BB Modss

Welcome fellow boat lovers, in this thread im going to show you how im building a twin engine Nitro Hammer with your help! Ill be doing all the work, spending the money, and pestering my wife in the process but this should be 1 heck of a build! Id like to start by saying thanks in advanced to all the people that will be giving me ideas and suggestions about this build, Thanks! I have here a stock Nitro Hammer purchased from my LHS about 8 days ago, it has never seen water, other then a bathtub for cleaning/leak testing. I have chosen 2 sportwerks .26 engines for this conversion and have a lot of custom made fiberglass parts along with many other parts ill have to mod or have made..or make myself.

Lets get started shall we?
Here she is in stock trim with her .15 AquaCraft engine under the hood.


And here she is with the dual stringers getting glassed in.


This is where i am to this point.I have the 2 new engines coming next week and i have the flex shaft collets for the engines here, Now i need your help picking out a running gear set!, I need hardware based on a .187" (3/16") flex shaft.
I also need ideas on the best props for this setup. I plan on using a under hull prop setup unless some one has a better idea, iv seen a few boats like mine with surface drives but this hull doesent work well with them so im trying to avoid surface drives. Thats it for now ill keep this thread updated as i make progress and get parts in.Lets get to work rc boating guru's!

2916jr

I think it may be overpowered but that is nothin I am used to I have .21 in a tc3 turned into a drag car[>:] but I would keep checking this forum to see how u r doing on it

BB Modss

I agree, this boat will have almost 8hp total on 65% fuel with my adjusted ports and ported/stuffed crank. Right now i need a guru to pick a idea drive line for my project.

r/cmark42

My Feedback: (8)

I can't wait to see the end results!

cmiller73

Are you going to run 2 seperate props or 2-1 setup?

BB Modss

who makes a 2-1 system> id be interested in looking at that, also i remember a V-Drive system for rc boats from a while back, any body here know of a V-drive system?

[email protected]

don't you have to run left and right screws?

BB Modss

Ok after some looking around i have come to see that im lost.. I need input on this project, can i use my 2 engines in the stock rotation patter? or will i have to have a counter rotating engine?

misshydro

I hope your ida works for you.But I hope for you that hull holds up! That alot of power for a small boat.With at kind of hp/tork that hull will crack apart after a few runs on it.[>:]

gooycheese

If you are using two engine that turn the same direction i would think you would have a hell of a lot of prop walk. I would think you would need opposite rotating engines.

just my opinion

Paul

[email protected]

could you use a tranmission gear, have one on the left of the gear the other on the right. I saw a guy start his nitro runnning the wrong way, the boat went no were. so I'm thinking you need a counter rotation prop also.

BB Modss

Yes i have factored in quite a few things over the past many hours. From what i can see i have a ways to go. Tomorrow ill use my CAD software to prototype a 1:1 (might even play with overdriven ratios) transmission,more of a line drive. I can use it to control the counter rotating prop side, shouldest cost more then $200 to make myself 2 of them..even though the other side will be just for symmetry, ill also have a way to overdrive both props if need be..im sure power wont be any issue! As for the Hull im reinforcing the underside when i strip the gel down with Kevlar strips and special epoxy blend. ill also cut aluminum strips to reinforce the stringers, all this should be more then enough, plus the light weight will help me keep my total weight down

[email protected]

you said you'r using kevlar on the boat. I was talking to my bud he said kevlar is better then fiberglass, a lot cheaper then carbon fiber to. I asked him how to use it and all that stuff. He said buy a book, one problem I can't find a book. I want to buld a hull out of kevlar or carbon fiber and run two engines like you. I was hoping two .67 nitro engines with a gear drive and a clutch. Also I think I'm going bigger then 1/8 scale. My uncle is an architect and said to give him a plan of some kind and he can draw the design, then get a mold made. I just bought a boat kit the atlas van lines U-1 from dumas. I need to build my skills before I go after this type of monster. Best of luck with your build, you need a big fuel tank with two engines do you do the math on the wight to size ratio and balance.

BB Modss

I can help you with the Kevlar work, in fact PM me i have a few questions for you, and i can get you setup using Kevlar-carbon composite, along with my cook book on curing temps and pressures. The only true way to form carbon's and Kevlar is in a vacuum heated bag form, And the temp and vacuum effects the strength and flexibility of the carbons and Kevlar.

[email protected]

I will try to help as much as I can, I don't have a lot of RC boating experience. I have built some real boats with friends.

Hydro Junkie

Since you are running subsurface drive systems, counter-rotating one prop isn't needed like on a surface drive. Counterrotation is normally to eliminate propwalk, which you most likely won't have. I do think, however, that twin .26s are too much for this hull. I would recommend dropping back to a single .26 instead

BB Modss

Much to my disappointment its just not going to happen, even if i build the transmissions the boat just simply isent enuff to handle it..its to small for the power as i feared (local hydro dynamics eng friend confirmed this) So i have decided to go a tad bigger with a XXX Muscle hull from MHZ here is the boat http://www.theelitelab.com/xtdoc/Det...uctCode=m-1759 I hope it serves me well, and ill have a fer smaller parts for sale soon if anyone wants anything i have let me know.l


Now I can stick 2 super bad .12's in there and have a real screamer

[email protected]

[quote]ORIGINAL: BB Modss

Much to my disappointment its just not going to happen, even if i build the transmissions the boat just simply isent enuff to handle it..its to small for the power as i feared (local hydro dynamics eng friend confirmed this) So i have decided to go a tad bigger with a XXX Muscle hull from MHZ here is the boat http://www.theelitelab.com/xtdoc/Det...uctCode=m-1759 I hope it serves me well, and ill have a fer smaller parts for sale soon if anyone wants anything i have let me know.l

That sucks, but at least you'r not giving up. You want to here some disappointment you might think it's funny. My wife grabed my new monster truck from the mail and told me I'm not getting it back untill I redo the bathroom. My house is like a hundred years old(really it is) and I just want to move I hate working on my house! She won't even let me see the box. Any time I start a new project It winds up costing like 5,000. It could be a new bedroom door but something will happen and there goes another toy.

Hydro Junkie

In case you didn't notice, that boat is 63" long and designed for twin 26CC engines, not twin .26s

BB Modss

Yep i know how big it is.....

never said i was putting .26's in it...

Hydro Junkie

Just making sure, as others have wanted to try

Drmeff

That is quiet a jump... Nitro Hammer to a 63" MHZ hull

You would have been wasting your money with the Hammer anyway, just tooooo much motor(s)

2916jr

you can never have to much power
.21 in a tc3 converted to a drag car

BB Modss

want a real power house for the drag car? iv got a 4+hp .28 here with centax clutch 2 speed