GX390 Boat Build

[Mammoth]

Did the die break or the shaft?

Some of the teeth on the die broke. Luckily I was able to get the die off without damaging the threads on the shaft.

 

[65ShelbyClone]

What grade of titanium are you using?

Using big ol' taps and dies on Ti is really going about it the hard way and I get it, it's out of necessity. It would be a lot more cooperative with single-point threading in a sturdy lathe. It has some similarities to stainless steel.

 

[Mammoth]

What grade of titanium are you using?

Using big ol' taps and dies on Ti is really going about it the hard way and I get it, it's out of necessity. It would be a lot more cooperative with single-point threading in a sturdy lathe. It has some similarities to stainless steel.

Yeah, single point on a lathe is a much better way to go for this type of job. Carbide vs Titanium.
I don't have access to a lathe right now, so I'm just getting by at this moment in time.

Its 6AL-4V Titanium

 

[Mammoth]

Had to match the propeller shaft tunnel to the front of the propeller.



Got a tube and bored the inside to accept a seal. This will actually be a second seal to keep water out of the hull.



Had to go right here.



Then welded the tube to the propeller shaft tunnel. I battled everything imaginable to get it welded.



Still working on smoothing out the seams, but it should have a lot less drag like this.

 

[Wicked_Daddy]

Read this whole thread. Fascinating! Can't wait to see it on the water.

 

[Mammoth]

Was able to get the tunnel sealed up, and a simple lightweight footrest installed.

 

[Edwin Spangler]

SUH-LOOT! I cant imagine starting on that first bead, knowing how much more was left. Jeeeez!

Nice work man.

 

[Mammoth]

Cut the 6 flats on the end of the shaft to fit the propeller.





Did lots of welding to the tunnel.
Next is to make the end of the tunnel curve back down. That was one of the rules I read about on tunnel hulls. It has to curve back down.

 

[Grizzlymi]

Beautiful work! That thing is going to be a blast.

 

[Mammoth]

Beautiful work! That thing is going to be a blast.

I really hope it works. It's so experimental I have no idea how it will perform. It might not work at all. I'd be happy if it cruises at 20 mph.

 

[Grizzlymi]

What is the power plant for it?

 

[Whitetrashrocker]

What is the power plant for it?

Is the title misleading?

 

[Denny]

Is the title misleading?

Maybe he forgot how to read?