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        Discussion Apparition-II twin issues

#1 stalyoni Jun 28, 2012 08:46 AM

Apparition-II twin issues
 
Hey guys,

I have an apparition II twin rc boat with twin motors. Im having a few issues with it.

I have pulled out the stock motors and replaced them with 2 x tacon 2858 2681kv motors. I have 2 x 70amp esc's. 2 x 3s 4000mah lipos. I took off the stock props and put on counter rotating 38mm 1.4 props. I also swapped the flexshaft to counter rotating as well.

Its no where as quick as ive seen on youtube with the stock setup. I know the motors are about 200kv less then the stock motors but that shouldnt matter all that much should it?

Also having the 38mm props (counter) on it instead of the 35mm props (standard), would this slow it down?

I also cant seem the get the front to sit down. The prop angle is level and I mount the two lipos up under the front deck to get the front to sit down a bit. The back is still in the water allot.

Should I go back to the stock 35mm non counter rotating props?

any help would be great.

thanks.

#2 SARCFAN Jun 28, 2012 08:59 AM

How is the speed compared to the stock motors?

#3 bill34207 Jun 28, 2012 09:05 AM

If you have the prop rotation spinning out (top side of prop) try reversing directions and spin them in. That will lift the rear and push the front down.

#4 stalyoni Jun 28, 2012 04:09 PM

2 Attachment(s)
sarcfan this is the video im referring to :

Apparition-II Offshore Brushless RC Twin Hull w/ Twin motor - 3S 2P (4 min 11 sec)


My boat is slower then this one. But the back of my boat is sitting in the water much more then this one. The water line when im going flat out is just in front of the water outlets on the side.

bill34207 I already have the counter rotating props spinning inwards.

Does the 38mm CR props compared to the stock 35mm props make that much of a difference?

Also I have my lipos mounted right up under the nose on the deck besides the very two front sponsons as shown in the pictures below.

ATM my prop angle is level with the drive line, maybe I need to give it a bit of up angle eh?

#5 bill34207 Jun 28, 2012 04:51 PM

That doesn't sound right to have that much weight forward, drive line at neutral and it still squatting in the rear. Maybe we should have a look at your actual hull setup inside and out instead of the pix grabbed from the web.

#6 SARCFAN Jun 28, 2012 11:26 PM

Quote:

Originally Posted by stalyoni (Post 22023278)
Does the 38mm CR props compared to the stock 35mm props make that much of a difference?

According to my knowledge, if the bigger 38mm props don't overheat anything they should in all cases make any boat go faster than if fitted with 35mm props. Except if the 35mm props have more pitch or more ''meat'' in the blades.
What brands are the 35mm and 38mm props?

I've seen the same tendency where my boat would sag at the back. So moment it gets on plane with appreciable speed it levels itself out. If it was my boat I would play with the angle of the propshafts and make sure there is no binding in the propshafts.

#7 stalyoni Jun 29, 2012 05:06 AM

Im taking it out in the morning with dad. I adjust the props and put them up a bit more. Not sure what brand the38mm props are. The 35mm props are HK ones.

We also need to make another rescue boat for the apparition. We have a bodyboard with a EDF on the top but it wont push the apparition. We will make a bigger version.

I let you know what happens after I fix it up and have another run on it.

#8 wparsons Jun 29, 2012 06:22 AM

If you're having issues with the rear running too deep, raising the props is only going to make it worse.

Like Bill said, it'll be MUCH easier to help if you get pictures of your actual boat/setup to show.

#9 stalyoni Jun 30, 2012 04:23 AM

6 Attachment(s)
Well I changed the angle of the props. I made it so it was a little higher then straight. The boat ran allot faster and the nose was out of the water more. It was only sitting right on the back of the boat.

All in all the boat ran great today and im not sure it would go any faster. The front was skimming across the water a bit though but it was sitting in the water allot better and not sunk down at the back.

Before I took it out I added two more side outlets. So the water would come up one of the two pickups mounted to the back of the boat then split and go into the motor and esc and then out the side. Same with the other side. The new front outlets where working great. Its hard to tell if the back outlets are working good. The escs where warm to touch after a run but not hot. The escs will get the most water going through them.

Anyways I have included a few pictures. You can see where I mounted the lipos this time and it worked out great. BTW they are only 20c lipos.

Not sure how I can make it go any faster, except for run two 4s lipos in it.

I already have a 3000mah 4s ( will get another one) at my dads house but do you think the 70amp escs will stand up to a 4s lipo? Do you think my cooling is good enough for 4s? Also would I have to go back to a 35mm prop for 4s?

thanks

#10 SARCFAN Jun 30, 2012 04:43 AM

2700KV on 4s is a lot. I would not do it. I would rather prop up if temps are within spec. That will give a speed increase

#11 stalyoni Jun 30, 2012 04:57 AM

can you tell from the pics if its setup ok?

#12 bill34207 Jun 30, 2012 05:23 AM

Photo 2 bothers me. I'm surprised it's cooling at all with the water pickups so high. I'd suggest loosening the setscrew and lowering them so the tips are a little closer to the bottom of the sponsons.

#13 stalyoni Jun 30, 2012 05:34 AM

Quote:

Originally Posted by bill34207 (Post 22036701)
Photo 2 bothers me. I'm surprised it's cooling at all with the water pickups so high. I'd suggest loosening the setscrew and lowering them so the tips are a little closer to the bottom of the sponsons.

that would put the tips under the water and will only create drag wont it. Arent they only just meant to be on the top of the water so the water shoots up into the tubes?

Just read that this guy used 4s lipo and 38mm props with this motor.

http://www.hobbyking.com/hobbyking/s...dProduct=15190

which is pretty similar to mine but I would like to know how many amps it was pulling

#14 bill34207 Jun 30, 2012 06:07 AM

If those tips are still skimming the water at full throttle the hull is not getting on a full plane. If it were fully "aired out" you would not be getting any cooling with them where they are. (unless by some stroke of luck the prop spray was being pushed into them).

For 4s you will have to upgrade your esc to probably 120 amp ones.

#15 stalyoni Jun 30, 2012 06:11 AM

Quote:

Originally Posted by bill34207 (Post 22036829)
If those tips are still skimming the water at full throttle the hull is not getting on a full plane. If it were fully "aired out" you would not be getting any cooling with them where they are. (unless by some stroke of luck the prop spray was being pushed into them).

For 4s you will have to upgrade your esc to probably 120 amp ones.

when I was on full plane the water was pi$$'n out the side of the boat. Only at low speeds it would just trickle out.

Hmmm 4s would mean two new motors, two new esc's and one 4s lipo. Maybe its not worth it after all.


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