Kevlar inlay VS glassed-in wood stringers

[fox88gt]

Hi everyone,

You guys are probably tired of me asking questions about my upcoming Dumas Scarab project. But this one will probably be simple for those who have build a large mono before. I am concerned about the overall weight of the boat when its done. My initial estimates are saying this boat could weigh 20lbs or more! To that end, I'm considering a kevlar inlay in the boat instead of going with the wood stringers and fiberglass that came with the kit. Will this offset some of the weight? Can I get away without the big wood stringers? Seeing as I'm not mounting a big nitro or gas engine in it, I wont really need the big stringers if I can get the hull strength with the kevlar.

Opinions are greatly appreciated!

Jeff

Also, any guesses on a cost to have this done would be appreciated too.

[Fluid]

First, Kevlar would not be my choice for strengthening a big mono. Carbon fiber provides the stiffness that the lack of wood stringers leaves. But IMO you are better off with the wood. One, you already have it. Two, it provides a much better mounting for the motor and packs. Three, it gives all the hull strength needed.

I would not worry about the extra pound or two. Twenty pounds is not too much for such a large mono. My first 10S cat (41") weighed 21 pounds and it performed very well. But, I had adequate power aboard.

If I recall correctly you were planning on using twin 36mm motors on 6S? IMO that is a very bad idea. No one in the previous thread had any experience with a big mono on little twins. Lots of BAD recommendations there. Good luck to you!



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[Rocstar]

Go with the stringers. My 59" mono weight in at 32lbs with batteries. I didn't use rails, BUT it was carbon fiber reinforced and had a bulk head, cf battery tray, and aluminum twin motor mount that gave the hull strength. I agree with Fluid on the motors. Not sure what your speed goals are but I am sure 36 series motors will leave you disappointed.

http://forums.offshoreelectrics.com/...uot&highlight=

[fox88gt]

Thanks for the replies guys. I'm glad to hear you guys think the wood stringers will do the job, that'll save a few dollars on the build and I'm looking forward to doing some glass work anyway:)

In regards to the motors, I have gone away from my first idea with the smaller motors. I have been using fastvee's Waverider Navaho 58" build as a guide for this build. His later vids show his boat running with these motors:
http://www.himodel.com/electric/HiMo...740PRO-4T.html It appears his is running very well with decent run time using these motors.

These are discontinued but I'm sure I can find a similar motor - unless you can direct me to a motor you think will work with twins on 6S each?

Jeff

[Rocstar]

If you're set outrunners and not looking for high speed, these from Fightercat will work.

http://fightercatracing.com/index.php?page=shop.product_details&flypage=flypage.tpl&product_id=125&category_id=11&option=com_virtuemart&Itemid=97

[fox88gt]

Thanks Joel, those motors and mounts are pure eye candy! Hoping for 40 MPH out of the Scarab. Not looking for a 60 mph speed demon, as I intend this to be a very scale build (upholstered seats, nav lights, backlit helm, throttle levers, cleats, rails, cupholders, scale driver, removable GoPro mount, etc). Good thing we have long winters in wisconsin!

Jeff