Model Boat Mayhem - Forum

Dry Dock / Shipyard: Builds & Questions => Pleasure boats, Sports, Race, Power and Leisure Boats: => Topic started by: essex2visuvesi on March 06, 2010, 03:09:28 PM

Title: Ebay Vietnamese Aquarama RC Conversion
Post by: essex2visuvesi on March 06, 2010, 03:09:28 PM
Just had one of these delivered
http://cgi.ebay.co.uk/For-RC-Assembled-and-Handicraft-Wooden-Boat-Model-26_W0QQitemZ170455023594QQcmdZViewItemQQptZUK_ToysGames_ModelKits_ModelKits_JN?hash=item27afe93fea

The postage was a bit steep but I paid less than 20 quid for the model

First impressions is that its a very well made model.  Close up some of the fittings look a little cheap but if you use the 2 foot rule it looks nice and Im sure will look stunning on the lake in the summer
The downside of the kit is its rather a heavy old hector.  It weighs in at just under 3 kilos

Powerplants
A pair of speed 400s

Batteries
I have some 2 cell 7.4v  4000Mah Lipo cells that should be adequate for power supply

Propshafts
I Plan to use these
http://www.cornwallmodelboats.co.uk/acatalog/Raboesch_Precision_Propshafts.html
Raboesch Exposed Propshaft with Support Bracket 230mm M2

Props
Will be these ones
http://www.cornwallmodelboats.co.uk/acatalog/plasticm2.html
Graupner Part No: G2307.25 and G2307.25L

Rudders
http://www.cornwallmodelboats.co.uk/acatalog/boat_rudders.html
2x Micro Rudder 33x22mm
These will be linked to work from one servo (exact details as yet undecided

Speed controller
Ripmax no limit RC car controller I had spare.  It will easily handle 2 400s as it was designed for use with "Very hot" 540 car motors

Receiver
Futaba 2CH 40Mhz (Have many of these for some reason)

If anyone else has done a conversion to this model I would be interested to hear how you went about it.
Also some anyones thoughts on the choice of motor, prop, rudder etc would be most appreciated
Title: Re: Ebay Vietnamese Aquarama RC Conversion
Post by: pompebled on March 06, 2010, 04:43:04 PM
Hi Essex2visuvesi,

These boats look stunning, but if you're planning on making it run like the sportsboat it is (on the plane), two 400 motors are not going to cut it (by a longshot...), you'll need something more substantial.

Check the 'horrorstories' on this forum!
http://www.rcgroups.com/forums/showthread.php?t=980347&highlight=equipage+riva

Biggest issue with these boats is the fact that the interior isn't sealed against moisture and the wood will swell up and crack, making a very leaky hull.
Dealing with this and reducing the weight of this heavy hull would be to strip the boat as far as you can, sand down the bottom down to the bare wood and reinforce it with a thin layer of glasscloth and epoxy resin.
Once that is done, take a Dremel and remove as much wood (and MDF) from the interior as you can and reinforce the inside with glasscloth and epoxy resin aswel.
To get to the parts you can't reach, pour some thinned epoxy into the hull and turn it around until you're sure every nook and cranny has been reached by the epoxy resin, pour out the remaining resin.
If in doubt, repeat the resin pouring, or the hull will get wet in the spots you missed and it will crack.

Once you've prepared the hull for running in the water, ask for motorsuggestions.

Regards, Jan.
Regards, Jan.
Title: Re: Ebay Vietnamese Aquarama RC Conversion
Post by: essex2visuvesi on March 06, 2010, 05:19:50 PM


Biggest issue with these boats is the fact that the interior isn't sealed against moisture and the wood will swell up and crack, making a very leaky hull.


Thanks for that info but I think maybve the specs have been changed since those posts were made.

The reason I say that is because I have opened mine up and It appears to have been coated on the isde with some kind of resin or varnish.

how much larger should I go engine wise? a pair of speed 600BB turbos or bigger still?
Title: Re: Ebay Vietnamese Aquarama RC Conversion
Post by: pompebled on March 06, 2010, 05:45:02 PM
If you search the fora for the motorisation used, you'll find that two 700 motors would work well in a light scratchbuild hull, but it's too heavy for theEquipage hull, as you'll need 12-24 NiMH or the Lipo equivalent to power these motors.

Two 600 motors will be on the edge to get such a heavy hull on the plane, the runtimes will be short, due to the weight restriction, which will not allow for large battery capacity.

The weight/power ratio of small brushless motors is much more favourable for your hull, with two long can 380 1300-1500KV motors you'll have more power than with two 600 motors.
Using the (relative) light Lipo's as a powersource is a much better option to get this boat running on the plane in my opinion.

If it were my hull, I'd add glass cloth and epoxy resin to the running surface anyway, as the hulls are assembled in a very humid environment and if it's only covered in resin, or varnish, it will dry out and crack over time...

Regards, Jan.
Title: Re: Ebay Vietnamese Aquarama RC Conversion
Post by: craftysod on March 06, 2010, 07:12:42 PM
These hulls do crack.
I bought the Rivarama,and after 3 weeks sitting in my living room,cracks appeared in the paint on the bottom of hull.
So far got 2 race (with gearbox) 600's in it.
Propshafts/rudders fitted.
Plenty more to do before goes near water
Mark
Title: Re: Ebay Vietnamese Aquarama RC Conversion
Post by: essex2visuvesi on March 07, 2010, 09:13:42 AM
Thinking outside the box on the Engine front I do have one of these from a stillbord RC plane project lol
http://www.horizonhobby.com/Products/Default.aspx?ProdID=SAIE060T

Think that will have enough power?  :}
Title: Re: Ebay Vietnamese Aquarama RC Conversion
Post by: pompebled on March 07, 2010, 09:37:51 AM
I'm not very familiar with IC engines, but the rpm does fit.

An electric twin motor set-up with batteries will weigh about 1000 - 1100 grams, depending on the specific components selected, if your Saito (737 gr) including mufflers, gas tank and gearbox (to drive two propshafts) will weight about the same, and you have room to cram it all in the hull, it certainly is an option.

Oddly enough, the website doesn't give the dimensions of the motor, or how much Hp is has, but as you have it at hand you should know that.

The biggest challenge will be to make a fourstroke engine watercooled.

Regards, Jan.
Title: Re: Ebay Vietnamese Aquarama RC Conversion
Post by: Martin [Admin] on March 07, 2010, 12:17:01 PM
Essex2visuvesi, could you take pictures of your so we can what you are actually dealing with?
Title: Re: Ebay Vietnamese Aquarama RC Conversion
Post by: craftysod on March 07, 2010, 01:18:44 PM
Peterm on this forum has done a conversion,he uses 2x540 motors
Title: Re: Ebay Vietnamese Aquarama RC Conversion
Post by: essex2visuvesi on March 07, 2010, 01:56:31 PM
I'm not very familiar with IC engines, but the rpm does fit.

An electric twin motor set-up with batteries will weigh about 1000 - 1100 grams, depending on the specific components selected, if your Saito (737 gr) including mufflers, gas tank and gearbox (to drive two propshafts) will weight about the same, and you have room to cram it all in the hull, it certainly is an option.

Oddly enough, the website doesn't give the dimensions of the motor, or how much Hp is has, but as you have it at hand you should know that.

The biggest challenge will be to make a fourstroke engine watercooled.

Regards, Jan.

Full specs and dimensions on page 21
http://h1072147.hobbyshopnow.com/ProdInfo/Files/SAITO_Twin-Cylinder_Four-Stroke_Manual.pdf

gives out roughly 0.9HP

Ill take some pics and dimensions of the boat later