Now that the battling season is over I have decided to gut and modernize my Rivadavia. In the IRCWCC, the Rivadavia is a 5.5 unit, 28 second boat, 3 props, 1 rudder. I built this boat from 2009-2010 while I was in college in the basement of my fraternity. The hull was a Baden hull from Australia since the general dimensions were the same, which I modified to move the casement guns flush with the side of the hull. Due to low financial resources when I built it, it had all of the 'old' tech, to include poppets, stock motors, and lead acid batteries. I battled the boat from 2010 through 2012 when I was able, but the boat sat in my parents attic from 2013 to early 2016 while I lived away from the mainland. This was my primary boat for battling season this year, I made it to 6 events. The boat did OK, but it is time for a major refit. Here are some pictures. The gun arrangement I use is two stern sidemounts, then dual guns in the aft wing turret, angled at 15 degrees. I also have a bow sidemount installed, which goes with a second stern deck I have. The second stern deck, which is the original deck, has the traditional class 5 setup with a stern sidemount and dual stern guns in the aft-most turret. I verified the center of gravity of the boat for reference during the rebuild, at battle weight of 21lbs 4oz Here are the internals, which will be completely replaced (more or less). The water-resistant box held up for a while, unfortunately towards the end of the battling season the moisture in the box started taking out servos which caused some pond-side adjustments. Fortunately the gun servo's and the pump servo held out. I used two 4S, 13.2 V 4200mAh zippy packs per sortie, though I could have gotten by on one based on how many mAh they would take on a recharge. I pulled all of the guts out last night And here are the BBs which were in behind the internal armor. Here are shots of the water channel. The plan is to remove all of the old water channel and replace it to improve stability The water channel is mainly 1/4" balsa sheets. Most of the stern area has two layers, with a total height of 1/2." I added some foam along the edges and in the very back. The area for the batteries and the water-retention box was only 1/4" high, while the bow was 1/2", with some foam. Here is a list of issues I have had with the boat and/or things I want to improve. 1) Stability - I had a hard time keeping the boat level, it would list to one side or the other based on how I moved things around. I think that this was primarily a function of waterchanneling, probably too high in some areas, and too low in others. The boat always rolled over when it sank. 2) Pumping ability - related to 1), I had a hard time getting the pump to maintain a prime, or staying afloat with a steady pump stream. I think the issue was the amount of water that had to be in the boat in order for the pump to prime was pretty close to the amount of water that would sink the boat/make it roll. Maybe I'll install an auto switch w/ override to help out. 3) Drive setup - The drive setup changed throughout the year, the final iteration used a 16,000 rpm no load mabuchi 12V motor geared down, and controlled with a hobbywing ESC (the one that could handle 12V), and a 1.9" or 1.7" Kort prop. When the ESC worked correctly, this was a good setup, but I've decided to go brushless 4) Poppets - time to replace with solenoids. The guns work pretty well, especially since the boat used poppets with a single 1/16" hose. 5) Batteries - I will most likely shift to using two of the 20Ah liFe bricks in order to be able to run a Titan pump motor. I also am not as afraid of the bricks from exploding as I am with the Zippy packs which go puffy. I may still use 1 zippy pack for drive. Based on the issues, here is my plan for what to replace. 1) Replace the drive shaft, stuffing tube, and motor mount. The drive shaft will be upped to 3/16" stainless steel to handle the brushless torque. The shaft will run directly into a Traxxas Villain gearbox with 32 pitch gearing. 2) Replace the water channel. I need some help on decided how to do this part. Does anyone have recommendations for how to configure the waterchannel? One idea is to have primarily 1/4" balsa, with raised areas in the bow and stern. The other way to go is make 3/4" high with the exception of the battery area which would be 1/4." This is generally how I did it in the California, and it sank nice and level last weekend. Any help from those who have nice stable boats would be great! 3) Install solenoids and CO2 lines 4) Make a new smaller water resistant box for firing boards, receiver, and the pump switch board. 5) New pump (the old pump housing has taken a beating and has worn-out screw holes) 6) Improved rudder servo mount, to allow for a larger gear on the servo to increase rudder throw. 7) Experiment with hose arrangement to the guns, consider going to 1/8" hose. Sorry for the long post. Again, if anyone has suggestions for waterchanneling I'd appreciate it!
I forgot to add that I did a sink test in the bathtub today to see how the waterchanneling and pump were playing together. I took the empty hull (with current channeling), added some lead acid batteries, and put the pump in. The water had to be at least 1/2" deep to have the pump start with a good prime, and it would pump down to about 3/8" high water, and then slowly spatter out water until 1/4" deep. Without the internals the hull would not roll on its own when full of water, which was a good sign I think. I think that I will want water channel 3/4" high in the bow and stern, and maybe for about 3/4" around the outer edges on the sides, since at that level of water the pump would work well. Thoughts?
If you're using the traxxas servo back there, throw that out and get something else. Instant solution to increasing movement range without doing anything major.
Thanks for the reply's Nick. Yes, the boat rolled to port most recently, possibly due to the two guns in the wing turret. However, prior to installing those guns, the boat would roll to starboard. The boat only sank level a few times that I can remember. I think having the large box off center could have also contributed some. What do you recommend instead of the Traxxas servo? I had just switched to using a Traxxas servo based on recommendations from others
I will be watching this with interest. I would consider building a Rivadavia if the proposed rudder rule passes.
Are you sold on the water channel being the issue with the rolling? I would first look at the weight of the superstructure. You should have weight to play with using your proposed batteries. I would suggest getting some lead buried inside your water channeling (Way down low).
I have been using the Hobby King waterproof servo. I did not have to replace any this year. https://hobbyking.com/en_us/hobbykingtm-waterproof-analog-servo-3-2kg-0-17sec-40g.html At this price I will probably replace all my exposed rudder servos this winter as a maintenance issue.
Hitec all the way... for the cost of two Traxxas you can have 1 of the Hitec and so far they are worth it. I have one of these, bought when the 646WP was out of stock. I keep it as a spare: https://www.servocity.com/hs-5646wp-servo#258=24&259=25 I use these in the Baden, and have a couple of spares for other boats.: https://www.servocity.com/hs-646wp-servo#258=24&259=25 The Hitec is a world apart in quality, speed, and operation over the Traxxas. When I got these the Traxxas were all relegated to secondary and convoy ships. When they run out.. I will just invest in the 646WP in all ships. In fact most of my Texas group including Jeff has been using or migrating to these servos.
I just have to say wow!!! I couldn't even imagine spending ^$40 on a boat servo. To me personally, I don't even thing it's necessary. I'm still using the same (self waterproofed) rudder servo in my cruiser that was installed at the beginning of last year. I've been sunk many times since then, plus I've done sink tests in our pool. I never did any maintenance at all to it and it still is working great and should continue to. Servo cost $3~.
You were lucky You were lucky..... My most consistent results have been with Hitec so far. My goal and focus is to keep a ship working and have ended up with Hitec after many many many sorties in the ship and running into various issues with different parts. I also have a traxxas servo that never failed not after 30 sinks.. but I like the quality and tight gears of the Hitec. Others may have different reasons for doing what they do.
Not lucky, just a proper waterproof job. I'm sure I can get consistent result with any of my other servos. I just haven't been able to prove it since my first one hasn't failed.
Yes I am sure you did. I appreciate that you can do such a good job on the servo. Most folks are unable to such a good job.. then when it fails... .there may be a Baden nearby..... MUWHAHAHaHA
Yes, I drive a cruiser. But I'm a bad cruiser captain. Got into a lot of bad situations last season and sank often. Did a little better this season, but I'm still learning.
The job might be good, but my process is also easy for anybody that can operate a screwdriver. Maybe I'll do a tutorial so all captains can have cheap waterproof servos.
So I did sink a lot, probably about 25 times this season. I had been scotchkoting servos, and I had one or maybe two fail this year, so reliability is very important for me. In regards to the rudder size, the boat will actually spin about its midpoint with the current rudder and prop arrangement, but the throw for the servo seems to be less in one direction, so I will get a larger gear. Thanks for the product info Johnny. Back to the most pressing issue for moving the project along, are there any thoughts on the water channeling? I will probably add about a pound or so of lead or steel under the water channeling, midships all of the way outboard. I will float the hull again tomorrow to figure out how much weight I can add. I see the options as either 1/4" along most of the length, which would require more water for the pump to prime, though I know some people use this setup effectively. The other option would be 3/4" high except for the battery and maybe the solenoids, which would allow the pump to be effective with less water in the boat, but raise the center of gravity of the boat. Any thoughts?
Too much water channeling can cause a ship to list. When it fills with water the light water channeling is low and the baby water is high. Keep the main water channeling at 1/4". Put more in the bow just the first 4-5". Same in the stern. Make sure things can't move in the ship also keeps the ship level.
In the Baden I use 1/4 just like Bob says and I also cut out slots for the batteries so they can sit as low in the hull as they can. Most of my issues with list has been a lack of prep but I do what I can with it.
Thanks Bob, hopefully I will get to it this coming week along with the stuffing tube/motor mount replacement.
