Pro Boat Formula Fastech Jet Drive Project

[Diegoboy]

*** UPDATE ***
Video on Post# 150
*** /UPDATE ***

Disclaimer! I am not responsible for damage done to you, your friends/family, your boat, or your property as a result of following anything described herein.


I already started this one before I realized, I need to take pics.

On 10/02/2008 @ 7:16AM I made my choice

Thanks for those bottom pictures.
I have now found my next "jet" boat hull!
I'm excited about this one!

On 10/23/2008 the jet drive arrived, so the project begins.

Start with either a bare Fastech hull (like I did)



...or strip down a Fastech to it's bare hull.



Pull out the stuffing tube:
Remove the hatch, place the hull upside down and score a line around the stuffing tube base where it exit's the bottom of the hull. Score a line in the same manner to the stuffing tube where it enters the hull as well. Apply heat with a torch (keeping the flame directed away from the hull) and heat the stuffing tube from the outside. Once it's nice and hot, grab a set of pliers, channel locks, vice grips, etc. and twist the tube. you will hear pops, that will be ok. Do not twist degrees yet!
Keep this technique going until the tube lets go. Start twisting the tube 180 degrees now and get it out carefully.



Image from the bottom.



Assemble the jet drive you have chosen. I choose the Graupner 40mm

[calcagno45]

awesome!! cant wait to see the finished project!!!

[Darin Jordan]

This is going to be TOO COOL!

How is the hull quality??? I'm seriously considering getting one of these and seeing how it races!

[rockwerks]

This is going to be TOO COOL!

How is the hull quality??? I'm seriously considering getting one of these and seeing how it races!

I Was thinking of buying the parts and building a hull skinned in thin alum. for bashing up all these small creeks and rivers we have here. maybe even set up gates to get through........a whole new venue for scale racing

[Diegoboy]

This is going to be TOO COOL!

How is the hull quality??? I'm seriously considering getting one of these and seeing how it races!

This hull is surprisingly well built. The transom looks to be about 1/2 thick! *Correction 3/8"
Here's an inside view of the transom...

[Spot Me 2]

Very cool. Where did you get the jet drive from?

[Diegoboy]

Very cool. Where did you get the jet drive from?

From funrcboats.com

[Doby]

Ummmm,,,what happened to your snake boat?????

[Diegoboy]

I am considering scraping the Mamba project. It's too nice a boat and I'm to poor a driver. If she sits on the shelf long enough for my driving skills to improve, then...
I'd hate to wreck this boat, I honestly feel that the Mamba is too good a boat for me to run right now. I know, it sounds like an excuse, or even a cop-out, but it is the truth. I can't drive a boat. Why does the FEMBOT club only have 1 boat in the water at a time? Because I have been known to hit other boats.

[Diegoboy]

Locate the position of the jet drive suction tube and trace the opening on the bottom of the hull. Hand draw an opening inside what you just traced by 1/8".
At the front end of the inner drawing, drill 2 9/16" holes (1 at each corner) and using a 1-1/4" hole saw, drill the back end of the inner drawing.
*note: start the drill into the gel coat, then reverse the drill and drill backward to prevent splitting the Fiberglass & Gel coat.



Next, Connect the dots...

[ace028]

I Was thinking of buying the parts and building a hull skinned in thin alum. for bashing up all these small creeks and rivers we have here. maybe even set up gates to get through........a whole new venue for scale racing

Do you mean water rock crawling? lol

[Diegoboy]

With a small hacksaw blade, cut out the opening for the suction tube.

[Meniscus]

That's it? That's as far as you've made it?

Speaking of driving, how come you depth perception is just fine to "eyeball" locations for various components for a boat, but as soon as there's a liquid surface, you claim you can't tell distance?

(thinking that I don't want to ride with Diegoboy in a vehicle, let alone a boat)

Project looks good

[Steven Vaccaro]

So far so good. Looks like the perfect hull for this!

[Eodman]

Will those drives hold up to brushless motors?

[Diegoboy]

That's it? That's as far as you've made it?

Speaking of driving, how come you depth perception is just fine to "eyeball" locations for various components for a boat, but as soon as there's a liquid surface, you claim you can't tell distance?

(thinking that I don't want to ride with Diegoboy in a vehicle, let alone a boat)

Project looks good

I don't run a boat 2 feet from my face, otherwise I'd be great! We all would. The farther away, the greater the issue becomes.

A classic example of my perception of depth. The tree in the water is clearly visible, My eye told me that my SV27 (Shock Therapy) was well behind the tree. My eye lied to me! Watch this...

[Meniscus]

LOL, I've heard about this somewhere before.

For the record, I understand. It was merely

[Diegoboy]

LOL, I've heard about this somewhere before.

For the record, I understand. It was merely

I know! No offense taken

[Meniscus]

I think you were lucky there weren't two targets on the lake, otherwise it would have sunk

I do have to say though

[Meniscus]

[Rex R]

you may find driving easier if you can gain some elevation, say for example a 3 foot stepladder, or the back of a pick-up truck.

[Spot Me 2]

Yes, PLEASE put the mamba on the shelf for a while!! A 20 acre lake and you hit the only 2 foot thing in it.

[Meniscus]

you may find driving easier if you can gain some elevation, say for example a 3 foot stepladder, or the back of a pick-up truck.

Good call Rex Personally, I think he's been looking at the scale boats a little too much

[Meniscus]

(thinking we'll have to put training buoys in Loch Fembot to help hone his skills)

Hey, no new pictures? I thought you were working on this boat? Or is that just what you tell everyone else?

[Viking]

Diegoboy;
I have a depth perception problem too, but I only see with one eye, which makes it really difficult. I seem to be having that problem with your boat. That hole looks to be too far from the transom. I have that same jet in an Electro Vee 29" and my intake starts 3 5/8" from the transom. Yours appears to me to be further than that. I'll add some photos. I ran a V drive with the motor over the shaft, you can see the motor mount in one of the photos, no motor in there. That kept the CG (center of gravity) in proportion. I don't see how you are going to mount a motor in front of that shaft and balance the boat. Unless you shorten the shaft a bunch. That is a 40mm impeller in that jet and it takes some HP to spin it. No short motors need apply.
The yellow tubing from the jet into the hull works great for cooling the motor and ESC.
Good Luck;
Viking

[Diegoboy]

Viking,
Thanks for the concern, Does this picture help? I measured your oic and used a known object to Gage the distance.( steering pivot point to transom) and it seems the same distance to me...

[Viking]

Diegoboy;
Man I think you are in trouble.
Your ruler clearly shows the hole is 4 1/8" from the transom, that is the exact way I measured my boat and it measured 3 5/8"
The part of the jet that the impeller is in ( the jet chamber) has a flange that the nozzle is bolted to and that flange should be on the out side of the hull. that way you can seal the jet chamber to the hull, and get the nozzle off for maintenance.
Weeds and sticks get in there and around here acorns. The photo below clearly shows this. The chamber is inserted through the transom and into the intake duct. I sealed mine with 3M "5200" sealant.
Not a big deal you can fix anything in fiberglass.
Consider this the further back the intake is the more it stays in the water. there is no thrust when the jet is sucking air.
I have had the idea of an aluminum jet boat rattling around in my skull for a couple of years. My Electro Vee jet was great the ABS vacuum formed hull would give when it hit rocks in the stream. My Challanger twin jet Fiberglass hull is taking a beating. So much so I may pull the jets and do twin screws, counter rotating of course.
Sorry to be the bearer of bad tidings;
Viking

[Diegoboy]

Viking,
I got it covered. Worry not my friend!

[ghostofpf1]

Do you mean water rock crawling? lol

I think he means scale racing emulating full size river jet boat racing like this...

http://www.vidilife.com/video_play_1...River_Race.htm

Ghost

[Viking]

I like it "Water Rock Crawling" here is the Electro Vee
http://www.youtube.com/watch?v=sLurjY0OYkQ
and here is the Challanger twin jet. both are brushed motor driven.
ttp://www.youtube.com/watch?v=faWJTGbdM9Q
I don't know where the echo came from on the vid !?
Viking