Another Genesis Question.

[plpflyboy]

OK I know there are probably a ton of posts on this topic but most point on going to 6s and that's not what I would like to do at the moment. I am looking for a prop my setup is as follows.

Leopard 4082 2000kv
Turnigy 180amp esc
Turnigy nano-tech 4s 5000kv 45-90c batteries. x2 (parallel or run one at a time )
3/16 flex cable
and a cnc 445 prop.

The hull runs fairly wet at the first step. Batteries are placed about even with the motor and esc and the strut is level with the rear of the sponsons. Boat runs flat with not much of a rooster tail. What prop would you guys recommend and any setup help.

[lenny]

Can you post some pictures of the setup as if rtr ?
Also do you have any straight line video's of it running you could post ?
And what speeds are you getting with it now ?

[Alexgar]

40-42mm

[plpflyboy]

I do not have a Video and can post pics later. As far as speed goes I dont have a gps, but can say that my stock revolt will outrun the genesis atm.

[plpflyboy]

Here are some pics of how I ran the boat today.

[lenny]

I can not tell where the strut is set,
Put the hull on a flat table and let the prop and rudder hang off the edge on it.
Than take a picture and also measure it,
The strut bottom should be level and flat with the sponsons and table.

I would move the packs back to the transom about 1" to 2" from where they are and see how it rides than.

[JonD]

Hi plpflyboy

Your batteries look way too far back to me. Where is your COG? It should be around 0.31 to 0.33 with the cover on. I'm running 0.33

As lenny said, for the Genesis you need to check your strut/prop height and and get the bottom of the strut level with the sponsons when sitting on a flat surface. Also the prop angle needs to be neutral in line and parallel to the flat surface for a good starting point. I remove the prop shaft and stick a 3/16 inch 300mm brass tube up the bum of the strut so as to be able to measure the angle accurately. Then you can try adjusting a little
+ or - to get the boat balanced. I have the prop angle about 0.4 degree down at the back with a M445 prop on my Genesis.

4082 2000Kv with 4S and 445 prop should be a good combination. Is it M445?

Cheers,

Jon

[plpflyboy]

The prop is a cnc 445 made by fighter cat racing. I have a attached a pic of the boat sitting flat. The 0.33 - 0.31 where exactly are you getting this reference point at? I was thinking about elongating the slot for the strut to maybe bring the prop up a hair more.

[1945dave]

A couple of things. While I don't think it hurts all that much the pointed streamline tail nut does not help you. One it is larger than the prop and strut which makes for a blunt surface causing drag. On a surfacing setup this might not matter all that much but like I said it does not help you.

I also notice you are using the ES3 or are those ES5 battery connectors? Most of us are using 5.5 mm bullet connectors, some guys are moving to 8 mm bullets and even heavier gage wire to provide all the electrical power available with less resistance and heat.

I see you are a full scale aircraft mechanic so you should have all the smarts needed to handle anything we are doing here, but I will relate a story of one guy that drove 100 miles to meet me so I could help him figure what was wrong with his Genesis. It turned out he was running two 2S batteries like you are but they were wired in parallel so he was under powered by a factor of 50 percent. Since you also run a Revolt I think this is not your problem but any issue is going to be something simple.

[plpflyboy]

The tapered prop nut came with the kit I bought to upgrade the shaft. Will find a replacement. And those would be ec5 connectors. I use them for simplicity over any other reason. The batteries and what not all have 10 gauge wire. I believe it is something simple myself and am overlooking it that's why I am here. Temps are Luke warm on wires, esc, and motor after about 4 laps around a smallier sized pond. A friend thinks I need to prop up. Batteries are 4s and I can run them as a single or parallel. Will try to move the prop up more and check my strut angle tonight and run it tomorrow.

[Fluid]

You need to use a FLAT table top to set the strut. Many tables are not really flat near the edges, this can lead to the strut being angled down or up fro parallel to the sponson bottoms. One or two degress can make the difference. If you angle the strut up a little at the prop end it will help to lift the bow, but too much is not good. BEst to start with a known flat surface/setup.

I would not prop up yet. The 445 is a good size, I'm just not familiar with the lifting characteristics of the FC props. If they have more lift than an Octura prop then you will need to angle the strut up at the prop end.



.

[1945dave]

I am grasping at straws here but:

Are you sure the speed control is set correctly? That is are you sure you are getting full throttle? We have had a few guys on this forum not get full throttle and I believe many had the T-180 ESC as well.

Been a while but I have several of the T-180's and have not had any real problems but using the programming card does not set the range of throttle response. That needs to be done with the transmitter and involves listening for the proper beeps while you set the full range of response for the throttle/stick movements. One guy was only getting about half his throw. That would cause your problem big time. If on the water you can tell the transmitter to go half speed and let the boat settle out at half speed and then pull the trigger or push up the stick from there and get very little extra performance that could be your problem.

Regarding the T-180 speed controls they are famous for having a inaccurate voltage cutoff point. I beat myself up trying to figure out why my first T-180 speed control dropped down to half speed so quickly and it turned out to be the value for safe voltage drain for the lipo batteries. It should be 3.0 volts per cell (4S equals 4 times 3 for 12 volts) and just because you set that correctly with the programming card (the default is 3.2 volts) and with proper testing you will find manytimes T-180's drop down to safe mode far too soon. If you need further clarification on this give me a call and I can try to explain this better.

Dave

[plpflyboy]

Hmm that could definatly be part of my problem. I do have a programing card and have the values on it set. I will re read the manual and look at setting the throttle end points. So you set the LVC for 3 volts per cell? I was always told to keep it up around 3.4 or so for a buffer. I have flown planes and helicopters (mostly gas) and kinda out of my element on this boat stuff. Also I did move the strut up father with the best flat surfaces I could find. Removed the prop and rudder and set it on multiple tables and even the wall lol. Living in a apartment isnt the best for model building and setup. The prop comes extremely close to the rudder support bracket but does not touch. Thanks for the help guys. Off to read some more and possibly call Dave.

[lenny]

It is called calibrating the throttle range of the transmitter,
As for the LVC you could just set it to off and time your run's for 3 minutes.
Than just check the cells with a tester to see where they are at,
And also check all the temps to.
If those packs are in good shape and the boat is trimmed out right.
You should see about 5 minutes of run time and may be more.

[plpflyboy]

After each run or adjustment I do check my temps. Not so much battery voltage. As a rule of thumb I try to keep my runs to 5 minutes total on each pack. Gonna try and give her a run tomorrow weather permitting. Thanks