My first rigger build (Etti Demon)

[kfxguy]

After messing around with the tfl arrow for a bit I got hooked on riggers. I always had a preconceived notion about them being super easy to make go fast. Not really the case. Actually the opposite as they take some tuning to get right. Anyways I loved the look of this rigger and I ended up with two of them. I'm building this first one for my buddy Joshua (Shua) and it's turning out so nice that I had to post a mini build thread on it. We won't be racing them, pretty much just running for our own pleasure so the weight isn't as important. It's still going to be light but not as light as if build one to race.

First motor we are trying is a castle 1415 2400kv on 3s and 4s. I've got mid 60's with a plastic hull mono with one of these motors so I think 70+ is doable. Sf120 esc (rebranded as a turnigy 120). I epoxy coated them and added an additional cooling tube to the other set of fets to try and keep it cool. I have a couple differ kv tp 3640's to try also. These little motors are mini beasts so I'm anxious to try them out. Servo will be a hitec 8775mg in both of them. Here's some pics......

These sponsons are a work of art. A carbon fiber lovers dream.....




Center tub with an idea on layout. It does come with a nice CNC cut carbon fiber motor mount.

[kfxguy]

I'm picky and I don't like a nasty boat. I could have skipped this step but that's not me. So I did an inlay. Not just any ole inlay however. I used black light weight fiberglass. Why fiberglass? Well one its light, two...if it gets flipped over then the radio will still get signal to it. Cool thing about some riggers is the prop still touches the water upside down and I've been able to drive it back in.


Before epoxy. Looks quite like carbon.





Epoxy laid. Looks pretty good!



Very close to carbon

[kfxguy]

I wanted to get an idea of weight. I think I forgot the boom tubes, receiver, flex and boom tube clips. Accounting to epoxy and everything it should come in under 3.5lbs. The esc I ended up with is a little lighter however

[kfxguy]

I had a dilemma. I needed a low profile servo mount and a way to seal off the ramp and make a wet well for the strut. I like adjustability no matter what as long as I can do something about it.




Here's where the drive tube goes in.

[shua]

Looking Awesome!! Love the innovation

[kfxguy]

Time to mount the plate and do the stuffing tube




And after peeling the tape

[dmitry100]

kfxguy: How do the struts adjust if the stuffing tube is glued in a fixed position like that?

[kfxguy]

I got two of each collets because I haven't decided which way I'm going. Pros and cons for each. The set screw one is easier to fool with in a tight spot and lighter but may not grab as good. What you guys think?

[kfxguy]

kfxguy: How do the struts adjust if the stuffing tube is glued in a fixed position like that?

Because that big hole to see in the rear (wet well exit) allows the tube some movement because the brass tube is affixed further forward in the floor plate. Think of how a cat is and its the same way essentially but just enclosed in the wet well. I made it smooth in there so it keeps no water residue either.

[kfxguy]

I think the layout will end up being something like this

[kfxguy]

I used a beefy steering rod. I don't like flex. I always end up going faster than I initially plan so if it goes past 70mph then steering slack and flex becomes a factor. See that beefy rod in the photo....notice I used a plastic servo horn. Two reasons. One is I couldn't find a billet one short enough although I could shorten one and 2) if it has a hard crash then something needs to give.

[kfxguy]

Now it's time for something a little different. Gotta relocate to my other shop where my mini mill is. I have to slot the boom tubes so the clamps will be able to squeeze the tubes and hold them in place. I could have just used a dremel and a cutoff wheel but have you ever tried to cut perfectly straight slots the same length with that? Yea it don't turn out well. This is more work but it's a nicer outcome.

[kfxguy]

I put this build off for quite a while or should I say I started it, all excited but then put it to the side. I was trying to find ways to mount the aluminum tubes in the sponsons securely. There's no way to get inside the sponsons so I had no idea what I was going to do. No build thread I've come across discussed this so I come up with my own method which should hold well.

First I made sure once I drilled my holes that everything lined up. It didn't. Following the template that came with the boat still resulted in the front holes being drilled over an 1/8" off from each other. Boy was I pissed off. I was about to order another set of sponsons but I used this to my advantage. I enlarged the holes a little to get them to line up but in doing that it allowed me more access to put more epoxy to the outside for a stronger bond. So on to the process....

I marked each aluminum tube where it came out the sponson. Then chucked each one up in the drill and spun it while running rough sand paper on it for a better bite being carful not to get unsightly sanding marks past the mark I made showing me what part sticks out the sponsons. Then I used jb quick, put a glob on the end that goes inside, some also at the other end that touches the outside of the sponson. Then a small blob inside sponson and right inside the drilled hole. You gotta do this quick because jb quick sets up in about 4 minutes. Once I got epoxy in all four spots I slid the tube in and used a square to make sure it was straight. I held it till it set. I did one at a time. The rear is where I started because those lined up perfectly. Remember the front ones were off. I found some brass tubing to lined them up and use a tool to line up the front.

[Beaux]

Man that's nice.

[grsboats]

Travis looking really good and pm sent.Gill