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Old Sep 28, 2005, 05:16 PM
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Joined Jul 2005
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Battery use with Monteleone Model

Hi,

I am just setting up a Monteleone Monocarena boat. It has got a 550 "Peak Panther" motor in it which I am running with a 25amp esc and 7.2v 1900mah battery.

I took it out for the first time yesterday and was a bit dissapointed at the speed it obtained. (I bought my 6yr old daughter a cheap 20 one from ebay so she didn't want to play with my real one and it goes faster!!!)

Can I safely connect 2 of these batteries together in parallel and will it give me additional performance?

Any advice gratefully received...

Gino
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Old Sep 29, 2005, 12:10 PM
Boaters are nice people.
Sneek, Netherlands.
Joined May 2004
5,116 Posts
Hi Gino,

To be honest, I was anticipating a posting from you on this subject...

The boat looks rather big for a 550 motor, so making it faster can be done in a number of ways, doubling the batterypacks and running them in parallel isn't one of them.

What you can do:
(in no particular order)

- run the boat on seven instead of six cells, most 550 motors will handle this without getting too hot. Make sure to check the temperature by making short runs (2 minutes tops) and bring the boat in to check.
If the motor isn't watercooled, make it so, a cool motor performs better and lives longer.

- Stay with the six cells and mount the next size prop, or if there's no room, one with a higher pitch.
Also on the testruns, check for overheating frequently and make the motor watercooled.

- Change the motor for a hotter one, the Graupner 600 race should work, car motors usually rev too high without having the torque to turn the prop and will overheat.
Car motors work well in a boat when geared down.
- Try a long can 660 motor (more torque) to turn a bigger prop, this motor will also run on up to eight cells, watercooled mind you.

- If the boat has the prop under the boat (as I expect), change to a surface piercing drive.

- While you're at it and your daughter's boat is still faster, go for major surgery and update the boat to a 700 motor, 12-14 cells, a strut & rudder(surface drive) and a 42-45mm prop.

That should enable you to go fast enough...

If possible could you post some pictures of the boat, side view and rear view, and please tell us the size of the boat.

Regards, Jan.
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Old Sep 29, 2005, 05:06 PM
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Joined Jul 2005
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Hi Jan,

That predictable eh?!

The boat's 800mm * 172mm and weighs about 1.4kg - profile picture attached

The prop shaft exits on the underside of the boat but powers a 40mm prop at the rear of the boat - see picture attached. Is this as you describe a "surface" drive or does it need repositioning?

I think from your suggestion, I am going to try a bigger motor with a higher ratio gear system and a bigger prop. What do you think of this one?

Robbe - Navy Power Set #4120
Geared high performance motor drive unit for sports boats and working vessels. Set includes 600/24 motor and compact 3.7:1 gear reduction unit, 50 mm prop, prop shaft and coupling.

Length: 238 mm


I know there will be better engines than this but I can get this one for 23 complete which I can afford to get now if it's going to do the job.

Will I need a different battery to drive this motor now or will my 7.2v 1900mah be OK?

Will my Ripmax 25amp ESC be Ok with this motor as well?

Thanks for your continuing help and advice...

Gino
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Old Sep 30, 2005, 12:35 PM
Boaters are nice people.
Sneek, Netherlands.
Joined May 2004
5,116 Posts
Hi Gino,

Looking at the pictures there are a few things that catch my eye:

- first of all, I like the hullshape!

- 80 cm, thats a boatsize for a 700 motor on 12-14 cells in direct drive!

- With the battery way back in the boat, where is your CoG? When you balance the boat on your fingers, it should be 18-20% from the rear.

- The motor is already geared down, that's good, by how much, 1:1,5?

- The propshaft seems to be very long out of the stuffing tube, totally without support, this doesn't look right.
Tell me if there is really some 40mm of 'bare' propshaft between the prop and the rear bearing.

- as the propshaft comes out of the bottom of the hull, it is a subsurface drive, not bad in this set-up, but it obviously needs some tweeking to get it up to speed.

- how often did you run the boat / charge the battery? Nicad's need a few cycles to get up to full power, so if you ran the boat only one time, it's no wonder it was slow. How do you charge the battery, with how much current (mAh)?

- The 4120 set is for "slow" boats, not for what you have in mind, besides that, you already have a gear set, it's a matter of finding the right set-up to get your boat going.

Regards, Jan.
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Last edited by pompebled; Sep 30, 2005 at 12:46 PM.
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Old Sep 30, 2005, 06:03 PM
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Joined Jul 2005
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Hi Jan,

Thanks for your support in helping me get started with this hobby, it is much appreciated...

Re the battery - I put it there because it's the only place where it doesn't put the boat off balance, but as you say, it moves the COG up to about half way. I'll have a look at repositioning it, perhaps adding a clip to the lid.

The gears a 1:2 ratio and the prop is set out as follows:[list]The tubing is 75mm long and ends at the back of the aft panel[list][list]The prop shaft then extends 30mm to the rear of the propeller[list][list]There is a 5mm gap between the propeller and the rudder[list]
Does this seem to long or is it OK?

Your point about the battery is key I think. I've only run it once, I didn't realise the battery needed to charge a couple of times to gain strength - it was brand new. I'll be trying it again tomorrow and will run it down and recharge it again. I'm using the charger that came with my little girls boat. The spec is 12v 300mah. The battery suggests a charging time of 9hrs. Does this sound OK?

So do you think I'll be OK with the motor that's in or should I look to replace it, leaving the existing gear and prop in?

Do you think it's worth putting a water cooler on the motor as well? Our local shops got a full kit for 4 with aluminium coil and brass collector!

Gino
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Old Oct 01, 2005, 02:55 PM
Boaters are nice people.
Sneek, Netherlands.
Joined May 2004
5,116 Posts
Hi Gino,

Adding watercooling is always a good thing, as a cool motor performs better and lives longer.
Check if the coil will fit, as the propshaft runs under the motor.

As for the propshaft itself, I guess the previous owner has removed the original direct drive 600 motor (yes , I've been googling..) for the geared down motor, which could work fine.
What he also did, is take a longer propshaft to extend the prop to where it sits now.
This is not necessarily a good thing, as the steering will be very direct and nervous.

This is what I suggest:

1) switch the ESC to the other side of the boat and test if the battery in that place will give you a better CoG. The boat will list to one side, but the proptorque should compensate partly when the boat starts to move. If the boat lists too much, compensate with some weigth.

2) Loosen the setscrews on the bigger gear and shove the propshaft into the boat, until the prop sits against the rear bushing with 1 mm play. Fasten all setscrews again.
Lubricate the shaft and make a testrun.

The charger with 300 mAh is fine, but only allows for one run a day.
A quickcharger will charge your battery in 45 minutes or less and gives you more "Oompf" when running the boat.
Make sure to let the battery cool down to ambient temperature, before recharging.

Let me know how things go.

Regards, Jan.
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