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๐ฌ Re: Revell Gato Class Submarine Conversion.
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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Hi Bill.
You have made a really nice looking model. This project will take a while but I am looking forward to it. The propellers, shafts and joints can be found on ebay. The item number is 273490619808. The seller is rc-sub-workshop. They are a little expensive but they do come with all of the required parts. I will let you know what they are like when they arrive. They are coming from Hong Kong I think. Peter.๐ ▲
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Remove Ads ๐ฌ Re: Revell Gato Class Submarine Conversion.
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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Nice model.
Martin. ▲
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๐ฌ Re: Revell Gato Class Submarine Conversion.
5 years ago by ๐ฌ๐ง Scratchbuilder ( Vice Admiral)
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Hi.
Good luck with the Gato Submarine.A great project. I built one from the same kit some three years ago although she is only a surface boat. I would be interested to know where you got the shafts from. I turned my own at home and also made the A brackets, adapted the original rudder etc. I attach a few pictures of her on the pond. Looking forward to reading more on your progress. Regards Bill๐ ▲
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๐ฌ Re: Revell Gato Class Submarine Conversion.
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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The joints will be in the hull space along with the universal joints for the motor connections....I hope.
I have just drawn the motor position layout and it looks like two 25mm diameter geared motors fit the bill. I would like to know what rpm I should aim for. I would have thought that speed of the boat was fairly unimportant. slow is good, but torque would be. I was thinking around 500rpm at 6 volts. We will see. Thoughts would be welcome from more experienced builders. The inside of the Water Tight Compartment will be 66mm. This allows for both motors to be almost entirely below the tube centre line. ▲
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๐ฌ Re: Revell Gato Class Submarine Conversion.
5 years ago by ๐ณ๐ฟ jbkiwi ( Fleet Admiral)
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Magnetic rod joints, neat idea! (miniatures of magnetic table mechanism would be cool) depending on the magnets you might need to come up with a separating tool (neodymium magnets especially would be a mission in a tight space!) or will the joints be out in the hull space?
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๐ฌ Re: Revell Gato Class Submarine Conversion.
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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Hi jb.
This is all new to me as well. There will be a sealed tube about 50cm long inside sealed with o ringed bungs at each end with further sealed barriers inside to hold the flotation bladder. I have the tube and the material for the bungs which I will start soon. The tube should be relatively easy to remove as I will use magnetic joints for the operating rods. This project will take some time and will be quite expensive.๐ ▲
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๐ฌ Re: Revell Gato Class Submarine Conversion.
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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Hi Peter,
It a bit of a challenge but you will get there. Good luck. Martin. ▲
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๐ฌ Re: Revell Gato Class Submarine Conversion.
5 years ago by ๐ณ๐ฟ jbkiwi ( Fleet Admiral)
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That's an impressive piece of plastic! How will you service the internals etc once glued together, o-ringed hatches or is the tube a complete drop in/removable module ? Must be a job trying to keep everything dry in subs, bad enough with racing boats! Certainly will save a lot of hull construction work doing it with the kit. A bonus would be that gluing bits to this material is easy and it's reasonably durable.
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๐ฌ Re: Joining the fuselage.
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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Fairy Dust.
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Remove Ads ๐ฌ Re: Joining the fuselage.
5 years ago by ๐ฉ๐ช RNinMunich ( Fleet Admiral)
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We try to please Peter ๐
The ultimate 'Green' motor!! I just wonder how you control them! ๐ฎ ▲
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๐ฌ Re: Joining the fuselage.
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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One of them is perfect. It is a magic motor. According to the Amazon spec. no battery is required. Instant weight saving.๐
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๐ฌ Re: Joining the fuselage.
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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Thanks Doug.๐
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๐ฌ Re: Joining the fuselage.
5 years ago by ๐ฉ๐ช RNinMunich ( Fleet Admiral)
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Here's a couple on Amazon UK which should do nicely ๐
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๐ฌ Re: Joining the fuselage.
5 years ago by ๐ฉ๐ช RNinMunich ( Fleet Admiral)
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"That is one of the things that I hate about some of these motors, the lack of information on them."
Seek and ye shall find Martin๐ ▲
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๐ฌ Re: Joining the fuselage.
5 years ago by ๐ฉ๐ช RNinMunich ( Fleet Admiral)
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Hi again Pete,
Check the specs before you order! MFA's 380 version does about 19k revs!!๐ฎ Look for original Mabuchis or Johnsons. They are a bit tamer๐ 25mm could be a problem! I think the 380s / 385s are all 27-28mm๐ค Scrape a mil off the inside of your tech rack tube!? OR, go for a 280 size (23.8mm dia๐) such as this from AliExpress- ▲
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๐ฌ Re: Joining the fuselage.
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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Hi Doug. Just seen your last comment from yesterday.
I have a lot of preparation work to do on the bow and stern end caps before I fit the `wings` on. I have just purchased a Dremel to help with this work. I will practice first before cutting into the model. You know what practice makes. Smaller mistakes.....Maybe.,๐ ▲
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๐ฌ Re: Joining the fuselage.
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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Thank you.
Martin. ▲
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๐ฌ Re: Joining the fuselage.
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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Hi Doug,
That is one of the things that I hate about some of these motors, the lack of information on them. Martin. ▲
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๐ฌ Re: Joining the fuselage.
5 years ago by ๐ฉ๐ช RNinMunich ( Fleet Admiral)
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Don't think so Pete. Gearboxes are usually noticeable as 'bolt-ons'.
Cheers, Doug ๐ ▲
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Remove Ads ๐ฌ Re: Joining the fuselage.
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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Thanks Doug. I was looking at geared motors to keep the rpm down but reading what you have to say, the 385`s at 6 volts should be good. Now to see if I can get these at 25mm diameter maximum.๐
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๐ฌ Re: Joining the fuselage.
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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Perhaps they have gear boxes? Might account for the extra length.
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๐ฌ Re: Joining the fuselage.
5 years ago by ๐ฉ๐ช RNinMunich ( Fleet Admiral)
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๐ฌ Re: Joining the fuselage.
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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Get well soon Martin.๐
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๐ฌ Re: Joining the fuselage.
5 years ago by ๐ฉ๐ช RNinMunich ( Fleet Admiral)
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๐ฌ Re: Joining the fuselage.
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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Hi Peter.
I honestly don't know. They were just two that I had lying around, I have to open up my WTC to try and sort out a small problem so when I do I will see if there is any markings on them. Unfortunately I will not be able to do that for a while as I am having slight health problems at the moment. Martin. ▲
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๐ฌ Re: Joining the fuselage.
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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Hi Martin.
What motors have you fitted in your Gato. Thanks. Peter. ▲
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๐ฌ Re: Joining the fuselage.
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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Thanks Doug. I think I will come up with my own idea to keep cost down. Any idea of 385 motor rpm at 6volts.
Thanks. Pete. ▲
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๐ฌ Re: Joining the fuselage.
5 years ago by ๐ฉ๐ช RNinMunich ( Fleet Admiral)
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Hi Peter,
My U25 at 107cm is about 8/10 the size of your Gato, but probably heavier as it's hull is made of four planks of carved wood!๐ฎ Anyway she goes just fine using two 385 motors on 6 or 12V driving 3 blade 30mm props. On 12V way too fast of course but it's fun to show up the speed merchants once in a while๐ Re dive plane retraction- Here's two possibilities! This one from the German model Sub tech expert Engel where I got my Akula 2 kit. It comes with a controller. ▲
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๐ฌ Re: Joining the fuselage.
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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As the submarine does not have to move very fast and has two motors driving 35mm propellers, does anybody have a suggestion on how many rpm the shafts need to go. I am sure that torque is more important than rpm but a forward speed of around walking pace should be enough. Your thoughts would be appreciated.
Peter. BTW jb, the bow planes are in the kit, the actuating mechanism is the item I have to figure out. ▲
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Remove Ads ๐ฌ Re: Joining the fuselage.
5 years ago by ๐ณ๐ฟ jbkiwi ( Fleet Admiral)
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Might I suggest carbon fibre sheet, rod and tube for the bow planes? nice and strong (+ resin coat ) and totally rust free.
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๐ฌ Re: Joining the fuselage.
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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I had a couple of broken servos so I used the main cog from them.
As you need to plan at least three steps ahead. Depending on your WTC and how many channels you will be using and how the bow planes servo is mounted you may find that you might not be able to get the planes to retract. I hope the attached photos will help. Martin. ▲
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๐ฌ Re: Stern Module assembly
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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Hi Peter,
I had the same and had no problems after it was glued, go for it. I would say good luck but you won't need it.LOL! Martin. ▲
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Remove Ads ๐ฌ Re: Stern Module assembly
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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Thanks both. I will add suppression next.
As for the warp, I think I will take a chance and glue as is. As the material is probably HIPS, the melt point is very low and I fear further damage could occur if heated. My main fear would be even further warpage as it cools. Better the devil and all that. ▲
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๐ฌ Re: Stern Module assembly
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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Hi Peter,
I have found that it will glue together without any problem, you will have to hold it together tightly with masking tape until fully set. Keep up the good work. Martin. ▲
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๐ฌ Re: Stern Module assembly
5 years ago by ๐ฉ๐ช RNinMunich ( Fleet Admiral)
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Hi Pete,
"I have now purchased my chosen motors. They are MFA 360. ... I wonder if I have to put the usual three suppressors on the motors if running a 40Mhz transmitter." Most definitely!! Considering the attenuation of RF signals under water the last thing you want to do is take risks with interference๐ฎ As the RF signal level falls off when you dive the boat any local interference, i.e. from the motors, will become more significant at the RX input. Re warped stern parts. You could try gently (and I mean gently Bentley!) warming the part (hair dryer?) while weighting it down on a flat surface. You may want to put some shaped wood block supports inside to ensure the part does not bend inwards. Cheers, Doug ๐ ▲
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๐ฌ Re: WTC construction.
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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Hi Peter,
That all sounds great and I hope it all works out. It will be the simplest of things that catches you out. Like the wires will pass through but the connector on the end won't. The radius of the tube prevents you from fitting the bits where You wanted to fit them. I spent more time working out everything before actually making it, and I thought I had it all sorted out, but when it actually came time to make it that is when the problems started. These are complex in there construction so I tried to keep it as simple as I possibly could. Good luck, Looking forward to your future posts. Martin555. ▲
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Remove Ads ๐ฌ Re: WTC construction.
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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Hi Martin.
I have a 3mm gap all around the tube. I have not thought as far as the connection between the forward and rear planes yet. I will stumble over that one later. I am still considering having a tube through the centre or near the top for wiring. I will see how it pans out. (Wish this spell checker used proper English and not US English). The inner tube is a nice slide fit inside the WTC. My plan is to get the servo, battery and motor frames to hold it in place. The length is only a guess at this stage and if only a small amount of water is needed to submerge the submarine, then I will probably shorten it. I have used 4mm wall section tube for the ballast tank and I am going to tie rod the caps in place using brass bolts with SS threaded rod between. I will modify the bolts with M4 internal threads and o rings under the heads. Should work a treat....I hope.๐ ▲
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๐ฌ Re: WTC construction.
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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Hi Peter,
You have done an excellent job on your WTC so far, well done. I wish I had the equipment and materials to do the same. Like you I had to do a lot of forward planning before making my WTC. Having a water tight tube inside a water tight tube is a good idea as it reduces the risk of leaks. But have you enough room between the inner and outer tube to pass wiring through ? I am assuming that the forward and aft bow planes will have separate servos operating via a Y connector. Or are they being operated separately. How are you going to hold the inner tube in place.? The centre section on my WTC is a separate tank with a through tube to enable my wiring to pass through (you have probably seen my thread on here) I think I also mentioned that you will not need to pump in much water to get the Gato to submerge. And after experimenting I decided to fit a party balloon to also prevent leeks around the wiring through tube. I ended up venting the air as I had pressure problems. Martin555. ▲
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๐ฌ Re: The ballast unit prototype.
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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Keep up the good work.
Martin555. ▲
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๐ฌ Re: Stern Section
5 years ago by ๐ฉ๐ช RNinMunich ( Fleet Admiral)
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"As the tubes are not long enough to reach the rear bearings and skegs, "
They are not supposed to be Peter! The stuffing tube box stops at the hull exit, so what you are doing is correct to the originals๐ Doug ๐ ▲
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๐ฌ Re: Stern Section
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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Nice work Peter, keep it up.
Martin555. ▲
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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Thanks Doug.
Following several tests I have carried out, the valves are strong enough for the job but only if the flow direction is correct. I did consider that the pressure was causing the problem but discounted this when I found that I can fill in stages and the valve closes each time. It will not, however, open when the pump is reversed. It does energise and throw the valve when the circuit is activated with no water present. My latest plan is to use the forward and reverse functions of the pump with each circuit protected with a one way valve and a separate solenoid valve for each direction. To make this work, I will have to ensure that the input valve only works in forward and the output valve in reverse only. To do this I will need a small circuit to split the load. I have most common components here but no brain for designing the required circuit. I will enjoy building it though. With the valve plumbed the right way, I filled the tank in stages to 80% full and held it for 1 1/2 hours, mainly as I could not pump it out. I had to remove the input pipe to empty. It was holding a decent pressure. I will not fill it this much again for safety and I will make a simple safety valve. I got my 4 year old grand child to draw a scheme of my latest plan with the wires for the valves waiting for a circuit. I will ask him to improve his drawings for any future attempts.๐ For reference, the flow does go in the side connection. I just checked your comment on polarity. You are right, they work either way around. Ooooooppppssss!!! Oh, nearly forgot; I have been advised that if I use crawler mode on the ESC, the output voltage is the same in both directions. ▲
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Remove Ads ๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ฉ๐ช RNinMunich ( Fleet Admiral)
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Hi Pete,
Thanks for your PM. I'll get back to you on that. Some thoughts! (Doh my 'ead 'urts๐ค) The Solenoid Valve. Suspect number 1! 1 Tested a few of my solenoids and electro magnets from a batch picked up for a song at a local flea market. (Felt a bit of a twit doin' a song and dance routine in the middle of the market๐ค, but it worked๐) Sooo, the solenoid doesn't care about the polarity of the supply volts, as was already beginning to dawn on me. As soon as the current flows in the coil (either way) the magnetic field is there and drags the core in on mine. 2 I note that your valve has input and output at right angles Pete.Which end is the tank connected to? If, as I suspect, it is connected to the side tube it may be that the back pressure from the tank is jamming the valve against the opposite side. That, combined with probable reduced voltage from the ESC in reverse (Suspect number 2!) AND the 1.4V drop of the bridge rectifier (2x0.7V of the diodes, Suspect number 3) means the solenoid coil is not getting enough current to create a strong enough field to overcome the friction of the side pressure. Solution? 1 Pt 1 tells us we can dispense with the rectifier. 2 Then connect the tank to the pipe which is in line with the solenoid, thus eliminating the side pressure on the valve plunger. If back pressure from the tank then causes the valve to open / weep then the valve return springs are not man enough for the job. ๐ญ As mentioned above, it could also be that you pumped in more water than you actually need, thus creating unnecessarily high pressure in the tank. That's what I meant about unrealistic test conditions. You might be chasing a Ghost Pete ๐ฎ 3 Check ESC programming possibilities to see if the reverse voltage can be increased, to 100% if possible. 4 Most transmitters these days have a 'servo travel' function, up to 150% independently at both ends. Maybe (if available on your TX Pete) that could be used to increase the reverse voltage when applied to the ESC channel? If nun o that woiks then, as Grandad (a master carpenter and cabinet maker) liked to say- "If all else fails .... use bloody great nails!" ๐ And Change valve! I'll PM or mail you on the two valve version Pete. G'night all, Doug ๐๐ด๐ค๐ค ▲
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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I agree with Doug regarding testing.
I think that by the time your WTC is complete it will be heavier than mine, Therefore you would need less water ballast. My WTC weighs 4 3/4 Lbs.( no extra weight added) When I placed my WTC in Big Blue it floated and the water level Was just above the centre. I attached some lead underneath just to level it up. Then pumped in about 3/4 of a cup of water she then submerged to the bottom. When I first placed the WTC in slowly it look as if it was going to sink, so I was quite happy when it stayed afloat. I don't know if this helps. Martin555. ▲
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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I agree Doug. Problem is that I cannot, so far, find a valve that is not too large and have relatively small connections. (tube connectors)๐
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ฉ๐ช RNinMunich ( Fleet Admiral)
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Hi Pete,
Where as I tend to agree that you need a solenoid with more shove, and above all stronger return springs, I don't think that your test set up is properly simulating the operating conditions. With your test set up there will never be more than ambient air pressure on the input side of the valve. Whereas under operating conditions in the wet stuff the pressure on the input will rise as the boat goes deeper. This will help counteract the back pressure from the tank. Also I don't think you will need to fill the tank so full and thus create such back pressure. A truer test would be an immersion test with some weight hung on the tank to simulate the projected all up weight of the sub. In this respect Martin's test in Big Blue was much closer to reality. Once properly trimmed on the surface 'any' additional weight will start sending the boat down. I'd be surprised if you need more than about +10% to submerge. Don't know the trimmed displacement of the boat or the capacity of your tank so can't be more precise. Cheers, Doug ๐ PS I also think you'd be better off spending few bob more on a decent brass valve instead of cheap plastic. False economy, saving in the wrong place Pete!!๐ ▲
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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I have done further tests on the system. Everything is working well once. Then it all goes wrong. The pump will not prime to refill. I am sure that the solenoid valve is not up to the task. It is being pushed open when the pressure is direct onto the piston and jams when the pressure is adjacent. I need a much stronger solenoid and one which blocks across the flow. I will have to see what I can find. Still interested in our fundamental test error though Doug.๐ค
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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What did we miss Doug.
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ฉ๐ช RNinMunich ( Fleet Admiral)
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Theoretically it might be possible to burn out the coil, but usually only if excessive voltage applied.
BTW: I looked again at your tank test and I think we've all been making a fundamental error! Namely ignoring the test conditions! More tomorrow, I'm bushed so G'night, Doug ๐ ▲
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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Doug,
I think I have a solution to the valve problem. It depends on your answer to this question. Am I right in saying that if a solenoid does not throw and the power is still applied, no damage is done as it is only an electro magnet. Thanks. ▲
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ฉ๐ช RNinMunich ( Fleet Admiral)
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I reckon we three must be cousins! ๐
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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"I want to but my brain and hands do something else."
I know exactly what you mean, I suffer with that quite a bit too. Martin555. ▲
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Remove Ads ๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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Sorry Martin. Keeping things simple does not compute. I am afraid my brain will not allow. I want to but my brain and hands do something else. I must have a strange genetic flaw. I must find a way around this. I know what you mean and agree, but those gremlins will win in the end.๐
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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Although I like your idea for your WTC ballast I think in my own personal opinion is that there is no need to over complicate the system.
Making a simple bladder system is tricky enough. If the Gato that you are making was much bigger then yes a better system would be ideal. Maybe it's me but I think you should keep it as simple as possible. Martin555. ▲
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ฉ๐ช RNinMunich ( Fleet Admiral)
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Mornin' Peter,
Can you post / mail me the valve instructions please. Hopefully there is a sectional diagram included. "The reason I was trying to avoid the piston system was to avoid the out of balance nose or tail first dive." If the boat is properly trimmed at the surface in the first place with the tank correctly positioned there is no reason why it should dive tail first! Real subs don't usually static dive (or surface) anyway. Always underway with a few degrees down / up plane to assist. Trick when diving is to switch to level planes (a little UP plane at the stern) at the right time to level off at the required depth! There are some neat auto trim / depth holding modules around to help with that๐ (Another reason for going digital servos!) Cheers, Doug ๐ ▲
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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Hi Doug.
I was thinking exactly as you. The pressure vessel I have made is of 4mm section at 52mm i.d. I have a sealed bolted rod holding the caps is place. The caps are 24mm thick Nylon 6. The pipe connector is M5 with a 2.2mm hole. Not much pressure area here. I think I might continue but taking extra care. I did further tests yesterday and found that the solenoid valve works perfectly when not connected to the pump and under pressure in both directions. The problem is the valve. Do you think I need a more powerful one or do you think the valve only works in one flow direction. For some reason the instructions show a direction of flow but as the valve only blocks the through hole, I cannot see why. The reason I was trying to avoid the piston system was to avoid the out of balance nose or tail first dive.๐ ▲
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Martin555
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ฉ๐ช RNinMunich ( Fleet Admiral)
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Hi Peter,
whereas I find that perhaps a little exaggerated if the materials used are robust enough, and I don't really think the pressures generated will be that great. However, I have to admit that I found the whole thing a little suspect, from the functionality point of view, right from the get go. So I kept out of the constructional side to see where it went๐ I have a piston tank system for my Akula. Does this mean I can cancel my pump / solenoid control experiments? ๐ค Cheers, Doug ๐ BTW; If you put a bladder in the same construction it won't make a ha'p'orth of difference to the internal pressures generated! ▲
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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I have been advised to stop with this method of a ballast tank. A veteran at this subject has advised that I am making a potential bomb which could injure somebody if it decided to go. He said that a simple fracture around my pipe connections could send parts flying causing potential injury. Now that it has been pointed out I see what he means. Back to the drawing board and a bladder system I think.๐ค
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ฉ๐ช RNinMunich ( Fleet Admiral)
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Absolutely Martin๐
Also the solenoid will not much like the pulsed voltage from an ESC. Especially if the 'On Time' is reduced when the ESC is in 'Reverse', as Pete suspects. To operate they depend on a steady DC voltage to maintain a constant magnetic field. After all, a solenoid is nothing more than an electromagnet with one part moveable! Apply an AC or pulsed voltage and it will try to chunter back and forth at the frequency of the AC voltage or the Pulse Repetition Rate ๐ค Go for the microswitches and a relay Pete๐ Cheers, Doug๐ ▲
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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Hi Peter,
You can do that just by using the pumps on/off switch. To make it dive or surface slower switch the pump on and off in stages. Martin555. ▲
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RNinMunich
MouldBuilder
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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So that I have full control of the dive. I like to vary the time it takes to submerge. Very realistic.
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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Hi Peter,
I am sorry but I am struggling to get my head around this. Can you explain to me why you want to adjust the flow speed of the pump. Martin555. ▲
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Remove Ads ๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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Don`t forget, it probably won`t take any where near 80% fill to submerge some way down under the water.
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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If I am not mistaken the real submarine would take between 30-60 seconds to get decks awash, so for the scale of your model 40 seconds would be about right.
At speed with plains set it might reduce the dive time a bit making it quicker to submerge. So really you should not need to control the flow rate. Just had another thought. If that took 40 seconds to fill the tank at full speed then you will require a second pump connected. By connecting the two pumps to a two stage switch setup you could start filling with one pump then to fill quicker the second pump will kick in. The same for emptying. Martin555. ▲
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MouldBuilder
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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I like your switch idea but I would like to control the flow rate of the pump. I can fill the cylinder to 80% in about 40 seconds. I would like to make this variable. Hence the speed controller.๐
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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I think that the three switch method I suggested earlier is the simplest way.
Martin555. ▲
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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I am continuing to have a problem with this set up. Almost. I have substituted the micro switches for a 60A speed controller. I connected up the solenoid valve and it only opens on the filling cycle. It will not activate when trying to empty it by using reverse. I then fitted a bridge rectifier in parallel between the pump and the power supply. Again it works in forward but not reverse. I tried the valve on its own and it worked perfectly through the bridge rectifier with whichever polarity I had it connected to. I cannot figure out why it will not activate in reverse. While writing this I think I have just thought why it won`t work in reverse. If I am not mistaken, the Hobbyking 860 dual halves the output in reverse. Probably not enough power to activate the solenoid valve. Can anybody think of a simple way around this. I could get a speed controller that does not reduce power in reverse but I would like to try to get around it another way.
Thanks.๐ ▲
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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Excellent Graham,
I like the diode bridge rectifier idea. Martin555. ▲
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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Thanks Martin and Graham.
A super mechanical idea Martin, That would work well. I thought some arrangement of diodes would do the job Graham but never thought of a bridge rectifier. As both pump and solenoid work on 12 volts and that I have a bridge rectifier, I will try that first. Thanks to you both as they are both great ideas.๐ ▲
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ฌ๐ง Graham93 ( Vice Admiral)
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Two more ways to control the valve.
If the valve is the same voltage as the pump, then a bridge rectifier as shown in the diagram on the left will keep the polarity of the supply to the valve constant. As an alternative, especially if you had a valve of different voltage, then a relay wired as shown in the diagram on the right will also work. ▲
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๐ฌ Re: Gato Ballast Tank Test
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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Hi Peter,
I am assuming that you will be using the small servos if so your tube will be lighter than mine to start off with. My ballast tank has an internal dissension of 120 mm in length I think that yours is larger so will have more weight of water. Re: valve The only way I know of at the moment is if you have a third micro switch attached to the same cam with just enough cut out so that in the middle position the valve will be open and ether side will activate the valve. Run negative wire directly to the valve and positive to the switch common then from the switch to the valve. I hope that makes sense. Doug would explain this better than me or he will know a better way. Nice job well done. Martin555. ▲
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๐ฌ Re: Lightening the hull
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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We think alike Martin. I was going to write to Bob. You nudged me in to doing it.
Thanks. Peter.๐ ▲
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Remove Ads ๐ฌ Re: Lightening the hull
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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If you look at Bob Martin's web site (the nautilus drydocks) they use solenoid valves on there submarine systems.
Or maybe send him an email explaining your problem and he might have a solution. Martin555. ▲
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๐ฌ Re: Lightening the hull
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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Thanks Doug. Lots for me to ponder over.
Going back to the solenoid valve, I am learning that it is extremely difficult, if not impossible, to find one that can flow in both directions.๐ค ▲
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๐ฌ Re: Lightening the hull
5 years ago by ๐ฉ๐ช RNinMunich ( Fleet Admiral)
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Hi Pete,
I would be tempted to make new stronger planes from brass sheet anyway. Your "remaining plastic pegs" are going to be pretty weak and vulnerable!! On my Type 1A U-25 the planes are brass sheet connected by a 3mm brass rod. The rod is slotted at the ends to fit over the planes to enable a good strong solder joint with little chance of snapping under load or if you hit something!๐ฎ Short lengths of 3mm I/D brass tube were epoxied into the hull to act as bearers. A control arm was made from 1mm brass sheet, with a 3mm hole at one end for soldering to the rod, and a 1mm hole at the other for connecting the operating Bowden cable using a clevis, aircraft style๐ With this type of wooden sandwich hull construction it is virtually impossible to do this for the stern planes, so only the bow planes are controllable. The construction of the stern planes is the same though. They are simply clamped in a neutral position by a screw. Maybe sometime I'll try milling out some more wood to try to fit a planes control arm at the stern. I'm not hopeful though so it's not on my priority list๐ Same principles were used to make, fit and control the rudder. Which incidentally was completely rebuilt with skeg, lower bearing and guard after finding a book at the Deutsches Museum here in Munich showing how it should be! Krick had severely oversimplified. The book also showed me the shape of the hydroplane guards, which Krick had simple left out along with the net saw and other hull details. Correcting these omissions and the hull shape itself, Krick shape was too fat and round, took longer than the basic construction๐ค Hope the attached pics make this understandable. Happy glug glug glugging๐ Cheers, Doug ๐ ▲
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Martin555
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๐ฌ Re: Lightening the hull
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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I have already started the repair. I have a 16mm length of 4 x 3 brass tube and glued a 5mm length of solid Aluminium in the middle. I am going to drill the control arm hole in the centre and glue in place. Then I will slide the remaining plastic pegs of the planes inside the tube at each end and glue. This should sort it out.Thanks Martin.๐
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Martin555
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๐ฌ Re: Lightening the hull
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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I am sorry to hear about the aft dive plan braking.
Repairs would be a bit challenging. If it helps I drilled out the centre and inserted a piece of brass rod.( from tip to tip of the plains) One way that you could get over it is to cut out enough from underneath to enable you to fit the control horn again and then with glue and filler repair the cut out area. Martin555. ▲
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๐ฌ Re: Completing the Aft Section.
5 years ago by ๐ญ๐บ MouldBuilder ( Vice Admiral)
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At the moment I still have my factory Mike but not for too much longer. I will retire in the next few years and will have to do everything on bench machines. Looking forward to it really.๐
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Remove Ads ๐ฌ Re: Completing the Aft Section.
5 years ago by ๐ฌ๐ง mturpin013 ( Admiral)
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I had not followed this from the start as I'm not a sub mariner. However, having now read it from the beginning I found it most interesting. There's been some very nice machine work been carried out, I'm most jealous of your surface grinder, I have most engineering machines but I can't justify a surface grinder, but nice to have
Applause for some nice work๐ ▲
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๐ฌ Re: Completing the Aft Section.
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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Well Peter despite having some tricky problems with the build you are making excellent progress.
Keep it up. Martin555. ▲
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๐ฌ Re: Completing the Hull.
4 years ago by ๐ฟ๐ฆ redpmg ( Commodore)
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Like your build Peter - first thought that you might have stolen my quality inspector - Willy even turns his head upside down checking on things to make sure they are correct - on a cold night a week ago he pulled my body-warmer off the back of a chair and inserted himself into it - you can see the resemblance !
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Remove Ads ๐ฌ Re: Completing the Hull.
5 years ago by ๐ณ๐ฟ jbkiwi ( Fleet Admiral)
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I see the QC officer is there making sure everything is purrrfect๐ (sorry) Looks like a lot of work to convert these. Looking good so far.
JB ▲
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๐ฌ Re: Completing the Hull.
5 years ago by ๐ฌ๐ง Martin555 ( Fleet Admiral)
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Hi Peter,
You are doing a really good job on the Gato conversion. It is surprising the amount of work required to convert it from a static model to radio control. Keep up the good work Peter. Martin555. ▲
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