Basic question: propellers and stuffing boxes

[modelnut]

I'm working on my NAUTILUS today. Sanding sanding sanding the hull . . .

A question occurred to me, how do I attach the propeller? I have a real R/C hull that comes with the propeller attached. That propeller turns and apparently has a coupling inside to connect the motor to the driveshaft. But how is that done exactly?

I know that I need something called a stuffing box. That's a sealed exit through the hull that the driveshaft turns inside. It keeps the water out and the lubricant in. I found out how to make a stuffing box for a surface R/C boat (a target for R/C subs!) But I also found a site that says that such a box won't work for an R/C sub. Something about oil leaking under the increased pressure as the sub dives.

What do I need to do?

-Leelan

[myles yancey]

Hi Leelan

May I make

Hi Leelan

May I make the following suggestions to you

1st: obtain copies of the following books on R.C. submarine model building
Submarine technology by Norbert Bruggen ISBN 1-900371-04-9
Simply Submarines edited by Chris Jackson ISBN9 781900 371407
Simply Model Submarines Revised edition edited by Chris Jackson ISBN 978-1-900 371-82-7

For painting your submarine get a copy of Dave Merriman Video; Weathering and Painting at D& E muinatures

For techincal building I recomend the following Persons,

Mr. Robert Demmick of OTW.
Mr. Mike Dory of the Sub Committee
Mr Skip Assey of the Subcommittee
Mr. Tony Gallonio of SubRon 4 & the Subcommittee
Mr. Jeff LaRue of The Subcommittee
Mr. Jim Butt of the Subcommittee
Mr. Marc D'antonio of FX Models
Mr Art Broder of SubRon 4 & the Subcommittee
Big Dave of the Subcommittee of Bigdave water tight cylinders
Mr. Mike Shubar of the Subcommittee Shubar Sub works
Mr. David Merrimen at D & E Minatures

above all else try and locate any subcommittee members in your local area and join a local Subron nearest to you.

These are just a few of the people how can help you.

Happy Modeling
Myles

[modelnut]

I have a few of

I have a few of those books. But they breeze by what i want to know as if it was simply too dumb a question to bother with. At least I don't remember anything about propellers and stuffing boxes. I will dig them out again and go over them with a magnifying glass.

There is or was a group in Atlanta. There is no one in Athens where I live. I work weekends so that precludes any club meetings. I am stuck with emails and online sources.

-Leelan

[Guest]

'Model submarine technology' certainly does

'Model submarine technology' certainly does not breeze through the topic of sealing a propshaft, however some of the terminology used may be a little bit difficult to grasp for a newcomer.

I would recommend you purchase a complete propusion set-up from Norbert. This takes all the heartache out of it, and the unit will be top of the range.

For a boat your size, a 500 motor will be more than adequate.

Here is the link

http://modelluboot.de/Zubehoer/Wellen_Motore.html

The unit needs to be mounted on a bulkhead, but everything you need is included.

Norbert takes Paypal, and you can email him in English

[modelnut]

Not sure I have that

Not sure I have that one. The books I do have contain reprinted articles from RC boat magazines. There is a lot about trimming and using servos. But I don't see anything about getting the propeller to work.

Just went to the site were I bought my propeller. They have couplings and an adaptor. Just have to figure out which one I need.

Please be gentle. I have been a lurker and SC member for many years. But the closest I have been to a working RC sub is a video on the Web. Never even been in the same room as one.

I know my learning curve is going to be steep. But I do not have to do it all at once --- just before I die. I am sure that I will ask a stupid question or three.

-Leelan

P.S. 45.5000 EUR = 56.5338 USD for Motoreinheit 500. Now I know more than I did.

[Guest]

Well 'Model Submarine technology' is

Well 'Model Submarine technology' is about the only book worth considering if you want in depth knowledge of building a working submarine from scratch.

The unit I mentioned is straightforward, because it comes complete with everything you need in one combined unit. Any other option will require you to fiddle about making up your own motor mounts, find suitable couplings etc.

The other option open to you is to purchase a WTC from one of the major vendors. This is an attractive option for someone inexperience with submarines, as most of the hard work has been done for you.

[modelnut]

Thank you, SubC!

I will look

Thank you, SubC!

I will look for that book.

I have the shell of a WTC but no innards. Haven't tested to see if it will fit what I am building yet. But it should. The SKIP is about the same size.

-Leelan

[modelnut]

Just test fitted the WTC.

Just test fitted the WTC.

I was wrong. THe WTC has lots of doodads inside it. Has a motor like you mentioned mounted and everything. But something sticking out of the thing will not clear the inner diameter of my sub. So I either need a smaller WTC etc or I need to find a thinner PVC pipe with the same outer diameter. OR I could lay up a new pipe from scratch --- strengthen it with fiberglass . . . Then the WTC would fit.

THe WTC came with lots of things but no instructions and no brand name. I have no idea what any of it is or what it does except for the motor.

-Leelan

[Guest]

Can you post some pictures

Can you post some pictures of the set-up?

[modelnut]

Label
Business end
Problem area

3.5 inch diameter.

Label
Business end
Problem area

3.5 inch diameter. Any ideas?

[myles yancey]

Label
Business end
Problem area

3.5 inch diameter.

Label
Business end
Problem area

3.5 inch diameter. Any ideas?

Hi Leelan

you need to post a picture of your cylinder so people can see what you are dealing with, the information is good but a picture is worth a 1000 words it let people get a better picture of what you want to do.

[modelnut]

Well. Here is the problem.

Well. Here is the problem.


I am basing my sub on a PVC pipe like Steve Neill did his NAUTILUS. But I suspect his PVC pipe had thinner walls than mine.
My PVC is .25 inches thick. It's sturdy but probably too heavy.

BTW Steve used a 3 inch WTC in his boat. Mine is 3.5.

Thought about grinding out the interior but can you image the dust?

I could build another cylinder by hand. But there is no guarantee that it will be true (read "straight".)

Or I could buy a 3 inch WTC package.

If anyone would check out my pictures and identify whose WTC this is that would be helpful. I bought it from an SC member many years ago and it came without instructions or any info about its maker.







-Leelan

[wlambing]

Leelan,

Based on your pics,

Leelan,

Based on your pics, that's a D & E 3.5" cylinder. There's a really huge difference between the hulls that cylinder will fit and hulls that will take the 3.0" tube!

From the top picture, the intereference items on the WTC are the gas reservoir (bottle) fill valve and bottom end cap. Even with thinner (1/8") wall PVC, you'll have a heck of a time getting a good fit. Your choices are pretty simple here, either a 3.0" WTC, or a larger diameter (thus larger scale boat) length of PVC.

Take care,

Bill

[scott t]

Maybe you could bump up

Maybe you could bump up the size of the hull pipe to a 4 Inch.
And use the thinner schedule pipe.

The WTC looks to be of a Meriman mfg.

http://www.caswellplating.com/models/sub-drivers.html

-Scott

[modelnut]

Leelan,

Based on your pics,

Leelan,

Based on your pics, that's a D & E 3.5" cylinder. There's a really huge difference between the hulls that cylinder will fit and hulls that will take the 3.0" tube!

From the top picture, the intereference items on the WTC are the gas reservoir (bottle) fill valve and bottom end cap. Even with thinner (1/8") wall PVC, you'll have a heck of a time getting a good fit. Your choices are pretty simple here, either a 3.0" WTC, or a larger diameter (thus larger scale boat) length of PVC.

Take care,

Bill

That's what I thought.

I have been all over town and found no PVC pipe of the same width that is thinner, which might have done it. But i have done too much work to give up now.

Guess I will have to save up for a 3 inch WTC. But $500 is a bit hard to put together at the moment. Knew this would be a years-long project.
Heck, it's been that already.

Did some looking around on the Web. From what i can tell I have a Merriman 3.5 inch WTC on my hands.

How heavy is too heavy for an RC sub? Mine is ~38 inches at the moment. The PVC pipe is .25 inch thick. It's almost four pounds by the bathroom scale. Foam would support some of this. But should it be this heavy?

If so, then this will be one big static model. I will have to try to make a foam version to form a fiberglass hull over. Kinda messy for my little apartment.

-Leelan

-Leelan