<table class="tborder" border="0" cellspacing="0" cellpadding="5" width="100%" align="center"> <tbody> <tr valign="top"> <td class="alt2" width="175"> <div class="smallfont">
<div></div> </div> </td> <td class="alt1"> <table width="100%"> <tbody> <tr> <td width="90%"><! icon and title > <div class="smallfont">Discussion - Robbe Type XXI And The Cats Meow</div> </td> <td width="10%" align="right"><! End of show warned sign ></td> </tr> </tbody> </table> <hr size="1" style="color: #a7a7a7" /> <! message > <div>I have been busy as allways with this project to build a Type XXI by Robbe with my new Aquacasing and thaught I might share some of the advancements.

First I had to determine just how long the casing should be and how it should become acssesable for maintenance.

If one does not know how the XXI is originaly made with the supplied casing there are certain drawbacks to that designe that can be easily and economicly corrected with a casing that does not require a single large modified screw and most of all a stresed inner component tray that has been known to crack and fail if over tightened A major pain to repair that sinario and if it should fail while in the water well its all over,she will sink in a hurry.

So what I did was to make an Aquacasing that will fit the Robbe XXI and is almost as long as the original casing except that its far more safer to use and can go much deeper and most of all stays dry.

The pump ballst system uses my non pressurized ballast tank type that will give a scale dive and serface and hover operation for this great sub.
The single central tank houses the ballast pump that can run in the wet and is water coolled by the same water it pumps in and out.There is no need for a solinoid valve to keep water from entering the tank past the gear pump ,by using a certain type of filter that has just enugh tensile water restriction to prevent water from entering the tank.
See the operation of this very simple ballast system in this website.

Also in the tank is the hydraulic masts sytem that is also very simple and inexpensive to make and is very reliable and scale like right down to the noise of the pump and is very cool and variable speed.

Well by enlarging the diamiter of the ribs except for the last aft one to fit a 4 inch white PVC shd 20 or thin walled tube to huose the Aquacasing which just so happens to be just under 4 inches but to make a nice slidding out fit I had to round down just a 2 mm of the lugs on the casing and in it went with no snags.

To enlarge the ribs all at once just use a 0ne inch drum sandsing drum and drill clamped in a vice that has the original casing inserted so that the preciese alighnment of the ribs is set then remove the tube and sand or ream away till the 4 inch tube fits slightly lusly.

When the hull halfs are made with the ribs inplace but not dreid yet insert the 4 inch tube for a set alighnment and thats it.

The tube and Aquacasing come out all at once then the outer tube is slid off and then acsses to the Aquacasing is possible,thats it very simple and very solid costruction.

The 4 in tube is then set in place inside of the finished hull with a screw and a stop tab so that it is always set in place when removed and the ballance of the sub is not upset and retains the casing.The smaller last rib in the stern holds the end cap to perfection without any reaming just the vent tube indexis the casings rotation so that it will always be in the right possition for ballance and the masts thrust rod will pass at the right point.Very easy to do and works fantastic,much less mechanicals thatn my first XXI as seen later.

I which I had done the Aquacsing mod to the first one,now I have to do it to mine
Also the original setup riquired a seperate mini casing ahead of the main casing to operate the retraction and operation of the forward dive plains,this eliminates that problem which also requires external electrical wires for the servos inside,not very good.

The Aquacasing eliminates this by haveing a servo in the front cap and a bulkhead partition glued in place to make a mini dry space that is adjustable in size and has excelent acssesability, totaly watertight with just a magnetic connection to operate the plains via lincages or rods and cleeveses.

A gear pump the same type used threwuot the sub is placed out in the bow and it operates the retraction and extention, see vid of it on my sub ,very cool indeed and very scale like operation!

For the electrical charging there are 2 wires pos and neg that are acsesable from the front hatch and eliminates the need to remove the casing from the sub to charge,battery runs in the wet.
The wires are always hot yet are seperated and sealed by a simple solution ,a lenght of silicone large tubbing inserted over each exposed wire end both seals and seperates the wires and makes easy acsses to the circuit.

For the other 2 circuits like the dive plain retraction pump and nave lights a military speck watertight gold plated multypin rotary lock connector is used and they work very nice and I supply them if needed in a variety of number pins from 2 to 14.

The 4 inch tube is drilled with abunch of holes for both water to escape and air to escape and is very important for operation of the sub as traped air will cause an imballance,always watch for that in all builds and iliminate it.

One nice side effect of my ballast system is the bubbler effect that can be made to be seen as the sub dives and looks very scale like also ,a network of small tubes placed aruond the sub would work very nicely and would add to the effects.

Let me know if I can build one for you

Enjoy the vids!
<font color="#22229c">http://s82.photobucket.com/albums/j...=DSCF0001-3.flv</font>
<font color="#22229c">http://s82.photobucket.com/albums/j...=DSCF0001-2.flv</font>
Dave Amur Sub Yard </div> <! / message ><! attachments ></td> </tr> </tbody></table>

See more details of the build here http://www.rcgroups.com/forums/showthread.php?t=1087821 and the rest to come on this site like the hydraulic masts.
I must say that she came out beutyfull in all ways ,she has plenty of freeboard and power to spare ,justa single noch on the dual thaughtles makes move out to walking clip .The hydraulic diveplains are smoth and a blast to work! as are the hydraulic masts.Ill post a vid of them tomorrow.Soon she will be on her way to her new Captain in california and i will saying god by bonvoyage to a great sub I built very differently than that of the kit maker she is also much lighter than the normal Type XXI as 4 huge bars of lead has to be added I only needed 1 and a 1/8th[:'(].
Dave

Dive plains have a magnetic link that when the inner guts come ouit the diveplain servo rod disengages from the actuating mechanism.

 http://s82.photobucket.com/albums/j2...DSCF0001-2.flv

Dave

http://www.youtube.com/watch?v=dACidIgoickCHECK OUT THE MASTS!The other masts are also operational.

another clip http://www.youtube.com/watch?v=a6IXVXZLW2M

DIAGRAM

DIAGRAMS BASIC LAYOUT

The hydraulics layout

Some build pics

She is finished !

A few days ago I finaly shipped her off in a huge wooden crate to California and with a sob she went onto the UPS truck.She was fun to build and runs so well and majesticly.

The pics show the aft sections acsses that very good on this sub .Notice the the green cannon plug it makes an easy water tight connection to the mating plug for all of the circuits ,2 ESC s and one light circuit a total of 6 wires done with marine grade 16 gage wire of variuse colors for easy identification.

The wire with the silicone tube on it is actualy 2 the hot pos and negative wires that directly charge the main battery,since the batery runs in the wet it can be charged without having to open up the sub,nice!When turned on the wires are no longer hot so that if ever water gets to them electrolisis will not ocure.Also easy readings can be made of state of charge extra can be made along with the LED voltage gage I inmstall in all of my subs.This gage can be seen threw the limber holes at the stern while in the water also so that one can always have easy remaining power reading.
Just seperate the two wires and connect via wire clips and your ready.

The vid is not to clear butat least the operation canbe seen.

http://www.youtube.com/watch?v=GlpcAtsVf6A

http://www.youtube.com/watch?v=stCAsOyqtgE

It has been a while since I updated what is going into my XXI now ,a remote operated anchor and winch,2 ea. 5700 mah Lipo packs in the forward compartment and the Eagle Tree Seagul Telemitry system will be set up to minitor the lipos voltage and amps as well as stop alarm.The motorshave temperature sensors and the prop shafts have Hall effect sensors for acurate prop RPMs.
Servo position sensors are built into the system so I use them to indicate and confirm that certain servo switches have engaged likethe dive and surface swich and vent soliniod switch.It is nice to know audibly that these very important items are working.
Also a water alarm to indicate any water intrution into the aft section.This alarm is setable by the user as all the alarms are so that say a continuse Beep is for the water alarm,another type of beeping for say the motor temp or depth thats right!.
Also anew ballast pump has beenemployed that is far superior than the previuse one,I will keep on with the older pump but for hydraulics only.The new pump is very high quality unit made to transfer liquids at a rate of 2L/minute! Thats a nice amount forany sub,itis a gear pump also that has a servicable gear head and largespecial plastic gears,O ring sealed housing with 4 screws,simple easy service.This pump at 12 voltsruns very quite and smothbut most of all it pompswater with a strong suction the pumps specks says it will pull at 1.5 meterhight ,that is prity strong.The flow is reduced by a gear driveof the motor if not this pump would be extramly stong at 12 volts.I realy like the quality of this pumpand will be installing them in all my subs that have the older pump.
It can also beused in the wet with just some sealing withGoop,it justfits into my Aquacasinglateraly or even horzontaly so it will fit into most casings.Run it on 6 volts and stillplenty of water is pumped.
Let me know if you need one.
It has 3/8 in barbed hose niples so a reducer can be used.
I also redesigned the masts from the all up or down platform to theindividual mast hydraulic system I used on the first XXI I built for a customer.
Also to charge the Lipos a dedicated charging circuit is on the outside of the casing in the rear section so that there is no need to remove the casing when chargeing.

When the casing is installed into the sub a window into the casings rear area above the 2 motors threw the sleeve,there I plan to install a voltage /amp digital indicator andLED4 step power indicator,that way at a glance I know that the sub is on and ready for sea.

Also seen in the pictures is the forward end cap with the anchors gear drive motor and U jouint /tuffing box of 1/8 diamiter shaft and bushings,the end has an engagement fitting that engages with the winches input shaft and winch made from Legos,works very smothly and water will never harm it.
The servo moves the planes mechanism also made from Legos,the black disck is a magnet that engages another magnet on the mechanism,this way the entire casing is self contained there are no external servos to get wet and more items can be added like the anchor,both the anchor and diveplanes connct and disconect by simply inserting the casing into its sleave or inserting the casing and its sleave all at once!Everything self alighnes and ready to go,no need to open the front hatch at all.

Dave Amur Sub Yard Happy Navidad

Just installed wireless telemitry system,it monitors many peramiters that I have selected.Motor temp of the right side,amps,acumulated mam ,voltage ,pack voltage and when to return to base,ESC temp,prop RPMs and depth in mms the sub dives or surfaces all in real time and set with limit alarms so that I know whats upor if I have gone too deep for a shallow pond lets say.The Electrical peramiters are all read by one single sensor, a ring hall effect one that when placed at the main leads powerfrom the Lipo pack shows a host of operating peramiters,even if weeds get tangled up in the prop the amps draw goes up the set alarm will alert me that there is a problem and to bring her in or an electrical event.Even the servos glitches and possitions are minitored live as needed along with how much power there using!

The reciever like unit with all of the wires connected to it is the recorder,it is light and has all of the required markings on it so that you wont have to worry about hooking up the wrong thing,just like a reciever it all installs in minutes the temp sensor just slides in under the motor and the one for the ESC is in the cooling fins,the RPM mini magnets are the hardest to install with CA no biggie its done in minutes the sensor is a magnetic induction type,set for prop head speed the softwear even has the gear ratio adjustable by the user,totally user freindly and fun to use.

A water sensor also alarms ,high temp and Lipo cut of warning alarms are also programed in a few easy steps,the screen with the gauges is the stock picture the une I use was set by me becuse I like digital readouts beter there more acurate and easy to understand,but one can set what ever one likes,all can be seen live at the pond with a laptop or in front attached to the radios mast but in didgital form only.
later I might find a mini computer to display it like on the Laptop but at the TX.

This is cool stuff to the max and has been around for sometime with the fliers and I have been loving it for some time now as well !great range and works underwater.

Dave Amur Sub Yard

go to eagletreesystems.com

A diagram of the casing with Telemetry for the XXI.</p>

</p>

Now the fine tunning and testing begins with the completed unit,so far very good results,no glitching all functions working.</p>

</p>

Dave</p>

History of the Type XXI in German,civilians where evacuated on them,interesting.

http://www.youtube.com/watch?v=5CIJV...layer_embedded

Dive plane vid ,note the dual cylinders ,smothe variable speed operation ,the gear pump is in the bow wet.



Dave http://www.youtube.com/watch?v=jYVnn...yer_detailpage

A diagram of the dive planes hydraulic system</p>

Ahoy all Captains again just thaught I would give an update on how the Type XXI is coming along.
It has gone threw a so many internal modifications from the original kit that it is a very different animal and performs very very well with a long run time and super easy to charge and maintain.
She is balanced to perfection and runs at periscope depth as long as one likes and I mean a long way around the Osceala pond.
She used to be very weathered but now more realistic.

Enjoy the pics Dave