The plan at the top of the thread shows a specific Water Tractor tug plan specifically designed for the VS drives, including the large straight keel at the stern. I suggest Green72West should either use VS drives or use another type of hull for Schottel drives.
Hi Doug, It may be more impressive if you used the 'Hedgehog' as that had a much bigger spread (more splashes). For your purpose the projectiles need to be heavier than balsa but able to float (but only just). https://en.wikipedia.org/wiki/Hedgehog_(weapon)
Why do you need Schottel drives? The Voith Schneider drives in that configuration can move the boat in any direction? Schottel drives will require fairly big penetrations through the hull, and apart from the installation complications, should (in my opinion) be unnecessary. This is a link to a fairly comprehensive brochure with photos of the real thing that will help in understanding the concept etc. http://www.gemimanevrasi.com/Tug_Boat_Technology/Voith%20Wat...
Hi Ed, I have MTroniks ESC's including a couple of PNP types. What I do is to start by moving the stick to reverse then back to the middle, (You can observe the direction of rotation). Then to the top and back to the middle. This works. The SLA batteries have nothing to do with the issue.
Ideally the centre of the weight needs to be near the middle of the boat. The original plan looked OK, maybe it required the batteries a little further back. The whole propulsion system did look a bit heavy for the boat.
Hi Doug, I have used the floating periscope on my other submarine too. On that one there are two sets of two. If the periscope tubes slide easily and the float is big enough then it will work. I have used aluminium tubes on the HMS Triumph. The U boat scopes are both aluminium. They are loose so I can put one or both in before sailing. The floats are balsa wood and painted for sealing.
My suggestion would be to contact the Kehrer shop directly. They are most likely to answer any of your queries. Looking at the booster nozzle it looks like a circular section squeezed into a smaller square with the cross fins to straighten out the jet thrust.
My crew were made by Shapeways. Somewhat expensive, but I needed an unusual scale. I asked a question and the designer got back to me. I was able to select from a few different groups and he also did a few pose mods. The crew is available as U-181. I think they can be scaled down to any scale, although the Revell U-boat crew are also available and a lot cheaper. Some of them now sail on my 1/72 Z39 destroyer. So far I have put 9 crew members onto the U-boat and I have 3 remaining. They are for the front 105mm gun. My periscope has a very simple working method. A balsawood cylinder at the bottom of the periscope. Sub dives and the periscope comes up. Sub surfaces and the periscope goes down.
There are 2 ballast tanks 750ml each - allowing nearly 1.5kg of ballast. I have only fixed half the crew to the boat, and only some key ones in the conning tower. You cannot see them when at a distance and certainly not underwater, so a calculated view. They do stand out on the photos so it looks more realistic. I think the newer tube internals allow for smaller subs but there is hardly any space left within this model.
[Score: 9/10] 77"/17500g U-181 Capable of 4mph and a runtime of 90mins Twin Propellors (3 Blade 35mm) Geared to a Mabuchi 550 (3 Blade) Powered by NiMH (6v) 10Amp/h Batteries Controlled Through MTroniks 20A ESC - Comments: This is an Engel kit, but heavily modified. The deck was replaced with 2mm polycarbonate and slots cut with a slotting tool on a lathe/drill. There are 3 access hatches instead of the original 1. The internal layout was completely revised. The dive system is the Engel Tmax that works very well. There are too many other changes to mention, but suffice to say they were to make the submarine more realistic and also easier to maintain.
Hi Boatshed, Fortunately my submarines and I are safely on the other side of the planet. I agree with Doug. Communication and common sense are essential to happy sailing. 😎 However, a colleague of mine that sails his subs in close proximity to others including out of control yachts, feels the need for a sign. It severely detracts from the realism of the model and has still been run into. Perhaps a 'muppet' flag on 'power boats' will make them obvious and enable local submariners to dive to safety.
An anecdote. My HMS Triumph submarine has a piano wire antenna with the periscopes (not the working antenna) bent to a diamond shaped tip (for safety). A few years ago in the same venue as my previous post above, HMS Triumph was submerged and heading roughly towards the jetty. Hard to know exactly where. I decided to surface to be safe. At the same time three large swans were gliding along gracefully in the vicinity. Suddenly one of the large swans went vertically upwards about two or three feet with his large wingspan fully well extended. The sub's antenna has come up right under his bottom and given him the surprise of his life. The sub surfaced after a few more seconds directly under where he was. It may have got kicked down in the scramble. No damage to either but for the few of us watching it was hilarious. No video unfortunately or it may have gone viral.
There is an old British war movie 'Appointment with Venus', about the rescue of a prize cow. It features a Fairmile D in some great scenes. If one is building a Fairmile D then the boats in this movie will provide inspiration.
Hi Rowen, I have had water cooling on all my patrol boats running at 12Volts, whether brushed or now brushless. For the brushed motors I have used aluminium tube coils with water pickups between the propellers and rudders. I did try water jackets a couple of times but found too much friction loss and therefore lack of flow. For the newer brushless outrunners I use a brass tube soldered to a brass plate across the front of the motor fitted between it and motor mounting bracket. I agree with Doug with regards to the disconnection of the red wires on the ESC's. This is now common practice, especially if you have an external receiver battery.