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Author Topic: Amati Riva Aquarama Build - With some mods...  (Read 1023 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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Derek Warner

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Illawarra Live Steamers Co-op
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www.ils.org.au

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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