seaplane tender

HI.

I`ve just about got the hull finished for the Seaplane Tender which John Parker  featured in Model Boats Winter Mag. He mentioned using brushless motors but not what size they are. Can anyone tell me if the the HYDRA COMBO which Mtronics advertise on the back cover of model boats would be o.k

Thanks

Tony

Tony. I think that they should be ok, as they sell them for boats...HOWEVER.. I did ask but cant remember for sure what size they are , I would go with brushed personally for a while yet, unless you want to go REALLY FAST. Weight is not normally an issue in model boats, and so you can put up with a slight loss in efficiency for a substantial cut in price....how big is the tender?

 

Ashley

Thanks Ashley.

 According to John Parker in the magazine it really needs brushless motors to keep the weight down. The Tender is at 1/12 scale which makes it around 39 inches with twin screws.

 

Tony

 

Hello Tony,

 

Sorry, I've only just spotted your post and fear my comments will come too late:

 

If you are more comfortable with brushed motors, then by all means use them, but bear in mind that with this model they won't fit under the scale motor housings and therefore will compromise the appearance apart from being heavier/less efficient.

 

If going brushless, it is hard to be specific as the range is bewildering and depends on where you are in the world.  Look for an outrunner of 28mm diameter and a KV rating of 1250-1500, such as the HiMark C2808-1360 I used and suggested on the plan.  The '28' of the designation refers to the diameter, the '08' to the stator length (go for 8 to 12mm) and the dash number to the KV rating, which is the rpm attained per volt of supply. 

 

The motor that comes with the mTroniks combo would probably be a little slow at 950KV, but it's quite a nice motor and you might be happy with it.  Upping the supply voltage to 12 volts would more than make up for the rpm loss.  On 7.2v, it would I think still give a good scale speed, but most of us look for having a little more than this.

 

I have subsequently fitted 1517/3-blade propellers from the Propshop to my model and find these are a very good match for the motors I used.  The fabricated ones I had fitted at the time of writing the article got completely mangled when I ran over a semi-submerged palm frond at the lake.

 

Hope this is of some help to you (or others).

 

Best regards. 

Hi there Yabbie 1

I started taking pics as I was building the  hull for the seaplane tender but unfortunately my computer crashed before i had chance to save them to a memory stick so I have had to start againafter the hull was planked. I dont fancy using the fibreglass mattting method (the thought of it terrfied me) so I put two coats of SP epoxy resin the inside and outside of the hull. It is ver strong and rubs down well with wet and dry paper.

Brushless motors in the U.K (well my area ) are regarded as something alien and only really used for model flight so only run in one direction. However I did get the Mtronics ones and the are same measurements of your and do seem very very powerful specially as they are so small. I have got the motors and shafts, twin rudders and servo fiied now. the well deck is finished including motor boxes. I didnt  see the need for cooling fans in our climate. I should have the rest finished by the end of may. I think it is a very pretty little ship.

I will keep your specs for the motors incase these are too  small

 Thanks Tony

 

Glad to hear you're making good progress, Tony.  Hmm, yes, the glass fibre sheathing does tend to put people off, but it makes a tough hull.  We'll be be interested to hear how you make out with the mTroniks motors so be sure to keep us posted and include some photos of the completed model. 

 

Yabbie1

Thanks.

will probably send a few build pics next week and when the Mtronics prove successful I will send pics of trials