Joel's 25'' Radtek CF Mystic Twin

[Rocstar]

Getting started on this one. Motors, batteries and a few other items came in.
Installing TP 2935s with T120 ESCs (overkill, but the same size as the 60A & 90A).




Installing the hatch bolts. These will be countersunk so they can be tapped over.


Finished the motor mounts.



What it looks like with the TP 2935s and Dinogy 3s 2250mah batteries.

[Fella1340]

Great looking little boat. Going for twins is very cool. The pictures make the scale seem much larger, the TPs look like monsters in there. Looking forward to seeing this one built, should fit under the hatch in that big mono of yours!

[Rocstar]

should fit under the hatch in that big mono of yours!

[Fella1340]

The big mono, its incredible. Not to many high end mono builds out there. I will be starting a 50" mono soon and you saved me a whole bunch of thinking with the sf300 mounting. (I will try to be original). I love that boat, hope you plan on keeping it. Sorry, off topic. The radtek hull looks quite nice, great lines. Are you happy with it as recieved for fit and finish? Keep the build rolling, looks like you will have to be creative mounting everything inside. Doesnt look like fingers will be fitting in to many spots! Thats half the fun, the other half is cursing yourself.

[Rocstar]

The 59'' Outerlimits is sold and in good hands. This little Radtek hull has a nice finish, nothing needs to be done to it. It's small inside but laid out well with just enough room. The only issue if building a twin is the small area to mount the stingers. Nothing out there fits, but Keithbradley designed a set of stingers just for this hull (saved me the trouble). I should have them tomorrow.

[Fella1340]

I saw the drives on his site. Are they just mounted to the hull with 2 bolts at the stingers rear and
by design they come straight back in a "neutral" position. It didn't sound like they were adjustable in the description. I must be miswing something and look forward to seeing them. For all I know they don't neee adjustment! Nice touch with the beqrings to.

[iridebikes247]

looks good, how are the batteries going to be mounted btw?

[Rocstar]

@Fella..The're not adjustable. The idea is the flat bottom will add lift and hopefully help keep the hull flying level. If needed, I could remove some material where the stinger mounts to change the angle.

@Mike..Dual lock Velcro will keep the batteries from moving plus I wedge pool noodles on top to keep them from coming loose during a hard smack!

[rickwess]

Just the thought of trying to squeeze my hands in that hatch makes me squirm. It's going to look nice.

[Fella1340]

I hope the stingers work out well and it flies like a rocket across the lake! Without seeing it qnd the unlikely need to lower them arises could you drill and tap/weld or even epoxy (into drilled hole) a piece of 3 or 4mm rod at an accessible point inside the hull ending up with a threaded piece through the hull attached to the stinger and make adjustments from there? It looks like they sit flush to the hull, any way of squeezing a few mm out when mmounting instead of sitting flush (thats how it looks in the very vague photo ans sparse info given. Its reqlly easy to speculate about something I havent seen but if even 2 plus mm were available it would be worrh it to add a throufh hull adjuster.it xoule be juwt the thing it needs wirh the added bonus of being veey cool. I had to mention because I have never heard of a cat wirh no adjustment. Put the drives to the Beltsander or milling machine if neee be. a nut on each side epoxied inside the hull, you could use a nice cqp bolt for adjustment wirh qnother nut for locking things up. Include in your build thread. I would almost consider running the stuffing tube out as far as the sringer would have been, use a few pieces of next size up tube to strengthen thngs up, maybe a piece of polished out aluminum k&s tube for nice finish. find a lock collar to sliee over and use the throuth hull adjustment attached to collqr. I cqnt see to type I am so tiree. I will drop this adjustment business to. I just thought it would be very cool. Thinking bqck the lock collqr on tube would not work as it would drag rhrough the water. A soldering iron with q piece attached topside of tube thougb..... Ok I am stopping. Sorry, I hope you dont mind. Just can't imagine one without being able to raise up qnd run loose. goodluck with it and I will follow it a lot quieter from now on. Get buiilding!

[properchopper]

Hi Joel,

It's raining, I'm waiting, bored, on a new project hull to arrive, so contrary to my aversion to joust with the theorists I'll jump in and give you my seat-of-the pants take on the stinger mounting to confirm that you have them correctly mounted. In fact when I first saw them I was blown away with how brilliant they were. Quite amazing, actually. And given that I'm absolutely sure that your rig will be quite ballistic, the angle they're mounted is just fine. Here's why, although I'm sure you're aware of all this but just to reinforce your decision :

Tunnel boats, by virtue of the tunnel aerodynamics pack air and create lift. Tuning the boat to stay on the water at high speeds needs to be done by balancing the combined effects of aero lift, prop lift, CG, and strut angle. And (please forgive this shameless name-drop) the fastest FE Cat hulls in the Country are all in my Club and to the best of my knowledge the struts are all neutrally set.
The only tunnel I have where I mess with strut angle is my P-Ltd oval boat. Because of it's moderate oval-rig speed (which creates zero, if any aero lift) I use strut up-angle to lift the hull under power in the straightaways to reduce drag. Works like a champ.
My SAW tunnel has zero strut angle and the well-designed stepped sponsons air the hull out nicely. I adjust CG to balance the running attitude underway with consideration to the lift created by my ultra-bizarro SAW prop.

The 25" Mystic, at the speeds you'll be reaching, wont need any up-angle to get the hull aired out, nor will it need any down-angle (which plants the nose at the expense of lifting the stern). Straight is Great. I was with Radik during the first test(s) of the hull. I think you saw the video. With some attention to CG, this hull will rock. My plans include one for next year's SAWs as well (single motor - rulz is rulz).

I could go on. It's still crappy outside. I think I'll eat some worms.

Later,

CT

[Fella1340]

propper chopper,thanks for clearing that up for me. Its nice to get solid information that backs up your statement. I have no problem being wrong especially when someone takes the time so I can understand the rational behind why this is being done. I was confused by it because Keith bradely isnt going to all the trouble of making them if they.werent solid performers. He doesnt put his name on anything that is Crap thats for sure. At the same time the top guys are going to the trouble and expense of using click drives on the top performing cats and praisng the merits of using them. If a neutral drive position is the common setting for running fast why bother with the click drives in the first place? Is the money being spent because they hold the drive in a neutral position well? what qbout adjusting drives t suit condtions for sport running? I feel like I am missing something still. Unless the 25" radtek is only being run SAW it would seem the boat will be at a disadvantage running in different conditions. Then around I go again. Sorry for taking up your spqce Joel on this issue. I really want to have a solid understanding on this. Lets see some more of the build!

[Rocstar]

Adjustability is a nice option. However, of the twin SAW boats I have built, the stingers stayed at neutral except once. And I'm not entirely sure I needed to adjust them. Now these were all cats with "ride pads" and not of a dihedral design. This little Mystic is being built for one purpose....to go as fast as possible. When I saw that Keith had a similar idea to what I wanted to do, I figured I could't far off base. The LIMITED amount of real estate makes options a bit difficult. The main challenge will be to keep the hull on the water at high speeds. I think the flat bottom stingers will help. This picture gives you an idea of the amount of room we're working with.

[Rocstar]

Here are the stingers mounted.






The bigger the props the faster....Right?

[properchopper]

Our single motor rigs like an extra blade to plane off quicker :

https://www.youtube.com/watch?v=JgRzweFct0M:thumbup: