Model Boat Mayhem

Dry Dock / Shipyard: Builds & Questions => Pleasure boats, Sports, Race, Power and Leisure Boats: => Topic started by: DJW on January 06, 2020, 02:34:02 PM

Title: Amati Riva Aquarama Build - With some mods...
Post by: DJW on January 06, 2020, 02:34:02 PM
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 (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/ (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.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: coch y bonddu on January 06, 2020, 02:58:16 PM
Come on what are you waiting for we are all waiting




Dave






Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on January 06, 2020, 03:48:43 PM

Hi Dave


OK, here's what we have so far:


Some wooden bits...


(https://www.modelboatmayhemimages.co.uk/images/2020/01/06/20200106a.jpg)


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


(https://www.modelboatmayhemimages.co.uk/images/2020/01/06/20200106c.jpg)


And some components:


(https://www.modelboatmayhemimages.co.uk/images/2020/01/06/20200106b.jpg)


Plenty to be done.
David.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on January 07, 2020, 06:11:38 PM
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.


(https://www.modelboatmayhemimages.co.uk/images/2020/01/07/20200107.jpg)


Anyone else have one of these in build..?


Best regards to all
David.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: coch y bonddu on January 07, 2020, 07:35:32 PM
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/ (https://www.componentshop.co.uk/)








Dave
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on January 07, 2020, 08:47:36 PM
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.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on January 10, 2020, 12:10:43 PM
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.


(https://www.modelboatmayhemimages.co.uk/images/2020/01/10/20200110a.jpg)


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.


(https://www.modelboatmayhemimages.co.uk/images/2020/01/10/20200110c.jpg)


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


(https://www.modelboatmayhemimages.co.uk/images/2020/01/10/20200110d.jpg)


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]
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: ukmike on January 11, 2020, 09:44:40 PM
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.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on January 11, 2020, 10:53:02 PM
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.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: ukmike on January 12, 2020, 03:05:43 PM
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.









Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on January 15, 2020, 05:39:18 PM
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:


(https://www.modelboatmayhemimages.co.uk/images/2020/01/15/20200115b.jpg)


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:


(https://www.modelboatmayhemimages.co.uk/images/2020/01/15/20200115c.jpg)


(https://www.modelboatmayhemimages.co.uk/images/2020/01/15/20200115d.jpg)


(https://www.modelboatmayhemimages.co.uk/images/2020/01/15/20200115e.jpg)


(https://www.modelboatmayhemimages.co.uk/images/2020/01/15/20200115f.jpg)


(https://www.modelboatmayhemimages.co.uk/images/2020/01/15/20200115g.jpg)


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:


(https://www.modelboatmayhemimages.co.uk/images/2020/01/15/20200115h.jpg)


Regards to all.
David.
 
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: ukmike on January 15, 2020, 06:28:23 PM
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.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on January 16, 2020, 08:27:54 PM
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.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on January 17, 2020, 04:34:18 PM
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.


(https://www.modelboatmayhemimages.co.uk/images/2020/01/17/20200117a.jpg)


(https://www.modelboatmayhemimages.co.uk/images/2020/01/17/20200117b.jpg)


(https://www.modelboatmayhemimages.co.uk/images/2020/01/17/20200117c.jpg)


(https://www.modelboatmayhemimages.co.uk/images/2020/01/17/20200117d.jpg)


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.


(https://www.modelboatmayhemimages.co.uk/images/2020/01/17/20200117e.jpg)


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


David.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: Capt Podge on January 17, 2020, 04:56:13 PM
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.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: RST on January 17, 2020, 09:55:34 PM
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.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on January 20, 2020, 05:08:39 PM
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:


(https://www.modelboatmayhemimages.co.uk/images/2020/01/20/20200120c.jpg)


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


(https://www.modelboatmayhemimages.co.uk/images/2020/01/20/20200120a.jpg)


Best regards to all.
David.



Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on January 21, 2020, 01:07:10 PM
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.



(https://www.modelboatmayhemimages.co.uk/images/2020/01/21/RCSetup600.jpg)


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


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


Regards to all
David.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: Davo on January 21, 2020, 05:38:32 PM
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
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: coch y bonddu on January 21, 2020, 09:25:25 PM
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
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: derekwarner on January 21, 2020, 10:03:12 PM
Dave.......post #3 indicates Brushless motors and controllers purchased for the build............... Derek
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: TomHugill on January 22, 2020, 10:41:54 AM
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

Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on January 22, 2020, 03:21:08 PM
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... ok2


@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...


(https://www.modelboatmayhemimages.co.uk/images/2020/01/22/20200121a.jpg)


(https://www.modelboatmayhemimages.co.uk/images/2020/01/22/20200121b.jpg)


And this is after my saw...


(https://www.modelboatmayhemimages.co.uk/images/2020/01/22/20200121d.jpg)


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


(https://www.modelboatmayhemimages.co.uk/images/2020/01/22/20200121e.jpg)


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.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: SailorGreg on January 22, 2020, 05:30:34 PM

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
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on January 27, 2020, 03:39:06 PM
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]
(https://www.modelboatmayhemimages.co.uk/images/2020/01/27/20200127b-Custom.jpg)


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.


(https://www.modelboatmayhemimages.co.uk/images/2020/01/27/20200127d-Custom.jpg)


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


(https://www.modelboatmayhemimages.co.uk/images/2020/01/27/20200127e-Custom.jpg)


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.

Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: ukmike on January 27, 2020, 05:54:09 PM
David.


A safe idea for an aux. power source is on my Biggish Aquarama thread, may help.


Don't forget to keep an eye on the weight of your boat.


Mike.


Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on January 30, 2020, 04:32:53 PM
Hi Mike


Thanks for that, I've been following your larger Aquarama build closely, looking good..!


I'll be adding the inline fuses for any auxiliary power use for sure. I'm thinking that you're adding the diodes as a precaution / protection, as you're sharing the Lipos for auxiliary power supply, is that right..?  If so I'm only planning to run the auxiliary power requirements off the lipo that's not providing power the the receiver.  Talking about weight, I'm looking at 2 x 4,000mAh Lipos at 310g each, do you think they're about right or too heavy..?  What lipos did you end up using in your Amati build..?


The build continues, transom is now on and some of the subframes being put together. With the transom bonded in I'll be looking at betting the rudder frames and posts in soon.


(https://www.modelboatmayhemimages.co.uk/images/2020/01/30/20200130a.jpg)


(https://www.modelboatmayhemimages.co.uk/images/2020/01/30/20200130b.jpg)


A lot of dry fit at the moment to gauge how much space there will be to play with.


(https://www.modelboatmayhemimages.co.uk/images/2020/01/30/20200130d.jpg)


Here's my first pass at a mod to the frames to provide a flat chine in the mid section of the hull to promote lift / planing and throw water clear.  My plan is to get to the planking stage and see whether the new shape can be planked well, or if it introduces to many headaches, if it does, they'll be planed off and back to the triangular section add ons.


(https://www.modelboatmayhemimages.co.uk/images/2020/01/30/20200130e.jpg)


Best regards to all.
David.

Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: ukmike on January 30, 2020, 04:56:10 PM
Hi David.


I added the blocking diodes so that should one of the batteries loose some, or all, of it's voltage for any reason it would not be possible for the good battery to attempt to charge the faulty one. You won't need them if your batteries are independent.


I finished up using 3 cell batteries for my boat, 2500mah. The boat was much too fast, but given that I have little interest in sailing them,  I soon sold it.


Thinking about your intended transmission idea, I would  go with 3 cells.


Mike.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on January 30, 2020, 05:24:15 PM
Hi Mike


Thanks for fast reply. My initial choice of motors are smaller and less power hungry that your 540L's I think, so maybe I can go with 3,000mAh (rather than the 4,000mAh) that should still give good runtime and save on weight too. Gearing my motors down may keep it more of a scale speed, I hope. I've got the components together to make up the gearboxes / mounts, it's a case of whether I can get it all light enough to be useful.


And..  After all the work / time / effort / head scratching / ingenuity that you put into your boats, surely you must want to run them..!


David.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: ukmike on January 30, 2020, 06:21:37 PM
David.


If the boat funfills my requirement , i.e .


First and foremost, it should float, most important.


Secondly, it must be able to turn, ideally left as well of right.


Thirdly,  be able to go forward and backwards, although backwards isn't essential, but it  can prove to be handy.


If it meets all the above criteria, I then run it, (in the water), if all is well, without problems, it is then sold.


If there are a few problems, I fix them, pop it back into the water to confirm all is now well.


If all is well,  sell it and start a new project.


Mike. 😋





Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on February 14, 2020, 12:53:34 PM
Progress update...  I have a belt drive mount built and running:


(https://www.modelboatmayhemimages.co.uk/images/2020/02/14/20200214a.jpg)


Weight is 117 grams with the motor, motor on its own is 74 grams, so mount is 43 grams. Machined from aluminium angle and bar, two ball races. Plan is to place a collar on the shaft so rear ball race takes forward thrust, shaft pulley will take reverse thrust against front bearing. Teflon washers used as required. Reduction is 3:2, distance between shaft centers is 30mm. As its an outrunner I'm cooling the mount which I hope will act as a heatsink for the motor...


Here's the rear view:

(https://www.modelboatmayhemimages.co.uk/images/2020/02/14/20200214b.jpg)

And here's it all running:


(https://www.modelboatmayhemimages.co.uk/images/2020/02/14/20200214d.jpg)


No vibration and runs quietly.  The shaft exits the mount just 12mm from the base of the mount so this should allow a shallow shaft angle compared to standard installation. Belt is an MXL timing belt with 45 teeth, it's rated up to 20,000rpm, I'm running at around 13,000rpm maximum.


Need to build another one now...  Should be a bit quicker as I've made up a few of the parts at same time as developing this one.  Then it'll be onto the P brackets and tubes.


Best regards to all.
David.

Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: derekwarner on February 14, 2020, 01:55:26 PM
David......looks very tidy  :-)) ...if you percieved any belt tension deflection, you could consider reversing both toothed pulleys so having the belt inby or closer to the bearings in the motor and frame


Derek
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on February 14, 2020, 03:06:41 PM
Hi Derek


Thanks for that and yes, sounds sensible.  The motor shaft is long enough to lock onto with the grub screw when reversed, and I haven't cut the main prop shaft for length yet.


Best regards
David.

Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on February 18, 2020, 11:17:53 AM
Two new P brackets for the Riva:


(https://www.modelboatmayhemimages.co.uk/images/2020/02/18/20200218a.jpg)


Solver soldered brass with teflon bushes:


(https://www.modelboatmayhemimages.co.uk/images/2020/02/18/20200218c.jpg)


Some polishing required...


(https://www.modelboatmayhemimages.co.uk/images/2020/02/18/20200218d.jpg)



Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on February 24, 2020, 06:15:32 PM
Been looking at dry fitting the shafts to see what kind of base I need for the motors / mounts, and where they need to be.  Using two frames to keep the shafts the required 87mm apart, parallel and correct clearance at the prop end. Bit of work required on the standard frames to get the desired lower shaft angle:


(https://www.modelboatmayhemimages.co.uk/images/2020/02/24/20200224b.jpg)


At the motor end the shaft is around 20mm from the line of the hull, I think this is 15mm (ish) lower than the standard install. And looking at the resulting shaft angle its a shade less than 8, I think standard for this kit is 12 or more, so will be interesting to see the effect on the water...  Now I have the sizing details to measure for the shaft tubes.


(https://www.modelboatmayhemimages.co.uk/images/2020/02/24/20200224a.jpg)


Final pic is checking the sizes of the Lipos and location in case mods are required at this stage of the build.  I'm happy with the amount of fore / aft flexibility of the mount position to be able to use the lipos mass to trim the boat come the glorious day... The Lipos are Turnigy 3,000mAh, 3S 15C Graphene packs, they come in at a reasonable 212g each:


(https://www.modelboatmayhemimages.co.uk/images/2020/02/24/20200224c.jpg)


Regards to all.
David.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on March 03, 2020, 10:18:26 AM
Morning All


Been busy moving the hull construction on a shade, and working on some of the running hardware.


Rudder posts and shafts are now trimmed for length, ended up with two 'O' rings at the base of each post, a Teflon bush and seal at the top.  No oil tube planned, just a bit of light grease from time to time.  Also seen in this pic are the modified exhaust tubes, these will allow the coolant to roll out as per the full size Aquarama, I hope. I'm planning on building in an accessible 'stub' to the exhausts so that if space and weight (and ingenuity) allow I can add a misting unit.


(https://www.modelboatmayhemimages.co.uk/images/2020/03/03/20200303a.jpg)


This shows the rudder arms in place and the centreline servo position, I think that cutout in the transom is to accommodate the standard rudder arm, so will be filling that in:


(https://www.modelboatmayhemimages.co.uk/images/2020/03/03/20200303b.jpg)




Here's the stbd shaft in vague alignment and start of a motor mount. Also added a couple of horizontal 'planks' in the battery / RC space, I'm going to add some of the RC gear / ESCs to these with Velcro straps to keep them ventilated / higher and free up 'floor space', wiring where possible will run in the void created.


(https://www.modelboatmayhemimages.co.uk/images/2020/03/03/20200303d.jpg)


View of that space from above:


(https://www.modelboatmayhemimages.co.uk/images/2020/03/03/20200303c.jpg)


More woodwork fixed in toward the bow:


(https://www.modelboatmayhemimages.co.uk/images/2020/03/03/20200303e.jpg)


I'm coming up to the point where I need to seal some of the interior woodwork before it becomes inaccessible. This build will see action on the water, so any opinions re using thinned varnish or finishing Z Poxy resin..?  I think the varnish would be thinner / lighter, but the resin more waterproof / resilient.


Another question.  I'm using 35mm diameter Outrunners, so the case rotates and has fixing points on the rotating case... Has anyone tried adding fan blades directly, say from a 30 / 40mm PC fan to the Outrunner case to assist airflow/ cooling..? It should be possible to mount the fan case too, to duct the airflow and prevent fingers being lost... The motor mounts will have water cooling, but these Outrunners are not really built to be watercooled. IMHO.


Regards to all.
David.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on March 05, 2020, 03:09:36 PM
Some of the mods taking shape...


Bow going on a diet:


(https://www.modelboatmayhemimages.co.uk/images/2020/03/05/20200305a.jpg)


Exhausts now have coolant and misting tubes installed:


(https://www.modelboatmayhemimages.co.uk/images/2020/03/05/20200305b.jpg)


This is a great suggestion from UKMike, as used on his Aquaramas, using a grub screw to secure the prop to the shaft.  Looks so much better when using P brackets as it does away with the usual locking nut also more secure.

(https://www.modelboatmayhemimages.co.uk/images/2020/03/05/20200305d.jpg)

And here's a bit of testing with a fan on the end of the Outrunner, fits quite well...  This is a 40mm PC fan, generates a good airflow around and through the motor and the case will fit to the mount with a small bracket.


(https://www.modelboatmayhemimages.co.uk/images/2020/03/05/20200305e.jpg)


(https://www.modelboatmayhemimages.co.uk/images/2020/03/05/20200305f.jpg)


(https://www.modelboatmayhemimages.co.uk/images/2020/03/05/20200305g.jpg)


(https://www.modelboatmayhemimages.co.uk/images/2020/03/05/20200305i.jpg)


I'm going to build in the attachment points for this on the mount, then if it's needed it'll be available.


Best regards to all.
David.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: tsenecal on March 05, 2020, 09:10:56 PM
Has anyone tried adding fan blades directly, say from a 30 / 40mm PC fan to the Outrunner case to assist airflow/ cooling..? It should be possible to mount the fan case too, to duct the airflow and prevent fingers being lost...

AXI has brushless outrunners with fans built in to their design... there is no reason not to attach them and see if they make a difference.  i presume you could remove them if the don't help.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on March 17, 2020, 05:52:51 PM
Afternoon All


Tried adding the fan case to the motor mount as per last post, but not enough space available so will try leaving the blades exposed.


Been working on building a misting unit based around one of the 20mm ultrasonic discs, not finished yet but here's some of the work to date.  Case and end caps made up from nylon bar, the input side if the disc will be fed with circulating water, so no need for a significant reservoir. Plan is to split the output and send mist to both exhausts.


(https://www.modelboatmayhemimages.co.uk/images/2020/03/17/20200317b.jpg)


This is the unit being tested:


(https://www.modelboatmayhemimages.co.uk/images/2020/03/17/20200317a.jpg)


And here's the main components 'dry fitted':


(https://www.modelboatmayhemimages.co.uk/images/2020/03/17/20200317c.jpg)


And just for UKMike...   :-))  Checking the weight, 22g.


(https://www.modelboatmayhemimages.co.uk/images/2020/03/17/20200317d.jpg)


Will be testing next with circulating water to see if the unit can handle continuous running and will post the results.


Crazy days we live in, stay well everyone...
David.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on March 23, 2020, 10:29:50 AM
Morning All


Looking like the 'virtual world' of the forum is about the only place still open...  Time to self isolate in the shed for a few months maybe...


So, a small update, two sets of motors / mounts / propshaft assemblies are now ready:


(https://www.modelboatmayhemimages.co.uk/images/2020/03/23/20200323a.jpg)


(https://www.modelboatmayhemimages.co.uk/images/2020/03/23/20200323b.jpg)


Next I'll be adding some support in the hull for fixing the P brackets, and the motor mounts.


Any comments / thoughts / advice on the order to actually fix the hardware to the hull..?


a. Fix in now and plank around the hardware.
b. Plank first layer than fix in hardware.
c. Plank both layers then fix in...


On another matter, the water pump that I found on amazon is utter rubbish, leaks from everywhere and no pressure. I stripped it down to find a small nasty brushed motor (sold as brushless), and a load of ill fitting plastic parts, so its now in the bin. I've found some very nice micro pumps on the RS site ( [size=78%]https://uk.rs-online.com/web/p/water-pumps/0480150/ (https://uk.rs-online.com/web/p/water-pumps/0480150/)[/size] ) I think I'll have to bit the bullet and get one of them. Given the state of the planet right now, I'm working out the pitch to my wife as to why I 'need' a 50.00 water pump smaller than my thumb...


Stay well.
David.

Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: ukmike on March 23, 2020, 01:09:02 PM
Hi David.


That's a Micro Pumps product.


Have another look on their website, you may not need the 3rd nipple.


The M410 is probably best suited for your needs but you have to pay a lot more money.


The R.S. example may not have the output that you want, better more than enough output, then control it by voltage.


Also, neither of them are are self priming.


Just my thoughts.


Mike.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on March 23, 2020, 02:17:46 PM
Hi Mike


Agreed that the 410 range is very nice...  but at a hefty price...  {:-{


The third nipple as I understand it can help with the priming issue.  So firstly I'm thinking keep the pump low in the hull, effectively below the waterline so there will be a tendency for the inlet to fill when at rest. Then if required put a line on the third nipple to allow air to be bled off, but that would be a bit tedious, I'd hope that's not required.


I have an account with RS, so easier to make the purchase via them, I think its a re badged TCS 200 series...  The RS version linked to does appear to have a similar static pressure to the 410, 330mbar to 380mbar, and has a flow rate of 650ml/m, and agreed the voltage can be used to tweak the output, seems it can run between 5 and 7v.


I think your 410 option would be best for a complete one stop solution. However I'm going to try the 200 and see how it goes, it's a third of the weight, there's a guy on here who keeps telling me to keep the weight down..  ok2  If there's an issue with flow I'll keep the pumped flow for the ESCs and misting, and add conventional pickups for the motors.  Maybe a 410 when I graduate to the larger Aquarama... :-))


Best regards and stay well...
David.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: derekwarner on March 23, 2020, 11:10:51 PM
David.....just a word of caution if you intend to use the vessel in brackish water


The TCS series pump is listed 616 S/S connections, but aluminium body, so even if this is internally anodised, internal corrosion could be an issue depending on the level of water salinity


A second consideration could be a mesh filter on the suction side [fuel element stainless mesh] as used on aero engines are a good thought


Using the largest bore size water tubing would also minimise pressure loss/drop, as the centrifugal pump output ~~330mB ...
[I had to do a mental calculation  :embarrassed: ......about 0.33 of 1 atmosphere = ~~4.7 PSI] :o


If you think of most applications for similar type/size pumps [motor vehicle water washers], each have flooded suction.......[so hence the 3rd port on the RS 200 pump]...but this would be for priming only as I doubt the rotor of the pump could create a vacuum sufficient to draw the initial slug of water


Just a final consideration is the question of running the pump flow in parallel or singular flow path between both motors?


[the latter is discharge from motor 1 = suction to motor 2......this is critical as the fluid in a parallel flow will result in virtually all fluid taking the easiest path of pressure resistance with all flow going to one motor  :-X


Derek
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on March 24, 2020, 11:34:55 AM
Hi Derek


Some interesting comments there, thanks..!


No plans for the boat to see salt / brackish water, so that shouldn't be an issue.


Pressure calculations are enlightening, the spec sheet mentions a 1.9m 'head', I thought that would be a useful pressure to be working with, that's about as far as I'd got.  Agreed re largest bore pipes throughout to get best flow.


Hadn't thought about debris filter...  Biggest issues I've had where I operate are with leaves, I had thought that with a flush inlet these should be avoided, I guess an inline mesh filter would make sense for smaller debris...


I hadn't heard the term 'flooded suction', I'm guessing this is what would happen when the inlet / pipework / pump are below the waterline and no 'air lock' in between, with an essentially open outlet side and centrifugal pump the tendency would be for the pump to fill.


I hadn't considered the flow not being even, but of course you're correct. My thought has been to split the cooling circuit into two after the pump, for the port / stbd motors / ESCs, then feed the outlets to the port / stbd exhausts.  I guess I'll see by eye whether the flow is equal.  If required I can add a restriction (clamp) to the max flow side.


I think I'll test the whole cooling circuit in an existing (old) model, that would highlight any issues before building problems into the Aquarama.


After UKMikes comments about the limited capabilities of the smaller pump (which I agree with) I was thinking of looking at a hybrid solution to reduce the demands / reliance on the pump, just a case of plumbing really.  At the end of the day I'd like a realistic flow of water through the exhausts when at rest / low speed, so I'd thought I would need a pump when there's no / low flow past a water pickup.


I could build in conventional water pickups in the propwash, then take a feed from this pickup to the pump... Use the pumped water for the ESCs / electronics, then rejoin the outlet side to the main water circuit at (or just before) the exhausts.  I'm thinking this would offer some advantages:


1. I can get away with a lighter / smaller pump.
2. A quick blip of propwash would help prime the pump.
3. Once primed, the pump would cool the ESCs / electronics full time and give realistic exhaust flow.
4. As propwash increases the flow would get to the motors via a dedicated circuit.
5. I think the pressure increase on the inlet side when at speed would be (almost but not quite) matched by the back pressure at the exhaust outlet, so the pump would not get into a 'race' condition.
6. The electronics get full time cooling.


Hope the above makes sense.
Thanks again for your comments.
Best regards to all.
David.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: NickelBelter on March 24, 2020, 04:45:41 PM
Can you share your source for the timing pulleys and small belt?  I have a problem with very low-set shafts in a model and I'd like to use a belt drive to avoid lots of grinding away the frames to line up a normal dogbone connector. 
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on March 24, 2020, 05:02:39 PM
Hi NB


Sure, I use: [size=78%]https://www.motionco.co.uk/ (https://www.motionco.co.uk/)[/size]


The belts are MXL size: [/size][size=78%]https://www.motionco.co.uk/timing-belts-timing-belts-c-25_38_27.html (https://www.motionco.co.uk/timing-belts-timing-belts-c-25_38_27.html)[/size]


The pulleys are here: [/size][size=78%]https://www.motionco.co.uk/timing-pulleys-timing-pulleys-aluminium-c-25_35_48.html (https://www.motionco.co.uk/timing-pulleys-timing-pulleys-aluminium-c-25_35_48.html)[/size]


And they have a really helpful centre distance calculator for whatever pulley combination you choose.


I also use their pillow block bearings and accessories such as locking collars and shafts.  Looks like they're happy to ship overseas, but I don't know if they're operational right now with the lockdown that we have in operation here...


Hope that helps.
Best regards
David.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: NickelBelter on March 24, 2020, 06:28:37 PM
Thanks, that's VERY helpful, especially since I am restricted in the diameter of the shaft pulley.  No need to get them in a hurry, usually takes about 3 weeks for something to arrive here from a UK seller.   :-))   I'm assuming it's easy to ream the hubs out from 3 to 4mm if they don't have the right size pulley in a 4mm bore.
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: DJW on March 24, 2020, 07:39:09 PM
Pleased to assist. Should be no problem to bore out to 4mm. What are you building that needs the shallow angle..?
Title: Re: Amati Riva Aquarama Build - With some mods...
Post by: NickelBelter on March 25, 2020, 05:46:19 AM
A destroyer, and I didn't think ahead to cut away the frames ahead of where the shafts enter the hull, and I'd rather not have to grind U-shapes into them now if I can help it.  Had to do that once with a rotary file and it was nerve-wracking.