aquajet 775 prop selection

[ReddyWatts]

Go to the directory where fecalc is loaded, then open the text file and add the jeti there. Only add one line at a time just in case you enter something wrong, so you can go back and correct it. If you add something wrong the program will not open.

[kck741]

That boat is fine!!!

[mocars2]

Nice looking boat, very nice pics.

[bobswworld]

This was built this way when I bought it, it has one deans with the tamiya stuck in it, yeah I need to do that.
Where is the best place to get some quality batteries and still be able to make house payment?
Here are some pics
Was trying to use the FE calculator but it won't take any additional items, I input them but they dissapear. Was trying to add the jeti 600 controller.
Any Ideas?
This forum is great!!!

[skidooguymxz550]

change to deans. i don't know if they'll give you any more power but your connectors will never melt together whch is a pain.

mabey they will cool things down to. less rescistance

[Steven Vaccaro]

Should it only run 14.2 volts, it is now running 16 cells, tested voltage at motor and it is seeing 22 volts at full charge!! I am concerned about this voltage. But it screams. maybe I confused parallel with series, but it is running 16 cells at 19.2volts

16 cells wears the motor out quickly. 14 cells is a good option.

As for one pack getting hotter. it could be there are not the same capacities. Packs will change with age.

For instance at full charge one may be 3300mah, but the other 2800mah. So where you are running after a while, one may run out before the other. This is a problem.

[kck741]

hey bobsworld do you have any other pics of your cen 775 I love that boat!!

[bobswworld]

Should it only run 14.2 volts, it is now running 16 cells, tested voltage at motor and it is seeing 22 volts at full charge!! I am concerned about this voltage. But it screams. maybe I confused parallel with series, but it is running 16 cells at 19.2volts

[SJFE]

Well it may live quite a while..or not. If you plan on running this boat for a while @ 14.2 volts I suggest the 700SC here @ OSE. That motor along with the new batteries will last you quite a long time.

[bobswworld]

Thanks for the speedy replies, the batteries make sense, as I said am new to this.
Forgot to mention that one pack was considerably hotter than the other. Guess I still got a good deal even having to buy new batteries. It runs wicked for 3-4 minutes.
Have priced new batteries and the powerizers seem to be half cost and I guess half reliable as well. will look into your suggestions sjfe
Is the voltage the norm for this fe setup, will this hurt this motor? according to the controller all seems ok with it. Just worried about the motor.
thanks

[SJFE]

Those are the powerizer cells that cooked Roby76's big cat. I have had a failure with them also. I would suggest gp3300,elite4500 or the ib3600 cells.

[Steven Vaccaro]

You could go down to a 40mm. But I think the problem are the cells. They shouldn't get that hot after 3-4 minutes. They have a high internal resistance.

[bobswworld]

Hello,
I gave up on my dumas project, and went ahead and bought a used 775 that was already set up according to I THINK this sites recommended set up.
It has a graupner 700bb 8.4 motor, jetti 600, two 8 cell 3300 sc packs in parallel, and a 42 mm prop with a drive dog, in which I THINK is your upgrade prop for the cen 775, cause it has a sleeve, maybe i am wrong.
Was wondering if I went to a smaller diameter prop if I could get more run time, and draw less amps. Did some calculations, forgot where the formulas came from!! but it said I was using 49.5 amps, I only get maybe 3-4 minutes but it is very fast. Would I sacrifice the speed or would a smaller prop make it better? New to this field but am hooked once I drove this boat.
Oh also the batteries get pretty hot, the motor and controller are water cooled and seem normal temp as I can hold onto without a burn but not the batteries. Is it ok for this motor to run such high voltage?
Thanks in advance for any help