hi
i build a 44' cabin crusier running two 700 bb motors sc-480 esc 12 volt gel cell ,two three blade 1-1/2 props ,getting bad run time 15-17 minutes barely getting back to shore ,only running half stick no racing around ,it also has15led lights ,that run off the main battery i dont think they are using THAT much power ,i was thinking of going with 2" props ? heres some vedios ,the dancing dolls and ipod run of there own battery thanks rye

http://www.youtube.com/watch?v=nzajB...e=channel_page

http://www.youtube.com/watch?v=RRwvp...e=channel_page

Can I put my hat away?
Did none of the advice Jan and myself gave you make any sense?
Your motors are stalling due to the size of the props.The folks who use 700bb motors use nicads and race around for 2-3 minutes with the motors turning at 10,000 rpm.
If you can't get those revs at full throttle then your props are <span style="font-size: larger;">too big</span> for submerged drive on a 700bb.If you use your 900 motors or these you will get more power at a fraction of the current draw.

To give folk some background information you could have posted as a follow up on the other thread

Tony

I'm willing to give rye the benefit of the doubt.I have the same problem with one of my runabouts.It's like my EDF jet, it looks and glides fantastic for a few passes and then it's dead stick time.Some gave me the same advice as you but the chump who built it for some reason fused/glued the prop onto the shaft, so to "simply" change all that is (I feel) more trouble than it is worth.Maybe he's just looking for a second opinion.

"give rye the benefit of the doubt" I don't think it's the builder at fault here it's the motor being overloaded by the size of prop.End of story.
Jan said try smaller props.I agree with his suggestion with some emphasis.
What do you think he should do for longer sail duration?

hi guys  </p>

sorry i forgot that page,i have a hard time understanding motor esc battery  set up ,ok i had the motors i use them  willing to change them and props too  boat weights about 12 lbs without batterry  i just what to cruise around the pond ,can u tell me what you guys would use  thanks   rye</p>

[youtube][/youtube]
I didnt say your advice was wrong, just that he may have had a reason not to follow it-and he wanted a second opinion.

If a change of props is going to be done, take the opportunity to get a smaller diameter - give the motors a change to spin up.  If the hull tries to sit down at the stern when powered up, try fitting a small trim tab at the bottom of the transom to stop the water closing round the stern too suddenly and giving unwanted extra drag.  When cruising, the boat should leave a nice hole in the water.

Rye,the email alert I got from the last post has prompted me to look at the esc size thread again.

I thought at that time(two months has passed) the logical solution would be to put the 900 motors in the cruiser and the 700bb motors in the pt boat.I didn't mention that at that time as you were reluctant to remove the motors.
There is,however,a problem with that :- as I looked through the rcgroups forum at your posts.You must be adding ten pouns of lead shot to all your models.

Jan's suggestion of replacing lead acid batteries with nicd packs could be done on the pt boat.With 700 motors and small props it could cruise rather than stroll along.If it weighs us much as the other models,however, thatt would be like throwing the proverbial deck chairs off the Titanic.
Your memory must is worse than mine.Over the course of a year there have been....well.....quite a few rcgroups posts telling you to use smaller props on the 700 motors over a year.

Smaller and /or (much) less pitch, to let the motors rev out, as said before.

This is the last time I'm gong to answer to this thread, after all, it has all been said before.

Regards, Jan.

hi guys </p>

frist let me apoligize ,i was getting frusturated with trying to understand motors and prop size so i call my hobby store who dont deal in boats  but turn me on to a older man who makes props and he is making me a set of props 1-1/4 with much less pitch  but i have to have the rods cut down at the threads to 1/8 inch at 540 threads now they are 3/16 10/32 threads so now i have to find a machine shop but i like to thankyou guys for the help and learn how to listen to you guys ,jan you been great you help me out before and i sorry i got you mad  so until i get the new props and rods cut i let you know how it when    rye</p>

since you arn't looking to go fast maybe you can wire some extra batteries in parallel to increase the run time, pretty sure that would help