Quintanius

Very good. Thank you for the advice JM. Should I worry about grinding the edge of the ribs to follow the contours of the hull? Seems that this would provide more surface area for the armor to adhere onto, instead of just a corner or so. 1/4" thickness is quite a bit of surface when there is an angular transition...or am I getting to detailed with that thought?

I like the idea about locking the stern and bow keel in place. What I had envisioned, was to get the baseboard down, attach the stern keel...and thats where I had stopped. I do need to think about the shimming of the bow and stern cap though.

I had followed the advice of a builder that suggested adding the shims to elevate the bow and stern later. So I cut the ribs less the total cap and deck thickness evenly across all ribs, with the idea of shimming them later. This was to facilitate building the hull upsidown, or right-side up.

Whene I stacked all the ribs last night (they looked beutiful) the top and bottom were very close, if not perfectly even. A bit of sanding will flush them all out evenly.

So, thinking now, I'll attach the stern and bow keel, set the ribs for those in place, add a few in the center here and there, and then start attaching the cap-rail from the center out toward the fore and aft - Perhaps tack glue the caprail temporarly to the stern and bow ribs...little bit of CA glue, or a few well places little nails ought to do it...any thoughts?

TH


TH

johnmCA72

Actually, you've touched on an interesting issue that it's too late to address unless you want to do a bunch of re-cutting. The issue is that, your rib patterns each represent a lateral slice thtrough the hull with zero thickness, but your ribs have thickness. You'll need to decide which plane - front or back surface, or somewhere in between - of the ribs are going to correspond to the planes represented by the patterns. For example, if the planes of the patterns are going to be the forward-most edge of the ribs, then your ribs will need to be installed behind those points, as measured down the center of the ship. Around the middle of the ship, front=back as far as the rib surfaces are concerned. As you go farther aft, the hull tapers inward & you can grind off rib edge surface to match the contour of hull plate surface, giving yourself more to glue to as you say. The trouble is that, as you go forward of midship, the hull tends to expand behind the plane of each rib, but unless you've allowed for this by enlarging your patterns, it's too late to do much about it. You can leave it as-is & have less surface to glue to (glue will at least partially fill the gap); you can grind the forward edge of the ribs to match the hull contour, but that's going to make the hull smaller in that area; you can re-calculate & re-cut the forward ribs; or you can set the forward ribs ahead of the defined sections & grind forward, but this will alter your spacing. Will anybody but you ever know about it? Probably not.

I don't understand the shimming.

That's probably a good idea. You can remove the clamps & check the alignment. If it's off, it should be easy enough to break it up & re-do if you think it's that bad.

I've seen some ships that came out bent, or even with a general twist all the way down instead of being straight. I think I remember seeing one that bent one way, then back the other. Whether the builders remember or not, I can't say - a lot of little oddities get forgotten once the ship is on the water & you move on to other things. Everybody's different, though, & I can see where it might bother some people forever, knowing that their ship is twisted, even if it's not noticeable to anyone else.

JM

Littlehui

hi, I make stuck at making the hull part. My keels are done and now i am trying to cover it with balsa sheet. But the problem is, i cant connect the sheet tide and making curve nicely... anyone hav an idea? i m now using a 3/32" balsa sheet, or should i go for a thiner one? lke balsa skin?
my frd of mine, a plumber, suggest me to use silicon or somthing similar to plug the leak is it a skill that actually works on model?

johnmCA72

You've got to use whatever your club says to use.

Don't try to force the sheet - let it bend where it wants to go. For example, if you try to force it to follow the curve of the main deck so that the grain is constantly level, it's going to bow out down below as the hull curves inward. Let the sheet follow the curve. It will tend to bend upward at the stern, & to a lesser degree at the bow. Typically, the grain of the wood will be parallel to the ship's waterline near the middle, & bend up at either end. It's a lot easier to just "go with the flow" & fill in the smaller, left-over spaces, than to try to force it to all run parallel for the entire length. Let it bend where it wants to, & trim the excess.

If you have to, cut the sheets into sections. Try to find the biggest, flattest area of the hull & cover that. Then, cut out triangles, trapezoids, etc. to fit what's left over. Try to keep the pieces big, for your convenience, but there may be areas where you need smaller pieces. Another technique that can help is to cut narrow wedges out of the sheet that allow it to bend across its grain. Start with a slit, bend the sheet so that it overlaps the slit, see how much overlap there is, & trim off the excess. Dry fit the sheet sections, then glue them up before dry fitting the next section. Trying to dry fit multiple sections isn't going to work - get the biggest one on a side glued down solid 1st, then work from there, trimming as necessary to get a good fit. Then glue it down & fit the next-largest, etc. until they're all done.

Per your club rules again. Most don't allow fillers like silicone. Not to mention, it's not going to sand very well so your finish won't look very good. First, get your seams as small & tight as you can reasonably get them - they'll never be perfect. I use either light spackle or Minwax Sandable Wood Filler on my seams.

JM

Quintanius

Well, the weekend was not as productive as I had hoped it may be. Notching, sanding, and dry-fitting the stern and bow keel with the ribs was the highlight of it all. It looks stunning though. The stern has a very large keel – very deep, with a center post ruder, contoured to follow the keel-line. There sure is not a lot of boat under the waterline back there, and the rib spacing is quite tight in one or two spots. Trouble I’m having now is what to do with those odd-shaped ribs at the stern and bow. They do not allow for a lot of hollowing out, due to the narrow (and tall) bow keel vs. rib profile, and in the stern, where the ribs float very high of the baseboard elevation. Several inches are just keel space, where the concave ribs form the cavity for the props and sweep up to the deck in a dramatic but narrow curve.

Question:
Can I just drill a few holes in those narrow ribs, to allow the flow any water flooding those compartments to drain to the main body of the vessel? I thought of filling the bottom voids with some type liquid (???) that hardens, instead of trying to bridge those gaps. Any thoughts on what I could use? Silicone? Epoxy?

I notched all the ribs for the baseboard, and transferred them to the baseboard. To clarify my next question, some detailing of the work I had done to the ribs may be in order.

Thinking that I will need to skin the boat with 1/8� wood, I decided to make my life easy and use the baseboard as the “bottom�. When I cut the ribs, I used the “original� full size (with armor) rib contour as my point of offset. From this point, I drew a line 1/8� UP, which bisected the 1/8� offset from the rib curvature I drew in. So the ribs are a smooth curve, and at the bottom, they all have a 1/8� (rectangle) at the width of the rib section where it meets the baseboards outer edge. I then notched my ¼� deep space for the baseboard, ½� from either end to fit into the notches I will cut from the baseboard.

http://i78.photobucket.com/albums/j1...Stern-Ribs.jpg

As you can see, if one were to “offset� the rib contours back out, the curves would meet those bottom most points. Problem is though, that when I drew these edges on the baseboard, some of them did not follow the “contour� of the “I� line, which is the base of the baseboard, or very bottom of the hull.

So I nailed a few pins at those points, and took a strip of thin balsa. This I used like a French curve to follow the pins, adding more to keep the balsa strip tight against the others. This gave me an approximation of what the baseboard “would� look like.

Question:
Should I go back and re-work the original contours of those ribs that don’t “match�, or trust in the plans and keep working?

Tough decision, since I did everything that I could to stay within 1/16� of an inch, maybe even less than that. But perhaps scaling the plans has introduced some error somewhere…

TH

Umi_Ryuzuki

Drill holes in the narrow ribs.
In the past, we have had members fill voids and other such areas with resin.
They usually end up taking it back out. Typically because the boat ends up heavy.

The first few inches the boat, in most club, is allowed to be solid. Balsa, or foam and fiberglass.
I usually mark that point, by where the first "full" rib hits the base keel of the ship.
Verify this with the club's rule set you are working to.

It sounds like you have good handle on the construction, I would cut your baseboard to first, and work out, or if you have already layed strips, the cut your baseboard to fit, and fill any gaps with thin strips ov balsa prior to fiberglassing the hard hull.

johnmCA72

I'd go with the holes. Make them pretty big (like about 1/2" or so). Use epoxy. Position your holes so that you don't need to use so much of it (i.e. so that there aren't big pockets to have to fill up. Epoxy will add weight, which means less of something more useful later on.

I generally trust my plans. However, if you have misgivings, it might be worth the effort just to settle things in your own mind to check & rework anything that doesn't appear to match like you think it should.

Some plans have errors built in. There's a vast range of quality out there & there are some sources that I automatically question whenever I see them. I've found discrepancies between plan & profile, & even between different portions of the same view. Sometimes "executive decisions" need to be made, to determine which of a pair of conflicting views you're going to go with.

JM

Quintanius

That makes sense. Also, for the baseboard, I'm using a 4' long section of 1/4" plywood for the center, and about another 12"-16" for the bow and stern section, to (hopefully) prevent warping, and make it easier to work the 3 seperate sections. I'm using a 3/8" deep rib at the joints, using those also for lateral support of the deck. I hope this wide rib will be enough to hold the joints, when glued right on top of it.

Not sure if I ought to join those 1/4" planks of the baseboard with wooden dowels, like toothpicks or something similar?

WOW...I think I just had an idea - just had a mental picture of a rib, with its grid pattern. Since I'm planning on a waterchannel design, and I have the slots already scretched into the base, I can cut the channel from the bibs, cut out the internal wood, and leave the rails for the deck AND...since I wanted something to keep the ribs in a vertical and alligned to each other, I had thought to insert an aluminum strip 1/4" wide by 1/2" deep at the top of the ribs along the whole length...!

http://i78.photobucket.com/albums/j1...Rodney/RIB.jpg

Problem solved...I was trying to figure out how to get the core out without having to change the blades every time.

For a channel...I thought of using an Aluminum C Channel, about 1/2" by 1-1/2" wide. This would also act like a keel, stiffening the hull...or should I just build it out of wood?

TH

johnmCA72

I've never heard of anybody building with a baseboard in sections, but I suppose it can be done. Part of the reason for using the technique is to be able to use fewer parts.

I like to build up the area around my water channel with 3/8" balsa - just because it's convenient. I leave cutouts for the batteries, partly to let them sit as low as possible, but also because it makes a "well" to keep them from shifting (I discovered long ago that it's bad to have big, heavy boxes of lead shifting around in your hull!). Also, the pump well can be easily cut out to whatever shape & size I need. After everything is installed & the ship trimmed & balanced, I mark the location of everything important with a grease pencil & cut my balsa to shape, glue it in place, & epoxy over it to waterproof. I know that a lot of people do their water channeling early in the process, but I prefer to leave it to later so that I can fine-tune the locations of my batteries & other heavy stuff.

JM

Quintanius

Thanks for your thoughts JM. I'm at the stage where the guts of the ribs need to be cored out. I was looking at my baseboard and the width of the ribs. Looks like 2-1/2" wide channel will work nice, for about 42-44 inches or so. I have no idea what the size of dimension of the pumps are, just that they will be mounted aft, somewhere between the motors. I'd love to build a collection basin for the water and the pump. Do you have any idea what the general rules are for determining pump size? Do people just use the suggested pump units? Or is there a calculation for the penetratable surface area vs displacement or something? perhaps I can just order some and get those installed before building the channel...

TH

johnmCA72

It depends on the club. In my club, like most Big Gun clubs, rate-of-flow is limited based on the ship's displacement. Small gun clubs generally use the "unit" system, where a pump can be any size, with any motor, & any flow rate as long as its discharge nozzle is restricted to 1/8".

Example from my club: HMS Nelson, at 44,250t, would be allowed to pump 75 gallons/hour (48 seconds or more to pump a gallon). Now, that's in a 1:144 scale club, so it may not be enough for a 1:96 ship.

JM

Quintanius

JM...

I ran into the MWCI website. They run 1/144 scale vessels, but the guns they use are only BB's, and the turrets are fixed....or so I thought by looking at some pictures. Whats the difference between them and the Big Gun Clubs...seems to be a Us and Them phenomenon...not sure how this all works. I read some of the history. Yikes...but they do seem like they are active and organized...but the thought of not having rotating turrets seems...odd, to say the least.

TH

johnmCA72

See http://www.ntxbg.org INTEL page for a list of who all I know about, & which formats they belong to.

Small gun:

- Single caliber (0.177" Crossman/Daisy BB) for all guns.
- Allows arming of main guns only (some exceptions for torpedos).
- "Unit" system where 1 gun/50-capacity magazine OR 1 pump = 1 unit (also 1.5 unit gun/75-capacity magazine).
- Ships classified by units. Guns/pumps limited to number of units per ship (ex: 5-unit ship can have any combination of guns & pumps totalling up to 5 units - could be 1 gun & 4 pumps, if somebody wanted to be so silly - usually 1 pump, remainder of units as guns).
- No rate-of-fire restrictions - can fire as fast as the captain wants/mechanism permits.
- "Quadrants" defined, larger ships must cover certain quadrants to prevent over-arming any particular quadrant.
- Rotation is seldom used, largely due to the gun technology that makes it difficult to implement. Some larger ships are required to have 1 rotating turret.
- Pumps' only restriction is outlet diameter, not rate-of-flow.
- Only ships from a defined list are allowed, each assigned a number of units & speed.
- Speed is generally considerably faster than Big Gun, assigned to give/eliminate advantages/disadvantages to a particular ship class to even out competition.
- Reverse in combat is allowed & frequently used.
- 2 "national" organizations with local "chapters".

Big Gun:

- 3 or 4 calibers, depending on club, from 0.177" - 0.25", depending on what the original ship was armed with.
- All main & secondary guns may be armed, down to 3", if the builder can figure out a way to do it.
- Rotation of turrets & elevation of guns are common.
- Rate-of-fire limited based on caliber of gun, to simulate reloading times.
- Pumps limited by rate-of-flow, based on ship's displacement.
- Speed based on scale chart & documented speed of the original ship, generally slower/more realistic-looking.
- Reverse is generally frowned on in combat, other than to extricate the ship from situations where going forward isn't practical.
- Allows any ship laid down or in commission between 1900-1946.
- No "national" governing body, except in Australia; elsewhere all local clubs are self-governing & set their own rules.

I'm sure I'm missing something.

JM

darkapollo

FWIW, big gun is more realistic.

johnmCA72

My thoughts, too. When I started, I didn't know that there were local small gunners so I made my choice thinking I was going to be the 1st one around here doing combat, so I picked what looked like I'd enjoy more. FWIW, I've got a small gun ship sitting on the far back of the rack.

JM

Quintanius

JM,

That confirms my suspicion and recent findings. I'll stick with the Big-Guns!
I've been speaking to the gentlemen over at the Yahoo site about it also. I figured I'd twist something up during my first construction project. So I'm 20$ short on some wood, most of which I can probably re-use for the 1/144 scale ribs. If I want to build more than one vessel (which I'd want to do - eventually - I'm thinking) then 1/144 seems the wiser choice. (There goes the thought of getting a trailer out of this for my 1/96 Rodney from the wife.../sigh...)

All I had to do was re-scale my drawing, add a few lines for places where I'd want to cut stringers, and allow space on the top of the ribs for notches to caprail. What kind of weight ought the vessel weigh at 1/144? Also, earlier you spoke of some speed charts for vessels. Where would I find that?

For a scale prop, I'm not certain I can trust the plans, which only show a graphic representation of the props. Anyone have some info about the size of a prop for the Cherry Tree Class (HMS Rodney) at 1/144 scale?

TH

johnmCA72

That's all a matter of personal preference. There are plenty of people who like small gun & wouldn't dream of doing anything else.

Those aren't all gentlemen - I'm on there, too.

I have no idea about the weight - I suppose that could be calculated. I may put mine on the bathroom scale, just to see.

We have a speed chart at http://www.ntxbg.org - go to the COMMS page & see the Techincal Appendix. Nelson gets the warship minimum maximum of 25 kts, which comes out to 45 sec./100' on the chart.

Mine is 1.5" dia., 3 blades, pretty shallow pitch - I think it's 25 deg., if I remember right. 1/8" hub. I've seen photos that show 3-blade props, so I know that's right, but for pitch & diameter, who knows? All I have to go on is my plans, which may or may not be right. I drive direct with 2 @ RS-540 motors at 6V. I have to dial the speed down a bit - it still has the rheostat from way back when I first built it; no ESC until that thing burns up.

Most clubs allow some oversizing of props (scale + xx%) however be aware that you can have clearance issues if you go too large. Be careful ordering from the small gun suppliers, since the small gunners allow grossly oversized props (& only use a small number of standard sizes) which clear the hull by installing the shafts at absurd angles. If you install your shafts per your best interpretation of the plans, & skin the hull, you might find that oversized props don't fit. Also, paint can build up more than you might expect, & can cause prop clearance problems.

I don't know what the deal is with props. I've had several good sources over the years, that did fine work at a good price & shipped promptly - they've all quit! Loyalhanna Dockyards seems to be a good, going concern. I don't remember ever buying props from them, but they carry several lines & have a good reputation: http://www.loyalhannadockyard.com/

JM