If the hull is in decent shape structurally i cant see any problem if you get the balance right it should go well. If you are concerned beef up the mounts or put a bulkhead in it or both. Mine now runs on brushless and moves along quite well. I`m sure Jerome Grainger put a Merco or Webra 61 in his Cigarette in the 70`s. I`ve run my Surfury on an Irvine 40 and was pleased with performance and handling, that now runs on a brushless and its quicker. Pics are of Surfury with Irvine 61 which was a bit heavy and my version of the Black Tornado
W1 by jbkiwi Chief Petty Officer Posted: 3 days ago
This is my scratch built 36" RNZAF British Power Boat 64' HSL (arrived in NZ 1940). I actually went on board this vessel in 1968 when it was still in original form (the RNZAF having disposed of it in the 50s) This vessel is still around and has been recently re modelled (2nd time since early 70s) and I was lucky last year to have met the present owner and go on board (2nd time in 49yrs!)and take a few photos. The vessel was modified a number of times by the RNZAF over the years (air intakes, removal of the fore deck machine guns, wheelhouse turret etc so I sort of went in the middle. I found a few drawings of the type in an old mag which had side and top views plus the bulkheads and their positions, so I took them along to a copying shop and kept enlarging them until I had the desired proportions. This worked out quite well and using a few methods from other models I had built, managed to frame (ply) the hull and then fully strip plank it in balsa. It was then fiber glassed. The deck is ply, lined and varnish stained. The wheelhouse is varnished balsa with the top removable for access. The wheelhouse interior has detail such as controls, instrument panels, skipper, steps to wardroom etc but is not too detailed as it is not seen. The boat has full lighting by remote switch, lights are all LED. The propulsion side has dual everything (motors, ESCs, sound units), would have had 3x but ran out of space! Motors are 28mm 2200Kv water jacketed in-runners (cooled by remotely switched pump) using 30A Chinese ESCs (have 5A BEC, Fwd and Rev). Twin sound units are 'GT Power' car units which have around 40 different sound selections, from Cosworths to diesels and are computer programmable (as well as manually on the unit ) for various functions. I am using one of the v8 sounds (8 cyls short in my application) which I think is as near as you are going to get to 3 Napier Sea Lions (for which there is obviously no sound available) They 'start' 'Idle' and are fully proportional in fwd and rev and can sound quite realistic (will attempt to put up a vid later). Batteries are 2x 2200mah 2s 20c LiPos which will last around 2hrs at least of sailing (they also run the sound units) Still have a few small things left to do (have just made wheelhouse air intakes) but don't want to get too fiddly. Just want to keep it a practical model.
Slightly more comfortable - The bending is done simply by soaking in hot water for 10 - 15 mins and then forming around a suitable paint tin/circular object and left a couple of days to dry. The skins must be absolutely dry before fitting as further drying out when glued to the bulkheads will twist the whole hull.
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 Gerd, It's not my plan! The plan is from 'green72west' who started this thread and seems to be confusing Schottel and Voith-Schneider. Either that or he wants to use two Z-Drives instead of the Voith drives. His intention is not clear. Either way he doesn't need to cut chunks out of the keel, that's nuts😲 Cheers, Doug 😎
Hi Haig, seems to be a common mistake to get Schottel Drives (Z-Drives) and Voith - Schneider confused with one another! First two pics show a twin Voith propeller on a tug hull (as on the plan above) and the operating principle. 3rd pic is cross section of the Z-Drive as produced by the Schottel company. It is a 360° rotating 'pod'. Newer versions have electric motors built into the pod and don't need the mechanical Z transmission from inside the hull. With such pods under bow and stern even bow and stern side thrusters are redundant 😊 4th pic is the Graupner version, Mk II. https://www.graupner.com/Schottel-Drive-II-new-version-/2335... Cheers, Doug 😎
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...
I have hopefully posted photos of stern/bow shape of bulkheads + side view of the hull. there are 20 frames in the hull. how can I install x2 graupner schottel  at the bow. I will have to leave out the keel under hull. thankyou Green. the plans are 1/50th scale.
Hi Mike. The bulkheads are all slotted as is the keel. The front of the keel is also located in a slot in the base board and so therefore all of the bulkheads are automatically held square in both directions. It has been glued and on a trial run, the skins fit well. I have been as careful as possible. The manufacturer has thought about assembly. The jig is not card. It is a strong sheet of 3mm Depron. If you see the picture above, you can see the slots for the bulkheads and the centre front slot for the keel. It does seem to keep everything in place very well.😊 I am going to try to fit the skins tomorrow. I wll report back if I don`t do myself an injury trying.🤓
Is there anything that holds the bulkheads at 90 degrees to the base? I assume you fastened this base card template flat to a wooden building board otherwise there is a danger that the bulkheads could be out of true hence my comment - bulkheads at 90 degrees. Its also important that it stays in the jig while the skins are applied. Is the structure already glued? as my comments may be too late
looking at the bulkheads I would suggest that the structure is meant to be built upside down on a building board. Each bulkhead should be fastened to a piece of 12mm sq timber then fasten to the base board at the appropriate spacing keeping them upright and square, then the keel can be glued in place followed by the chines keeping all the structure square and true. Just a thought. Ill post a picture of a similar vessel I am building at present in this way, but will be tomorrow.