Tweet
I decided to document this build, since it's been awhile since I've publicized one. 
I picked up this Keith Bradley Boats Radtek 25" Carbon Mystic a bit ago for the purposes of building a SAW Cat to play with. What can I say... small boats travel well!
The plan is to set this up for the N2 class SAW racing. 1 motor, 2S1P, and a whole lot of tuning.
I asked that this boat be laid up "light but strong". It can VERY well laid up, and very strong. Not the lightest boat, however. I don't think it's too bad, and it will definitely survive the abuse it's going to get.
Fitting a single motor in this thing is going to be a challenge. I've decided to make a dropped down "engine well" to allow the motor to fit under the hatch. I'm building a plug for a mold so I can form the well from vacuum bagged carbon. More on that later.
While getting that ready, I have fitted a rudder and fabbed and fitted a strut assembly.
Rudder is this OSE part number: http://www.offshoreelectrics.com/pro...prod=ose-80055
It's a little long, but otherwise about the right size for what I need to do. I'll be shortening this blade quite a bit, and will likely eventually replace it with a stainless knife blade. We'll see how this holds up. Offset is to the left to help counter prop-walk and hopefully help to control the boat at speed.
The carbon strut blade material was made for me by Brian Buaas. Nice stuff. Very rigid. Super light. I'll be running a 1/8" stubshaft on 1/16th inch wiredrive, so the strut will employ the bearings in each end. More on that later as well.
Because of the very tight mounting spaces on this boat, using backing nuts, or nut-plates, was not an option. There isn't a flat surface inside the transom for them to seat properly against. To allow for a solid mounting, I cut a couple of short pieces (about 1" and 1 1/4") of 5/16" aluminum rod, and epoxied them inside the transom at the mounting points. Once the epoxy had set, I drilled and tapped through the transom with a 4-40 tap, and mounted the hardware with 4-40 stainless socket head screws.
On the rudder, I'm not sure what the original size of the pivot is, but it's likely metric, and definitely not "SAW" level "tight". It's a little sloppy, in other words. To remedy this, I used a 0.125" (1/8") reamer to size the brass bushings and the rudder pivot hole in the rudder, and will be cut a 1/8" stainless axle rod to fit. This will provide a much tighter and more precise fit. Don't need rudder slop at 70+mph.
I picked up this Keith Bradley Boats Radtek 25" Carbon Mystic a bit ago for the purposes of building a SAW Cat to play with. What can I say... small boats travel well!
The plan is to set this up for the N2 class SAW racing. 1 motor, 2S1P, and a whole lot of tuning.
I asked that this boat be laid up "light but strong". It can VERY well laid up, and very strong. Not the lightest boat, however. I don't think it's too bad, and it will definitely survive the abuse it's going to get.
Fitting a single motor in this thing is going to be a challenge. I've decided to make a dropped down "engine well" to allow the motor to fit under the hatch. I'm building a plug for a mold so I can form the well from vacuum bagged carbon. More on that later.
While getting that ready, I have fitted a rudder and fabbed and fitted a strut assembly.
Rudder is this OSE part number: http://www.offshoreelectrics.com/pro...prod=ose-80055
It's a little long, but otherwise about the right size for what I need to do. I'll be shortening this blade quite a bit, and will likely eventually replace it with a stainless knife blade. We'll see how this holds up. Offset is to the left to help counter prop-walk and hopefully help to control the boat at speed.
The carbon strut blade material was made for me by Brian Buaas. Nice stuff. Very rigid. Super light. I'll be running a 1/8" stubshaft on 1/16th inch wiredrive, so the strut will employ the bearings in each end. More on that later as well.
Because of the very tight mounting spaces on this boat, using backing nuts, or nut-plates, was not an option. There isn't a flat surface inside the transom for them to seat properly against. To allow for a solid mounting, I cut a couple of short pieces (about 1" and 1 1/4") of 5/16" aluminum rod, and epoxied them inside the transom at the mounting points. Once the epoxy had set, I drilled and tapped through the transom with a 4-40 tap, and mounted the hardware with 4-40 stainless socket head screws.
On the rudder, I'm not sure what the original size of the pivot is, but it's likely metric, and definitely not "SAW" level "tight". It's a little sloppy, in other words. To remedy this, I used a 0.125" (1/8") reamer to size the brass bushings and the rudder pivot hole in the rudder, and will be cut a 1/8" stainless axle rod to fit. This will provide a much tighter and more precise fit. Don't need rudder slop at 70+mph.
Comment