Cheers Alex, at least someone noticed!
The next item I need to turn my attention to is the steering. First the servo, there are of course a number of ways to mount the servo, the choice of which is mainly personal preference so here’s mine; I wanted to mount my servo in the same plane or aspect as my rudder arm/tiller, but this boat has a vee hull which doesn’t lend itself readily to mounting a servo square, either up-right or on its side.
Pic1. So I made a carbon fibre mount (first making mock-ups out of cardboard) this was glued in place then a commercially bought Ali servo mount bolted to this.
Pic2. I positioned this with the centre of the servo horn directly in line with the rudder, and as near to the transom as possible but still allowing access to the bolts securing the servo.
Pic3. Shows a stub of 10mm dia Ali tube which has been glued in place with acrylic adhesive that allows the linkage free movement through the transom, kept waterproof with a rubber billows style grommet. This will be secured in place by a small cable tie after the hull has been painted.
Pic4. Now for the prop shaft, the one I bought was over-long for this hull and needed cutting down, otherwise the motor would have ended up too far up the bow and I would have had problems balancing the boat & maintenance access to the motor itself. I sourced the correct diameter Ali tube to support the CF main shaft from a supplier on e-bay and bought a 100mm length only for a few pounds, and proceeded to the heart stopping surgery of cutting quite an expensive piece of hardware in half!
I removed 90mm of carbon shaft, cleaned up the ends and then bonded the whole thing back together. This operation isn’t for the faint hearted and I won’t be planning on repeating the same procurement mistake again!
I mounted my shaft approximately 5mm starboard from the centreline of the hull, this offset is to counteract the torque of the motor. One important thing to note, the shaft needs to be offset parallel with the centreline which means the motor mount needs off setting as well.
Now for the battery mount
Pic5. Some people like to Velcro their batteries down, which can be perfectly acceptable but if the Velcro adhesive is softened by water or shaft lubricant/WD40, there is a chance they can be thrown lose just when you don’t want them to be! A lose pack 280g of cells can make a mess of your set-up!
I’ve made mine from a piece of Ali L shaped angle bonded in place and added a Velcro strap to secure the cells.
And now for the cooling system which is a very important part of the boat.
The build-up of heat can wreck the motor, the ESC and Lipo cells. (you really don’t want a catastrophic failure of a large pack of lipo cells in a little GRP boat).
Pic6. Shows the start of the water’s journey from the rudder pick-up through the transom (via a bonded Ali tube)
Pic7. Then it connects to the side of the battery mount (not essential but at £50 a pack – why not help keep them cool?)
Pic8. Then it will join a water cooled ESC (on its way from HK at the mo)
Pic9. Then on to the motor mount. I’ve chosen a water cooled mount instead of a water cooled jacket that surrounds the brushless in-runner because I want to get the angle on the prop shaft to the bottom of the hull as small as possible. This sort of mount allows me to get the motor right down in the bottom of the hull. It’s not as efficient cooling wise so I will be adding a snap-on set of cooling fins to the top of the motor to help.
Pic10. Shows the final run of tube which is attached to an exit nipple out of the side of the hull (above the water line of course)
In the North; http://www.ampdraggers.co.uk/In the East; https://ostendospreys.wordpress.com/In the South; http://www.electrafying.com/ & http://shpowerboats.co.uk/In the West; http://www.swambc.webeden.co.uk/#/swarm-home/4581722394