Revell typ VII/41 RCABS (Big Dave) build

[Ralph --- SSBN 598]

I have not been following this threat with any regularity.
So if this has been said I apologize.

With the RCABS system, I found it easier to start with the balloons full of air and trim the boat to the waterline.
Next, I would remove the air from the balloons to see if the boat submerged correctly.
This would tell me if the balloon air volume was enough to do a full surfacing and full just negative dive.
If the boat did not dive from the surfaced waterline, the balloon volume needed to be more.
If the boat submerged and was very negative, I could add more above the waterline detail with corresponding below the waterline ballast.

Trying to work from submerge trim to full surface trim is a fight and a loosing fight at best.

[redboat219]

I have not been following this threat with any regularity.
So if this has been said I apologize.

With the RCABS system, I found it easier to start with the balloons full of air and trim the boat to the waterline.
Next, I would remove the air from the balloons to see if the boat submerged correctly.
This would tell me if the balloon air volume was enough to do a full surfacing and full just negative dive.
If the boat did not dive from the surfaced waterline, the balloon volume needed to be more.
If the boat submerged and was very negative, I could add more above the waterline detail with corresponding below the waterline ballast.

Trying to work from submerge trim to full surface trim is a fight and a loosing fight at best.

But does the wtc contain enough air to fully inflate the bladders?

[Dolfin]

Hi
@redboat I think there is enough air in the WTC. When I inflate the balloons the space in the saddle tanks is almost completely filled. I think more is not necessary and might destroy the plastic somewhere. I’ll start new trimming as Ralph describes at weekend. I will come to terms with it even if the boot does not reach the correct CWL in the end the system does not work badly. Maybe I’ll order two smaller bladder from there:

http://www.rcsubworkshop.com/ListTable.aspx?tp=c&cid=29

Honestly I don’t like the punch balloons so much is for my a little bit mess to install.

[redboat219]

Here's a picture of Big Dave's Type VII. As you can see it's also at the correct water line.
Too bad BD no longer here. He could have given tips how he did it.

[Dolfin]

Hallo,
Yes, it’s almost perfect. I feel really sadness about BD. He could help a lot, but I let his work live on.
It would be interesting to know if he used styrofoam and where.

[redboat219]

https://subcommittee.com/forum/showthread.php?31790-Suggestions-for-Revell-Type-VII-C&highlight=Waterline+type

[redboat219]

.................

[redboat219]

I'm thinking of reconfiguring my BD RCABS wtc to a peristaltic pump with a water bag. The front section will hold the pump while the middle section will hold the water bag. The back section will be for the Rx, ESC, servos and drive motors.

[Dolfin]

Hi,
The idea isn't bad, but I'm afraid it won't work that way. I think you need a bigger ballast volume because Type VII has a very high proportion over waterline. You would have to trim the boat to CWL and check how much weight it takes to submerge. Maybe experienced submarine builders will know more here.

The simplest system is propel gas. I have 2nd Revell Typ VII with such system and works great about 10 times submerge with one fill.
Is built something like this:

https://www.rcshipyard.com/uboot-viic/

but with better CWL. You can also easy build the gas canister with copper fittings.

And see there

https://die-panzerwerkstatt.de.tl/Kilo-Klasse-U_Boot-1-d-144--k1-Trumpeter-Kit-Nr-.-05903-k2-.htm

https://www.maximus-modellbau.de/English-Version.htm

I have the Kilo class from there.

Why you don't build the BD RCABS anymore, because of the waterline? If I manage the CWL as shown in the photo, I am satisfied.
Greetings

[salmon]

I cannot agree more with Dolfin's comment "Why you don't build the BD RCABS anymore, because of the waterline? If I manage the CWL as shown in the photo, I am satisfied."
Romel, do not delay because of waterline. Just get it built. Having one under your belt will help you on making modifications. Do not try to be creative yet when you have proven working systems in hand.

Peace,
Tom

[greg w]

Since I have BD's type VII I will chime in again. When I got it there was no cylinder in it anymore. I was able to get one of his kits from CG Bob at carmel a while back and also a complete wtc that turned out to be from Dave's kits as well. I haven't put the boat back together yet but the was no foam in the hull when I received it. That being said his experimenters kit did come with foam so it may need some but I just haven't had time to work on this project yet. Greg

[redboat219]

I cannot agree more with Dolfin's comment "Why you don't build the BD RCABS anymore, because of the waterline? If I manage the CWL as shown in the photo, I am satisfied."
Romel, do not delay because of waterline. Just get it built. Having one under your belt will help you on making modifications. Do not try to be creative yet when you have proven working systems in hand.

Peace,
Tom

Tom,

Point well taken. Also I realized, out of respect for Big Dave, it would be sacrilegious for me to alter his design.
If I want to go with an alternative ballast system I make my own WTC.

Who know's, might even be the one to get it to go CWL.

[salmon]

Tom,

Point well taken. Also I realized, out of respect for Big Dave, it would be sacrilegious for me to alter his design.
If I want to go with an alternative ballast system I make my own WTC.

Who know's, might even be the one to get it to go CWL.

You might, you are an excellent researcher and have great ideas. You just need to put it into action and just go for it.

[Dolfin]

Hallo,

@Greg, Is your kit with 2 bladders if yes can you post the measure of them,please.�� Would be nice, but no rush take your time.

Today I was trying trimming again which ended in a mess. I full inflate the balloons and put the boat in water with a few rubber band around the hull. I added foam till it reached the waterline and yes this was so much that the boat couldn’t submerge correct. So I give up for today��

[greg w]

Mine had the punch ball balloons but they rotted away before I got it. I knew Dave pretty well and I don’t think that he would be upset with anyone redesigning his cylinder. He considered it a way to do things but not necessarily the only way. Personally I will rebuild mine his way and if I’m not happy with it I will build a replacement system. That way I can get the boat back into the water. Greg