Simon's 13" Balsa Cat

[crabstick]

On the ESC Simon,

I once had a similar problem so I removed the spring from thethrottle of the pistol radio, and made a ratchet, similar to what Aircraft radio has on the throttle, worked well, even used it on my nitro boats.

[Simon.O.]

Now the esc is the least of my worries.
This motor is giving me a bit of stress and I have not even got the hull wet.
There is a major vibration and the motor is the cause. I will run it one time on the water but I have very little confidence in this motor. The vibration makes a lot of noise, more that I am happy with.
If all goes bad then I will swap in the motor that is destined for the 18" hull and get a new motor for that one, a bigger one possibly !

[Simon.O.]

I have the esc sorted now, a good read at luchtime today on the HK site got me the info I needed, This is now deffo a pistol compatible esc.

I just got back up from the workshop after wiring in the 450 size OR to see if that made it all better. No !
This thing makes about the same amount of noise as the smaller OR.
I am now at the point that I assume that 6 pole OR motors are louder in a hull than 2 pole IR motors and I'll have to live with it.

I just hope some of the residents near the pond I run at do not mind at 8am on a Sunday morning.

[Jesse J]

are you sure its not in the shaft? you run wires right? try swapping a different wire in. I have had them get small bends right at the coupler and make all kinds of vibration - to the point of breaking loose the mount - or maybe that was the 50 mph tumbling crash....

[crabstick]

I just hope some of the residents near the pond I run at do not mind at 8am on a Sunday morning.

Just tell em to be grateful i don't bring a gas boat up there with an un muffled Quickdraw Hotpipe on it

[Simon.O.]

are you sure its not in the shaft? you run wires right? try swapping a different wire in. I have had them get small bends right at the coupler and make all kinds of vibration - to the point of breaking loose the mount - or maybe that was the 50 mph tumbling crash....

Jesse, it is deffo the motors, I have run them in the hull on the bench with nothing attached, then with a coupler only and then hooked up to the wire shaft.
Funily enough they are no noisier with the shaft all hooked up.
I'll have to wait a week or two until I can get one in the water and see how it goes.
The main issue is that the quarry pond has a great acoustics and the sound bounces all over the place.

If anyone complains then I'll deffo get Matt to bring up a gasser.

[peells]

yea really Crabstick, the electric is quieter than a vaccume cleaner and sounds better too!

[peells]

Cool great sound effects will make a great video (or audio)

[Simon.O.]

A bit more progress, curing the balsa sealer in the cold weather takes time and I have other things to do as well.
Hatch is now made.
Motor is mounted.
Stuff tube is in.
Strut holder is made.

To do:
Sand and seal more and then varnish.
Make a rudder and standoff assembly and then set up the steering linkage.

I think two more weeks and this will hit the pond !!

[peells]

Ahhh Warping the old Hatch!! I know the process well, now if you paint the inside the paint will shrink causing the warp to go the direction you want in theory anyway a few nice coats should do it, you may want to tape it into place for a few days putting some balsa blocks on the high spots (before painting)

[Simon.O.]

Peter, you are absolutely right on the painting thing. I find that the sealer I use pulls the balsa inwards. Once the topside is done too it all evens out a bit.
This was under so much lead as it is actually 2 layers of 2mm balsa layed at 90deg to each other. A 4mm laminate in effect. Much stronger yet still a little bit of flex.
It does take a few days to get this right. I learnt a lot doing the hatchs for my new tow-in boat.

[peells]

Simon,
You might try laying the balsa at 45degrees to each other as opposed to 90 degrees it should form eaiser, but if you check my lynx build, you will see I am no stranger with warping hatches, on my present build I may use some styrofoam to build my hatch and then coat it with epoxy that seems to work rather well (no warping) easy to work with as well.

[Simon.O.]

Peter I'll give the 45deg thing a whirl with my next build, should not be too far away for that one. I have a wet and cold winter looming soon.

Here is the rear hardware, it is ready to run when I get a small heatshrink sleeve onto the rudder pushrod tube.
It is functional and is similar setup to the 18"
Some of the parts are recycled but the rudder is new

A bit of time polishing all the metals bits may happen in the deep dark winter.

[peells]

Looks like you are gettingf there!!! I hope you do not need any extra room up front for the batteries.

[Simon.O.]

Peter It will now be a while until I know if I need more weight up front.

It got wet today and my first impressions are good.
I did not pin it hard from a standstill to see if it did a corkscrew impersonation, I gave it gentle power and now know what Jesse means when he once described his small cat as 14" of torque roll over fun.
The torque roll is massive and during the transition from displaced to planning ( if you do it gently) it is nearly frightening how much the hull rolls over to the right.

Once on the plane it was a different ball game. This thing was moving all the right ways for about a minute and then it all went quiet.
The motor dropped a coil and made quite an interesting smell in the boat. Not that real cooked esc or blown lipo smell but a new one (for me) that is more like hot varnish.

Upon later inspection is is clear that one of the coils on the motor has decided to retire. Fair enough as it was one of the very cheap OR motors from HK and I should have got a Turnigy from the start.

I will fire one more OR motor into this hull before I revisit the idea. There is room to fit a small 20-40 watercooled IR in there and I will take that option if OR's are not going to be fun.

I think somehow that OR's may be a lot of fun though.