ORIGINAL: Mikeup
I would'nt put transom blocks on or in. Make motor on rails for CG purposes, you have the room. Build as normal build but put metal rails in with lockdown where CG fits the bill.. Don't worry about rudder, pond is almost dry as are alot of them. 2 x 4 wouldn't float. LOL! Farmers here are cutting corn crop down to feed the cattle, pretty sad. No need to reply as you have your building plans and you know what else is coming. We can talk later, ok.- what i mean with motor on rails is the whole works, gas tank, wood for support; rudder with dimensions you've typed. Now with your knowledge and my dumbness ,you'll come out ok!!
I actually was going to install a set of rails on the hull and slot them to be able to slide the engine back and forth to get the balance just right. I have 3 different engines I will try out on this new boat if it isnt too heavy at the end. I have a .29, a .30, and my beloved .46. The .30 is the lightest at 9oz w/o muffler, the .29 is just shy of 10oz and the .46 is roughly 12oz. Each of these will create the need for thrust line adjustment. My past experiences have been so-so when it comes to engine placement, and my original premise to drill 3 sets of holes to have a few options to try works okay, but ends up being a lot of extra work to get all of those holes to line up each time. So I'll do it differently for sure. This way, the entire engine stand can be moved. The fuel tank and control cable clamp will be a "set and forget" type of thing. Should be much easier to dial it in this way.
I'm building the hull with a normal transom as I did before, using the same 3/16" plywood as the top deck is made of, and the sponsons are 1/8" maple plywood. I will add a turn fin to the port sponson, and I think the 1/8" ply should hold that okay. I'll use a little silicone sealant behind the turn fin bracket to seal it and add a little extra holding power. Beyond this, I'm not getting real crazy with beefing the hull up. I will add some small chunks of balsa in a few spots in the tub and sponsons only for skin support. I am not going to fiberglass anything on this one except the bottom of the tub as this skin will be made from solid wood in several strips laminated together.
ORIGINAL: dadkins
looks good Tim - it's been a while since I have visited RC U - The re-re- rebuild looks good - I like that the sponsons and stern have a flat ride plate to ride on verses the kinda point on the last one - should be much more stable.
Took mine out last weekend for a little rip - Added a larger air rudder and tweaked my motor sideways a little - It ran pretty good - fast to the point of air induced wheelies - ran through three tanks and only had to retrieve it once.
Take it easy. boat looks good !
Dave
Good to see you around, Dave! Both the tub and sponsons do not have a flat ride pad, the rake is one continuous curve so really the riding surface will be a point. For a hydro to be successful, it needs to more-or-less "skip" across the waters' surface rather than ride just below it which is how the old hull ran. The new hull is longer and wider by 2" or slightly more, so this should increase stability as well as dropping the weight as much as I possibly can. I will use some small 48oz in. micro servos in this, and the lightest AA cells I can find. I am not building it as beefy as I would like just to save weight. If it folds up, well.. it folds up. I will wear my swim trunks when I go to test it, just in case I need to swim after it. My test pond is 10 feet deep or less, so it cant go far.
Good to hear your boat is running well. I'm hoping we can get together one more time before summer is over to do a little boating. It would be nice if I can get this boat done so I can test it out and I'll bring my minikaze rocket with me now that I've tweaked the snot out of it..