included

Doesn't work like that Jorge. It has to be in a female former so that the fibers are being stretched outwards against the mold surface instead of crimped inwards and you end up with wrinkles and poor fiber volume fraction. I've a lot of reading on this, female is the only way to go.

The sheet metal should be supported by longitudinal battens inside the frames spaced closely to get rid of most of the waviness. Again this is for a one off, if building several you could justify a bit more of a substantial mold such a a 2 piece mold with a vacuum bag sleeve inside...

 

Ah okay. ... Well, then battens would do it. Love it!

I don't know the material but it seems you could edge butt, tacky tape, then duct tape over that and fairing would be minimal.

 

remember the uni!

IMHO, best to lay and bag the assembly - uni tapes (cheaper than cloth) and biaxial - in female half molds as any bulk waviness is inside the mast.
using half female molds also allows you to reinforce attachment points easily.
layup in 2 halves, run conduit and mast track, join, fair if necessary, and layup fine cloth with vacuum bagging against the mast itself.
big question, do you want to gel coat the female mold or paint after joining?

are you going to have a professional design the layup schedule? this was on the web and is for a wing mast with plywood base so your schedule would be different -- from Spoonberg and just for reference

 

Making a ply mandrel and wet laminating then vacuum bagging over it (multiple times) is a huge amount of work. Try the method I described on previous page and you'll see how quick and easy it is, just make a 1m long section to test.

I'd hire a composite engineer to design it- although it wouldn't be too difficult to figure it out, I have lam schedules for similar masts but the RM of every boat is different so it should be checked.

I'd opt for spreader less mast with upper and lower shrouds coming back to the same chain plate. No diamonds or any other junk, single forestay. All synthetic fiber shrouds. It's all DIY friendly and quick to setup- check out Colligo marine website to see how it works. We used this on our last cat and it's so simple and lightweight. I think it even works out cheaper than stainless at current prices.

 

Groper, how do you feel about unstayed masts?

 

I considered it, there's pros and cons like everything else. I can show you a few well built cats which use twin unstated wing masts if you haven't seen them?

Down side is added cost, reduced living space where the masts intrude under the deck etc... twin unstayed masts cost a bomb, cost was the biggest downside for me, but resale considerations being less ' typical' I think it would lead to a more difficult job selling it...

 

Thanks, scratch that option. Like the idea of less cabling but not at the expense of lost room and value.

 

I just read this

The SIG45 is delivered with a pair of Yanmar 29hp diesels, making manoeuvres in marinas very easy. Cruising speed at 2200 revs is 8 knots.

We also offer an optional diesel electric system, which provides ultra-quiet motoring, and significant fuel efficiency benefits over conventional diesels.
The system comprises a diesel generator and two direct drive electric motors. The system is as much as 15-20% more efficient than conventional diesels. This is in part because electrical transmission losses are less than mechanical transmission losses, and in part because the diesel generator is able to run closer to its optimum rev rate for more of the time. From a weight perspective, conventional diesels and the hybrid system are similar. However, compared with a twin diesels and a genset, the hybrid system is considerably lighter.

Also my friend Mario in Croatia just pointed out this new battery by Tesla - https://electrek.co/2016/10/28/tesl...-in-home-energy-storage-14-kwh-inverter-5500/

It's more powerful than the Johnson Controls version Torqeedo sells, has a one year longer warranty (10 years) and this is the biggie it's about 1/3 the cost. That is a pretty big deal.

 

Install regular diesels that have 1/3 the power to make it have equal sustained performance to their system then tell me how much less fuel thier system uses and how much lighter it is.

That is an outright lie the likes of which I have mentioned previously in this thread . A marine transmission might have 5% loss. The electro mechanical conversion probably wastes 20% at the gen set, 20% at the elec motor and if they size the cable well they might loose 4%. So there is your big gain over the 5% transmission loss they are probably referring to in the fine print.

So much crap spewing from this industry, and I work in it.

 

I don't know about the efficiency, that statement comes from Lebreton, not me.

What I like is the weight comparison. I don't want Groper passing me with his lightweight outboards!! LOL

 

It does not matter who made the statement. The matter is it is false and misleading advertising. I suspect it came directly from the oceanvolt or some such. The guys who say thier "10 kW Oceanvolt motor easily outperforms and is more power ful than a 30 hp diesel." Spelling powerful incorrectly to avoid litigation.

The weight comparison is against diesels with 3 times the sustained power capability. More unfair advertising.

More talk here if you don't want this thread polluted with EV drivel. http://www.boatdesign.net/forums/propulsion/electric-horses-really-bigger-55435.html

 

Hybrid Propulsion

You might have a look thru this subject thread on another forum,...rather lengthy and a lot of bull at times. But inter-dispersed there are some knowledgeable participates.
http://www.cruisersforum.com/forums/f48/oceanvolt-hybrid-motor-172720.html

And here is another subject thread right on this forum (I've not had a chance to look thru this one)
http://www.boatdesign.net/forums/propulsion/electric-horses-really-bigger-55435.html

 

CF is has too many idiots and you will be dumber after reading that thread, but I agree some knowledgeable people. Most would not last 5 posts on bd.net. Take a look at our own Daquiris posts toward the end of the thread I linked to see the graphs he made which utterly destroy the BS in a way anyone can understand. Well most CF posters probably wouldn't.

This links to the best post on the whole internet comparing electric and diesel "power" that I have seen rather than just the start of the thread. Examine the graphs he went out of his way to make. Well worth his time, and anyone elses that looks at it.

http://www.boatdesign.net/forums/propulsion/electric-horses-really-bigger-55435-3.html#post772775

 

The price point of the tesla power wall 2 is quite remarkable. I have installed a solar system for an off grid farm house and I used a lithium battery I built from Winston cells at 15.3kwh. The cells alone cost me about $9000aud. The inverter charger was another $7000 but it was a high quality unit with slightly higher output. If the power wall 2 has the same functionality then it really changes things in terms of cost.

For example in marine use, you could put one of these in each hull and run a pair of electric motors off it. It will also handle your house AC loads and provide your house battery storage of 28kwh. All this for $11k usd is excellent. You only need a single genset as a charger / hybrid power source. Again however, the problem arises if you need to motor for a long distance your propulsion energy would be essentially limited to your genset output. It wouldn't be cost effective carry around or fit a huge 20kva for example so your stuck with low power for long motoring stretches.

It's all way too much for a lightweight performance cat tho- honestly Jorge- you can't beat a pair of gas outboards no matter which way you look at it. Have zero diesel engines or gensets. Just 1 of the power wall2 and some solar and wind is all you need. Very simple and effective and lightweight, with very little lost volume in the hull and no noise ( except motoring of course)