31" nautilus

[chips]

I'll be scratch building a prop from brass sheet and a wheel collar. Waiting for the WTC I ordered 8 weeks ago.

[chips]

I cut five brass blanks the same size and soldered them together as a block. The prop shape was traced on the top blank, and the block of blanks was cut and filed to shape. Reheated the block to separate the blades and cleaned them up. I'll solder them to a wheel hub later.

[chips]

The prop is finished.

[bob_eissler]

Wow, looks nice

[chips]

I got the pivoting or flex prop shaft parts made up and installed. I used some wheel collars and brass stock. Stainless steel 4-40 bolts secure the bracket to the hull/

[bob the builder]

Beautiful work!

Is the long shaft on the prop itself required so that it clears the fins when in full tilt position? The prop doesn't usually have a lot of clearance between itself and the rudder. Do you have enough room for the rudder as well?

In the past when people wanted me to use the stock prop rather than a rearward-swept scimitar prop (which works awesome, btw) I pulled the prop closer to the hull and put a notch in the fin to allow for the blade tips to pass through unobstructed. Not ultra-scale, but looks and works great.

[chips]

I had two short pieces of 1/8" stainless shaft. In the pictures I posted earlier, the longer of the two shafts is attached to the prop. The prop does clear the fins in full tilt. I do have enough space between the rudder and prop. The prop is almost centered between the rudder and the hull. I have since swapped the two stainless shafts around, the prop is attached to the shorter piece, and the Dumas u-joint to the longer piece. This gives me a little more pitch angle at the prop.

The mailman delivered the Sub Driver today. It fits in the Lexan saddles I made up and installed. I did put a thin layer of RTV silicone on the saddles tonight. I'll end up installing some sore of locating pin to help secure the Sub Driver.

[bigdave]

Looking good Bob.
You will be fighting off giant squid in no time.
And you will find the scale prop is very efficient like Bob said.
I am going to try and get my Ray Mason hull running again for Carmel.
I am sure it will require a new cylinder as I built the current one 21 years ago.
And it's C02 ballast. My paintball gas bottle is WAY out of inspection. BD

[chips]

Today I went and picked up a few items from the hobby shop. Took the cylinder with me to size up and purchase some batteries. I've also been working on a transport box for the NAUTILUS. The box is made from pine boards and finished with a couple coats of clear polyurethane varnish. I add some soffit vents to the ends for ventilation. On this box, the soffit vents are trimmed down to 1/2" thick. Some small blocks glued inside the bottom half secure the model's display base. The small blocks are cushioned with some green felt. Two Velcro strap secure the model inside the box bottom.

[chips]

I got the receiver, LiPo guard and ADF installed in the cylinder today. I relocated the ESC from the centerline to the starboard side, after lengthening the wires to the motor. The wires leading from the ESC to the battery were laced together with some #1 braided black silk suture thread. I shortened the leads of the three servos in the tray by 4". I installed some new plugs from EMS. I had my wife assist me with programing the ADF; she plugged in the battery while I held the ADF "set" button. I had installed the WTC saddles before I received the WTC; the universals are misaligned by about 1/8". I'll correct the discrepancy on the saddles by attaching some sandpaper to the cylinder and sanding them down.

[JWLaRue]

..... the universals are misaligned by about 1/8".....

If I am stating the obvious.....please ignore!

Having the two ends of that Dubro universal is not necessarily a problem. Bridging the offset is what they're intended to do. That said, minimizing the offset is not a bad thing.

-Jeff

[bob_eissler]

I don't think there is much efficiency lost through the mis-alignment as long as it doesn't vibrate much. Guess it does look a little less than perfect and you have done a grate job so far on it. Now I want to get mine built!

[bob the builder]

I wouldn't worry about that offset at all. Your tilting prop arrangement takes advantage of the dogbone's versatility in that regard anyway. You won't notice one iota of difference.

Also, if you drop the rear of your cylinder by 1/8", you'll need to drop the front by that amount or more. If you only drop the rear, you'll wind up unable to vent the entire ballast tank as the vent is located to the rear of the ballast chamber. If the rear is dropped, air will be trapped in the forward section. It might not be a lot of air, but it will be some, and having a bubble running forward and backward in there while you're submerged is not a good thing at all.

Leave it be! You'll be fine.


Bob

[chips]

Both saddles will be sanded until the cylinder motor shaft is the same level as the forward prop shaft. If they are not closer in vertical alignment, I have an issue with the dog bone binding on the prop shaft universal - photo #4.

[chips]

Sanded down the saddles, and got better alignment on the dog bone.