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Author Topic: Amati Riva Aquarama Build - With some mods...  (Read 1506 times)

ukmike

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Re: Amati Riva Aquarama Build - With some mods...
« Reply #25 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.


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DJW

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Re: Amati Riva Aquarama Build - With some mods...
« Reply #26 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.








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





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.





Best regards to all.
David.

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ukmike

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Re: Amati Riva Aquarama Build - With some mods...
« Reply #27 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.
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DJW

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Re: Amati Riva Aquarama Build - With some mods...
« Reply #28 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.
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ukmike

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Re: Amati Riva Aquarama Build - With some mods...
« Reply #29 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. 😋





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DJW

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Re: Amati Riva Aquarama Build - With some mods...
« Reply #30 on: February 14, 2020, 12:53:34 PM »

Progress update...  I have a belt drive mount built and running:





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:



And here's it all running:





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.

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derekwarner

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Re: Amati Riva Aquarama Build - With some mods...
« Reply #31 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
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DJW

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Re: Amati Riva Aquarama Build - With some mods...
« Reply #32 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.

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DJW

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Re: Amati Riva Aquarama Build - With some mods...
« Reply #33 on: February 18, 2020, 11:17:53 AM »

Two new P brackets for the Riva:





Solver soldered brass with teflon bushes:





Some polishing required...






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DJW

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Re: Amati Riva Aquarama Build - With some mods...
« Reply #34 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:





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.





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:





Regards to all.
David.
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DJW

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Re: Amati Riva Aquarama Build - With some mods...
« Reply #35 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.





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:







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.





View of that space from above:





More woodwork fixed in toward the bow:





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.
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DJW

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Re: Amati Riva Aquarama Build - With some mods...
« Reply #36 on: March 05, 2020, 03:09:36 PM »

Some of the mods taking shape...


Bow going on a diet:





Exhausts now have coolant and misting tubes installed:





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.



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.














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.
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tsenecal

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Re: Amati Riva Aquarama Build - With some mods...
« Reply #37 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.
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DJW

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Re: Amati Riva Aquarama Build - With some mods...
« Reply #38 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.





This is the unit being tested:





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





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





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.
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DJW

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Re: Amati Riva Aquarama Build - With some mods...
« Reply #39 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:








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/[/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.

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ukmike

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Re: Amati Riva Aquarama Build - With some mods...
« Reply #40 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.
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DJW

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Re: Amati Riva Aquarama Build - With some mods...
« Reply #41 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.
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derekwarner

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Re: Amati Riva Aquarama Build - With some mods...
« Reply #42 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
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DJW

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Re: Amati Riva Aquarama Build - With some mods...
« Reply #43 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.
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NickelBelter

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Re: Amati Riva Aquarama Build - With some mods...
« Reply #44 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. 
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DJW

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Re: Amati Riva Aquarama Build - With some mods...
« Reply #45 on: March 24, 2020, 05:02:39 PM »

Hi NB


Sure, I use: [size=78%]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[/size]


The pulleys are here: [/size][size=78%]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.
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NickelBelter

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Re: Amati Riva Aquarama Build - With some mods...
« Reply #46 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.
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DJW

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Re: Amati Riva Aquarama Build - With some mods...
« Reply #47 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..?
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Re: Amati Riva Aquarama Build - With some mods...
« Reply #48 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.
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