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[DJW]

Hi All


Just started the build. Been reading the existing build logs with great interest and learning a lot, some great results being achieved..!


My background relating to RC and model boats, built and raced Multi boats in the 70's, then left to play with some full sized boats... Dabbled with a couple of electric boats in past 10 years, plus a Dragonforce 65 yacht, and a TREX 450 helicopter.  Stronger on the metalwork side than the woodwork if I'm honest...


So onto a bigger challenge (for me), the Amati Aquarama...  Reasons for posting here:


1. I welcome any input from those that have gone before me with this kit.
2. I plan to use the kit as a basis and to incorporate some more bespoke work, so welcome any thoughts if I stray too far from reality...


Currently working on preparing the basic structure, keel and ribs, getting the stern sorted out ready to assemble.


Some initial thoughts and plans:


1. I didn't like the look of the Amati motors / running gear in the supplementary kit, so...


- I have a couple of Overlander 3530 Outrunners rated at 1100kv, 340W each. Matched to 3C lipos (to be decided on when actual space in known.) [size=78%]https://www.overlander.co.uk/tornado-thumper-v3-3530-14-1100kv-brushless-outrunner-rc-motor.html[/size]


- Plan is to build a watercooled mount for each motor that will allow use of a toothed belt arrangement (3:2 reduction so slower shaft, more torque) so I can get the propshaft to a low angle. ( I see videos on YouTube of these models running very bow down and suspect the steep shaft angle of the kit is one of the reasons.)


- Custom made 4mm propshafts / tubes running exposed out of the hull via bushed P bracket. PropShop 1415 brass props to start with.


- 2 x Shark 30A watercooled ESCs [size=78%]https://www.ztwoem.com/product/shark-30a-bec/[/size]


- Custom rudders. I think they need to be close the full size aspect, maybe scaled up a shade, but not too deep.  I see the models banking over when turning and think standard (shaped) model rudders will start to give lift so compound the banking.


2. I'll be using a Futaba T6EX six channel system, and will set it up for 'normal' steering / throttle behavior, and add mixing for reducing inboard motor speed during a turn, and motor only turning on left horizontal stick.


3. LED lighting throughout including dashboard (saw this on a YouTube build log, very cool..!)


4. Modified exhausts.  I'd like to get the coolant just rolling out of the end pipes as seen on the full sized boats.


5. Modified chines...  I think one more reason for the bow digging in is that there's a lot of structural weight up in the bow, and that's where the underwater section of the hull is least buoyant (narrowest / deepest V) and doesn't generate lift at 1/10 scale. (No offense to Carlo...) So, I'm pondering a mod to the ribs to give a one plank widths 'flat chine' for some of the hull length. Aim would be to add some lift at the forward planing area of the hull, and at the same time to deflect some of the water away from the boat...


6. Looking into how best to add a Ski pole...  For a 1/10th Skier... To Ski with...


7. On a more down to earth note, using Titebond 111 for the woodwork, and so far very pleased.

So, there you go.  Other matters to discuss like planking, waterproofing and varnish finishing (a black art if ever I heard of one...)

Please let me know if there's appetite here to document the build.

Very best regards to all.
David.

[coch y bonddu]

Come on what are you waiting for we are all waiting




Dave

[DJW]

Hi Dave


OK, here's what we have so far:


Some wooden bits...





Stern / Transom still needing some work to get the fit right:





And some components:





Plenty to be done.
David.

[DJW]

Built a 'slip' today to get the keel and frames square. Two forward frames bonded in place. Couple of holes being added to frames before bonding to allow wires to be routed along the length of the boat.


Ordered some 'warm white' 3mm LEDs for the docking lights and some 1.8mm versions in warm white, green and red for the various other locations. Handy that the LEDs come in bags of 50...  In case the resistor calculation is off...     All 3V LEDs that use 25mA, running from a 11.1V Lipo, I'll be testing with a 330 Ohm resistor paired with each LED.


The chrome fittings that come with the kit look reasonable quality to me. I've seen some comments saying otherwise.  I've seen on some pictures and videos that the fittings were hollow, they're solid now.  So they'll need to be drilled / machined to take the LEDs.





Anyone else have one of these in build..?


Best regards to all
David.

[coch y bonddu]

Best place to order Led's from as they will supply the correct resistor for your voltage is Component shop.




 https://www.componentshop.co.uk/








Dave

[DJW]

Hi Dave


Thanks for that. Just been reading through their LED guide. Very useful indeed, thanks again.


https://www.componentshop.co.uk/led-exp/

David.

[DJW]

Build progressing...  Playing with LEDs in series to reduce cabling and reduce use of resistors.  This is two 3mm warm whites for docking lights plus on 1.8mm warm white for cabin interior. On test for 24 hours and seem fine.





Structure now has forward 3 frames bonded to keel and bow reinforcement in place ready to shape. Everything else dry fit at this stage.


[size=78%]


Next bit could be controversial...  Given this will be a working model rather than static, I'm thinking of modifying the mid section frames to produce flat chines, to generate lift and throw water clear... Aft and bow sections remain as Carlo intended.


Given the weight of the lipos towards the stern I think this will lift the bow when under way...  Against this is a slightly deeper 'Vee'. Any comments before I get the saw out gratefully received.





Stern takes a bit of figuring out to get the bonding order right.





A pair of 4mm shafts and two brass props from Simon at the Prop Shop are on their way, looking forward to seeing them..!



[/size]

[ukmike]

David.

Please think hard and long before you cut anything, it would be very difficult to correct if you finish the boat and the modifications turn out to be detrimental to the performance.

The Amati  Riva builds quite heavy for it's size and is prone to shipping water into the cockpit, especially on turns.

I would give some thought to weight saving at every stage of the build where possible and it is very possible.

Regarding lifting the bow, it would be better achieved by weight saving in the fwd cabin, try not to go overboard with unnecessary detail, after all,  it's very  difficult to see in there, unless you use lots of lighting.

Lastly, don't forget that if the bow goes up the stern goes down, thus negating your shallow shaft angle.

Just my thoughts.

Mike.

[DJW]

Hi Mike


Sensible stuff. Agreed with the weight saving advice.


You have to take your share of responsibility for this build..! Your build log and insights of what can be done with this kit contributed to my decision to attempt it. Just saying.


I'm sure something needs to be done to the Chines, I saw you used some triangular section. Did it work as hoped..?


I saw that you mentioned Rustins Yacht varnish at the beginning of your build, then used Le Tonkinois, a problem with the Rustins..? I was considering Rustins sealant, filler and varnish.


How did your boat ride on the water..? Did that scale rudder shape help stop the excessive banking in turns..?


With hindsight, anything you wish you had or hadn't done during your build..?


Thanks again for your input.
David.

[ukmike]

Hello David


The spray rails worked reasonably well but I couldn't test it without them of course. I based my decision whilst watching on another Amati Riva, built from the same kit.
When the chap brought the boat in and lifted it out he had to invert it to pour out the water which it shipped in during the 10 min. run. It ran awfully, particularly when it turned at speed.


Regarding the Rustins varnish, I did buy some and tested on some scrap Mahogany, it took over a week before it was hard enough to rub down, so I did not use it. I know nothing about their filler, having never used it.
I make my own fillers for the appropriate timber.


The LeTonkinois it by far the best, (my opinion ), I won't use anything else. If you go down the LeTonk route, make sure you order the Classic and not the Vernis Marine No.1 which is thinner and doesn't have the level of gloss. It is very good, but my preference is the original Classic.
The family that started the LeTonk factory 80 years ago have recently sold out to a large German company, so if you decide on using it, buy it now while it is still the original recipe.


I've never considered feathering the inside prop whilst turning, I personally see no need, the full size Aquarama didn't have it and can't see any need for it although I know some modelers do use it.


Mike.

[DJW]

Hey Mike


Thanks for these comments.  I'll get hold of a couple of small tins of the 'Le Tonk' classic, I'm not far from Maidenhead, I'll see if I can call over to the importers.


I think I'll go with your route of the additional mahogany section to 'enhance' the chine / spray rail, did you find a supplier or make it up..?  Can't find any after a quick search online...


Feathering the inner prop...  It'll be a programming approach, so can be tweaked or plain taken out if it doesn't help.  I do think a lot of the Aquarama models out there generate lift from deep rudders. So if I can induce a bit of turning effect just from from the motors, it may help. We'll see...


Progress on a few areas of the build...


Two beautiful 35mm props from Pro-Shop have arrived:





And I'm working on the rudders to go with them, milled and shaped from 3mm brass plate, silver soldered to 4mm stainless shafts. The plates are about 40mm long x 25mm deep:

















Just need to finish and polish them, next will be working on the posts, 'O' rings or seals going in, to stop the water coming up, not sure which yet.


Frames drilled for coolant pipes and cables to keep them out of the way:





Regards to all.
David.
 

[ukmike]

Hi David.


1/2 ltr. of the varnish will be more than enough, I put 15 coats on my build and still had almost 1/2 tin left.
It's far better to apply many thin coats than a few thick ones. LeTonkinios hates being applied thickly and gives it's highest gloss when applied very thinly.


I cut my own Mahogany for the spray rails, as like you, I couldn't find any either. If you get stuck I will cut some for you.


Are the propeller blades soft soldered into the hubs ?


The rudders look good, very nice work. The drilling of the frames for tubes, cables etc. is just the job, keeps the motor / battery bay very tidy.


Excellent work David, your boat will turn out to be superb.


Mike.

[DJW]

Hi Mike


The props are from Simon at the Prop Shop, cast bronze in one piece, fine work indeed.


I'll pick up some mahogany rectangular section and see what I can do, I'll let you know how I get on.


And ' Superb' is what we all aim for I guess, and then we do our best...


David.

[DJW]

Rudder posts yesterday and today... Made them up from 7mm id brass tube and some custom brass fittings upper and lower. Lower has close fitting with shaft plus an 'O' ring to stop water coming up, upper has bronze bush to keep everything lined up plus a seal.  No water will be getting in that way...  Lower has a narrow section to pass through the hull with a flange to fix to hull with epoxy.  Posts still need to be cut to length when hull is a little further on.














Also set up a rig to test where the servo and arms need to be in the hull.  Amati show the servo installed offset to the port side controlling port rudder which is then linked to the starboard rudder with a cross bar.  I'd like to mount the servo along the centre line to give more tuning options.  This will allow keeping the rudders syncronised and parallel with all the arms set at 90° (so same as Amati and same as full size Aquarama I think), or to test with offset rudder arms to give an asymmetric throw. Theory being that the inside rudder should turn a little more than the outer during a turn as the outer side of the hull prescribes a larger circle during a turn than the inner. I see this as one of the options available to use to keep the Riva on an even keel during turns out on the water.
Keeping the rudder arms turned in as in the pic is neater, but arms will need trimming to avoid the transom woodwork.  If this isn't viable they can face out.





Would be interested if anyone reading this has tried / tested / used this asymmetric throw approach with any effect.


David.

[Capt Podge]

I've never tried using a test rig for rudders but your latest update has sown the seed for any / all future projects.
Looking forward to seeing your results...  .


Regards,
Ray.

[RST]

I've tried the assymetric rudder throws before just for giggles. Isn't why hacnkey cabs claim to turn so tight? Can't say I noticed much difference to be honest but the theory is sound, or not worth bothering depending which way you think about it.  I find it more intriguing why the "standard" raboesh tiller arm is assymetric rather than aligned with the rudder stock like servo horns are.

[DJW]

Afternoon All


My Aquarama project came about partly because I'd like a building challenge, and partly because I'd like a scale boat to pull a scale waterskier.


Current waterskier is the 'Pink Panther', he started out like as part of a Happy Meal, my children are now in their 20's so he's been around the lake a few times...  Plan is to use experience gained with him to develop something a little more fitting for the Riva, maybe a 1/10th Ms Bardot.


Here he is braving some frigid water being pulled by an old Kyosho Majestic that I have:





If you'd like to see the short video: [size=78%]https://youtu.be/klgUejovf_k[/size]


(Apologies in advance for the music...  It's part of the GoPro App...  Best to turn it down a bit...)


Anyway, back to the reason for this post, I'm not finding much detail online about the Ski Pole mount on the Aquarama. I wondered whether anyone reading has any additional pictures or plans that show it in place in a little more detail..?





Best regards to all.
David.

[DJW]

Playing again with the rudders and RC Setup on the rig to test that I can achieve what I'm hoping for.


The Amati Aquarama has a tendency to bank heavily in turns. I'm looking at ways to counter this. The RC setup gives asymmetric rudder throws and adds in independent motor speed control to add turning force independently of the rudders. The setup also allows motor only turning.  Importantly all the functions variable once built in and are reversible if it doesn't work...

Have to give credit to others online for tips on how to do this, use of the V-Tail function and also the change to Mode 1 on the transmitter.






There's a video of the functionality here: [size=78%]https://youtu.be/wmmUGpZXJyA[/size]


[/size][size=78%]Apologies if this is old news...  Its new to me...  [/size]


Regards to all
David.

[Davo]

The integral spray rails are a good idea.  I did this on a Sea Nymph simply by over-running the side skin below the bottom skin, then profiling with body filler.  This avoids adding a difficult thin strip of ply.  I did as per your design some years ago (40!) by putting drafting tape externally over the gap and laying a fibreglass strip internally.
David

[coch y bonddu]

Just an observation but wouldn't the ACTion P94 combined mixer speed controller would surley do the same job as it speeds up and slows down motors on command of the rudder.This is purely and not a critisism of your thoughts but I personally don't think it will have any effect on the handling of the boat not one bit.


Reason for my thoughts it is an inherent hull design....just my thoughts


Dave

[derekwarner]

Dave.......post #3 indicates Brushless motors and controllers purchased for the build............... Derek

[TomHugill]

Hey David,


I've had a quick scan of your thread and found it very interesting as this is something I went through with my 1:7 scale aquarama.


I was never very happy with how the smaller scale ones were so bow heavy at low speeds, had such a high bank angle and pushed up such a big wake when not on the plane (even if the real ones a bit guilty of this).


The way mine got round this was similar to what you proposed, a flat chine to stop spray and a slightly deeper v to help it get onto the plane easier.


https://youtu.be/Bm_7vzyg5zg

https://youtu.be/9MVdxpuU0K0

Theres a few more pictures here too

https://www.modelboatmayhem.co.uk/forum/index.php/topic,49270.msg501059.html#msg501059

[DJW]

Afternoon All


Thanks for the comments.


@Dave, you could well be right that these tweaks make no difference at all...  I agree that at this scale the hull has inherent issues.  And the P94 does indeed seem to have similar capabilities (for brushed motors). I think if those capabilities can be replicated in the existing RC hardware, that's useful for testing the option. Also a saving of £80.00.... What I'm trying to build in are some 'variables' that I can adjust once the boat is on the water to see if they have any beneficial effect.  If they don't...  Then I'll owe you a beer...


@Tom, yes, looks like we agree on the chine mod issue.  The full size boat had so much weight toward the stern, basically over the flat planing section of the hull. Two big V8s and then looks to me like the fuel tanks were against the transom.  I think there are three options:


1. Plank the hull as normal, then add a shaped triangular section along the chines to flatten them. (As UKMike has done with success with the Aquarama hull)
2. Cut the frames to provide flat chines and a deeper 'Vee', then plank.
3. Add some triangular fillets to the chine area of the mid section frames, then plank the revised shape...


Still mulling those options over.


Agreed again re putting the bow on a diet to keep the weight down.


Thanks for the links to your 1:7 scale, beautiful looking boat, the video's show it riding perfectly.  If I can get close to that when on the water I'll be very pleased.  Working at 1:10 scale makes me yearn for a bit more space in the hull...


@ David, perfect example of the flat / reversed chine mod working very well and encouraging for my build, thanks for that.


Made the mods today for the rudder servo to be moved to the centreline. Had to remove some of the keel to do this but have made the mount strong enough to add some strength back. I hope...


Also took off the original rudder servo mount supports to free up some space on the port side:


So this is as per the kit...








And this is after my saw...





And then the vandalism to the keel and the servo in place...





Next step will be to get the transom fixed in place, the structure for the rudders and then get the rudder posts trimmed to fit and in.


Another question...  My thoughts have been to keep heavy items (like lipos) as low as possible.  But, if they were higher would that go some way to counter the tendency for the hull to dig in / bank when in a turn...? Their mass being thrown in the opposite direction.


Best regards to all.
David.

[SailorGreg]

Another question...  My thoughts have been to keep heavy items (like lipos) as low as possible.  But, if they were higher would that go some way to counter the tendency for the hull to dig in / bank when in a turn...? Their mass being thrown in the opposite direction.

If I were you I would keep them low.  A high centre of gravity will make the hull more tender and prone to heeling/rolling, so I doubt it would fix the potential handling problems.  Having seen videos of other Riva models, I suspect a lot of the turning issues are due to turning at full power.  You might have to learn to throttle back a bit as you go into a turn.

I'm enjoying your build - thanks!

Greg

[DJW]

Hi Greg


I tend to agree with you, I think using the lipo mass is one of those options to keep in the bag when it comes to [/size]evaluating the boats characteristics on the water and getting the trim right.  And agreed re speed of turns.  I'm just wanting decent handling at scale speeds. Pleased to hear you're enjoying the build log.
[/size]
[/size]In other news... Real world has got in the way of much on the build for past few days, I have made up the docking lights:
[/size]



Amati fittings drilled to take warm white 3mm LEDs. (I prefer the yellow light to the harsh blue tint of the true 'white' LEDs.) Foil is from Aunt Bessies Yorkshire Pudding cases, just the right thickness, wife thought I'd lost it when I dug them out of the bin...


Some parts have arrived in the post...  I now have a small (24x45mm) and lightweight 3 to 5v brushless water pump (100 to 200mA), I'l like to check whether it will serve to get water around the ESCs and motor mounts, and in particular I'd like to get water coming out of the exhausts while the boat is stationary, like the real Aquarama at idle.





I also found these Buck Converters on Amazon to step down the Lipo voltage:





22x17mm, input 4.5 to 28V, steps down from 0.8 to 20V.


I'm thinking to maybe use the balance lead connector via a switch with one of the above Buck Converters, or possibly the BEC output from the second ESC, need to investigate that as an option, then use an RC AUX switch for RC use.


Also been working on the motor mounts, but not a lot to show at the moment.


I'm slowing the hull build while these parts are evaluated / built to see if any hull mods are needed to accommodate.