Thanks Iunnrais. I have been debating whether to look at the product Bob had mentioned for adhering stuff to the hull or using thickeners with my current 105. My only issue is I ahve 105 and 207. Following the west systems chart, I would need to get a different hardener and 403. Or can i use 105/207 and 403, and instead of being clear, it would not be clear lol... If it means buying another hardener, I may just get what Bob suggested to adhering stuff to the hull, and the 105/207 to seal everything once in place. Thanks again.
The 207 should be fine, you'll just end up with a whiteish product once the additives are in. The normal hardeners are sorta amber colored (unless they are a bit older like mine and have turned reddish)
So it has been a while since I last updated. I have not been able to make much progress as I have been busy with school. The next step I need to do is make the skegs and install the propulsion and steering. Quick question before I go any further, should I be making motor mounts and have my rudder/servo setup all ready before drilling? I don't really know how any of that will look and function yet, so I don't want to drill and be screwed. Alright, so back to where I am, I have been bringing together the material I need for the skegs and propulsion steering. Below is a picture of the things I have so far, including propellers (2 x 5 blade, 2 x 4 blade), 2 struts for the outer props, 3 dogbone joints (I thought I had 4, might need to buy another), 8 x flanged ends (5/16 inch diameter with 1/8 inch hole for prop shaft), and finally that big thing is a jig I made to hole the 5/16 inch brass tubing in place. Now this was made 5 years ago, so I don't know how accurate it is. I will have to check the spacing with that on the plans. Here is a closer shot of the jig. Finally, here is the overall spacing measurements of the jib. Have not compared them yet with the plans. So now that you guys know where I am what, any suggestions on how to move forward? I have no clue how to do the skegs, nor what material to make them from, so maybe there? Any input is well appreciated, and thanks! Micah
Are you planning on powering all four props? Great for a scale venture, but hurts turning for a combat ship. Better would be to power the inner props only to increase water flow over the rudders. Now that I think of it, the 1/96 scale ship modelers mentioned powering only the inner props for scale speeds and using the outer props for a speed boost. For skeg material, I might have went with a 3/8" thick aircraft ply and cut a slot in them for the prop shafts.
Hey Mike, Considering I have all the equipement for powering all four props already, preference would be given to that. I understand it might have a negative impact of turning, but how much is it? Is it considerable measurable on the water, or more of a slight nuissance? Also, I have see other vessels powered by four props. Is that simply captains choice...looking at trade-offs? Also, I am building for Big Gun, so I am not sure if that will have an impact on going all four versus inners only. Thanks, Micah
With all 4 props going, each will be going slower so that you don't go over your max speed. This reduces flow over the rudder by around half, which significantly affects turning power. With the lower speeds (and therefore lower thrust limits) of Big Gun, you will really be hamstringing yourself in the turning power department. On the plus side, a pair of outer props left to freewheel (vice the normal fixed drag props) will eat up more energy, allowing MORE power to the center shafts and therefore more turning power. So leave the outer props in the stuffing tubes, but don't hook them up to motors. Let them spin and have better turning
Just a quick question regarding the outer props. If I feed a 1/8" rod (do I want brass, steel?) through the outer stuffing tubes, how would I make sure it does not get pulled back out of the ship by the drag? Meaning what would i secure it on the inside with if no motor present?
shaft collars are commonly available in both hardware stores and hobby shops. A shaft collar is basically a metal ring with a setscrew in it, that you put on a shaft to do exactly what you want: hold it in place. It's a good idea to put shaft collars on even the powered shafts, so in case of weeding or other emergency, you're less likely to lose the whole propshaft and prop. BTW, you've got ball bearings for your propshafts? Wow! I gotta get me some of those.
I like brass shafts myself to combat corrosion. Stainless steel works also. Do not use mild steel. such as music wire. It will rust in the shaft tube and make it near impossible to remove the shaft later on for maintenance. Ask me how I know! Ball bearings are nice! But they will require more maintenance than a sleeve bearing to keep corrosion free and running smooth. If you happen to forget to blow out any water and relube after a weekend's worth of battling, ball bearings will turn into crunchy ratchety bearings. Heh.
I like stainless shafts but brass is acceptable for allied propshafts. But for Axis, eet muzt be zee STAINLESS you schwein!!!!
So i will need to get some stainless steel 1/8" rod (stealing axis hardware!)and 4 shaft collars. Quick question, doesn't the 1 end of the dogbone almost work like a shaft collar? And ya those ball bearing ends are kinda cool, got orings on each side...cost a pretty penny to.
It _could_, but the collars are pretty dirt-cheap, so I always use a separate collar. Also, the collar goes right up against the end of the stuffing tube, which may not be near where you need the dogbone.
Notch the shaft where you put the collar or dumas end on with a c notch. Then if it loosens up, you have more time before it falls out. Also loose the bearings. They seize and fail. A simple three tubes of brass bushing or a bronze sintered bearing will be much better. The bearings in my friend's ship siezed and burned his motor, speed controller and entire wiring harness out. Cool smoke show but...... And he kept them lubed didn't help plus they're expensive
high-quality, sealed ball bearings are very nice. There is one person in my club who uses ball bearings and carbon fiber propshafts. It's a very high-performance setup in a very compact cruiser, and he's been using it for years without problem. On the other hand, his ship is so light that the foam superstructure keeps his ship on the surface, so the ball bearings in his ship never go deeper than 3 feet. in short: if you know and trust the quality of your ball bearings, keep 'em. If you're not sure, probably a good idea to try something else. For skegs: take a look at this photo: http://i65.photobucket.com/albums/h237/kotori87/IMG_0489.jpg that's basically what you'll want to do, with some minor modifications for your specific ship. The important part, though, is the same. It's a sheet of wood cut into the shape of the skeg and contoured to the hull, with a slot cut in it for the stuffing tube. Hope this helps.
Thanks for the picture Carl. How do you get the hole for the shaft rounded correctly using 2 piece? Should I be 3/8" inch wood, and drill into it with a 5/16" inch bit and just cut out the little bit left to make it into 2 pieces? Also, what type of wood would be best? When cementing the skeg to the hull and the tube in the skeg, should I use epoxy or some other type of glue? I've heard back and forth for the ball bearing ends. I don't know if they are high quality. If in doubt, should I get something else? If not, should I be soaking them in some sort of waterproofing agent before putting them into the tubes? Also, if I am going to use them, would I use CA glue to secure them to the inside of the shaft? What type of grease works best inside the shaft? How full should I fill it? Lastly, I can measure the length of the stuffing tubes on the outside of the hull using the plans, but how far into the hull should they go? I am assuming my motors mounts on the inside should be on the flat part of the hull, and not the inclined stern...if so, I could pretty much ball park their position and get a good estimate on length. Thanks, Micah
So a few updates, I was able to make the skegs and cut the holes for the stuffing tubes. i have never done it before, so if you see any classic mistakes etc, please feel free to let me know. Of course, keep in mind nothing has been epoxied in place, nor has my stuffing tubes been completely built.
Looking good, MK. That detail shot where the camera is inside the hull looking towards the bow really brings home just how BIG this monster is. Can't wait to see what it looks like finished! Keep it up!
To answer a few of the questions you asked above... Easy way to fit those skegs to your stuffing tubes is to use a dremel wood saw bit, and nibble out a channel most of the way through the skeg for the tube to slip into from the side. Keep test-fitting it, and when you are happy with the location, epoxy them together, and sand the 'open' side of the skeg flat. Definately use epoxy to hole the skep to the hull. Also sand the gelcoat so that the epoxy will stick better I would stay away from using the ball bearings. A few people successfully using them does not mean that they are highly successful in this application. I recommend in the strongest possible terms the use of a sleeve bearing (properly, a journal bearing). You can buy these to fit your stuffing tubes and shafts, or make them. There used to be a tutorial on making them somewhere, but I can't find the link in my favorites. But making them is pretty straightforward. How far inboard your stuffing tubes go is not very important, as long as they are well supported. Make them long enough outside the ship to put your drive props right in front of the rudders, and have enough of them inboard to be solidly mounted to the hull. If you need more space inside the hull to reach your motors without a crazy angle, make your driveshafts longer. Nothing says they have to have a stuffing tube all the way to the motor! Oh, that reminds me. Try not to have too much downangle on your shafts... thrust that is not dead astern (i.e. if it's pointing down more than a little) is wasted. Many people use white lithium grease in a squeeze tube or a small grease gun for their stuffing tubes. I did hand-pack my stuffing tubes with axle grease once in a pinch, but I don't intend to again unless I'm really in a pinch Took forever! Keep up the good work & press on! May Iowa and Musashi meet in honourable combat at Nats next year!
I am at somewhat of a standstill. I have been searching all over town for any form of a bronze or brass bushing for my stuffing tubes. The only things remotely close are the ball bearing ones, which of course, I have been prompted not to use. In addition, no where carries any sort of shaft collar. Now, I don't anticipate these would be that difficult to manufacture with a lathe, however, I don't have access to this technology. I have tried looking online with success, however, the shipping alone is 3-4 times the price of the parts. So, my question is, does anyone know where I could find these at a reasonable price locally (I am on Vancouver Island, BC, Canada) or where I could purhcase these online without a huge shipping cost. Thanks, Micah
I see that your stuffing tubes are brass. I have always made my own bearings out of K+S brass tubing. Perhaps 1" long. I just solder them into the ends of the stuffing tubes. It has worked out really well for me. Your ship is looking great. Mikey
