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.....

http://i218.photobucket.com/albums/cc243/ltzguy/DF4BA521-4695-4641-BC02-8F722DD5BA29.jpg (http://s218.photobucket.com/user/ltzguy/media/DF4BA521-4695-4641-BC02-8F722DD5BA29.jpg.html)


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

http://i218.photobucket.com/albums/cc243/ltzguy/99B749F6-2FCE-4761-9668-8CE3E65B1F63.jpg (http://s218.photobucket.com/user/ltzguy/media/99B749F6-2FCE-4761-9668-8CE3E65B1F63.jpg.html)

http://i218.photobucket.com/albums/cc243/ltzguy/C49D2159-880E-493E-8148-1B01BE57E6BF.jpg (http://s218.photobucket.com/user/ltzguy/media/C49D2159-880E-493E-8148-1B01BE57E6BF.jpg.html)

[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.


http://i218.photobucket.com/albums/cc243/ltzguy/A681CE9A-3E64-48BC-9E23-B7A25893E182.jpg (http://s218.photobucket.com/user/ltzguy/media/A681CE9A-3E64-48BC-9E23-B7A25893E182.jpg.html)


Epoxy laid. Looks pretty good!

http://i218.photobucket.com/albums/cc243/ltzguy/11652C31-F4F8-4EEB-95F7-5FC7CE09964F.jpg (http://s218.photobucket.com/user/ltzguy/media/11652C31-F4F8-4EEB-95F7-5FC7CE09964F.jpg.html)

Very close to carbon


http://i218.photobucket.com/albums/cc243/ltzguy/88450607-172E-49B3-AC91-658C3BBD5E38.jpg (http://s218.photobucket.com/user/ltzguy/media/88450607-172E-49B3-AC91-658C3BBD5E38.jpg.html)

[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


http://i218.photobucket.com/albums/cc243/ltzguy/ECEE20B1-FC34-4933-88B8-65E5D4931368.jpg (http://s218.photobucket.com/user/ltzguy/media/ECEE20B1-FC34-4933-88B8-65E5D4931368.jpg.html)

[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.


http://i218.photobucket.com/albums/cc243/ltzguy/BA312545-56CF-4B06-9C43-8A6E464CC93E.jpg (http://s218.photobucket.com/user/ltzguy/media/BA312545-56CF-4B06-9C43-8A6E464CC93E.jpg.html)

Here's where the drive tube goes in.

http://i218.photobucket.com/albums/cc243/ltzguy/C3018033-B71D-4E49-A871-2588DE25F60A.jpg (http://s218.photobucket.com/user/ltzguy/media/C3018033-B71D-4E49-A871-2588DE25F60A.jpg.html)

[shua]

Looking Awesome!! Love the innovation

[kfxguy]

Time to mount the plate and do the stuffing tube


http://i218.photobucket.com/albums/cc243/ltzguy/8EBF0E57-1D55-4E03-84B0-8E3323C9062C.jpg (http://s218.photobucket.com/user/ltzguy/media/8EBF0E57-1D55-4E03-84B0-8E3323C9062C.jpg.html)

And after peeling the tape


http://i218.photobucket.com/albums/cc243/ltzguy/44AD139E-5B0B-4F6E-BD24-271DE2562428.jpg (http://s218.photobucket.com/user/ltzguy/media/44AD139E-5B0B-4F6E-BD24-271DE2562428.jpg.html)

[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?


http://i218.photobucket.com/albums/cc243/ltzguy/27817E50-36D0-4866-9078-085A6F4CD759.jpg (http://s218.photobucket.com/user/ltzguy/media/27817E50-36D0-4866-9078-085A6F4CD759.jpg.html)

[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


http://i218.photobucket.com/albums/cc243/ltzguy/4FC4208D-3FB9-4ED2-81BC-2D391C5053EB_1.jpg (http://s218.photobucket.com/user/ltzguy/media/4FC4208D-3FB9-4ED2-81BC-2D391C5053EB_1.jpg.html)

[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.


http://i218.photobucket.com/albums/cc243/ltzguy/B2B44F90-4209-43B0-B538-5827E097BEE5_1.jpg (http://s218.photobucket.com/user/ltzguy/media/B2B44F90-4209-43B0-B538-5827E097BEE5_1.jpg.html)

[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.


http://i218.photobucket.com/albums/cc243/ltzguy/234B3E6D-43EF-4C4E-8035-00BD4114EF3A.jpg (http://s218.photobucket.com/user/ltzguy/media/234B3E6D-43EF-4C4E-8035-00BD4114EF3A.jpg.html)

[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.


http://i218.photobucket.com/albums/cc243/ltzguy/AB26CD53-E33B-4FA4-AEE6-498E4F3E54C3.jpg (http://s218.photobucket.com/user/ltzguy/media/AB26CD53-E33B-4FA4-AEE6-498E4F3E54C3.jpg.html)


http://i218.photobucket.com/albums/cc243/ltzguy/16B8B7B5-3AF1-4FDD-8911-323299CEBAB5.jpg (http://s218.photobucket.com/user/ltzguy/media/16B8B7B5-3AF1-4FDD-8911-323299CEBAB5.jpg.html)

[Beaux]

Man that's nice.

[grsboats]

Travis looking really good and pm sent.Gill

[kfxguy]

Travis looking really good and pm sent.Gill

Thx Gil and beaux.


I got brave tonight and started drilling the hull. I hate drilling. You don't have much margin for error and I like all my stuff to be lined up perfect.

http://i218.photobucket.com/albums/cc243/ltzguy/9B659704-D60F-482C-B6CB-E706036616DB.jpg (http://s218.photobucket.com/user/ltzguy/media/9B659704-D60F-482C-B6CB-E706036616DB.jpg.html)


And the final. It's to the .001 lined up according to my caliper. I roughed up the part of the tube that's in the hull and put a little fast epoxy on it to hold in place. Tomorrow night I'll epoxy from the inside.


http://i218.photobucket.com/albums/cc243/ltzguy/62BA6BB9-80EF-4BA6-BDA6-40C4109F3796.jpg (http://s218.photobucket.com/user/ltzguy/media/62BA6BB9-80EF-4BA6-BDA6-40C4109F3796.jpg.html)


Something that happened by mistake but was another blessing in disguise is I drilled through on sponson in the rear. I was adamant about not running the booms through the sponsons like I've seen on other builds. Just didn't like it. However one being drilled through came in handy with lining stuff up. See if you can guess what this will do.


http://i218.photobucket.com/albums/cc243/ltzguy/7CD0EEE1-A3C0-4CCD-9586-4DDB9B7798B5.jpg (http://s218.photobucket.com/user/ltzguy/media/7CD0EEE1-A3C0-4CCD-9586-4DDB9B7798B5.jpg.html)

[CornelP]

Very nice job!
The ""rear boom tube center marker" is a very good and safe way to install and align the booms. Even with that, I usually drill the holes a hair bigger than the tubes: this will allow for proper alignment on the table. Also, remember for next time that it is easier to align the booms and sponsons before glueing the tubes.
I align everything on a table, tack with CA and then epoxy everything (make sure the sponson inner wall is perpendicular to the table). To add a bit more strength, I make some carbon washers that go around the aluminium tube and get glued on the sponson or tub: it will get you more surface area.
Attached is a hydro that we make, ultralight, so all the walls are very thin (it gets under 1kg RTR with a 3S 4800 Naviga legal battery), to get an idea on the fixing.
On the last 3-4 riggers I did not split the aluminium tube anymore, as I fix them with adhesive lined heat shrink tube... I hate the collets.

PS: I do not know if I already gave you this link: http://astecmodels.myfreeforum.org/Data_of_ETTI_Hydro1_Demon__about53.html It is a build by Dee from Etti

[kfxguy]

So I got this puppy done. It turned out pretty nice for my first rigger. Made a maiden today with it and ran three packs through it. Flawless. Ran so good I didn't even adjust anything.


Here's the layout. Battery all the way in the front.


http://i218.photobucket.com/albums/cc243/ltzguy/9484CB91-8F8D-4230-9971-43A741D29035_1.jpg (http://s218.photobucket.com/user/ltzguy/media/9484CB91-8F8D-4230-9971-43A741D29035_1.jpg.html)

[kfxguy]

Maiden on 3s



http://www.youtube.com/watch?v=oPpDU02eNZs

[kfxguy]

And on 4s. This was with an x438 prop



http://www.youtube.com/watch?v=ZoRdoUG8UuM

[kfxguy]

I did get a gps reading on it later that day. I had changed props which it went slower but run much smoother. It did 51.2 but it needs some dialing in. Should easily go 70 dialed in.

[grsboats]

Great Travis now its time to go up with props.

[kfxguy]

Great Travis now its time to go up with props.

Yep. This weekend. I gotta change the motor and motor bullets. I'm waiting on connectors to come in. What I have on there isn't really what I wanted so I'm swapping to 5.5mm buckets and a tp motor with higher kv for 3s. 4s is too much weight for this boat I think.

[kfxguy]

Weighed it. Weighs 3.4lbs ready to go with a 4s 3100mah in it.

[Brushless55]

Pretty slick man!

[kfxguy]

Here's a newer video from last Sunday. I made some changes and it went almost 60 at this point. It's swelling the battery right now so I need to rethink my power soup and maybe prop. The motor and esc don't even get warm so I think I'm just not running enough mah. I'm thinking about going down to 3s with a higher kv tp motor and 1000 more mah.



https://youtu.be/lR-n-qUixFQ