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Author Topic: Chinese 20 warships  (Read 15024 times)

Captain Povey

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Re: Chinese 20 warships
« Reply #50 on: August 21, 2008, 08:28:54 AM »

Hi Tobyker, I think your idea of naming her 'Troutbridge' is excellent and I had not thought of it. Maybe because Ramona was breathing down my neck and might have objected. Last night I fitted all the bits from Action and if the battery and charger arrive in the post this a.m. I will post photos of the installation as soon as possible. Please do not laugh at the workmanship i.e the holes for the wires were made with a soldering iron. Appart from the fumes it was less messy and easier than drilling. A good application of silicon sealer will finish the job. It sounds as if you are going to a lot more to yours than I am willing to attempt so I will be interested hear how the rudder works out. My assumpton is (and I may be proved wrong and end up with a red face) that with the voltage down to 4.8 volts the current draw in the water will not exceed 1amp per motor otherwise it will not work. Also at 4.8 volts it might not go very fast. Cheers Graham
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tobyker

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Re: Chinese 20 warships
« Reply #51 on: August 21, 2008, 11:34:43 PM »

I dunno much about electrics but I thought a motor pulls the amps it wants irrespective of the volts or mAh of the battery. No doubt someone more familiar with the wriggly amps will set me right. Still waiting for postie with the props! I thoroughly approve of making holes using a soldering iron - I am planning to do some of those myself. Don't forget to launch her with a jug of, so far as I remember, "me old Mum Min's Humgrummit wine". Those were the days.
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FullLeatherJacket

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Re: Chinese 20 warships
« Reply #52 on: August 22, 2008, 07:27:51 AM »

I dunno much about electrics but I thought a motor pulls the amps it wants irrespective of the volts or mAh of the battery. No doubt someone more familiar with the wriggly amps will set me right.

"Starboard lookout here...........Leading Seaman Jacket speaking"

Now there's a Techno-Monster lurking elsewhere on this forum who would probably wax lyrical for a few hundred words on the subject if he discovered us, so let's Keep It Simple and hope we stay below his radar...... ;)

More volts increases the speed of the motor, whereas battery capacity has no effect on its speed; only on how long it will run for. Motors are dumb animals and have no idea what sort of current they want; it's a produce of the resistance, the load and the voltage (and probably a few other things which T-M would list at length). You can't alter the first so you play around with items 2 and 3 until you're happy.

Happy?

FLJ
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OMK

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Re: Chinese 20 warships
« Reply #53 on: August 22, 2008, 08:25:05 AM »

Happy? HAPPY?? I'll bet he's bleedin' delirious!

How do you do it, dude? Just HOW do you DO it?!!
(Perhaps you would be kind enough to pass it on to T-M).
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DickyD

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Re: Chinese 20 warships
« Reply #54 on: August 22, 2008, 08:41:19 AM »

Wonderful Dave, even I understood that. Would the T.M. be a certain B.P. by any chance ? :-\
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Captain Povey

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Re: Chinese 20 warships
« Reply #55 on: August 22, 2008, 06:04:38 PM »

Hello All, I am glad to say the battery and charger turned up today so the final wiring took place. The bench test proved to be better than expected and the electronics bits worked brilliantly (thanks Dave). I had not realised that the mixer actually reversed the inboard motor on a turn so steering will be better than expected. I had to fiddle a bit with the wires to get the prop rotations correct and the steering to go in right direction and then realised that the radio I borrowed from my son had servo reversing functions on it anyway. Doh! So next was the bath test, without superstructure, just to check it all worked under load. This also proved to be very successful and no problems appeared even with the nose wedged into the end of the bath and the throttle full on. Now its on to the reassembly and application of sealer to all those holes I made. I noticed that on mine the deck seal had not been fitted properly at the bow and has now been repositioned. Can anybody tell me the purpose of the hole at the stern and the point of the polystyrene in fill? I have also plugged the two holes in the rear deck that had rubber bungs in them. Ramona is now missing some large plastic knitting needles. I think it is a good idea, as already suggested, to replace the ballasting weights with lead as this will get the weight lower and maintain stability. I also reattached one of the missile pods with a screw. Not pretty but if another refit is needed then it can be done just by unscrewing things. Here are a few pictures of the lash up so far. Cheers Graham
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Captain Povey

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Re: Chinese 20 warships
« Reply #56 on: August 22, 2008, 06:07:32 PM »

Well I did not get all the pictures into the last post so here goes again.
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Captain Povey

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Re: Chinese 20 warships
« Reply #57 on: August 22, 2008, 06:10:05 PM »

Well it looks like I have a problem Houston. Yep it was being dumb again.
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Captain Povey

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Re: Chinese 20 warships
« Reply #58 on: August 22, 2008, 08:36:22 PM »

Well I have just replaced the weights with lead. Not as striaght forward as I imagined. Getting the weight right was ok but getting it distributed was critical especially accross the beam. More bath side time spent than I imagined. Here is another picture I missed off previous posts. Cheers Graham
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Captain Povey

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Re: Chinese 20 warships
« Reply #59 on: August 23, 2008, 10:00:11 PM »

Well it is all back together and ready for a sea trial tomorrow. Granddaughter has already been on the phone to ask if I am taking her boat over tommorrow. Fingers crossed for a success and a big improvement on the last run. I moved the life boats to allow easier access to the screws that were underneath them should it be necessary to undo them again. I have not put in all the plastic bungs over the screws yet and I may well plug them with more turned down grey plastic knitting needles at a later date. I replaced some of the rather poor quality self tappers with some stainless ones. I have one queston for the electronics boys out there regarding charging the battery using the socket on the boat. When I plug the charger in neither the led on the charger or boat is lit despite measuring a voltage at the battery lead socket. So just to be sure I charged the battery out of the boat using the Tamiya lead and the led on the charger then works. I noted that it is critical to replace the battery in the same position every time to ensure an even keel. If all goes to plan and weather permits as it has just started raining here again pictures will be posted. Cheers Graham.
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Captain Povey

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Re: Chinese 20 warships
« Reply #60 on: August 25, 2008, 11:16:51 AM »

Success, it worked and granddaughter was happy. I was concerned that she (the boat not granddaughter) did not want to turn to port at one point but then learnt that the steering works best at slower speeds. She also took on a list due to the battery moving. Once again accurate ballasting is critical. Sorry to say that I was so busy with this and my other boat that I forgot to take some pictures but the family did so I will post some when available. One other observation is that the two holes for the rubber bungs in the rear deck may have a use so bunging them up was probably not such a good idea. When I took my other boat out of the water after an hour or so she had taken on some water up the starboard prop tube. If this has happened on the destroyer then the only way to drain it is out of those bunged up holes. Cheers Graham.
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FullLeatherJacket

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Re: Chinese 20 warships
« Reply #61 on: August 25, 2008, 03:45:32 PM »

the steering works best at slower speeds.

Point of info for anyone who fancies emulating the good Captain's set-up;
With no throttle applied, the rudder command has no effect, but squeeze a touch of forward or reverse speed and the inboard motor goes into reverse. As you increase the forward speed so the mixer gradually reduces the degree of "mix" until, at full speed ahead and full rudder, the inboard motor is just stationary. It's a "compound" mixer which offers the best compromise between a 50% and 100% mix. The bigger P40C has the same software, whereas the Full Monty P94 has fully-adjustable mixes from 0% to 100%.
The gen on mixers is here
http://www.action-electronics.co.uk/pdfs/Twins%20Ver2.pdf
PM me for any further info or queries.
FLJ
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Captain Povey

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Re: Chinese 20 warships
« Reply #62 on: August 25, 2008, 09:10:39 PM »

Hi FLJ, Thanks for the explanation of how the mixer works. I was sure it was somrthing like that  :D but I couldn't seem to find the words. Cheers Graham. O0
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Weeds

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Re: Chinese 20 warships
« Reply #63 on: August 25, 2008, 09:22:16 PM »

link for the mixer and price?
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tobyker

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Re: Chinese 20 warships
« Reply #64 on: September 01, 2008, 10:27:16 PM »

Weeds, look at the ACTion electronics website in the Traders area.
Capt Povey and ACTing leading seaman Goldstein- pl note that at 0900 next Friday, Radio 4 is doing one of the "Re-union" series on the Navy Lark - with Sub-Lt Philips, Wren Chasen and others.

WARNING - THIS MAN KNOWS REMARKABLY LITTLE ABOUT ELECTR(ON)ICS

I finally got a tub of water, the destroyer, my AVO meter and some time all together in one place. The Stbd motor drew 0.35A off load, and 1.03A with the standard plastic 2-bladed 30mm prop fully submerged - about 0.65A submerged to the hub.
I then put on a 30mm Raebosch brass 3- blader, which drew .022A off load. Either my test set-up is wrong, or the heavier brass prop is acting as a flywheel, which might mean the motor needs less amps to keep it running. (The plastic 2-blader doesn't register on my electronic scales, and the brass one reads 6g. My set of scales which would show the weight of the plastic prop are 400 miles away weighing bits of car valve gear.) The brass prop drew 1.2A fully submerged.

Mind you, these readings of just over 1A in still water with the 7.2V pack suggest that you should be quite safe running ACTion's tiny ESCs on 4.8V - as Capt Povey appears to have demonstrated.

This suggests that the brass prop of the same dia as the plastic one is putting more watts into the water, and the boat is too fast anyway. Also, looking at the 3-bladers, they look far too big for the hull, though for tank steering they probably need to be. I have therefore ordered some smaller props and will run the test again with them, a freshly charged battery, and a new battery in the AVO. I've made the rudders and a servo mount, but haven't yet worked out a light but robust linkage which I can bolt out of sight under the deck.

What's the best hybrid bike I can get for 350? any ideas?
 
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Captain Povey

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Re: Chinese 20 warships
« Reply #65 on: September 02, 2008, 09:20:30 AM »

Hi Tobyker, Nice to see you back on board and doing some excellent experimental work.  8) I cannot comment on the props as I have never done anything like that. My only comment regarding loading form the different props would be that the heavier brass one will have a larger start up current draw because of the inertia. Thanks for the info on the Navy Lark I shall listen out for it. I am still waiting for the pictures of the destroyer from the family who have been on holiday. I do not know much on bikes although in my younger days I rode a few.  ;) Hybrid bikes are new to me so does an electric one count? I have seen those for around 400 so maybe a second hand one would in the price range. I saw a man on a uni cycle in bath the other day and with only one wheel perhaps they come at half price. Sorry just being flippant as usual. Cheers Graham.  O0
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tobyker

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Re: Chinese 20 warships
« Reply #66 on: September 10, 2008, 07:56:03 PM »

Rainy day and waiting for propellors (again) so out with the plasticard for servo mount and rudder tubes. The shafts I am using come from when I worked for a metal tube broker - does anyone remember when ballpoints used brass ink tubes? Of course no obtainable tube fitted the biro tubes so i had to take the next largest plastic tube, slot and re-glue it round the shafts twice, and then raise a burr on the end of a biro tube and ream the tubes out a tad. I still haven't worked out a linkage but it may be easier when everything is in position.
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Captain Povey

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Re: Chinese 20 warships
« Reply #67 on: September 12, 2008, 11:32:28 AM »

That is looking very good Tobyker. Unfortunately my photos have still not arrived. Cheers Graham
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Captain Povey

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Re: Chinese 20 warships
« Reply #68 on: September 15, 2008, 09:04:34 AM »

Hello all, At last I have a picture of the reworked destroyer on the water. The rest of the shots were done in a video format so if somebody can in instruct me in how to edit and upload to U tube I will put some of that on and post a link to it for those interested. Cheers graham.
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Captain Povey

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Re: Chinese 20 warships
« Reply #69 on: September 15, 2008, 11:13:24 AM »

Hi All, I have posted a video on u tube. If I have done it correctly it will be on http://uk.youtube.com/watch?v=GkXzo34TFGc, Cheers Graham.
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Captain Povey

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Re: Chinese 20 warships
« Reply #70 on: September 15, 2008, 11:39:32 AM »

Here is some more of the destroyer plus a bit of Smit Nederland.  http://uk.youtube.com/watch?v=JZauR9vaoho Graham
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tobyker

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Re: Chinese 20 warships
« Reply #71 on: September 16, 2008, 11:43:01 PM »

They are a bit quick, aren't they? There's lots of them on Youtube, too. I've started fidling about with linkages and will put up the pictures as soon as I've got them sorted.
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tobyker

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Re: Chinese 20 warships
« Reply #72 on: September 18, 2008, 10:51:45 PM »

A productive couple of days - got the rudder linkage 90% sorted - just got to seal where it passes through the rear bulkhead, as I may well leave the steerage free-flooding, because of the difficulty of sealing the aft deck. The servo, mount, rudders and linkage weigh 28g, so that will have to come of the aft steel weight. The radio box is presently bottom-loading, but I want access to as much as possible, so I've cut through the deck beneath the helicopter deck to make it top-loading, and am building a 3/4" coaming round the hole. I'm taking the radio box a bit further aft than the original, and will make it deeper with a fixed bottom, as I'm binning the breeze block weight and replacing it with lead flashing. Pics to follow when I've finished the new radio box. Not made up my mind yet exactly what's going in it, as I need to see what sort of amp draw and thrust my new props give me, when they arrive.
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tobyker

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Re: Chinese 20 warships
« Reply #73 on: October 09, 2008, 08:51:06 PM »

Things still coming along slowly, but no sign of my smaller props yet. However as pics show, I've got a rudder linkage sorted, and have lenthened and deepened the radio box, with top access hidden under the aft superstructure - the bit with the helo deck. I'm binning the helo, as it's too heavy and too high up. The breeze block weight is out, too, and it's supports removed. The radio box now goes right back to the deck mounting pillars just forrard of the motors - I've installed slightly thicker motor wires and led them through holes in the motor mounts so they'll go under the radio box (over the lead weight - if I still need weight!) and come up somewhere inside it near the ESC(s?) I'm still waiting to test the amp draw with the new props so I can decide whether to go for 4 or 6 cells, and depending on that, whether to go for combined screw and rudder steering or a single ESC. I also need to weigh the new props so I can see if I still need any weight between the prop shafts, where the 60g steel slug was.In order to simplify access I'm going to locate the aft superstructure with a magnet, and glue the bridge and the middle bit with the boats on, together. As the quadruple missile launchers as presently fitted foul the foredeck mounting screws, I'm going to mount the missile launcher ramps on to the side of the bridge structure, so they come off with it. The aerial I shall probably mount under the foredeck. For info, all the white plasticard is 1mm thick. I'm still not quite sure what to do about the free flooding steerage compartment - if I seal it I'll have to seal the aft deck to the hull, and that could be tricky. It may be better to leave it flooding, and try to seal the hole where the rudder linkage goes through the aft bulkhead as well as I can. The trouble is, the hole is quite near the sealing lip in the deck. This boat is representing good VFM in that all the problems are keeping me thinking for a long time and even with the ESC and other radio bits the cost per month should be quite reasonable.
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