Fightercat CF Cheetah Big Single build ~

[mekzoid]

Hi everyone,
This will be my first build. I decided to go with the Cheetah due to the width and the build quality, Initially was just going to get the fiberglass version, But Kevin offered the CF version to me for a price I couldn't resist.

I did a lot of reinforcing, I did a coremat sandwich (cf coremat cf) from the rear to the end of the hatch, then just coremat up the front as its quite hand to fit your hand up there. I wet the hull first, Wet the coremat then laid the coremat and poked it in place with a stick. At the moment it sits at 1892grams, heavier then I wanted it to be but at least it wont break.

The goodies:
TP 5660 1420 kv running on 2x 4s 5a Dinogy lipos. Under load, Should be spinning around 35k rpm with a 554 prop
Swordfish 300a ESC ( might change this, Not really sure at the moment. Advise would be great)

This will be a slow build as I have a broken wrist, Everything was done with my right (main) arm in a sling and cast!

I am looking to get 80mph out of it for speed runs and 70mph most of the time.

EDIT: Sorry about the pictures being skewif, I have no idea how to rotate them!

[Mattwarner]

Nice work on the inlay but I have to say this seems total overkill for this hull and I personally think a 60mph setup will be much more appropriate especially as this is your first build and even with all the reinforcement a 80mph spill is going to be a disaster especially with the weight of that huge motor.

Having said all that it's your build and I would certainly be interested to see how this runs!

[mekzoid]

Nice work on the inlay but I have to say this seems total overkill for this hull and I personally think a 60mph setup will be much more appropriate especially as this is your first build and even with all the reinforcement a 80mph spill is going to be a disaster especially with the weight of that huge motor.

Having said all that it's your build and I would certainly be interested to see how this runs!

Currently having stickers made out that has the text: "Overkill" haha

This is my first build, But not my first boat. Have played around a bit with 100kmh boats, But want something faster that I can spend the time fiddling with.

Surprisingly common setups for the cheetah are twin 4082s which equal 445 grams each = 890 grams + the weight of the 2 escs
The TP 5660 is 836 grams and only 1 ESC.

I do agree that 80 mph is fast for this hull, I want the record for the fastest Cheetah. Ill then put a 4074 in it for the wife then build something else that the 5660 fits into :) I will keep updating this thread, And will also take some video of the first run. I am really keen to see this run. If it breaks,well it breaks and I build something else haha

[mekzoid]

little update: Just added a cf support. And finished the coremat inlay in the sponsons.

All reinforcing has been completed and the final weight is 2.1kg, Quite heavy but the 'small' motor should be able to handle it /sarcasm :P

I am currently looking for some paint, I will just be painting the hull and leaving the hatch in cf. I really like the green below, any input would be great!

[kfxguy]

You need to add some floatation to the canopy. You never know. A new one ain't cheap. Im doing essentially the same build as you right now. I should be done with mine today. Check it out.
http://forums.offshoreelectrics.com/...hlight=cheetah

[mekzoid]

Yeah I saw your thread, It did get me thinking. I am going to wait to place the motor, then Ill sort that out. I will be doing the flotation for the hull intself today. I am not a fun of foam as I cannot remove it easily if I need to make repairs so Ill just be using pool noodles and see how they go.

[kfxguy]

If you spray the foam in the lid a small amount at a time then cut to shape and cover with a layer of cf, it will be a nice way to make it float.

[mekzoid]

Finally an update, Going slow as my wrist surgery is getting closer.

I am not exactly happy with the lines on the cf plate, But I learned from my mistakes and think the motor mount looks really good. This is my first build and is taking a while due to wrist pain but at least this keeps my mind off things!

The tp5660 was actually quite hard to fit in, It just misses the hatch by about a 1mm. The COG is a bit more then I wanted, Sitting at around 34% ish. The batteries are quite heavy though so I can always move them all the way back if need be.
I have never bought a motor that doesn't have a flat spot on the shaft, Do I need to machine a flat spot onto it?

Next I will be mounting the servo and finishing off the steering.
I will also be doing another layer of resin over all the carbon fibre to make it look presentable again.

Then I will do the driveline.

Would love some C&C, Will keep me going to finish the build.

[kfxguy]

Your crazy! Your motor mount looks fantastic! You do need to file a flat in the motor shaft. Very odd it doesn't have one. Keep up the good work! Btw.... I have another build coming up. I ordered another carbon fiber hull yesterday......

[mekzoid]

Another hull? really? What did you buy this time? :P You missus must be getting frustrated haha

[kfxguy]

Another hull? really? What did you buy this time? :P You missus must be getting frustrated haha

I'm gonna just call it the mini rivercat

[mekzoid]

Disappointing the amount of replies. Oh well it happens hey.

[srislash]

I don't know how I missed this one Todd, I haven't been on all that much as of late due to the new puppy and the no notifications from the board.
Looks like you've made the best of the ESC locating. Awkward suckers aren't they?

[Fella1340]

I felt the same way about the lack of replies on my build. People will catch onto it, it seems the less popular the hull the less input you will get. I have to say that's one crazy monster of a motor, it's the same size as I am putting in a 50" mono! Plenty of torque to go around and then some. I have the swordfish 300 as well. I very much dislike the way the wires come out the bottom. It's a tough one to keep the wires short and make a nice job of the mounting in a single motor build. I never thought of flipping it over, you have given me something to think about. The build looks great, don't see those those lines your talking about in the carbon plate. I look forward to the video, the extra weight may even help keeping in the water, who knows? It's named appropriately that's for sure. Good luck with the surgery.

[mekzoid]

Yeah I have no idea how KBB does his 300s, He must use tunnel for the wires as the logo is always facing upright. Its going to be quite heavy by the time its finished thats for sure. I am just finishing the rudder assembly today and I will upload more pictures. Thanks for posting fellas