U-Boot type VII/41, Assembly #1

[toppack]

While I was waiting for paint to dry on the Gato, I opened the Revell U-boat kit to study it a little closer and compare the assembly procedure of it to the Gato.
I can see that the U-boat hull is going to be much more difficult to split (top/bottom) and make look as good as I did the Gato.
I was able to hide the split seam gap under superstructure of the Gato but there's no way to do that with the U-boat.
Oh well, that's supposed to be next Winter's project. Just don't know if I can wait that Long? :confused: LOL :D

[toppack]

Well I started drilling the holes in U-boat hull. There are a great many original holes formed into the plastic already but they are all very small in total area, so I think I'll drill more larger holes at keel. How many are really needed for that model, for good vent/blow action of the Sub-driver?

[toppack]

I don't think I want to construct the long vent slots, above the saddle-tanks, (of original boats) ? :confused:
That looks way too difficult to modify and still have a strong sturdy RC hull?
(The way Glenn Cauley did his Great display model, See Pic)

[toppack]

How many holes are really needed for that model, for good vent/blow action of the Sub-driver?


No one seems to want to help me here so I'll just Guesstimate, and give it a try. That's my normal way of doing things Anyway. :p
That usually works out okay. :)

[Albion]

Most of the hull will be flooded anyway. On mine i am opening up the 8 slots on the underside of each saddle tank (4 front 4 back). I think this will be sufficient for diving / surfacing, it is more important to get enough vents in the deck

[toppack]

Yes I've noticed that there's not many places to hide extra holes in deck/sail, like there is in the Gato model.
I could leave some deck hatches open but that will look strange.

[toppack]

There are 8 rectangle shaped hatches or something at bottom of each saddle-tank, that I cut out, so I now have 16 more large holes in hull. She should sink Fast Now. ;)
I still haven't got the Idea of 'Making your boat models Sink' wraped around my brain, Yet. :)
I think I'll glue some stainless-steel screen on the inside at those holes so they won't look so open and obvious. Maybe that will keep out large Fish also. :D

[toppack]

I had already desided to leave the torpedo-doors open, so I'll drill out the 4 tubes, and that will give 10 more large holes (including the 6 in plates above and below doors).
And that will help Flush out those Large Fish and Mermaids that get caught in there. :D

What Mental Problem! ?

[deepseadiver]

let me see more pictures of what your doing im more of a visual man myself. I would say the holes you have all ready placed in the bottom sounds like more then enough. Having the topedo doors staying open i like that idea too.
Jim

[toppack]

Wow, I thought the rudder-post linkage-arm was difficult to do in the Gato. It's much more difficult in the VII, since there are 2 of them and there's even Less space in the VII hull.
I think I can Link them together with an (L) shaped Arm on one rudder-post but it's going to be a real hassel in that tight space, and still get enough travel of the linkage. :(

I'll take some pics after I get screen-wire attached to inside of saddle-tank holes.
(If it Looks Good, that is) :D

[toppack]

I noticed another difference, that I didn't expect, in the Gato and VII models. The plastic used in the VII is softer (melts easier) than that used in Gato. (At least it is in the kits I got.)
So drilling holes in VII Gums-up the drill bits faster.
But being softer probably makes it less likely to break accidently. :)

[toppack]

I found some places to drill more hidden holes, for air & water passages up thru sail, at the antenna stowage compartments on both sides of tower.
And under base of upper gun deck.
So it should have enough vent holes in deck/sail, without leaving any hatches open. :)

[toppack]

I found 2 errors in Instruction booklet for Revell U-boat VII/41. Thought I'd mention them for anyone else building this kit.
On page 12, windows #35 & 36, it shows part # 193 (hand-wheel) being glued to side of gun but should be glued to upper end of seat-bracket #192 and shows the guns seat-brackets (191 & 192) to be glued to gun assembly at the footrests, but should be glued at ends of brackets.
(Shame Be Upon Them!) :D

[toppack]

I think I'll wait about getting the smaller sub-driver for the VII, until my hand improves, and attempt the T-class and the 3.5 SD Next.
Hey, all I need to build IT is a Big Hammer! :D LOL :D
Or 'BFH', as it's known in the Antique Auto hobby. :D

[Nuke Power]

you should do both.

[toppack]

I'll finish the smaller VII later, hopefully after my hand improves from Stroke paralysis.
I have to use a lot of clips, clamps and vises to hold things and they tend to damage the very small delicate parts.

[Outrider]

Hey just as an idea i was looking around for another deck just for venting during diving and I came across a wooden deck made by nautilus models. It has holes everywhere and I think it'll be good but I'm not sure. Does anyone have any experience? Because it's wood I am afraid that more wait is required or some other problem will arise.

The link:
http://www.nautilusmodels.com/U-02/turm2.htm

[Nuke Power]

Stay away from wood at all cost with working boats. It will only end in failure. I have also seen people use the photo etches brass deck for the working models. It makes the thing so top heavy it is unstable and will never achieve scale waterline.

[Outrider]

So then should I just get a dremel tool and go along the deck cutting out holes to achieve what I'm looking do?

[toppack]

I just put holes hidden inside tower.
Only a couple of small holes in deck (at bow and stern), as long as the large vent areas above saddle-tanks are opened up (between hull and superstructure). Don't take out too much plastic there tho or it will weaken the hull too much.

[Nuke Power]

To get what you are trying to achieve a Mill or drill press with an X Y table would be best. I didnt even bother though and it looks pretty good I think. Making all those slats wwill weaken the main deck. Ofcourse that only comes into play depending on how you are constructing your boat.

[toppack]

I thought I would do a little work on my VII, while waiting for Mike to get my model-T parts ready to ship.
Since I need to have the tower removeable, for access to the video-camera mounted in it's base, I found a place to hide the single screw holding it to deck, down under the hatch/tube on upper-gun-deck.
The first pic below shows head of screw (in center of pic), gun-deck is removed.
Second the deck is installed with hatch/plug laying on top of it. I used a short peice of walnut-dowel for the plug, sealed with CA glue.
Third is hatch/plug installed. It fits very tight but is removable for repairs to camera if ever needed.

I'm still having problems with this dang digital-camera.:(

[Nuke Power]

Dont forget to paint/seal any joints you use CA on.
Have you tested the camera module to see what kind of foam it is going to need to stay afloat? Also what does it weigh? On a model this small that amount of weight, that high up, can destabilize it and prevent it from achieving correct trim. I had to GUT mine. Everything that didnt need to be there was removed.
Also a good thing to remember is never use wood.

[toppack]

My VII is just started construction, no flotation installed.
I put in the same light weight video-camera, in the same location, in the Gato I just finished and it worked out great. Since the cameras are mounted in base of tower, almost to deck level, and there's No WTC weight around camera, they are not top heavy. A least it wasn't in the Gato and it will be a long time before I'll do any in-water flotaion testing of the VII, to find out for sure, since I plan to shelve it when I get the T-class parts and finish the VII at a later date.
Since you changed the subject, I guess you didn't like my hidden screw Idea? ;)

[Nuke Power]

Am am just offering the insight that I have. YOu surely must have noticed the size diffrences between the 2 boats.

[Nuke Power]

I have never owned the video system so I could not tell you forsure. I am just saying that the 7 is a delicate balance act.

[toppack]

. I am just saying that the 7 is a delicate balance act.
Yes, I understand completely and appreciate the suggestions. :)
That's one of the reasons I'm switching tracks, over to a larger scale project, and saving the Mini-Balancing-Act for later. :D

[toppack]

I went ahead and installed the 1/8" prop-shafts and tubes in the VII. It was much easier to do than I expected. I used the plastic struts from kit, with no problems. I was afraid they would brake while drilling them but I drilled very slowly and they did great.
I've been working on it to keep from worrying about the T-class order. ;)
At this rate I may have the VII finished before the T-class parts all get here. :D LOL :D

[Nuke Power]

how did you do the shafts? Show pictures.

[toppack]

how did you do the shafts? Show pictures.
I drilled out the hull and struts so stuffing-tubes fit snugly in them and glued them in. I soldered some brass wire onto brass tubes, inside hull, to keep them from spinning or moving and I'll put a big wad of epoxy inside hull around tubes and wire to hold everything in place and to make it ridged. To correct for shaft misalignment to SD, I'll probably use 2 sets of U-joints. One set at internal end of stuffing-tubes and another set at SD output shafts, with intermediate shafts.
I'll use the small Robbe (hose type) shaft couplers. #1445
Those couplers are good to use for low torque motors since they have a safty factor of spinning if the the prop hits something or gets Locked up in something, but don't loose grip otherwise.
Hopefully the props are with the order that's coming. ;)
I'll take pics when completed.

[toppack]

I was going to order some more of the Robbe #1445 shaft-Couplers, since I don't have many more, but found out that Robbe no longer makes them. :mad:
I don't like the Dumas dog-bone couplers. (I call them Broken-Bone couplers)
Raboesch makes a pretty good, Small one, but it's too expensive, so I may have to start making my own couplings Now.
Man, It's Always Something! :mad:
I have thought of a simple design that may work, using nuts locked together on shaft with rubber fuel-line hose slipped over them. I'll need to test it, but I think it will work for low-torque motors, with small shafts and props.

[junglelord]

Not sure if this is the same thing, but could you not go neodymium
http://www.caswellplating.com/models/klikons.html

[Nuke Power]

This is how I did mine. The bras is to pieces of hollow square brass that can slip into each other. It makes drive coupling installation way easier due to the limited space inside and with the torque produced by the two 180 can motors its more then enough strength.

[toppack]

The main advantage of the Robbe 1445 couplers was that if the prop hits something and stops, the coupler would act like a clutch and not brake the coupler or prop, but had good gripping force during normal operation. None of the other couplers have that safety factor.

The Kli-Con magnetic couplers will not work for prop-shaft couplers but are good for servo-linkage-couplers.

[junglelord]

What size of motor in that beast?

A neodymium magnet of the proper size would handle the torque but may surpass the size requirements of the sub or the brass shaft....


The main advantage of the Robbe 1445 couplers was that if the prop hits something and stops, the coupler would act like a clutch and not brake the coupler or prop,

Neodymium should work well for that purpose.

[Nuke Power]

IMHO Your worriying about a non issue with the boat and trying to over complicate the thing. Your not going to break these little 1in brass props. The motors dont have enough torque to destroy the boat. The magnets would hold lateraly but would probably just spin around themselves.

[toppack]

I've never tried it but I certainly don't think magnets would work, unless you used Very Large magnets, which would be too much weight.

[toppack]

IMHO Your worriying about a non issue with the boat and trying to over complicate the thing. Your not going to break these little 1in brass props. The motors dont have enough torque to destroy the boat. The magnets would hold lateraly but would probably just spin around themselves.

I have personal experience with broken Dumas couplers and damaged prop because of a ridged coupler. So i like to have a slip clutch when possible.

[junglelord]

Thats exactly why neodymium is your answer...works perfect as a clutch.
:p

But come on, how could it not work for your model?
What size of motor you going to use?

[toppack]

Thats exactly why neodymium is your answer...works perfect as a clutch.
:p

But come on, how could it not work for your model?
What size of motor you going to use?

The motors will be what David puts into the 2.5" SD.
I'm not sure what he has in stock for them ???

[toppack]

About 10.mm size magnets may work if you also slipped silicone-rubber tubing over them, to keep them from spinning easily.
I may give your Idea a try, to see if it works. :) I have some magnets that size.

[Nuke Power]

do you have the SD yet. Is it instaled in the model?

[toppack]

Finding a good reliable, removable way of attaching the magnets to SD outout shafts will be the most difficult part of the assembly? I'll still need something with a set-screw type attachment, to go between SD and magnets?
Maybe I could epoxy the magnets inside brass Dumas-coupler end pieces?
And permanently attach magnets to shafts with soldered thinwall-brass-tubing, so the hose will slide tightly over it?
If this doesn't work, I'll send you a Bill for my time and Effort! :D

Not really, thanks for the suggestion.

Having this Forum as my 'Thinking Note-Pad' has been a great help!
Thanks Mike

[junglelord]

Would not just use the same plastic cleavice that the Merriman magnetic joiner encorporate?
But the end of the brass with glue and rubber cover would work.

[toppack]

do you have the SD yet. Is it instaled in the model?

No, I'm working Blind on this one. :D
This one was supposed to be shelved. I'm just trying stay busy while waiting for the T-class to get here. :rolleyes:

[toppack]

Would not just use the same plastic cleavice that the Merriman magnetic joiner encorporate?
But the end of the brass with glue and rubber cover would work.
The 2.5 mm size is Much too Small, with not enough twisting holding force, with both magnets or with magnet to plastic bonds. They are just Not designed for that application.

[Nuke Power]

I wouldnt worry about those drive couplings till you get the SD in and situated. Youll understand a bit more once its infront of you.

[toppack]

I wouldnt worry about those drive couplings till you get the SD in and situated. Youll understand a bit more once its infront of you.

You don't understand. I'm trying Not to Worry about the T-class, not getting here. So I'm trying to take my mind off it, by working on the VII a little and do what I can. :D

[junglelord]

Yeah, I built a 13 inch Seaview last week....waiting till the big boys come in then I can order my Sub-drivers.
:p

Trying to keep my mind busy and focused...but I drift off in to Seaview wonderland...
:D

[toppack]

This is a picture of the Robbe couplers that I like so well for small shafts (1/8" and 4.mm) , if anyone knows where there are any for sale, Please let me know?
Raboesch makes one that has similar end pieces but the center coupler is not the same.
Thanks,