Cheetah 6S: My first cat!

[larryrose11]

I wish I had a bare fiberglass hull with no reienforcment, so I could do that part myself better. Im pretty happy with my expirments with vaccumme bagging.

https://sphotos-b.xx.fbcdn.net/hphotos-frc1/477141_10200948374262165_1952599559_o.jpg

https://sphotos-b.xx.fbcdn.net/hphotos-prn1/902660_10200948374382168_1000067404_o.jpg

Perhaps Ill make a mold at the end of this season after I do the hull mods to correct the design flaw detailed here, perhaps a different hatch too.
http://forums.offshoreelectrics.com/...ull&highlight=

I would make a hull using the mold. It would be vaccumme formed, and out of a fancy pattern CF on the outside, and inner layers of innegra. It would be super strong, and probally lighter than what I have, 1.232 kg.

http://www.fibreglast.com/category/Patterned_Carbon_Fiber

[larryrose11]

I have not update in a while, and have made a lot of progress, but Ill update the thread in a sensical way.
OK: Vacuum bagging the CF inlay layers.
I decided to have 6 layers on the transom, 2 layers in the sponsons, and 1 layer on the tunnel, all 5.7 oz, 220 gsm, CF. Im usoing West 105/207 epoxy.

Here is the vacuum bag.


Here is it in process.

[larryrose11]

Not all went well. There were some pin hole leaks in the vacuum bag, and there was some bridging in the CF in the transom, and in the sponsors. Took me a while to sand out there is didn't make good contact. To make the repairs, I decided to go back to a tried and true method, compression molding.

Here is me compression molding some CF layers into the transom. You can see the breather material(cotton looking), and the peel ply Im using. I will to the same process on the sponsons.
The CF in the tunnel went really well. It looks dull right now till I put on the final top coat of epoxy

[larryrose11]

OK, Time for an update.
I have got a lot done, but Im trying t present it in a order that makes sense.
The interior CF layup is done, as much as Im going to.

The layers are:
Sponson bottom's: 3 layers, 5.7 Oz, 3k CF cloth
Transom: 6 layers 5.7 Oz, 3k CF cloth
Tunel: I ran out of 5.7 os cloth, and I used 1 layers of 3.7, and then a layer 5.7 Oz, 3k CF cloth

I used 2 methods of layup: Compression molding, and vacuum bagging.
Vaccume bagging is difficult when the edges of the vacuum bag are not smooth, and easily accessible. Lesson learned there.

I was able to make it look pretty good, but I did accidentally sand through a layer of CF when I was trying to make it all smooth, and using a pad sander. The sponsons are not so sommth, but they will be covered up by the large battery trays Im making.





Hhere is a good view of the Transom.

[larryrose11]

motor pr0n

While I finish blueprinting the hull, Ill show off the Motor, water jacket, and custom mount I made.

I realized that the mount I originally purchassed from Basstronich would not fit the motor I just got from ironjaws. A different mount would be necessary.
He sold me a Neu 1521 1y, a water jacket, and T180 ESC,

Here are some details of the mount I made.
Once I made some measurements, I laid out the mount points on a grid. and drew in the basic shape. I photo copied it, and taped it to some plate stock I had on hand.


I then put it in a break, and folded the feet, for a long mount contact area.


Folding metal like this is imprecise. So, I used the fold as a new reference point.
I put the folded metal into the mil, and squared out the top, making mothe side identical in height.
ONce they were the same height, I can lay them on their side facing each other (like in the pic above) in the mil clamp. Once secure, I drilled the mounting holes in both sides at the same time, so they are in alignment.
Once drilled, I bolted them together for shaping.



I gained a new skill!! buffing aluminum!!
Sanding the aluminum with 300 grit to remove any coatings, finishing with 400 grit. I can then use a buffing wheel with Aluminum compound, and buff it to CHROME!!!

I did this treatment on the water jacket, and WOW. Im going to do this treatment to ALL THE ALUMINUM parts I have!!
I got the large format water fittings from Kenetic. They are 4 mm ID, and a 6 mm OD thread. I tapped the water jacket to 6mm, and installed the new water fittings. There are fittings on the mount plate, but the diameter is so small, that it will constrain the flow too much. So, I wont use them.

Here is the final assembly (sorry, no in between pics))
You may notice you can see the thrust bearing between the collett, and the plate of the mount.

[tlandauer]

Wow, l am enjoying these pictures. I love the motor mount. Can't wait to see the finished boat! You should be proud of yourself!

[larryrose11]

Thanks tlandauer. I have alwayss been good at building functional hardware. I have been trying to up my game and build things that are beautiful too.

[larryrose11]

Blue printing the Cheetah hull.
Im new to catsamarans, but I I have read on here the sensitivity to the subtly of the hull shape. Small pockets due to manufacturing defects can cause the hull to get sucked to the water. I then read that the cheetah hull has a design flaw in the last step. The last step is not flat. It is an downward angle, acting like a big trim tab stet all the way down. Thanks to Tiquman for verifying with the hull designers about this flaw:
http://forums.offshoreelectrics.com/...ull&highlight=
Theis affect can confirmed by the fact that most people that have cheetahs setup the strut with a slight positive angle, to counteract this effect.
Throwing caution to the wind, I went about doing this procedure (outlined above) on my hull before It gets wet.
Here is Tiumans immage of the stock last step
http://forums.offshoreelectrics.com/...8&d=1354805693
So I put to tape around the last step of sponsors to act as a dam. I mixed up a batch of West system epoxy, and mixed in A LOT of micro-balloons. After some initial shaping, this is what I got


after a bit more dsanding, and refilling some low spots, I got it right on.


Here is another detail low spot I found, from original manufacturing.

I shot of primer fill in this low spot. Now the bottom is ready for paint.

[larryrose11]

Did I mention I gained a new skill? Buffing aluminum to chrome.
Sanding the aluminum with 300 grit to remove any coatings, finishing with 400 grit. I can then use a buffing wheel with Aluminum compound, and buff it to CHROME!!!
So, All aluminum parts I have in the boat that are not anodized, will be chrome.
I showed off the motor mount. Here is the rest of the hardware.



The rudder is not the one I started with. It is a Speedmaster unit. That's why there are 3 holes in the mount for it. The smallest hole in the bottom of the mount foot is for a nylon shear pin. The top of the mounting foot is rounded, to allow for the rudder to rotate, when it is struck by some debris in the lake. This feature didn't show up in the above pic.

I have 2 items left to buff out, the servo mount, and the transom plate.

[Heaving Earth]

It doesn't make it chrome you know. It just makes it shiny aluminum

[larryrose11]

Heaving Earth,
Technically, you are correct. It is not chrome plated.
I was more referring to chrome as a visual appearance, not a surface treatment or plating.
It does, however, have a mirror like finish.
Some pieces, like the rudder, required 2 types of compound. An aluminum type, and finish with a jewelers type.

[Heaving Earth]

I also buff aluminum out like you do. Looks sweet when finished

[iridebikes247]

nice job man. I did the same mod to a cheetah hull. Tiqueman got that cheetah running unbelievably well I did all of the mods on mine and sold it before running it lol. Look forward to seeing this one finished

[larryrose11]

iridebikes247
I like building a lot. I may end up doing the same. Get it running, and make the exterior beautiful over the winter.
Im beating around the idea of making a mold of the mod hull, and making my own upper. Making a CF hull out of a mix of CF and Innegra. Making a exterior of some fancy weave, Like this stuff http://www.fibreglast.com/category/P...d_Carbon_Fiber.

[ls1fst98]

sweet hull. love the vacuum bagging. teh blueprinting you and tique did made me look at my mean machine and i noticed my middle step is lower than the other two and at a slight angle. hull isnt finished yet and wondering if i should try to flatten it out to match.