robbe U47 Static Dive Build

[Guest]

Jason,

I have thoroughly enjoyed watching and reading this thread and seeing this model progress. One day I want to try exactly the same modification to this kit so I naturally paid close attention to your installation.

In fact when you have time a couple of shots and a bit more about the fitting in of the 750 Engles tank would be usefull. I know it has to be fitted at an angle so just how you got it in there would be worth knowing.

A lovely job, well thought out and executed and looks the part on the water. Many thanks for sharing.

For a similar thing on a slightly smaller scale have a look at my Revel U-boat RC conversion that I am doing at the moment.

[Guest]

Jason,I have thoroughly enjoyed watching and reading (deleted)

Thanks mate!! I enjoyed doing it very much!. I'll post an epilogue showing a bit more of the tech rack setup and I will check our your Revelle thread.

Regards

Jasonuppet: PS I love these emoticons.

[Guest]

Post Script Re- Tank Fitting

Hi guys and gals.

Here's some info and pics about my engel tank fitting to the U-boat.

I firstly laid the tank over the WTC tray to find a suitable method of fitting it. (Pic). I tried it with the threaded shaft (conrod) facing aft which would allow the added weight of ballast water to be forrard and help with diving etc. The problem with that was that I'd need to re-locate the 2 servos for the steering and rear vanes, to allow room for the rod.

I then tried it facing forward and thought I could adjust the diving trim later with lead and foam (as I did). This way I'd be able to route the rod between my battery banks which run down each side of the front under tray area. It has 15 sub C cells of 3600mah in all. 3 under the motors aft, 1 on top forward of the tank and 14 underneath the tray and forward. 7 one side and six the other. The reason I put only 6 on one side and the 7th on top was to allow room for the motor of the piston tank to protrude below the tray a bit which it needs to do to fit in the WTC.tube. BTW-The batteries standing up, are responsible for the tray being a bit above centre so that if you wanted to use them with the standard long bolt sealer thingy, you couldn't have them that way. It doesn't matter with mine, I trimmed the sides of the tray rails a bit to allow it to sit higher in the tube. (No probs) The tank is actually mounted a a bit of an angle down at the front so that the rod goes through the fore battery bulkhead and along under the tray. If it were level, the rod would need to be right in line with the tray or slightly over it as in regular boats the tray is a bit lower. This wouldn't be a big problem with my sub as I use a bracket on the end cap to seal it and it doesn't have the long rod bolt at the front to get in the way. I didn't however want to cut through the tray and further weaken it for the rod tube to be set inline with it. I used a bit of abs tubing for the tunnel to protect the threaded rod. It actually protects the wiring and batteries from the rod really. When fully flooded, the end of the rod comes to just level with the front bulkhead as in the plans position. This allowed me to fit the adc-1 unit infront of it where the sealer bolt/rod woulfd normally be. (My WTC is very crowded indeed!)

Once I'd decided where I was putting the tank, I marked out the outline on the tray and removed the necessary battery bay bulkheads (kit battery bay area-not mine) I left the front one and just cut the motor side out (tank motor). (pic) I worked out roughly where the rod would go through the bulkhead and drilled a hole in it. I cit out the tray along my lines (see pic) and dremel ground it to let the tank fit in snugly. I then put the tank in and extended the rod through the hole a bit. I slid the tray into the WTC tube to where the tank touches it and worked out how much angle up at the back I could have and still fit it under the top of the tube. I put little squares of thin ABS inbetween the bottom of the tank and the track rail and shimmed it to that height. I then pulled it out and extended the rod out a bit at a time while marking and removing the tank then drilling the bulkheads and re fitting the tank to do the next one and so on. Once it was all snug and the rod could go right out freely, I retried the fit in the tube to be sure. I then fitted the plastic tube to cover the rod and glued the shims at the back etc. I then shored up the side rails with strips of ABS to make up for the lost strength.(pic) The side rails were also cut down with the tray rails earlier and needed more strength. Later on I followed an idea from a reader and coated the tank-rail joins with a thick layer of clear silicone which made it much stiffer. It also helps keep my Adc-1 copper pipe which goes along the side-in place.

The flood ballast water pipe comes out just under the tray at the back (pic). The ballast aft of centre problem was easily compensated for with a bit more foam under the deck and high up aft to slow down the sinking of the back of the sub. The 750m tank allows plenty of reserve ballast for the U-47 and with a bit of extra lead just infront of the tank and in the very bottom, I can sink her stationary with no problem and as level as you like. Lists and pitch angles when ststic diving are easily removed by moving or adding/removing bits of foam which is later coated with epoxy resin or glue-not polyester as it disolves the foam. Once sealed you can then glass over it if you wish or just leave it. I used a few strips of ABS glued accross the hull in places to glue the foam to and I also glued some directly to the underside of the brass deck plating.

(Bunkerbarge)-I hope this helps!

Jason

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[Guest]

Very much appreciated Magpie. It is just this sort of in depth review that gives this forum its excellent archive of resources.

This only happens when people like yourself put the time and trouble into writing and posting so that we can all benefit.

Very many thanks for this, not only an excellent model but also an excellent write up.

[Guest]

My pleasure!!

Jason

[Guest]

Here's a post on todays pool run that went well. It has a video link of a 36 meg clip I took which shows how well she handles now.

I'm a happy chappy!

Jason

http://www.magpieyachts.com/files/YeaFestivalBoatingMarch19-06.wmv

:clap3:

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[Guest]

I'm not sure whether I am more envious of the facilities or the weather!!

Thanks Mags

[Guest]

Can't stop!

Must keep building!

I've assembled a new crewman today for the tower. He's sitting and having a ciggie. I haven't made the cigarette yet.

Jason

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[Guest]

Are the figures going to be removeable for diving or are you going to drown them!

[Guest]

They can hold their breath for ages as they're very fit.

Jason.

Staying on.

[Guest]

You want to make a recording of screaming and gurgling noises to play as it goes down!!

[Guest]

Seriously though, I looked at that and it being 1-40 scale, has pretty small crew that are barely noticable from a few metres away, so I think it's worth leaving sleeping sea dogs lye or sit/stand for the time in the clubhouse when my boat needs a charge and I'm flogging my yacht or tug around the pond and driving the other's crazy!

My officer lost an arm a while back and I couldn't find it, so I've epoxied over the OR crewman to keep him safe. Got to look after the crew aye?!

I was going to be serious wasn't I? Sorry

Jason

[Guest]

I put some new motors in the boat today to improve the range (hopefully). I went for graupner Eco 500s that are meant to only use 2 ams each at 67% revs. I'm running them on 6V so they should use a bit less than that I think. Must be better than the Robbe 550 ones anyway.

They drop straight in as the diameter and bolt holes are the same. They're just about a centimetre shorter and 100 grams lighter, so I added 100 grams of lead to the keel in the area so as not to stuff up my trim. I'm taking her out on Thursday to do my Scope disability program and I'll see how the new donks go then. I think my scope clients will be rapt as they've never seen an RC sub before.

(1st April) I tested her at the lake and she was toooooo slow so I put the robbe motors back in for now and I'm going to try setting up my TX for dual rate control on the throttle to save power as I'm a lead-foot with her.

Jason :byebye:

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[Guest]

Here are a couple of pics from todays motor trial. It was as rough as!!

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[Guest]

Finally works!

I made a compromise and reduced the prop pitch a fair bit and re-fitted the Robbe motors. I also used self control (no-you can't buy it from Hobbyco), and kept the speed down a bit via the throttle setting. I ran her for well over an hour constantly at mostly scale speed with occasional show off speeds to avoid Target collisions etc. I static dived her about 5 times right to the bottom (1 metre) and blew ballast the same amount of times of course, or she'd still be on the bottom!! I'm happy with that. Over an hour of fun is ample for me. I actually took her out and went on to sailing my target (yacht) before she slowed down noticably so she still had charge, although I don't think it would have been a lot.

Here's a video clip of the day that mainly features a Lafeyette from engle, but it does show my u-boat briefly. The other subs (2) came out for charge and went back in while mine was still running! There was an Albacore there too.

http://www.magpieyachts.com/files/2apr06surrey3submarinesVid.wmv

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