--- The Crawler Innovations Water Skippin' FOFFer Build ---

[Nova's Ark]

Billet Works Design had contacted me last year about water proof closed cell foams for water crossing vehicles. I had never given rc water crossings any thought before. Then I saw the Billet Works Designs you tube videos of Don's FOFFer driving on water and I knew I wanted to try it. I purchased a 12.5" Wheel Base Whiplash chassis per Don's recommendation. I actually started this build back in March. As usual, I'm too busy to really document a build thread, but I did take a few pics on my iphone knowing one day I would get around to it.

The plan for this build was to make it budget cheap, using items laying around the shop. In the beginning that was fine, but with each mod came the need for stronger upgrades somewhere else.

[Nova's Ark]

Specs at the time of the picture back in March:

Axial Axles:
Stock Cases, Gears, Lockers, Axle Shafts & Bearings
Front has aluminum knucks & C's
Rear has aluminum lock outs


Axial Transmission with:
Axial plastic trans case
Axial Slipper spur gear assembly
Axial top shaft & top gear
BWD HD Motor Plate
C.I. Outputs
RRP Steel Idler
RRP Hard Ano Output Gear
Traxxas 4927X Yokes
Traxxas 4951X Shafts


Axial Wraith RTR Wheels
Panther Paddle Tires
C.I. 5.0" Double Deuce Wide Inner Foams F & R


Electronics:
ESC - Traxxas VXL 3S
Motor - Traxxas Velineon
Tx & RX - Losikid hacked GT3B
Battery - Sky Lipo 40C - 3S - 3000Mah
Servo - Traxxas Water proof

[Nova's Ark]

Something new I have been working on as time allows. I will get some much longer and better videos soon.

[Nova's Ark]

Although the video above is short, with the Traxxas system in it, that is all I could really do. The electronics for this truck have been a long experiment. The Traxxas ESC could only do 3S max voltage. The best gearing I could find early on was a 52 Spur & 18 Pinion.

The next step I tried electronics wise was to leave the Traxxas ESC and swap in a 6900KV 2 Pole Castle Motor. Same gearing and voltage. Better, but still not right. The Traxxas ESC could not handle the amp draw at WOT. I then tried 50/18 gearing. Better but not right.

Next came a Castle 3800KV 4 Pole motor. The ESC could not handle the motor.

Next came a Castle Mamba Max Pro ESC. This ESC could power the motor, but the 4 Pole motor was too slow at 3800KV for water crossings. It did not matter what voltage I used. I used 3S, 4S, & 6S.

Next came a Castle 4700KV 2 Pole Motor. On 4S it crossed water fine. On 3S it was too slow.

[Nova's Ark]

As the months went by and time permitted, I would always come back to this rig. It is such a rush driving on water. You really only get one try to make a good pull across the water. If I mess up, it's me swimming in my pond to retrieve it.

As the electronics seemed to be ever changing, mechanical parts became the same way. Since the axles were stock, I cracked several cases before finally upgrading to an aluminum case in the front. On one of my first full length water crossings, the truck came across the pond, up the bank and into a tree. Pictured below is part of the damage. The front link had to be cut out at the chassis.

[Nova's Ark]

2 minute video of two days worth of water crossings in my back yard pond which is already very low right now. Texas could really use some rain. On the bright side though, it makes for retrieving the foffer manageable
I hope you enjoy

[ROWDY RACING]

AWESOME!

[JohnRobHolmes]

Thats just nuts, love it!!! The second day looked to have a lot more scoot to it, I could see when it would start out low and just pick up as you kept on the throttle

[stelerzman]

Killer rig and video. Nice job. .

[gabehunt]

this is on my "to do" list haha

niice job

[M1tch]

Great fun!! not tried that with my foff for a while.

[Nova's Ark]

Originally Posted by ROWDY RACING

AWESOME!

Thank you sir

Originally Posted by JohnRobHolmes

Thats just nuts, love it!!! The second day looked to have a lot more scoot to it, I could see when it would start out low and just pick up as you kept on the throttle

Thanks JRH. I'm excited to see you at Nats next month

Originally Posted by stelerzman

Killer rig and video. Nice job. .

Thank you sir

Originally Posted by gabehunt

this is on my "to do" list haha

niice job

They are worth the build because they are constant fun, and thanks

Originally Posted by M1tch

Great fun!! not tried that with my foff for a while.

Get it out and take some video

[JeremyH]

Are we gonna get to see this truck hit that little pond at the bottom of the mountain in LRC this time?

[Nova's Ark]

Current Pictures and updated specs:












Axial Axles:
Front Axle;
GH Racing Aluminum Case
Hot Racing Aluminum C's
Hot Racing Aluminum High Steer Knuckles
Axial Over Drive HD Gear Set
Axial HD locker
Stock Axial axle shafts and stub axles
Full bearings

Rear Axle;
Stock Case
Axial HD standard ratio Gear Set
Axial HD Locker
Stock Axle Shafts & Bearings
RCP Crawlers aluminum lock outs


Axial Transmission with:
Axial plastic trans case
Axial Slipper spur gear assembly
Axial top shaft & top gear
BWD HD Motor Plate
Crawler Innovations Outputs
RRP Steel Idler
RRP Hard Ano Output Gear
Traxxas 4927X Yokes
Traxxas 4951X Shafts


Shocks:
Front; Traxxas 2660 3.5" Big Bores
Rear; Losi 3.5" Rear Buggy Shocks


Vanquish Products V4 SLW 2.2 Beadlock, 1" width, 600 hubs
Crawler Innovations 1/4" wheel wideners for VP wheels
Panther Paddle Tires
Crawler Innovations 5.0" Double Deuce Wide Inner Foams F & R


Electronics:
ESC - Castle Creation Mamba Max Pro (water proofed using corrosion x)
Motor - Castle Creation 4 - Pole 5700KV
Tx & RX - Losikid hacked GT3B
Battery - Sky Lipo 40C - 3S - 3000Mah
Servo - Hitec 5646WP (Water proof)

Current Gearing:
50T - 32P Spur
20T - 32P Pinion

[Nova's Ark]

Originally Posted by JeremyH

Are we gonna get to see this truck hit that little pond at the bottom of the mountain in LRC this time?

It depends. If we / I rent a small cargo trailer to take to Nationals, then yes. With the three of us all traveling to Nats & each competing, that's a lot of competition luggage right there. Add in the C.I. store (although I was planning to bring less since I will be competing) and every bit of space is at a premium. I'm planning to only bring my comp trucks that I'm competing with. If that holds true by the time we leave for Nats, this truck will be left at home.

[Nova's Ark]

Since the primary purpose of this truck is for water crossings only, something needed to be addressed to limit it sinking to the bottom of my pond. Driving on water is a complete trial and error deal in regards to the water. I don't know a lot of people that have driven on water with a RC car. Do you?

So early on in this build I spent a lot of time on the phone with Don asking questions and building upon the information I learned from him. It gets old quick when the truck doesn't complete any pulls across the water. You have to swim in after the vehicle to recover it. After the 4th or 5th time the battery was usually dead and I was covered in pond water .

So after giving it some thought, I searched the shop for a decent lexan body. I picked up some Great Stuff spray expanding foam I filled the body full with spray foam and let it sit 24 hours to cure. I then went back with a hacksaw blade and removed the foam to fit the chassis. After the big foam pieces were out of the way, an air die grinder with a barrel sander finished it for final fit.

Here is what the custom foam body looks like underneath:




Mounted:

[JeremyH]

Originally Posted by Nova's Ark

It depends. If we / I rent a small cargo trailer to take to Nationals, then yes. With the three of us all traveling to Nats & each competing, that's a lot of competition luggage right there. Add in the C.I. store (although I was planning to bring less since I will be competing) and every bit of space is at a premium. I'm planning to only bring my comp trucks that I'm competing with. If that holds true by the time we leave for Nats, this truck will be left at home.

Michael and I will be bringing 5 trucks. I think the trailer is a good idea.

It will also be a nice way to store your CI stuff in the evenings....

[Hittman]

Originally Posted by Nova's Ark

That is a great idea!!! I would like to know how it works for you

[stelerzman]

Originally Posted by Nova's Ark

Since the primary purpose of this truck is for water crossings only, something needed to be addressed to limit it sinking to the bottom of my pond. Driving on water is a complete trial and error deal in regards to the water. I don't know a lot of people that have driven on water with a RC car. Do you?

So early on in this build I spent a lot of time on the phone with Don asking questions and building upon the information I learned from him. It gets old quick when the truck doesn't complete any pulls across the water. You have to swim in after the vehicle to recover it. After the 4th or 5th time the battery was usually dead and I was covered in pond water .

So after giving it some thought, I searched the shop for a decent lexan body. I picked up some Great Stuff spray expanding foam I filled the body full with spray foam and let it sit 24 hours to cure. I then went back with a hacksaw blade and removed the foam to fit the chassis. After the big foam pieces were out of the way, an air die grinder with a barrel sander finished it for final fit.

Here is what the custom foam body looks like underneath:




Mounted:

Great Idea, would like to some video and how it works. Just my 2 cent, you should have tinted the windows before the foam treatment.

[Nova's Ark]

Originally Posted by JeremyH

Michael and I will be bringing 5 trucks. I think the trailer is a good idea.

It will also be a nice way to store your CI stuff in the evenings....

Text message sent

Originally Posted by Hittman

[/CENTER]

That is a great idea!!! I would like to know how it works for you

Thank you. It works great. When the truck doesn't make it, the entire truck floats. It stays at about the body line of the truck on the side. With the paddle tires, you slowly apply throttle and it paddles over to shore and drives out. It is very convenient.

Originally Posted by stelerzman

Great Idea, would like to some video and how it works. Just my 2 cent, you should have tinted the windows before the foam treatment.

Thank you. I need to take some new video. I have not tested on water yet with the new castle 4 pole motor that arrived this week. When I do, I will get some video footage taken. My focus has been on comp trucks and getting ready for Nationals.