Darin's 25" Radtek Mystic N2 Build

[Darin Jordan]

OK... got a little more done.

Prepping and primering the plug came out great. Pulling the mold... well, let's just say I am still in the figuring-it-out phase of that.

Mold turned out OK, but some of the primer pulled off the plug, so I had to spend some time doing some refinishing to the mold surface.

I think I have it cleaned up enough to make a part, so I'll try laying that up tonight.

I'll get some shots of the motor setting in place tonight as well. This motor well is going to work really nicely, I think.

[gsbuickman]

Nice Darin'

I generally run 4-5s, but small 2s floaters are fun too ...

[Darin Jordan]

Nice Darin'

I generally run 4-5s, but small 2s floaters are fun too ...

I think this would certainly be easier to make happen using a pair of motors, but the rules for N2 don't allow it.

Small boats travel nicely!

And, frankly, I find it an incredible challenge to get real speeds from very small power systems... EVERYTHING has to be ideal, because you can't just throw more power at it.

[gsbuickman]

I understand how that can be a challenge. It goes back to the old argument of high rpm & small prop v's lower power & bigger prop.

I've got a Lil' 19" rigger project I am sitting on that I need to finish. Since its a small tub with a small footprint outback, I want to set it up with a 5000mah 2s1p, 2200kv speedgems motor, mini servo and a traxxas outdrive setup. It should be interesting for sure if I get r' figured out ......

[Darin Jordan]

Prepped the mold by waxing 3 times with mold release wax, then putting on a layer of PVA.

I used my airbrush to spray on a coat of white Polyester primer.

Once that dried, I did the layup using 1 3/4oz layer of fine woven fiberglass, and 2 5.5oz layers of 2x2 twill carbon fiber.

Bagged it up and did my best to get the bagging to conform to the pockets.

Placed in my home-grown autoclave (BIG cardboard box with ceramic heater...) and let this cure for 7 hours overnight at 125-degrees.

Pulled everything out this morning, but will let it sit for the day and will hopefully release a good part tonight.

A lot of work for probably ONE part, but I wanted to at least attempt to do this right.

One thing that is obvious... I use WAY too much epoxy. I really need to get better at wetting this stuff out without DRENCHING it. Epoxy is expensive, and this ends up wasting a lot of material.

[kfxguy]

Darin, I'm not sure if your setup to heat treat, so I'll make you an offer. Free of charge. My father in law makes really nice knives and has a true heat treat setup. Once you get your blade made, you can send to me and I can get it heat treated for you. Just a thought.

[keithbradley]

One thing that is obvious... I use WAY too much epoxy. I really need to get better at wetting this stuff out without DRENCHING it. Epoxy is expensive, and this ends up wasting a lot of material.

Darin- Try weighing the cloth you're going to use, and then mixing an equal weight of resin/hardener mixture. Use that amount to wet out the fabric. If you put breather cloth and pull vacuum from the top side you can get a lot of the excess resin you use out, which will make your part much lighter and stronger.

[Darin Jordan]

Darin- Try weighing the cloth you're going to use, and then mixing an equal weight of resin/hardener mixture. Use that amount to wet out the fabric. If you put breather cloth and pull vacuum from the top side you can get a lot of the excess resin you use out, which will make your part much lighter and stronger.

Thanks for the tip, Keith. Brian told me the same thing. Guess I need to pick up a few more pieces of shop equipment (good small scale, etc.)

[Darin Jordan]

Made a LOT of progress tonight. I'm starting to get excited.

First, the part came out of the mold beautifully. Mold isn't perfect, so either is the part, but it's really decent and will totally be functional.

After some cleanup and trimming, I made a pattern of the part, leaving plenty of overlap, located, and trimmed out the hole in the tunnel with a Dremel Cutoff wheel.

I fabbed up an aluminum engine mount plate that drops down into the well.

This part is only made up of two layers of carbon, so it's a little thin. To make sure the motor stays put, I used an aluminum doubler (.125" motor mount and double) and sandwiched everything together using JB Weld. Motor mounts using the top and bottom screw, the bottom screw being under the hull. Two additional screws were added to hold the mount in place. Once it all dries, I'll comment on how solid it is!

[Darin Jordan]

I was a little worried that the well would hang down to deep, but looking at it fitted and temporarily in place, I think this will work perfectly. Might even help as speeds increase.

Driveline installation should be pretty straight forward.

Tomorrow, I'll laminate the motor well in place and fair it in in the tunnel area...

The hull, at this point, weighs in at 1lbs 9.2oz, which is a little heavier than I'd have liked. One thing for certain, however, is that this boat will take some pretty serious "SAW" abuse! Being a Cat, it's likely to get air a few times in the quest for those bigger numbers.

Because of current NAMBA rules, N2 Cat is only allowed a single motor, so at least I won't be fighting the prop balancing issues that the twins have to resolve.

One smaller prop, turning insane RPMs, with a huge ESC... and hopefully with decent enough handling to go straight for a couple of 330ft passes. That's the plan!

If this hull performs as I'm hoping it will, I may talk to Keith Bradley about laying one up for me that is SICK light, so I can build another for M2 (1-Cell) Cat... Would be basically the same power system with a different KV and an appropriate 1-cell ESC.

[Darin Jordan]

Laminated the motor mount assembly into the hull today.

First set it in place, lining up the centerline, and then used medium thickness CA around the perimeter to hold in place.

Using a pattern I had made, I cut an overlapping piece of 5.5oz Carbon and used Super 77 to hold it into place. Then I wetted it out with the epoxy.

Once it had kicked off and was on it's way to curing, I turned over the hull, set the tunnel level, and filled the gap underneath with epoxy. That's all curing right now.

[srislash]

I like this idea here Darin. You don't think it will compress too much air?

[keithbradley]

Well, it definitely looks cool!

[kfxguy]

Nice work!

[Shooter]

Man, that is cool. Great idea. Getting that weight low should help all around. Might want to put a sponge in there as any water in the hull will migrate to the 'well' (speaking from experience)... he he he....