hemiblas

I took one of the chipped 37mm props and put it on and headed to small pond by my house. Sorry I dont have any video, but I was by myself and just decided to try it out. the battery, motor and speed control all kept really cool on the 2S lipo. I ran it mostly at 1/4 throttle though. Definetly much faster than stock, but once you get to about half throttle it just starts jumping up and down out of the water and loses control. I will probably try again in the next couple weeks at one of the bigger lakes, but it seems all you guys are right. if you want any speed out of these things its got to be a surface drive. thanks for all the input.

towmissel

we took a hammer 1700 kv brushless inrunner and 14 cells with the stock prop the weight
is what made it work I know it sounds like a lot but we got 29.3 MPH GPS and smooth and
handles well in turns we tryed bigger props 2 and 3 blade on lipo and everything under the
[>:]sun for run time and handling this set up was the best I hope this helps

hemiblas

Sweet! Can you give us some of the specifics on the setups you tried and what happened? That was my next step was to start playing around with setups but it sounds like you have already done that.

towmissel

too much prop makes the boat dive to the right almost a submarine now the setup I gave you
is for stock drive the young man did not have much money he wanted to run fast with stock
drive now I can install octura hardware all that stuff but for that much money you can buy a hull
and start from skrach but rtr dose not mean ready to run fast you have to make it run fast that is
the best we could do with stock drive and we tryed it all I love a challage this was one for
sure we have boats running 70+ MPH for 7 min. we do know what we are doing buy a
bby ovel master with with good hardware with your set up motor and ESC and you will be
running with the best of them we have a bby hydro 24 inch 9 turn motor aquacraft 45 amp
ESC 14 cell well over 60 MPH real heart stoper but always start with a small prop we have
it lucky we have over 170 props from 2 mm to 1/4 and a lot of battery chargers so
good luck and alway have a good time

Kevin

neil.cocker

Thanks for the info towmissel.

The weight makes sense to keep the boat down and in the water. I am awainting my 2048KV fiagao motor. I'll stick with the stock 30mm prop (not 37mm I said earlier mistake sorry) I have a 60AMP ESC (hope it will stand up) 12 Cells for me hopefully creating enough weight to keep the little hammer in the water. Thanks again for your input. Any further advise welcome.

Neil.

hemiblas

The main reason I was trying to go with a bigger prop was to keep the rpm down, but everything you guys said makes sense. I dont think that shaft system can handle to much rpm, but with 1700kv and 14.4v its about 25000 rpm and that seems to be the limit at which its stable. I may give it a shot with the stock prop and an 8 cell bettery. That will get me in the 25k range. If I need extra weight to keep it stable I can always throw some in.
Did any of you guys try the miss bud prop which is only slightly larger than the stock one?

towmissel

prop torque was to bad with the boat on a larger prop one time in testing we installed
39 mm 3 blade put the boat in the water armed the ESC and I punched it it dove to
the right so hard and this is with 14 cells the nose went under the water and I
had enough foreward speed that we saw the boat going to the bottom under power
the boat on lipo lite we had handling events fliping in turns unstable high speed runs
stuff like that the boat is a nice abs boat I like it but if I owened one I would go
with octura offset strut and rudder cost is 66bucks at offshoreElectric
stuffing tube and flex drive I think the boat would runnnnnnnnnnnnn
the young man did not have the money to put in the boat so good luck
and always have fun

Kevin[>:]

hemiblas

I had the same thing happen with the 37mm prop. Boat did a torque roll, pulled to right and went under water. That was only with a 2s lipo which was very little weight compared to the 14 cells you were running. I'm still thinking of trying the miss bud prop. Its only 32mm vs 30mm and not much bigger. I guess its so easy to swap them out that I might bring both with me when I start more testing. I have a pretty good assortment of batteries from nimh to lipo so I should be able to find the sweet spot where I can get this think up to speed.

hellomynameisdookie

Here are a couple of pics of the Hammer EP converted to surface drive. I'm now using 16 cells instead of 14 and the boat is a good bit quicker...enough to where it's kind of boring going back to 14!

http://www.rcuniverse.com/forum/fb.asp?m=5994389

hemiblas

Those are some nic pics. That may be my next project if the subsurface thing doesnt work out. I noticed on my turbo vee under brushless power has cracked the hull where the shaft exits the boat. It seems like that piece gets cut off and the hull smoothed on the bottom for the surface drive. I have a feeling the same thing will happen to the hammer after several runs so its good to know I can still use the hull if it breaks off.

hellomynameisdookie

No matter what you do you should reinforce the bottom of the boats hull with resin and fiberglass cloth. If you're keeping the submerged drive you might even consider glassing up around the motor mount to stiffen it up. With the added torque of a bl or larger can motor you'll need to beef it up a bit for the flimsy abs plastic to handle it.