jcplinux42008

I don't want to post again about the reduction gear because i blew it yesterday but watch the video at the bottom that i took today with direct drive

RC_Bob

What size prop are you using and how many cells w/direct drive?

jcplinux42008

I am using 12 cells with direct drive , i have a supervee speed control and motor in it. The prop is a rigged traxxas villain left had turn prop , it is way to big for the sub-surface drive , i didn't know much about this when i started modding the boat , its been a learning process , i had too drill out the prop because it had threads and i have a straight shaft , but the prop that came with it used a grub screw too hold it in place so i also had to use the same design , but they dont make props like that for r/c boats anymore i guess ,so too answer your question , becuase i have not been able to find the prop specs on the traxxas villain , i have no clue what size it is , i think it around 45-50 mm , someone has suggested to me before i think it was quicksilver too use an x637 , or x640 , but i think maybe even a 440 or 432 would be ok , you can tell it accelerates way too fast and has no more push behind it , if i give it full power for a few seconds it stops dead in the water until the speed control cools off , and water cooling the speed control would only minimize it it would still get way too hot , motor was fine and batteries were fine on temp , but the motor is water cooled. I also want too know ifi should just get rid of the bec i think my radio gltich may be coming from the speed control getting hot and that infering with the bec its running to my radio. Its scary seeing your boat you spent countless hours working on and hundreds of dollars on speeding uncontrollably towards the stone bank , especially since i have had this since i was oh 4 years old so its under 20 by just a few months. One mroe thing on the prop , i can get a replacement straight shaft with threads and a drive dog on OSE i would possibly have to cut or just move my motor back , i have a ton of run to go back with my motor but it needs to be angled becuase it was designed to have a gear going over the edge of a hump i will strip it down and get a picture of what i mean , and maybe someone could suggest how i can change that because it is annoying , i fear breaking my boat everytime i move the motor. I got a couple pictures i don't know how well you will be able too tell but right now the mount only holds down the very back of the motor , it doesnt twist or anything , but its barely holdin on , the graupner ujoint with the extra link in the middle would be perfect as long as it can take the brushless , i had one before and it was ok , but what about a flex shaft could i switch too one in the same stuffing tube as the straight shaft i don't know much about them. The whole reason i was originaly going to stay with the geardrive was because it was much easier too install with the design of the boat , but it bit the dust so its now direct drive again. i also included here some other pics with direct drive and a gear , don't critizize the u joints i know they are not straight i was pissed about the gear going out and i wanted to run the boat , i have no money too order parts , and so i took a drill bit close too 5mm and just rounded out the hole on the u-joint too fit the motor and put the grub screw on the flat spot of the motor shaft so zip it if you were going to say something about it.

RC_Bob

For the prop, 45-50 mm is kind of on the bigger side. The choices that you said are good ones. About 37-40 mm.

The BEC isn't required to be disconnected unless you use 14 cells. You could try and see if it makes a difference. I tried it w/my BJ26 and the radio signal was a bit clearer. But that was the Proboat esc. What radio system/type are you using?

The prop angle and tuning is a real biggy. I took a peak at your other video of the boat and I noticed that the prop is angled down quite a bit. A flex shaft would be good to handle problem but that means more [sm=greedy.gif]. Maybe if you set up the prop in a position like this pic it might take down the heat if you use a smaller prop for sub-surface drive, but it'll mean a lot more modifying(it's a little hard to see but basically the prop is further back):
http://www.proboatmodels.com/Product...RB3750&Index=6

jcplinux42008

The funny thing about the radio is that i bought a whole system a cheap futaba am 2ch , i cannot get the Tx too properly arm my ESC , so i had too just use my old Tx whichis still a futaba, but it does have its good days. On the prop angle , the one problem with modifying this is that its made of plastic , i know the prop is at an angle , but i think with a smaller prop that is just going to make it maybe a little slower than it could be with a surface drive, if i do anymore major mods too the drivetrain it will be too install a jet drive , doing some measurements i can see that it would fit the graupner jet drive and has a perfect little square in the bottom and the inlet would line up perfectly (almost) with the hump where the prop shaft now comes out. But i really dont want too try and convert it to surface drive that too much work for me currently , i think a jet will come eventually until then im just going to get a new straight shaft and smaller prop , and hope that puts less of a strain on the system I will also invest in the cooling jackets for the speed control maybe that will cool it down a little bit, despite the prop being angled it still gets out on a plane very easily , especially since i moved my CG forward a little bit.If you watch you can tell that the prop is rigged too because it wobbles at the end of the shaft everything you would want for smoother performance is not there and i really need to get it working correctly so i can just take it out and run it , for more than 5 minutes at a time. Ok here is a new video from today much more running footage hope you enjoy.
http://www.youtube.com/watch?v=pq4INnP3hUM