My TFL Pursuit coming up to speed.

[martin]

I have just checked the cg on my stock Pursuit with an Aquastar 3974-2200kv motor fitted & Seaking 180 esc,the esc is on one side of the boat behind the motor. 2 Gens Ace 3s 5000mah weighing 370g each are in the centre on the stock battery tray ( batteries pulled almost to the motor) & i have 30% cog. If i push the batteries a bit more forward just under the deck i get 32% cog.

[MADRCER]

Man, that's crazy to me. So, your boat is around 30% with two batteries that far under the deck? Seems like it would be a snow plow!

Here's mine at 30% or a little less...

Keep in mind my Esc is in the back of the boat along with a GPS. I also have a larger and heavier than stock dual pickup rudder on my boat. My 3d printed battery tray has been stragetically placed to and is much lighter than the stock long tray. You have a very large esc and a whopper of a motor upfront in your boat that you have to offset the difference by placing your batteries further back.

[martin]

If the cg is a little further forward than 30% with the battery as far back in the centre of the boat as it will go & the bow is a bit low, add a bit of positive to the stinger ( 1 maybe 2 degrees ). Also check the bottom of the hull for any hook @ the rear.

[martin]

MADRCER is your motor mount still in the stock position or have you moved it back towards the transom.

[TRUCKPULL]

I am building a Pursuit

I have installed a carbon fiber liner in the bottom and up the sides, 19" long.
I then put a strip of fiberglass tape 1-1/4" wide around the seem between the deck and the hull for extra reinforcement.
1/8" ply inside the transom.

I am now ready to install the motor mount.
In the picture it is not installed yet.
My question is the cg measurement ( from the outside of the transom forward)that I should end up with.

This boat will be for the "P" Speck Mono class -racing.

4S-2P - 5000 packs - 36mm Motor

Larry

[jim82]

30%= 9.6in. I have a 4070 1650kv I just put in there for the hell of it. Here is inside balanced at 30%.

IMG_20180715_160317966.jpg

[boatsrnew2me]

heres where mine balances out at 30% ....aka.....about 9.5 inches from transom. when i tried a lipo on the tray up front it was very nose heavy during balance test . even still i managed 55mph .i havent got much more running them on the sides ,although i just made a stinger adjustment ,i have not got to run it yet .hopefully monday .
but here is where my side mounted lipos balance out at .

stock motor mount location .leopard 4082 and flycolor 150 mounted up front .x645 prop

[MADRCER]

I am building a Pursuit

I have installed a carbon fiber liner in the bottom and up the sides, 19" long.
I then put a strip of fiberglass tape 1-1/4" wide around the seem between the deck and the hull for extra reinforcement.
1/8" ply inside the transom.

I am now ready to install the motor mount.
In the picture it is not installed yet.
My question is the cg measurement ( from the outside of the transom forward)that I should end up with.

This boat will be for the "P" Speck Mono class -racing.

4S-2P - 5000 packs - 36mm Motor

Larry

9.5 inches from the back of the transom is where you would want to start for race waters. Below is a picture of my boat balanced on a dowel of a magazine rack sitting right at 28% or so (with my batteries up front). I did have two short pieces of pool noodle on each side of the dowel to hold the boat straight up while I took the picture.

Screenshot_2018-07-15-20-00-14.jpg Screenshot_2018-07-15-20-12-42.jpg

[boatsrnew2me]

9.5 inches from the back of the transom is where you would want to start for race waters. Below is a picture of my boat balanced on a dowel of a magazine rack sitting right at 29-30% with my batteries up front. I did have two short pieces of pool noodle on each side of the dowel to hold the boat straight up while I took the picture.

[ATTACH=CONFIG]160309[/ATTACH] [ATTACH=CONFIG]160311[/ATTACH]

how about that ,mine was front heavy with a 6s up front .hey i got a magazine rack like that in my man basement...lol....just gave me a new idea

[MADRCER]

Everyone has a rack like that I bet...Lol FYI My math was off that was around 28% still with batteries up front. I do like 30% better for just ripping around.

[TRUCKPULL]

9.5 inches from the back of the transom is where you would want to start for race waters. Below is a picture of my boat balanced on a dowel of a magazine rack sitting right at 28% or so with my batteries up front. I did have two short pieces of pool noodle on each side of the dowel to hold the boat straight up while I took the picture.
[ATTACH=CONFIG]160312[/ATTACH]

My aim is to have as much weight at the CG or as close as possible.
I would to end up with the batteries centered on each side of the motor.
I will get all the hardware installed first, then arrange the motor and mount with the batteries, ESC, and radio etc. for the 9.5"

Here is a picture of what I would like to end up with. Items are just sitting there, not mounted yet.

Larry

[MADRCER]

My aim is to have as much weight at the CG or as close as possible.
I would to end up with the batteries centered on each side of the motor.
I will get all the hardware installed first, then arrange the motor and mount with the batteries, ESC, and radio etc. for the 9.5"

Here is a picture of what I would to end up with. Items are just sitting there, not mounted yet.

Larry

Looks good. You just using Velcro for mounting your batteries or are you mounting trays?

[TRUCKPULL]

Looks good. You just using Velcro for mounting your batteries or are you mounting trays?

I have tried trays once in the past, On this one I may just go with the Velcro and straps epoxied to the hull.

Larry

[Mike W]

My aim is to have as much weight at the CG or as close as possible.

I read somewhere that you actually want the weight distributed as far way from the CG as possible in a boat because it increases stability. Seems counter-intuitive at first but makes sense. Unfortunately it's hard to implement and keep power wires short.

[TRUCKPULL]

Does weight forward and aft of the CG NOT make for teeter-totter effect?

Larry