Osborn Miss Canada III help needed !

[jonathan szymanskiParticipant @jonathanszymanski41293]

Hi all/anyone!

The last time I touched a model boa wat about 20 yrs ago when it all seemed alot simpler!……I would wire up a graupner speed motor, a couple of micro switches and as many batteries as I coulf fit in the boat as poss and hope nothing melted! …was great fun!

now ive had an return to the game and bought myself a Osborn Kit 'Miss Canada III 1:12 kit to build…..im half way through….looking good ish, been throwing epoxy all over the place making a right mess, but having fun with it……just only stumbling block is the electrics and drive shaft/prop etc!……anyone have any knowledge etc on this with this boat…..? I'm thinking i would just stick a car esc in it as i would like to cruze at lower speeds most of time but also open up every so often and from what i have read the care esc's are better for that ( also a bit of reverse may be helpful ) … need to get the boat fast enough to hydroplane properly also! I have read loads of furums on brushless motors, prop sizes etc but just have no idea wat to go for. ( or do i really understand it all )…. not wanting to blast a load of money at it but also dont want to wast money on stuff thats going to blow up!

any/ all help appreciated

all the best

jon

[jonathan szymanskiParticipant @jonathanszymanski41293]

[Paul TParticipant @pault84577]

Hello Jon

Choosing the correct type of ESC depends upon the current draw from the motors so the first thing to do is select the motors.

A good starting point is looking at the motors that the kit manufacturers recommend.

Paul

[jonathan szymanskiParticipant @jonathanszymanski41293]

hi paul

the instructions are pretty old/basic and only mention a 7.2 volt battery and standard brushed motor….was thinking of a brushless setup with nimh battery …. have seen loads of them on ebay some cheap some very expensive and from what i can tell the specs seem to be the same so not sure if its worth spending the extra cash!

btw i noticed you from an old thread on something else where u mentioned a more traditional way of finishing a boat hull….i want to avoid epoxy if poss…..i have sanded and filled the hull so its super smooth…can i just thin some marine varish for a sealing coat …then layer up a load of coats of varnish with rubbing down etc for the top of the boat? and for the bottom of hull thin some primer and then paint a few coats of polyeurthane paint then cover with a coat of varnish? boats not going to be in the water 24hrs a day so thinking that would be allright? what do you think?

thank you for the help

jon

[Paul TParticipant @pault84577]

Hi Jon

Brushless are expensive and require their own special ESP (you might gather that I dont like them) I will have a search for the specs on your kit and see which motor combo would be best.

Regarding the varnishing what you have said is basically correct, I did cover it fully in an article about painting and varnishing for the website but I don't know where it is, if you are interested Colin might know where on line to find it.

Signing off now until tomorrow.

Paul

[Colin BishopModerator @colinbishop34627]

You can find Paul's article here:

**LINK**

Colin

[jonathan szymanskiParticipant @jonathanszymanski41293]

thanks colin thats ace! and paul any electrics advice would be great!

thanks all

cheers

jon

[Paul TParticipant @pault84577]

Hi Colin..Thanks for the link

Hello Jon

As the chaps here all know I am not renowned for my electrical knowledge so I like to keep these things as simple, and old fashioned, as possible.

After a little bit of research it would appear that your model is best suited to a 500 > 700 size motor. As a car builder you will be familiar with these types of motor so the only concern will be the best can size for fitting into the hull and wether or not you want to cool the motor.

The ESC and prop will depend upon choice of motor and as for batteries I always use NiCad simply because I have a lot of them.

As I said I am not the worlds expert on electronics and I would suggest that after you find the right motor you have a chat with Dave M as he is just about the best.

Incidentally I buy my batteries from 7Day Shop, I use their own brand which are very good and have never let me down.

Paul

Sorry to Liz who will now have to widen all the doors.

[jonathan szymanskiParticipant @jonathanszymanski41293]

Thanks paul…. Will take a look….I'm starting to think it best to go with brushed as I understand that so much better lol … Also your artical on boat finishing is very helpful! Thank you again

[Paul TParticipant @pault84577]

Hi Jon

I am known as a bit of a Luddite but I much prefer brushed motors simply because I understand them.

Thanks for the comment about the article I hope that it helps you with your varnishing.

Can you post some photos of your build?

Please feel free to ask if you need any more help

Paul

[jonathan szymanskiParticipant @jonathanszymanski41293]

super will do….!

[jonathan szymanskiParticipant @jonathanszymanski41293]

[Paul TParticipant @pault84577]

Hi Jon

Looking at the photos I would think that a 500 size motor will be more than adequate and will help keep the weight down. If you have one try playing with a Magic Johnson car motor.

Be careful where you position the motor ideally it should sit just rear of the centre point and angled to enable a straight connection to the shaft.

Paul

[jonathan szymanskiParticipant @jonathanszymanski41293]

cool will do…..i dont have a magic motor but have a coupe of other race brands to hand, cant remember the winds but i think one of them was a 12Quad ….it was pretty fast in the car at the time with alot of torque…..probly needs a good service now after 14 yrs sitting in a box! do you have an idea what amp boat speedo i would need to run it? i have a nice novak speedo but think its not up to boat usage…im going to follow ur advice and go for nimhs …the instructions recommend splitting a 7.2v stick pack in half and fitting them either side of the boat running along the edges….. u recon im pushing my luck if instead of 3 cells on each side i add 4 cells? think that would be 9.6v i think?

cheers

jon

[Paul TParticipant @pault84577]

Hi Jon

Splitting the pack is one way of distributing the weight but you might be able to position the complete pack over the shaft to the rear of the motor and still keep the weight low enough in the hull.

The number of cells will obviously depend upon the motor but keep in mind that whilst extra cells equals extra power they also increase the weight and change the effective buoyancy of the model.

The choice of ESC will depend upon the maximum current draw of the motor when its under full power in the water. Use the bath as a test tank and get hold of a basic multimeter to check the power draw.

If you like you could post a photo of the longitudinal cross section drawing and we can offer advice on best positions for batteries etc.

Paul

[jonathan szymanskiParticipant @jonathanszymanski41293]

Cool thanks will do that!

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