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View Full Version : Help!!!!!! Prather 46 prop/esc/motor combo??



cmoo
10-31-2015, 04:40 PM
i have a prather 46 mono and blew up my esc on my first run. currently running a castle 2028 with the xl2 esc on 8s. the guy i bought the boat from had a nitor O.S. .8 motor in it. i failed to change the prop from that set up and believe this is what could have caused my issue. any help would be great thanks. :help:

StevenBryant
10-31-2015, 05:48 PM
What size prop did you run? Did you water cool the esc and water proof it?


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cmoo
10-31-2015, 06:05 PM
Do not know the prop size. I bought it at a swap meet a while back. And yes I water cooled it and water proofed it. And when I open the box there's was no water in it. The prop measures 24mm from the tounge to the tip.

cmoo
10-31-2015, 06:08 PM
138386138386

Doby
10-31-2015, 06:41 PM
Show us the specs on the xl2 ESC.

cmoo
10-31-2015, 06:51 PM
do not have the exact specs but its rated around 200 amps up to 8s. castle doesnt show any specs on the unit.

Fluid
10-31-2015, 07:04 PM
The Mamba XL2 is the same basic controller as the Castle ICE 240 without water cooling. It should be okay in that big hull for the 2028 on 8S if the boat is trimmed right. The prop sounds like it is at least in the ballpark but just what is it? We need to see pics of the transom and the interior layout especially the wiring between the packs and ESC. And there needs to be a 1/4" gap between the drive dog and the strut. The more pics the better.

Another issue could be how the boat was driven. Lots of part throttle is death on ESCs as is running the packs down too far...


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cmoo
10-31-2015, 07:19 PM
138387

I only ran the boat 3 minutes for its maiden voyage so heat wasn't a factor. they guy I bought it from claimed the boat went 80 with the setup he had and the one time I started it up it sounded like a bat out of hell. That's the main reason I think it would be too much prop. Mind you I'm new to the rc boat scene

cmoo
10-31-2015, 07:39 PM
138390138391

Fluid
10-31-2015, 07:54 PM
We know you are new, we are trying to help. Three minutes is plenty of time to overheat a poor setup. How much charge did you put back into the packs? I asked to see the wires between the packs and ESC for a reason, long wires are a no-no. Exactly what packs were you using? You would have been better off leaving the ESC fan installed instead of the dubious water cooling and sealing it all up in a very small space. We will get you sorted out. And LOL at the claim that a Prather hull ever went 80 mph....that's near the world record for a real race hull. :roflol:

cmoo
10-31-2015, 08:15 PM
haha i guess im that obvious and i am using zippy 4s packs 5000 mah with a 30c rating havent recharged them since this all happened today.

Fluid
10-31-2015, 09:49 PM
If you are just running two Zippy 4S packs in series that could be much of the problem. That is a big hull and really needs four packs configured 8S2P. Three minutes running with just two packs probably drained the packs, no wonder the ESC gave up the ghost. One cause of ESC failure is inadequate power from the packs, either cheap packs or not enough capacity. You really want a minimum of 10,000 mAh pack capacity for your setup - that is two pairs of parallel packs in series.

cmoo
10-31-2015, 10:03 PM
Ok thanks for all the info. Just to clarify my boat was going tops 10mph. So this is all the result of lack of battery capacity. And not my prop choice. Thanks.

Fluid
11-01-2015, 12:03 AM
Without knowing the exact prop that is not known. The size should be stamped on the end of the hub. The pack capacity contributed to the ESC failure, we were not talking about speed, this is the first time you have mentioned that. Ten mph is silly slow for that setup.

There are likely several things contributing to the low speed: no gap at drive dog, strut height, pack capacity, prop size (too big OR too small), CG, etc. I didn't see any side shots of the transom or the pack/ESC wiring.....


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cmoo
11-01-2015, 02:09 AM
ok will be able to get pictures tomorrow talked to my grandfather(expert drag boat builder for 40+years) and told me it was "prop drag" meaning too much prop but for the amount of horsepower. i wanted an rc boat experts opinon.

cmoo
11-01-2015, 01:15 PM
update prop is an octura x457 and the batteries were almost completely full. and ran the two batteries in series. not parallel.

tlandauer
11-01-2015, 02:19 PM
As said, you need more than 10,000mah capacity ESPECIALLY for Castle Creation's ESC, they really want that capacity, personally told by the tech people from CC. Low quality batteries and inadequate capacity is the worst enemy for ESCs in boat application.
I have a DF 45" Sniper with Neu2230 on 12s2p with the same prop, runs fine. But not sure about your particular case,,,, not an expert on prop sizes.

EDIT: I would strongly suggest you post pictures of the areas that have been asked for by the real experts here, before people losing interest in your problem. There is a timing factor in these forums, if you got momentum, take advantage of it, posting more questions/comments is not going to "speed up'' their answer, concentrate on the area and go from there.
Good Luck!

cmoo
11-01-2015, 03:03 PM
138407138408138409

Although now taken apart this was my wiring.
Thanks for the info @tlandauer

Fluid
11-01-2015, 03:33 PM
Wow, where to start - wish we'd seen these earlier.

The battery wirng is terrible. Way too long, and those plugs are really only good to about 50 amps. Above that draw and they have huge resistance. Combined with the low pack capacity this can destroy an ESC which is asked to handle a lot of amps. Try to reduce the wire length as much as practical, bet it could be cut in half. The motor wires are much less critical.

The submerged drive is......antiquated. It has been two decades since I have run a non-surface drive. I would suggest converting it, but that is a lot of work so we can see what can be done with the current setup. The boat can certainly run okay, it is just out of most of our recent experiences.

The 10 mph top speed is silly slow. The fact that you ran three minutes but hardly drained the packs leads me to think that you never had full throttle applied, either with a weak throttle finger or a poor binding to the transmitter. That will kill an ESC quickly.

Let me do a bit of research of my old notes.......


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cmoo
11-01-2015, 03:50 PM
appreciate the continued interest in my issue, and i didn't realize how much i have to do. i was giving full throttle for the few passes i made before pulling it out and will rebind the transmitter prior to my next run. also willing to do the work for a surface drive.