New Miss Geico V2 on its way .

[TurboPete]

Hi guys Im new to the forum getting back into RC's after many many years so be gentle .lol

Just ordered a few days ago a New Miss Geico 29BL V2 , I also ordered a Turnigy 180a ESC and a Turnigy 3659-1900KV. I understand there are alot of factors in the boat speed especially if the hull bottom has minor defects , but besides doing any modifications to the hull to make it flat and true what would be a good prop for it . Ill be using 2 Venom 5000 3S 35C in series 6S.

Ive heard metioned x442 and x642 which one will work better for this combination .

Do you think in obviously ideal conditions that should get me 55 to 60 mph . Is it doable ?

Thanks,


Pete

[MAMBA2200]

Well first off welcome to the forum the boat you have purchased is a great hull the esc is also good the motor is a little high kv to be running 6s im not saying you cannot but you will be at a very high rpm. I will tell you that on 6sthat is gonna put you at right at 40,000 rpm 5s would be more along the lines of a more proper rpm load at 35,000 rpm. I have a mystic 29 which is the same hull and i run a 2150 kv on 4s which gets me in the mid 50 mph range with a octura m445 prop that is sharpened and balanced which i will tell you this prop performs very well on my boat. So as far as you want to get to the 60 mph range i would say to you run the boat on a 4s setup for a bit to make yourself more familiar with this new boat before you go out and burn something up or have a crash and damage your rig. Take it slow and eventually you will get faster just from your knowledge of learning more about your boat and listen to the great people on this forum and you will learn allot from these guys just as i have.

[TurboPete]

Thanks so much for your advise , so it would be better to run 2s batteries in series.
Now just to learn something here if I run them in 6s and as you say the motor turns 40,000 rpms will a bigger pitch prop slow the rpms down some and get the stern up some ? Oh is that more of a adjustment on the prop angle .
Ive been reading alot on the boards lots of knowledgable people here .

I also have a Central RC 58" Fountain being built.



Thanks Again ,

[Heaving Earth]

I see smoke in your future

[tlandauer]

Now just to learn something here if I run them in 6s and as you say the motor turns 40,000 rpms will a bigger pitch prop slow the rpms down some and get the stern up some ? Oh is that more of a adjustment on the prop angle .


Thanks Again ,

Why would you want to slow your prop by going to a bigger pitched prop? Your 40,000 rpm is already extremely ( unacceptable to my kind of running anyway) high, the amp draw will have the components destroyed in no time. Use 4s and start from x442, then try x642. You will see a M445 works well too. You need to adjust the height of your strut to dial the hull in, you seem to be thinking about prop LIFT when you say if the stern would be raised. LIFT props are used in hydros.
On my MG ( V1) the strut is all the way up---that is if you sit the hull on a flat (glass) table, the bottom of the strut is ABOVE the last sponson pads . How much your hull needs is something you need to experiment. Mine is about 1mm above. This setting is higher than what the ProBoat instruction recommends. I now have the Kintec Offset Rudder. To give you an idea: I had to file a slot for the prop to clear on my STOCK rudder bracket. Otherwise the sheer height of the set up will prevent the prop to rotate.
When I adjust my strut height, the whole thing moves up or down without tilting , I try to keep the prop neutral ( Zero angle), pointing the prop up ( Positive) or down (negative) is a last adjustment and the margin is very limited as the bore of the strut is "collared" to the stuffing tube and unless you attempt to re-bend the tube there is no real designed-in adjustment there.
Have fun,

[tlandauer]

Forgot to mention: I had to enlarge the long hole on the strut blade so the strut CAN move straight up or down---very important, otherwise you will be forced to move in a tilting arc, no good, trust me on that one.

[TurboPete]

I see smoke in your future

Thanks , very helpful.

Why would you want to slow your prop by going to a bigger pitched prop? Your 40,000 rpm is already extremely ( unacceptable to my kind of running anyway) high, the amp draw will have the components destroyed in no time. Use 4s and start from x442, then try x642. You will see a M445 works well too. You need to adjust the height of your strut to dial the hull in, you seem to be thinking about prop LIFT when you say if the stern would be raised. LIFT props are used in hydros.
On my MG ( V1) the strut is all the way up---that is if you sit the hull on a flat (glass) table, the bottom of the strut is ABOVE the last sponson pads . How much your hull needs is something you need to experiment. Mine is about 1mm above. This setting is higher than what the ProBoat instruction recommends. I now have the Kintec Offset Rudder. To give you an idea: I had to file a slot for the prop to clear on my STOCK rudder bracket. Otherwise the sheer height of the set up will prevent the prop to rotate.
When I adjust my strut height, the whole thing moves up or down without tilting , I try to keep the prop neutral ( Zero angle), pointing the prop up ( Positive) or down (negative) is a last adjustment and the margin is very limited as the bore of the strut is "collared" to the stuffing tube and unless you attempt to re-bend the tube there is no real designed-in adjustment there.
Have fun,

Thank You for the explanation. Im new to electrics, so I dont understand much about load and rpm's. I thought that rpm would cause the engine to smoke or batteries to smoke . I assume its more load correct? Seems that what your saying is that by me trying to slow down the rpm's it would cause more load on the motor and therefore more heat . I will try the x442 and try it at 4s first.
I bought the New engine because I saw it could run on 6s and was 1900kv , but I see there are alot of others that have motors that are 2000kv to 2200kv why is it that those dont burn up? Again Im just trying to understand and I appreciate the explanation.


Pete

[tlandauer]

Given the same set up parameter:
The load on a x 642 would be more than a x442 due to the increase of pitch. ( dia=same)
The load on a x642 would be more than a x640 due to larger diameter. ( pitch = same)
A motor may be rated @ 60,000 rpm, but in reality your 40,000 rpm on 6s IN THE WATER draws ALOT of amps = Heat = on the poor ESC
Most of people who used 2000kv or 2200kv with 6s had the same results, it is a matter of time, some see their "future" in minutes ( as I did one time) , some see them a bit later.
If you read a bit more, you will realize quite a few number of us share this experience and therfore you are receiving these warnings today.
There are so called SAW application, these are high rpm set ups , they are Straight A WAY races, Read more:http://forums.offshoreelectrics.com/....php?38961-Saw
Again, have fun, I am sure you will come to the right conclusion and enjoy this wonderful hobby.
BTW, you might have mis read, 2000kv and 2200kv are 4s set ups. I don't recall any body with LONG TERM 6s config. who did not have some form of failure. I use the words Long Term loosely.
p.s.We are really talking about the 180 a ESC here, as I said, the motor will spin at that RPM, it may last awhile too, depending on the quality of the bearing and how the rotor is made.

[TurboPete]

Thanks , so if you run a higher kv at 4s will that help run cooler and more speed given the same prop and 180a ESC?

The other question would be how do you get it to run cooler on 6s , do you need a bigger amp ESC?

Sorry again if its a dumb question . Ill go read the link now . lol


Pete

[TurboPete]

Ok I just read the link and No I dont think SAW is for me , Id rather take a couple of right turns here and there .lol

Sure would like to see it go 60 but not if it is going to go up in smoke, what will I need .


Pete

[stadiumyamaha]

It's not only the electronics.
That hull, unless seriously strengthened will not hold up to crashes at those speeds. It has a tendency to split when crashed.

[TurboPete]

Understood , thanks for all the great info guys. Ill check the hull when it gets here and make corrections as needed .

Gets here tomorrow so Im excited to get started with it .


Pete

[TurboPete]

Ok got my MG yesterday , must say it looks better in person then in the pics . I see what everyone has been saying on the bottom of the hull , I will need to make them flat for sure , one side looks like there is a small concave area and on the other side there is a fish eye in the paint . No biggie . Waiting now for some parts I ordered from OSE and man they are fast ordered yesterday and already have a tracking number .


Pete

[MAMBA2200]

steven is very quick about shipping thats for sure