Simons Bigger Cat.

[crabstick]

Looking Good Simon.

I thought you had learned the structural limits of balsa though and were going to use ply ?

[Simon.O.]

Looking Good Simon.

I thought you had learned the structural limits of balsa though and were going to use ply ?

You are rght in one way, I do know some of the limitations of the light wood.
This one has a few design criteria that allows for the extensive use of balsa.
It is lot heavier than previous builds not just in material thickness but in the framing and joins.
It will not be a stupidly fast hull either, I am looking for 60-70kmh or about 45mph. This way is will be stable and less prone to blowover or flips.
I have the riggers for speed and want to keep the Cats for onwater visual pleasure.
This one will be the bigger of 3 Cats. I will do a baby one next year so I have a full set of 3.

[crabstick]

I did notice it looked a bit thicker, you might find some 1/4 oz glass cloth and epoxy will give you added strength if you find you need it, the light cloth is not too hard to come by if you know where to look

[tylerm]

Simon mate i got some light glass for you if you want it, some carbon twill as well.

[Simon.O.]

Tyler & Matt I may look at some composite material if the wood is not up to the job. Like if I suddenly feed the 7xl with 5 or 6S for a giggle.

For now here are a few of the possible battery configs I can use
2x2S stacked
2x2S saddle
1x4S, this is the funny green and yellow taped pack. A PQ that had the shrink pulled as it got wet once.

All of these options give me the 30% Cg with the big green 5xAA rx pack where it is. I can easily shift the Cg a few percentage points with Sub-C ballast cells. I am sure this hull will like the added weight as do most of my smaller ones.

I have these options as I will never buy a 4S pack again. 2x2S is easier as if one pack goes off the boil then I can easily use the other in the 2S boats.
It gives me a lot more flexibility across the fleet.

[CornelP]

Somehow I think the saddle will be more balanced or 'settled', do not know how to explain it, just a feeling...
If you leave the motor so far back, you will have a problem if you go wiredrive... I snapped one because of the bend angle... hate it. I guess it also depends on thickness, mine was 2mm, but probably a 1.5 would have been fine, IF it can take the torque from the motor...

[Simon.O.]

Somehow I think the saddle will be more balanced or 'settled', do not know how to explain it, just a feeling...
If you leave the motor so far back, you will have a problem if you go wiredrive... I snapped one because of the bend angle... hate it. I guess it also depends on thickness, mine was 2mm, but probably a 1.5 would have been fine, IF it can take the torque from the motor...

I think I know what you are saying about the saddle config.

The motor is just on 13" in front of the drive dog and I have laid this out on my bench a few times to get all the angles correct. I do a lot of bench testing including running prototype stubs in struts with no lube etc.
I have run wires in a tighter bend than this will be with no dramas.
I will be using 062 wire down a 1/8" stuff tube sealed at the motor end.

Still thinking about a prop

[CornelP]

Well, my 30" runs now on a 45mm Graupner carbon... but it was smoother and cooler on 43.

[ozzie-crawl]

i am thinking a 440/3 for a 7xl 4s1p setup

[andym]

Hey Simon I am running an evil m447 on a 7xl in my Raptor Rigger and believe it or not it is OK temp wise and insane speed wise, will mod one for you if you like? I am so impressed with the build I will do it for free just supply the blank. A x or m442-45 would be awesome just send me the blank mate

PS; have 2 x 25c PQ 4s packs I do not use , you want em? Postage only

[Simon.O.]

i am thinking a 440/3 for a 7xl 4s1p setup

Given that this hull is a loose interpretation of the HOTR that you have run well and fast, I'll take your call on that one. I had a SV27 prop which I believe is similar to a 440/3 on the mono with the 7XL when it did aquatic qymnastics
It was a wicked prop for that motor.

All I need now is 2 things.
1. Confirmation that the SV27 prop is close to a 440/3
2. If so then I need a 440/3.

I have a 637 and a 642 (cut to 640) for testing. From there I need to find a suitable prop, like a 440/3
Plastic, carbon, Raw, S&B, blessed by the town mayor ? Anything is considered.

[andym]

I have a little 3 blader sitting there doing nothing, want it?

[Simon.O.]

I have a little 3 blader sitting there doing nothing, want it?

Andy, you know the answer to that question already. You are a Gem.

[Flying Scotsman]

Given that this hull is a loose interpretation of the HOTR that you have run well and fast, I'll take your call on that one. I had a SV27 prop which I believe is similar to a 440/3 on the mono with the 7XL when it did aquatic qymnastics
It was a wicked prop for that motor.

All I need now is 2 things.
1. Confirmation that the SV27 prop is close to a 440/3
2. If so then I need a 440/3.

I have a 637 and a 642 (cut to 640) for testing. From there I need to find a suitable prop, like a 440/3
Plastic, carbon, Raw, S&B, blessed by the town mayor ? Anything is considered.

The SV27 standard prop will not give the performance of a sharpened and balanced X440/3 and believe me all 3 bladed props are a bugger to balance. My 2 pennies

Douggie

[Simon.O.]

An update. I have been busy at work and at home with the school holidays, spring growth on my lawns etc.
I have got some work done on this hull.
My "thing"on this build is to have all of the joins reinforced and sealed. This is what takes time.
Here we have the hull ready for decks and with decking on the sponsons, and the HW nearly ready to fit.
This is still 2 weeks minimum to the water.

AndyM has kindly donated some gear (props and packs) towards this project and I'll see what arrives in the post next week, a bit like Christmas really.

Here ya go.