"Vintage" Raptor Rigger Build

[Darin Jordan]

I've had the pieces laying around for a "vintage" (about 2-years old... ) Raptor N2-Hydro... This would have been "state of the art" when it was first designed... Now it's too small to effectively work in N2 Hydro...

However, I've decided to build it up for something a little bit more interesting... Going to build this one to use a ROAR legal 05 Can motor (Brushed or Brushless 1/10th scale motor) on 2S1P and use a standard RC Car controller (Losi or ???)... Should all fit well, and will be VERY light, so the performance might be interesting...

Might also test the idea of using a ROAR 05 motor with 1S1P...

My plan is to use this tub, and adapt a set of the JAE .12 sponsons to it, or something similiar... I'm also going to move the rear boom to allow more room for batteries...

This is a side project to give me something to work on while things are drying on the Raptor P-Spec Hydro I'm also working on...

[Darin Jordan]

Rather than using a continuous single piece for the bottom, I decided to modify the shape just slightly, and use a clean break like they did on the JAE .12. I fabbed the forward and aft bottom pieces from 1/32" ply, laying the grains across the tub, rather than lengh-wise. I think it's a little more expensive this way, because it's hard to find ply in sizes wide enough usually to make pieces that long, but if it's in a couple of pieces, like this one is, it works out.

[Darin Jordan]

Also glued on an aft deck piece, and a doubler for the joint of the two bottom pieces at the back of the hull (like I said, my material wasn't wide enough to do cross-grain the whole length, so I had to do it in multiple pieces....) Both pieces are 1/64" ply. All glueing to this point is being done with FLAG laminating epoxy (Medium). Good strong stuff...

[kevakov]

Looks like fun !! Riggers are fun to build, I'm waiting for the JAE21 FE kit to come out soon, also have another Matrix Ultimate kit that is new in the box, not sure if that one is going to be built. If I do build the Matrix Ultimate the rear boom is going back some so the lipo's can sit on the floor, and I would change the sponsons some. Let us know how it runs!

[Darin Jordan]

Made a little more progress... Decided to wrap the bottom sheet up and around the nose piece, so I epoxied that and clamped in place.

I scaled down a JAE .21 sponson drawing to fit the 21 3/8" tub length I have here. I'm using 3/32" ply for the inside of the right sponson. For the outside of both sponsons, I'm using 3/32" balsa, laminated on the outside with 1/32" ply. For the inside of the left sponson, I'm using 3/32" balsa, laminated on the inside with 1/64" ply, and on the outside with 1/32" ply.

WHY I'm doing all this laminating is simply that I want a rigid, but light surface here, and also like the extra width of glueing area for the ride pads and top pieces. Also gives a little additional surface to help secure the booms.

With all the rough pieces cut, I mixed some laminating epoxy and put the pieces together, then set them in a "press" while the glue sets. I used the extra epoxy I mixed to put a coat on the inside of the tub to seal it.

You can see a pic of the comparison of the original sponsons to the new JAE design. Quite a bit different, and the ride pads are in different locations in relation to the hull. SOOOOO.... I spent some time locating the new sponsons to the older hull design. I am setting them on this hull with the same relationship that they have to the original JAE .21 design. The ride pads will be about 15 3/8" from the transom, with a sponson depth of about 3/4", perhaps a tad more once the ride-pad surfaces are attached to the sponsons.

Using the templates on the side of the tub and taping them in place, you can see that this will be an interesting combination. The JAE tub is FLAT... top and bottom... This Raptor design has an airfoil shaped top surface, and the bottom is flat for a bit, but has a kick-up about 4" or so from the transom. We'll have to see how it works out.

[Darin Jordan]

Here are a couple more shots of how the sponsons and tub will fit together...

[Darin Jordan]

After the epoxy dried on the sponson laminations, I stacked them up, clamped them together, then used my belt sander to sand the stack down to match the lines on the drawing, which is glued to the template piece.

Before I glue these to the foam cores, I want to locate the sponson booms through all the pieces and also to the tub. I located them to the templates I worked with last night. I'm still working out the boom sizes, so once I know what the tub tube sizes will be, I'll drill all this up.

[Darin Jordan]

I'm going to use the original front boom hole in the tube to locate the forward boom, but I needed an idea of where the motor will go so I can locate the rear boom.

I decided to place the motor about 1" further back than I did in my previous Raptor Hydro. With the boom layout of these sponsons, there is a TON of room to move the batteries forward, so this should allow for plenty of room for the cells and whatever ESC I decide to use.

[Ub Hauled]

[Darin Jordan]

To drill the tube holes, I used my drill press, lining the hull up with some squaring blocks.... The drill bit wasn't quite long enough, so to complete the holes through the other side, I'm using an old tooling drill jig I have left over from my days as a Jig Fabricator... Using a 9/32" drill for the holes in the sponsons... I'll come back later and drill up the tub holes a size, and will be using .310 OD carbon tubes through the tub, flush with the sides, with .225 OD carbon for the actual booms... I have some collars on the way to hold it all in place. Still working out the details on how I'll secure the tubes into the sponsons, but I have an idea that I'll share once I get the sponsons complete...

[Darin Jordan]

Let's get these sponsons going...

With the outsides of the sponsons cut out, I used my bandsaw to prepare a couple of pieces of pink Dow Corning foam.... Make sure all sides are smooth and true and that the sides you will be glueing the sponson sides to are parallel, sanded smooth, and then wiped down so they are dust free.

I used my building board's endstop to line up the sides onto the foam. The rear part of the tops of these pieces are perfectly flat, so they lend themself to lining this package up. Once lined up, I clamped them in place.

Using a drill block and my 9/32" bit, I lined the block up with the previously drilled holes, and drilled through the foam.

I used a piece of carbon tubing to keep the parts aligned in the first hole while I drilled up the second.

[Darin Jordan]

Once the holes are dilled up and I verified the alignment, time to epoxy.

I layed everything out in order, and applied some FLAG Medium laminating epoxy to the inside of the wood pieces, placed them on the foam, and lined everything up with the carbon rods I used previously.

This epoxy takes overnight to dry, so I clamped everything down to the board, then carefully slid out the carbon rods and let it all dry overnight...

After removing from the clamps, I used my small bandsaw to trim away the excess.

[Darin Jordan]

Excess foam is trimmed away. Still need to use the belt sander to sand the foam down even with the sides. Haven't gotten that far yet, but I did do a quick test fit onto the tub to see what that profile is going to look like and how it's going to sit...

Looks good so far!

[j.m.]

That's a skinny rigger, something different for sure.

[Darin Jordan]

Sanded the foam down to meet the side templates and trued up the ride surfaces.

Used the original pattern to layout the turn fin holes. Drilled them up to 7/16", then used some hardwood dowls for the hardpoints. Timmed the dowls to be just a tad oversized, epoxied and pressed them in place, and clamped everything down to dry... I'll sand them down flush once they are dry.

[Darin Jordan]

That's a skinny rigger, something different for sure.

It's exactly 2" on the inside... wide enough for any 2S Lipo pack and motor combo... Should be interesting...

[j.m.]

I was actually referring to how you had the sponsons right up against the hull, but that too.

[Darin Jordan]

I was actually referring to how you had the sponsons right up against the hull, but that too.

OH... Hahahaha... Yah... just test fitting them to see the profile from the side... they'll be out about 12" apart once properely fitted...

[j.m.]

So how are the sides constructed?

Seeing that gave me the idea to use a honeycomb and 1/64 ply to make light and rigid sides. Im definitely digging the 'keep it light' ideology.

[Darin Jordan]

So how are the sides constructed?

Seeing that gave me the idea to use a honeycomb and 1/64 ply to make light and rigid sides. Im definitely digging the 'keep it light' ideology.

I'm not sure if he pioneered the idea or not, but this is Brian's technique of using light balsa laminated, in this case, with 1/64th inside and out... VERY stout, especially once it's all sealed, yet very light... I LOVE the honeycomb idea, just never been able to find any in the right size...

I do, however, have some very trick aircraft structural foam, like they use for stow-bin cores, etc... very light, very rigid when laminated... Hmmmmm...

[j.m.]

Very expensive, but worth it in some cases:
http://www.acp-composites.com/home.php?cat=256

[Darin Jordan]

Well... I've been tinkering some more on this build... Got the skins on the sponsons, and put some hardwood insterts in the areas where the booms pass through. The idea is to be able to hold the booms in with screws... Not sure if it's going to work the way I have it, however, so they'll get glued in otherwise.

Finished off the tops of the sponsons with some maple hardwood pieces. Should look nice when the finish is applied.

[Ctonez]

thank you very much for your build threads. Always very educational.

-Corey

[Darin Jordan]

The Sponsons are basically done... Tough to see from the pictures, but I've glued in some 4-40 inserts into the hardwood inserts UNDER the boom tubes. If it works out, the idea is to drill through the boom tubes and pass the screw threw them, into the inserts, to secure. If it doesn't work out, simple epoxy will be in order. Would be nice to be able to easily disassemble it, however. Here's hoping I got everything drilled up straight.

To line up the outter carbon sleaves, I left them in one piece, and glued them into both sponsons at the same time, with 1/2/3 blocks clamped between. This kept them nicely lined up.

Once everything was dry, I sanded the outsides flush and but the two sponsons apart.

A little test fitting shows everything is lining up nicely....

[Darin Jordan]

The boom tubes will pass through the tub through a second set of carbon tubes glued into the tub, and will be held on either side with aluminum collars on the outside of the tub. Found a cool source for smaller aluminum collars. Found some Heli main-shaft collars at Horizon Hobby with 5mm ID and two set screws. Drilled them out slightly, and they fit perfectly over the carbon tubes.



The holes for the tub tubes are slightly oversized. I am jigging up the assembly, getting the sponsons exactly where I want them, and will float the center tubes into place and glue, assuring perfectly alignment. Just not good enough to simply drill everything up and have it come out lined up perfectly, so this way works well for me.

Too tired tonight to get the glueing going, but will double-check the alignment tomorrow and hopefully apply the epoxy to the tub tubes.

[Darin Jordan]

OK, now that I'm done revising the N1 Mono, it's time to finish up this rigger.

I'm going to try to use this as an N1 Hydro... These sponsons may be a little heavy and might not have enough AoA, but I'm going to finish it up and make some ride-pads to adjust the AoA to my liking.

First step... Mount the motor. Then driveline and hardware. Should go quickly once I get the motor mounted.

Back to work...

[Ub Hauled]

Darin, what is the design for your hatch? how are you making it?

[Darin Jordan]

Darin, what is the design for your hatch? how are you making it?

Will be a piece of either 1/64th or 1/32" ply, with grain going perpendicular to the length of the boat, likely reinforced on the back side with some very light carbon or glass. I might break it up into 2 hatches, depending on how everything lays out. Would be nice to just have a hatch over the battery area, and a seperate one over the electronics. We'll see. Gotta try to keep it as light as possible.

[carlcisneros]

Darin;
make sure a SEAL the insides of the turn fin dowels after you run the screws or thread inserts into them!!!!!!!!!!!!!!!!!!!!!
this is very imortant.

Carl

[Darin Jordan]

Finally got some time to get back to tinkering on this....

Have the motor mount installed, driveline in place, added some rear shoes, started forming the hatch, epoxy coated the whole thing, and painted the sponsons.... Still have to install the rudder (waiting for my new Spektrum S3040 digital micro-servo to get here), and finish installing the bubble for the hatch...

Total weight so far... tub, as pictured, minus booms - 6oz Sponsons, minus booms - 1.9oz (left) and 2.1oz (right)