Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Navy - Military - Battleships: => Topic started by: malcf on November 03, 2013, 07:50:43 pm
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I have started my build of HMS DRAGON using the Sirmar hull and superstructure,i have made gearboxes and am using Johnson 550/600 motors with a 3.1 reduction in conjunction with Sitek running gear,i am intending to use mainly styrene in the build in preference to wood other than motor and rudder mounts and maybe beams?,the build will be slow due to work comitments <:( but then again it is paying for it O0 and i still have to finish my Lloydsman off.
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Some more pics- i have opted for a dual motor mount to assist in aligning the propshafts and keeping thing parallel. :-))
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Good news you are building the type 45. You will have to check the Hull length. As this Hull is to short! And the extra weight of the grp mouldings can make her top heavy. If you check the guy robbie on the fleetscale forum. He had to make a few changes on his 1/96 diamond. The moulds of the sirmar type 45 was developed before the real one was launched. As you know you never build a model untill the final designs and the ship is in service. As for example look at the new QE carrier. They are changing the design each week!
Good luck Frank :-)) :P
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Didn't know you could get dual motor mounts - thanks for pointing it out, it'll be handy for a project I have lined up - oh, and I'll follow your build of course O0
Regards,
Ray.
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Didn't know you could get dual motor mounts - thanks for pointing it out, it'll be handy for a project I have lined up - oh, and I'll follow your build of course O0
Regards,
Ray.
Think they were made to suit by Malcs yes/No
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Yes they were made to suit the ship thought it would be easier to line up :-)) ,i have already been in touch with Robbie regarding differences in the hull and more so the Jecobin plans regarding rudder positions they are well out >>:-( .
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Due to an error in gear clearances and trashing one set of gears, i am now opting for my initial idea of the Astra motors but with a 1.2.5 belt drive ratio the motors are reving at around the 4000 rpm range uncoupled i expect some loss in the drive and hopefully expect around 8,500 rpm at the prop maybe ;), the prop pulley will have a bearing plate fitted on the ends of the shafts to give extra support due to the sideways pull of the belt, the motors will be mounted on two plywood bulkheads fitted in front of the pulley bearing plate and they will be adjusted like alternators on a car for belt tension ie: just enough so they dont slip.
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The bearing plate has to be removable to replace belts if they break so it will be retained with 3 m4 screws and inserts fitted to the wood blocks, I have altered the prop angle slightly to make room for the pulleys but dont expect this to pose a problem ;D
The motors have m6 coupling nuts welded to them two for the pivot and one for adjustment in a slot to be formed in the bulkhead to be placed nearest the pulleys.
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The belts by the way are from a vacuum cleaner shop,had to shop around to find ones the right size as they dont specify a size on the internet only the model that they fit,these are for a Hoover Cyclone v13 giving me about 45mm centers on the pulleys.
I am expecting a very quiet drive compared with the gearboxes with the johnson motors. :-))
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Have given up on the belt drive,had problems keeping belts on the pulleys have just bought two 2.5.1 MFA 540 geared motors from Maplins so they will be fitted this weekend ,i need to move on in the build and make some progress O0 .
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Timing belts and pulleys?
Regards Ian.
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I considered timing belts and wheels but the cost was a bit prohibitive and also the astra motors took up quite a lot of space especially above the waterline,it wasnt just the problem of them slipping off the pulley it was the combination of size as well if i was building a 1/72 scale model they would be fine i could have turned pulleys with deeper flanges they would have helped the belts to track straighter.
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Finally a bit of progress i have fitted the Mfa geared motors i am using cnc type couplings,i had trouble with one driveshaft seizing up with the brass collar that butts up against the prop tube it took ages to free up eventually with a bit of heat it came off but had scored the shaft a bit it has now been smoothed off with fine wet and dry paper and greased,in one of the pics i have attached a reflective tape to measure the rpm of the shafts they are averaging 5200 rpm out of water on 12 volts so am hoping it is adequate,the rudder tubes are fitted into blocks of wood drilled at 5 deg as per directions from my dear friend Robbie (type45) on the model warship forum the bottom of the rudders finish just inboard of the two prop end caps sloping outwards in a vee formation i am now after some tiller arms with 1/8" center holes to fit the Sitek rudder stems up to now all i can find are 4mm ones i may have to make my own to suit.
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Got a bit more progress today have made the spoiler thing on the transom out of aluminium bar sawn and ground with a sander and finished on the linisher and i secured it with stainless screws and superglue,i will fair it in with filler at a later date will most likely make the side ones the same way,i will be glassing over the screw heads as well, have also made up the tiller arms for the rudders out of brass the collar is turned down at one end and the arm is fitted over it and peined down and soldered i didnt want to trust soldering alone i know its a bit belt and braces but i didnt want them to break loose later,the servos will be connected by 3mm stainless wire fitted with ball links at each end.
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More pics-
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Lookin' real good :-))
Mark
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Have just made up the aluminium bilge keels (lots of sawing and grinding >>:-() and have secured them the same as the transom spoiler,the stabilisers are just pushed in the holes for now,i intend the pivot tubes to be as long as possible so as to be above the waterline, i am pondering over using one servo to operate them or two {:-{ and i have a gyro off an rc helicopter i would like to use has anyone done this ?.
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A few pics-
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I have done a bit of framing out today and fitted brass eylets in the hawser locations-
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Had a productive day today i have fitted the servo,s to the rudders and the stabilisers and have incorporated a ballast chamber with a central division for the rudder servo,s, i have opted for two rudder servos for one they are cheap enough :-)) and two they may help if one fails as long as its not the y lead, it is fitted with push in plastic caps for filling. ;)
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I have just had the Dragon in the test tank :embarrassed:,with one 7 ah battery she is 1/2" above the waterline with 2 batteries she is on the waterline and thats with just the superstructure mouldings sat on her so it is definately going to be one battery only and build as light as possible with few extra,s, i may opt for building new superstructure out of styrene. >>:-(
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Do you have a clearer view between the RC unit mount and the side stabalizers near the hull. Also with the servoes you operate together one rudder and one stabalizer vial one cable or something else?
Mick
Tumut Au
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Hi Mick the stab tube goes through the hull skin then a block of wood epoxied to the hull and then through the plywood servo mount,the stabs are homemade with longer shafts than normal these i intended to cut to size later but then i decided to keep them long so as not to let water in,the plywood mounts are set at 45 deg as are the stabs it keeps the linkage simple and due to the superstructure opening they are easy to get at,all four servo,s are connected by three Y leads to the rudder connection on the receiver and the way they are connected to the stabs and rudders ensures they operate in the correct directions,my friend Robbie on the model warship forum is building Hms Diamond and his way of connecting the stabs to the servo,s is quite complex with bevel gears and linkages, hope this helps you if not just ask away :-)) Malc
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Pics
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Pics2
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hi
nice build so far. I once did a build of a ferry were there was naff all weight that i coud put in her. What found helpfull was to.
1 weigh her down so she sits on the water line. Take note of that weight.
2 weight ever thing like motors ,superstructer etc to see were saving could be made. 10 grams here and there all add up.
Things like not using white metal fittings but using resin all helps.
John
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Thanks John i have decided to ditch the Sirmar superstructure and remake it with styrene sheet as it is very heavy,and the ballast chambers i have made i dont think i will need but may fill them with foam instead or remove them later {:-{ as to the fittings i hav'nt bought them yet so am running blind.
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I may seam like a lot of work . but you dont want weight up top and fiberglass can be heavy.
john
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Thanks for the info on the stabalizers and extra pictures.
Mick
Tumut Australia
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No problem Mick here are a couple of pics of my intended helicopter it is an Italeri 1/100th scale Merlin AW101, just have to make up some landing gear for it.
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Progress update-
I have been busy building the superstructure out of 2mm styrene and have added t section stiffeners to the inside,the helideck has now been made with a removable middle section it has the grid routed out to take a model warships etched brass grid and also the tie downs have been routed out so the brass tie downs are flush with the deck,the deck will be screwed down with m2 stainless steel c/sk socket head screws these are positioned where the drain covers are and hopefully will resemble them a bit after painting,i have also started the missile silo and the bridge this has also been routed out along with the windows.
The transom spoiler has been removed and reshaped as the plan details are wrong this was confirmed by my dear friend Robbie and the photo's he sent me.
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This is looking really good .......... I'm enjoying following this.
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Thanks Peter i will try to update more frequently its nice to have a response off someone :-)), sometimes you think you are talking to yourself >>:-( and no one is out there O0,i must admit to browsing the forum and not posting on other peoples efforts. :embarrassed:
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What's the best way on this hull and superstructure to get an invisible line between hull and top as this is what's putting me off the 1:96th and heading towards the 1:72nd from fleetscale which has the sides moulded in?
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Hi type 82 on my Dragon i am moving the joint up to the next deck level for the superstructure so the sides will be bonded and filled, the deck will lift off and also the flight deck will have a removable section to get access to the rudders etc, the forward deck will be bonded in position with limited access through the lift off missile silo i will post some pics shortly as i havnt posted any updates for a while. yours Malc
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Hi yes that's brilliant thank you