Simon's 13" Balsa Cat

[Simon.O.]

I am now building two cats at once and the build logs will be similar for the first few posts and then naturally there will be variations in the build that needs a separate thread thus we have two new balsa cat threads.

This is a scaled down version of my bigger Cat and should work out well, There are no plans at all and both of these two new ones are being built by eye with a few rough scetches on a pad on the wall.

I will announce the power setup as soon as I have chosen one !!

As it is common practice to measure a Cat from the rear of the last step this counts as a 13" There is a good rear overhang and the the strut will be aft of that too.

Some pics for now.

[Simon.O.]

I have now chosen a power setup
Motor

http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=5245

Pack

http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=9456

ESC

http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=9299

Prop

http://www.astecmodels.co.uk/catalog/product_info.php?cPath=25_99&products_id=796

A couple of pics from today. The hardwood is in the transom and I am now ready to spray foam fill the hulls prior to shaping and skinning the topsides.

[d.g]

Looks great. Cant wait to see it finished.

[Simon.O.]

I was off to cut a doorway in a solid cast concrete wall yesterday so decided to foam fill the 2 cat hulls before I left. I came home and near wet myself laughing at the mess.

Well a bit of cutting and sandind today got me this.
I have most of the decking on and will start on the hardware soon.
I need to sort out a motor mount first.
Then there is the reinforcing of the tunnel floor.............so much to do.

A few pics for you all.

[Simon.O.]

The bottom is now complete, it will need a bit of sanding to get it true and flat. That will be one of the last jobs before this hits the water.

There are no steps at the moment and I hope that I can get away without them, I can always cut/sand them in later.

The decking is 90% there and now that I have the power system I can setup the inside and the rear.

The power system is:
400 size Heli motor 3500kv with a possible power output of 220+Watts
Esc is 40-50A with Bec
Pack is 1600mAh 30-40C which is good for 48-64A

This setup will allow me to feed in a bigger motor if I have to. We'll see !!

I think I will shorten a few wires yet before the connectors go on.
Pack to esc will be 4mm gold bullets and esc to motor will be 3.5mm gold bullets

Pics from today.

[Simon.O.]

Right !
I have just fired up the power for this baby and guess what ? The esc is not pistol compatible.
I tried a lot of variations of the beep-beep programing and got no where.
I can adjust the timing etc but not throttle position.

Ah well that is what I get for buying a very low cost unit, at least it has a good BEC and I will do the old fashioned rubber band trick for running this for now.

It may end up with a whole new power combo anyway so I am not too worried.

The existing power train may go to a micro rigger !

[andym]

Nice builds mate, more power is always better though

[Simon.O.]

Sealed and ready for sanding-sealing-sanding.......then varnish, yay !

The motor mount (not yet fitted) is made up some old parts, I love recycling hardware.
It is drilled so that the small motor fits but if I need more later then the 450 size OR from the 18" cat can fit in here too.

I now need to make up a hardware set for the rear and only then can I set the stuff tube.

Hatch will be last !

Pics from today.

[andym]

Looks good, what is the weight like ?

[Simon.O.]

Looks good, what is the weight like ?

I have not weighed it yet but will when the hull is complete, hatch included.
Then I will do a full weigh in with bare hull all they way to Rtr.
Both builds will get the same weigh in.

[andym]

Balsa or marine ply ?

[ABPMotorSport]

nice cat you are building here are you doing any cooling on the motor?

[peells]

For that esc you could find a PISTIX out there I found some from Ray Fuller and they do work great I have been using one for some time on my larger boat and they correct the pistol style radio problem with this type of esc. I was looking at that one as well but you can get one from ebay that is only a 30amp for like 4.00 plus shipping and they are compatable it is a yellow mystrery
http://cgi.ebay.com/ws/eBayISAPI.dll...#ht_2471wt_911
here is the link you may have to copy and paste it into your browser

[peells]

I would bve intrested in seeing a video of this when it is finshed, great work, are you running out of room for everything yet?

[Simon.O.]

Balsa or marine ply ?

3mm Balsa and foam filled hulls. The hatch will be a new design that will have great impact resistance too. I am learning !!

nice cat you are building here are you doing any cooling on the motor?

The motor will not be cooled but I will cool the mount a little if needed, short hard and fast runs are all I do. Sport/Saw is what I call it.

For that esc you could find a PISTIX and they correct the pistol style radio problem with this type of esc. I was looking at that one as well but you can get one from ebay that is only a 30amp for like 4.00 plus shipping and they are compatable it is a yellow mystrery

I'll do the rubber band thing until I need a new ESC and then will get a mystery type like all of my others.

I would bve intrested in seeing a video of this when it is finshed, great work, are you running out of room for everything yet?

Video is alwyas hard. Room is getting tighter but it will all fit.