I'm thinking twin super Vee motors on 4s would make this hull rip :)
Heath
I'm thinking twin super Vee motors on 4s would make this hull rip :)
Heath
The guy who did my laser-cutting is very keen to help anyone worldwide out with similiar jobs on balsa and plywood. PM me for the contact details.
Hi, How do you guys secure the hatch. I am thinking of a base of ply around the
outline of the hatch opening and High density weather stripping. Any help will be
apreciated. Thanks
Norman
Must guys just use hockey tape to hold it in place, this also keeps the water out..
Heath
yep, I make a piece of balsa with my custom canopy and just tape her shut. If you wanna get fancy, you could make a little shelf, so the hatch doesn't fall in - they are WAY too cool looking when sitting nice and flush and the hockey tape is pretty clear so clean sailin!
lomodel Hi, Could you PM me the contact for laser cutting. I won' go through this
again. Thanks
Norman
Hi Jesse and all in this thread. Attached photos of latest progress. Have completed
sheeting and first coat of white polyurethane sealer and primer. Use white so I
can see any ding or imperfection. Once sealed will primer and fiberglass over
silkspan. Still a lot of sanding and finishing before it is smooth. Now for the hardware
from OSE. Regards
Norman
PS. Will work on hatch while waiting for sealer drying
Last edited by Norman2; 04-12-2009 at 08:51 AM. Reason: forgot some info
Great job Norman! I've been busy and you snuck this update in on me. I like the staggerd strakes, I think I noticed that on the plans but forgot when I was adding them... Sorry if I talked you into hours of bandsaw torture, I kinda like cuttin stuff on my bandsaw (one of my good friends). The trick to the lasercutting is to make sure you know how wide your slots will be compared to the thickness of wood you will be slotting. I have never done laser cutting, but definitely like the ease factor!
How ya gonna do the hatch?
Hi Jesse.It was hard work on the bandsaw but well worth it. I am using 1/32
basswood for the hatch. Will post pictures soon. I am building a shelf all around
the outline of the hatch opening 1/8 x 1/2" ply. It will sit on high density weather
stripping and will self lock in front and two screws will hold the back. Pretty neat
and my titan 29 never leaks. I will keep you posted. Regards
Norman
PS:I put the strakes in that position because I used to own and drive a 32' Champion Offshore cat and that is where it had the strakes.
the rear ones act as a mini turn fin and keeps the transom from sliding during turns. Hope it works. regards
Norman
Last edited by Norman2; 04-13-2009 at 07:05 PM. Reason: forgot information
I have a few 3S lipos that I want to run my twin version on. Will 2x 540 6XL motors with X442 props have enough oomph?
I have played with FE calc a bit and for Twin cats use the Hydro settings which should reflect the fact that 2 motors are in there.
This is still a guess. !!
6XL on 4S over 442 props will show.
101 amps 931W out of the motor 26.900 rpm 48 mph.
The question now is do you have the 6XL cans yet ??
If not, given that you have a bunch of 3S packs then you could go 6S on a higher wind motor and drop your amp draw for the same power output.
See it....find the photos.....sketch it it....build it........with wood
lomodel Hi, I used a polyurethane sandable wood sealer by Valspar. Got it in Lowes.
Silkspan a very light material used to cover R/C Aircraft wings. The fiberglassing
is only a very light and thinned coat of resin just to impregnate the silkspan. It is
very light but very strong. It could do without it but I need strength and a perfect
finish. Regards
Norman
Hi lomodel, Yes no fiberglass cloth. That would be heavy. Silkspan is 1 oz per square yard.
Will post photos. regards
Norman
I reinforced the plywood motor-mount bulkhead with glassfibre and glued the rest of the frame in place. I decided to do the sheeting with 1,0mm balsa instead of 0,8mm(1/32") to strengthen the hull a bit.
Hi lomodel, Looking beautiful and really straight. It is a lot of hard tedious work but
you will not be sorry. I have fiberglassed mine and now on the final coats of primer.
Need to wait for hardware, motor and esc from OSE which will be here next week.
Will report progress. I am having a hard time making the canopy but I just may
carve it from a block of balsa. How are you doing yours? Regards
Norman
Norman, I would really like to see your latest pics. For the hatch I had the longitudinal and cross sections of the cockpit laser-cut as well (see far left in pic) and will fill the four corners in with some kind of foam that will be shaped and fibreglassed. That will be stuck onto the hatch cover with supporting strips beneath it. Will post pics after the weekend as well...
I make my own canopies/hatches from insulation foam and epoxy.
First, I find a canopy I like and trace a sideview and top view. I gluestick this to a square-as-possible rectangle of foam, so the topview and sideview are nice and orthogonal.
I go to mr bandsaw and carefully cut out the two views, being careful to keep the piece opposite the paper with the trace (so I have a nice square base for cutting).
Then I get my 80 grit sanding block and get the rough shape, taking off the sharp corners - but not altering the base. Hang on to the chunk of foam cut off the base for next process. Once you get the shape you like, drop down to 220 or 320 grit depending on your patience.
Now get your hatch (I use a solid piece of whatever the decking was) and your base chunk of foam. I tape this hatch board to the chunk so it has the perfect curve of the deck. Then epoxy on the canopy where you have marked that it should go, I use a sharpie and eyeball it, but I am sure others will measure for precision. If you have the top chunk of foam, you can sandwich it on top of the hatch and add some weight to the top. Let this cure thoroughly.
Now, get your favorite epoxy resin. I have only glassed one hatch, but you can definitely add some cloth to this step if you wan. Leave the hatch in its tape down from the last step, you want it to keep the shape of your deck and all the epoxy that will be applied will do a good job of retaining the grace. The first coat of epoxy is ALWAYS ugly. All kinds of bubbles will come out of the foam, so don't despair. let this cure solid, then add one or two more to be sure it is SMOOOOOOth as a baby's butt. I like to leave the high gloss finish, but if you want to do some final shaping, go for it.
Last step. Eyeballing with a sharpie, I go around the bottom of the hatch about 1/2" within the edge of the canopy and then use dremel with cutting disk and retrace your pen mark. This allows you to remove all the foam and have more room vertically for electronics and airflow. Paint her up and tape her down! It is extremely durable and as cool as you can imagine!
now get to work, wanna see it!
Hi Jesse, Thanks for the advice. I am on my way to Lowe's to get the foam and
the resin. My canopy will be smaller than yours which I am copying from my
Champion Cat. But I got the idea. Thanks again. Will post pictures soon. Regards
Norman
Thanx for that extended explanation Jesse! What insulation foam you using, the pink one?
Hi lomodel. Probably using pink construction foam. Best for flotation. Regards
Norman
Ps: Yes Pink
Mine is the kind used as the base for the kitty. I just went to my LLS (lumber store) and asked if they had any scrap chunks, or dinged up boards; the guy took me to a 4'x 8' piece that had a corner broken off and asked me how much do you need? He then cut off a 24" x 4' strip and said, "tell em it is a scrap at no charge" It don't matter what color, just what ever is cheapest/free-est! if you like pink, then get pink. there are lots of colors and thicknesses, 2" allows for most custom and room for cutting. I prefer green or blue since that was free.....
Hi, Well, am now in the process of primer and finishing. Installed hatch but you
will notice it is a little bit indented. This will be corrected when I install 1/16"
weather stripping which is what I use to seal my hatch. Now working on the
canopy. More work. regards
Norman
Norm, you gave up on the canopy, i just gave up on this whole @#$%^ build! I made a complete mess of the sheeting and broke a few balsa parts in the process and the bulkhead designs need some tweaking as well. It all went great, I cross sheeted the tunnel floor with 2x layers of 1/32" balsa, beautifull... Then the sheeting started and all went horribly wrong. I only spent about $50 on balsa up to now, so no big loss there, only frustration. But it IS my first scratch build...
I'll probably tweak the design a bit and then start all over again in a few months. Tip: use 3mm Ply for the frame if you have access to a laser cutter. For a 30" cat, balsa just isn't strong enough!
Hi lomodel, Really sorry to see you gave up. Mine is ready to paint as soon as
all my stuff comes in from OSE. I will set up stuffing tube and strut up, mask the
strut and final paint. Cat will be medium metalic silver ( Mercedes Benz Color).
If I may, some advice. When I did my frame with 1/8" balsa, once I glued it
together on a jig, I fiberglassed everything with thinned out resin. This makes it
super strong. I used 1/16" balsa for sheeting and no problems. I then cross grained
with 1/64" plywood and no problems. The hardest part I have found is the finishing
with Putty and many coats of primer. The other problem I encountered was that
darn canopy. Finally gave up and ordered an SV 27 canopy which I will implant to
my hatch. Well, when at first you don't succeed try again. By the way, this is the
last time I try this. Next time I will buy a Jolly Cat hull. regards
Norman
What was the order of sheeting you did? Sides or bottom of sponsons first? I am now also thinking about the 32" eBay cat hull...
Hi lomodel, I first sheeted bottom of tunnel, then bottom and sides of pontoons.
I then reinforced all glue joints with more glue. I then added flotation and finally did the top. The whole thing weighs 15 oz. The chineese cat is pretty good
but should be reinforced with some CF. I thought about getting one but was determined to build one myself. Regards
Norman
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