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Heeee heeee. I'm reading this AT the beach!
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PS. That smaller prop looked a bit silly so I amended the original!
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The quality of your work is improving.
DavidWho is John Galt?Comment
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Hello all and a happy new year.
Thankyou David for the last comments, The Borei is coming along well, Whenever I start a new project I always like to try something new, a new way of building or some new technique or material in my design just to give me more options and hopefully end up with a better model and one that is more accurate. But also to improve on a previous model where something could have been done better.
Anyway..
having time off for school Holidays and borrowing the schools 3D printer over the break has allowed me to get a good grip on this new technology. As mentioned a couple of months ago I had started to develop the design for the Borei class in a 3D program. I have been teaching the use of "Blender' and although It isn't strictly a CAD program It does and excellent job for what I am trying to achieve here. It also handles the STL files that 3D printers like.
Over the last two weeks I have been flogging the thing. Giving it print jobs almost every day and learning the ins and outs of the technology and more importantly learning what errors regulary come up and how to fix them. I have found that the software for the printer that I'm using isn't always the best to work out scale and size however I have finally managed to work out a system that works.
Using a 3D printer has allowed me to rapidly prototype some complex parts that would otherwise have taken me extra weeks if not months to do. It has also allowed me to create these parts really accurately and repeatedly which is very important. Where symmetry is involved I have been able to create exact but mirrored stern planes and fore planes which, yes I could have done by sanding and filling bits of wood or other material, but would not have been able to start of at a position of such symmetry and consistency.
Having never made 3D printed parts I wasn't totally sure how I may integrate then into the design. would I just use the parts for checking size, fit shape and look or would I actually start using them for the masters/patterns that would eventually create the tooling? I didn't know how well the stuff would sand what kind of surface finish you could get with it.
After visiting Hardrock a couple of weeks ago down at Ourimbah and seeing the work he was doing on his cool little 1/96 Romeo, I realised that the finish you can get is very good. He showed me an automotive spray putty that works brilliantly.
One of the things that I have learn't about 3D printing is that the way the part is positioned of the printer can make a huge difference to the quality of the print out. Initially I printed out control planes and surfaces horizontally , yet have found that the best way to print these parts is to mount them vertically, where the layers places down by the printer more closely resemble the cross section of the surface.
Added to this is the face that you want to try and avoid overhangs. Material that does not have good support underneath. In order to support some structures the printer will need to create extra 'scaffolding' to keep and overhanding piece in position, I have had battles with the printer where the machine has simply created way too much support scaffolding and its been hard afterwards to find the part in the scaffold and cut it free.
Whilst thinking about how to position the part on the printer board I have also had to think through how the part once made the by the printer would also be best arranged to make silicon moulds and thoughts of the flow characteristics of the polyurethane resin come to mind. I am currently investing a fair amount of thinking into how I am going to set up the moulds for creating all the parts for the Pump jet, hence all my enquiries with HWSNBN as to pump jet fabrication and also how he has set up the moulds for the pumpjet parts. It is already looking like there will be ALOT of moulds for this back section of the boat.
Anyway enough for now.
David H
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Hello all,
What a crazy week its been.
The family and I took trip to our friends farm up in a place called "Nundle" about 3 hours northwest of Wyong on the Central coast NSW. Just south of Tamworth, the "country and Bogan' err I mean 'western' festival capital of Australia. Oops, I've probably offended someone. Then I came back and I had to cut a big section of concrete out of my driveway because the council told me to fix a tree root cracked bit of sewage pipe on my property and fix it or else they would take legal action. Option one, get specialists to go in with special equipment and do it from inside with some special high tech resiny stuff and the plumbing equivalent of a stent : $4000 thankyou or do it myself, rip up driveway dig and replace pipe and stick slab back and make it try and look like it wasn't dug up. $500 or so. no brainer.
Fortunately it wasn't too hot. We have had some real scorchers here, 35 degrees. Hardrock's shed would be 40 degrees, ( 1st degree burns on the soles of your feet as you run across the sand at the beach and asphalt on the road going guey..) I reckon...... Still I got a sunburn mark in the shape of the half round section at the back of the baseball cap where the press clips change the size.... Nice.
Back to the important stuff.
I have spent a fair bit of time reading through the HWSNBN reports on Pump jets and the like and all that I realised that I would need to break down even further the design of the pump jets to make ease of moulding and assembly a reality. I realised that the forward shroud with its support would need to be a two part design with the support and shroud separate for moulding. So I got onto blender and redesigned the ring so that it would have recessed notches in the locations where the support arms would attach to the shrouds. The support arms were extended just a little bit to go into the ring just a little. This would mark the locations for the 4 supports to fit into.
The same needed to be done for the rear stator section and shroud. The stator section has curved blades just like HWSNBN's seawolf design, On Borei, like Seawolf there is a lot of speculation as to the deign of these units. The stator ring was also notched to allow the 5 stator arms to recess into them after moulding. I don't know whether to assemble the stator support and main shroud support into their respective shrouds or leave that to the unsuspecting buyer...
Once I printed these out they fitted really well. Snug fit and the whole unit fits really well together. Still lots of sanding and filling, but it is coming along. I also printed out a natty little 15 blade fan. nice.... I have no Idea how I would possibly cast this little bugger...I think it will be for the De luxe units only eg.. probably mine...
Anyway that's enough for now, I should be able to get some further progress next week. It's tipped to be high 30's good fibre glassing weather...
David H
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Hummm.. Looks like trench warfare at your place. As an old digger, I have to tell you that unless you are at least 4'6" deep and have 18" of overhead cover you probably won't survive the opening barrage. Just sayin'.Comment
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Hello all,
Well its been a week of wall to wall heat here. Most days over 30 degrees and hot and sticky in the man cave. I have spent a bit of time laying up some moulds of the Resolution and Mike to have some hulls in stock. Although the Fibreglass is curing very quickly I am finding it's more itchy in this humidity as I am working over the hulls I also have to make sure that my sweat doesn't drip into the resin! What I would give for a thunderstorm...
Work on the Borei this week has been a little more subtle. Scribing and detailing the hull and designing and printing the fore planes that are located on the centreline just aft of the torpedo tubes. These fore planes are tiny and swept, which I have never come across before. Printing them out took next to no time and soon enough a light sanding then a coat of spray putty and they looked the part. With a slight taper towards the tip, I designed the shaft hole in them and so drilled a hole where they would be located in the hull along the centreline and mounted them. On Borei they have what looks like a pivoting joint, maybe these front planes are not all moving..
Most of the work that I have continued on with Borei has come in the form of scribing and etching, although I have also finally added the safety harness lines. This comes in the form of Styrene strip that is "0.30 x 0.40" This makes an excellent safety rail along the hull. I simply mark down where I am going to lay the rail and then lightly sand along the line. then carefully put down the styrene strip with a dribble of super glue down the length. then lay it down and line it up against a steel rule,wrapped with sticky tape to reduce the stick of the superglue.
Once the styrene is in place then a very light sanding and smoothing over then a shot of primer. As I am still working over the rest of the hull I need to be careful that I don't break any of the lines.
I will be going back over the alignment of the stern planes. I am convinced that they are not quite square according to the rest of the hull.
Enough for now,
Any comments, suggestions and tid bits on those fore plane being fixed or not would be great.
David H
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The Soviet's ... err ... Russian's employ articulated bow planes on some boats. These are full-flying surfaces but they change camber to enhance the vertical force they produce, much as flaps on an airplane wing, but working up as well as down. Typically a drag-link connected to the 'flap', made up to a standing portion of the operating shaft, causes the 'flap' to articulate as the main portion of the plane rotates.
DavidWho is John Galt?Comment
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Thank you for that feedback David.
I got into my car yesterday to go to the shops and the news came on announcing the passing of a man who has been a hero of mine since I was 18. Eugene Cernan commander of Apollo 17 and the last man to climb back up the LM ladder on the moon has left us at 82.
I had the very good fortune of hearing him speak in Sydney just 9 months ago. Got his autograph, will treasure it. Forget Usain Bolt , Cernan along with Tom Stafford and John Young ARE THE FASTEST MEN IN HISTORY.
of course here in Australia, I didn't see it at all on the nightly news feed because Kylie Minogues latest album launch and Mariah Carey's love life is far more important.
R.I.P Gene Cernan Space legend. Gemini 9. Apollo 10, Apollo 17.
Last edited by Davidh; 01-17-2017, 07:13 PM.Comment
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Hello All,
it's been a quiet week on the forum. Still good to see Hardrock powering ahead with the Romeo class. It's looking good.
One of the things that I really needed to get on with in order to finalise the arrangement of the stern is to check the accuracy of their alignment. Making sure that the vertical rudders top and bottom are indeed vertical and also that the horizontal planes are indeed horizontal. As shown in a couple of HWSNBN photographs, he uses a disc to align and make sure that the fins are 90 degrees to each other. So I made my own and then slipped it over the stern and pushed the brass pivot rods through. This showed me that I was out slightly on both the vertical and horizontal planes. Not only that but looking down on the top it became clear that the horizontal planes were skewed with the port side slightly ahead of the starboard.
These photos also show the propeller/ propulsor and immediately in front of it is the shroud support with it's four support arms. These parts will all need to be moulded separately so the propulsor will have five separate sets of moulds to make a complete unit.
I will have to come back to fix this and make sure everything aligns because if I don't it will bug me...
Onto the next thing and for a while a have been thinking about the underside. So often when we are working on these models we rarely think of the underside of our subs. However this area on Dolgoruki is guaranteed to be tedious as there is a large number of drainage/ ballast vents, from what I can make from the drawings. Gantu- surely you can dig up some really good Drydock underside ballast tank vent pics for me to glean over.
Once again I mounted Dolgoruki on my revolving level marking board. This would allow me to rotate her and make sure that all the associated vents matched up vertically and horizontally the equal distance either side of the underside central line. Using some thin metal templates I started scribing rows of vents in groups based on what I could glean from the drawings. There certainly seems to be more vents and interesting plate activity just in front of the stern planes and some door that I believe and for retractable thrusters. This is a departure from having them on the ends of the stern planes just like on the Project 685 Mike.
Until next time...
David H
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The rotor is way too beefy. Total blade area (developed, not projected), less the hub, should be about 60-70% of the disc.
This master is so much more refined than your previous work, Dave. Your lay-out tools and practices have gone a long way in tightening up the symmetry of your work.
Keep at it, Tiger!
DavidWho is John Galt?Comment
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"becker rudder" is the name....had them on one of our tugsThe Soviet's ... err ... Russian's employ articulated bow planes on some boats. These are full-flying surfaces but they change camber to enhance the vertical force they produce, much as flaps on an airplane wing, but working up as well as down. Typically a drag-link connected to the 'flap', made up to a standing portion of the operating shaft, causes the 'flap' to articulate as the main portion of the plane rotates.
David
grtz,
BartPractical wisdom is only to be learned in the school of experience.
"Samuel Smiles"Comment
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Thankyou David and Bart, (becker rudder, any relation to Boris Becker?)
Thanks for the feedback. I do have a 15 blade propeller that I could use and would love to make however I have absolutely no idea how I would go about casting it , let alone making the moulds for it. It has a much smaller blade aspect ratio and it looks cool, but manufacturing this would for me be a nightmare, cue a HWSNBN smorgasbord of delectable mold and procedure pic's and cunning notes.
I didn't finish doing all the scribing underneath the underside of the hull, the vent holes and some other distinctive hull fittings. Soon I intend on going back and finishing, particularly the back end where there is the retractable thruster motor and the like.
Now getting back to the alignment of the stern appendages, I spend most of a day getting the alignment right and needing to re-drill a couple of holes for where the vertical and horizontal surfaces need to be 90 degrees from each other. The next step would be marking out on the hull the location of these surfaces. I have decided that in order to make this assembly as logical as possible for the potential builder I would create a slightly raised profile for where both the horizontal planes and the vertical rudders would be located. The challenge would be that the fillet / raised profile for the and lower rudder would be easy and come out nicely in the silicon mould. The problem for the horizontal planes is that they are right on the part line between the hull top and bottom and the detail could easily get lost in the messiness of the Fibreglass.
To do this I cut out a profile of all the control surfaces out of styrene and sanded them back to accurately resemble the outline of the part. Then I drilled a hole for the shaft to fit through, making sure that It aligned with the holes already drilled. I also decided to cut a small rectangle inside each profile as I am thinking of leaving apart of the mold sprue on the part. This slot can then be cut out and the sprue extension can then be used to help secure the part onto the correct place on the side of the top of the hull.
Once these were in the right position it would simply be a matter of gluing and then using a small amount of filler and running it around the outside, sanding back and a light once over with the primer.
I have also used a similar technique with the outline of where the Sail/Fin sits. I cut out a profile of styrene that is just a little smaller than the outer perimeter of the sail fin outline. Then gluing this down on the hull where the sail will sit. It nicely covers the forward missile deck screw that holds everything down and will allow just a fraction of a millimetre of Fibreglass of the sail to sit around the outer edge of it.
Anyway, Until next time, comments or advice, greatly appreciated.
David H
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Check out the pictures. Some are of the 1/100 VANGUARD pump-jet masters, tools, and parts I produced -- that work very much like what you're doing with this Russian boat.
DavidLast edited by He Who Shall Not Be Named; 01-27-2017, 12:31 PM.Who is John Galt?Comment
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