Slow delta force Pathfinder

[Brothers 1718]

Hi guys I have a Delta force Pathfinder that I'm trying to dial in. It runs a leopard 3674 2200kv motor; a seaking 180amp esc, 4s 5000mah revolectrix packs and a CNC 1.6 pitch 46mm prop. The top speed I got while running was 37mph. I'd like to get the boat to run in the high 40s or even the low 50s. Can you help me achieve my goal please?

[Fluid]

Your setup should be faster, so something is not optimum. We need some details:

- where is the CG?
- what is the prop depth with the boat on a flat table?
- is there a gap between the drive dog and the strut?
- is the ESC properly linked to the transmitter?
- is the power 4S1P or 4S2P?

A few photos of the transom from the side and an interior shot would help.


.

[JestDanny]

I think your 1.6 x 46 mm is to much prop for that motor. To spin a 1.6 series prop I think you,ll need to drop down to a 40 or 42 mm prop. For the larger 45 / 46 mm props look more to spin a 1.4 series prop. I would try props with 2.5 / 2.6 inch total pitch to start?

[Brothers 1718]

I will be posting some pictures when I get home today this evening when I get home after work.

[RaceMechaniX]

Agreed on the prop load. Try a X440/3 Octura. Set the prop height so on a flat table the bottom of the drivedog is sitting flat on the table.

[HTVboats]

I have run the Pathfinder with motors from limited 36X60 to 40X74 2000 to 2200 kv. Speeds from 48 to 58 mph in oval trim. Holds NAMBA P/limited and IMPBA P cat 2 lap records. I would recommend a 442/3 blade CNC aluminum to keep it simple. We heat race with a 1714 ABC and a M445 cut to 43mm diameter. An X642/2 works also. All these should be in the high 40's and low 50's. The CNC 3 blades are here on OSE.
https://www.offshoreelectrics.com/pr...od=cnc-4214350
Tyler has the correct info on strut height.
Mic

[Brothers 1718]

The pictures as promisedIMG_20200120_183945872.jpgIMG_20200120_184013240.jpgIMG_20200120_184013240.jpgIMG_20200120_184000484.jpg

[Brothers 1718]

The motor is 8 and 3/4 inches from the transom and the esc is about 13 inches. One battery tray popped out during my last run sadly so I need to epoxy it in but they both sit at 6 3/4 inches from the transom.

[photohoward1]

For one that strut should be above the bottom of the sponsons...start maybe at and 1/8" an inch. Also hard to tell but the motor to shaft bend looks odd.

[Brothers 1718]

I run the boat on 2s packs in series ; the esc is properly linked to the transmitter and I leave a gap between the drive dog and the strut.

[Brothers 1718]

For one that strut should be above the bottom of the sponsons...start maybe at and 1/8" an inch. Also hard to tell but the motor to shaft bend looks odd.

Closer look at the shaft bend.IMG_20200120_201218028.jpg

[RaceMechaniX]

You should remake the stuffing tube. That poor bend is adding a lot of friction.
Pull the old stuffing tube out my gently heating it with a torch near the section where is passes through the hull. This will soften the epoxy holding it in.
Be sure the remove the teflon liner and cable when heating.
Set the boat back on the flat table and set the strut 1/16" above the table and flat.
Then rebend a new stuffing tube with only a single gentle bend. It will take some trial and error to get it right so buy extra material.
It should look like a nice gentle bend with the stuffing tube entering the stuff dead on straight.

[fweasel]

Its hard to tell for sure from your interior picture, and a moot point if you replace the stuffing tube as recommended, but the angle between the motor and stuffing tube appears off. This could be another source of friction and power loss. The flex cable looks to be bent over the exit of the stuffing tub in order to mate with the collet, which is both too low and at too low of an angle. When the collet is loose, the flex cable should be able to slip in and out with minimal deflection.

[HTVboats]

Here are some pics of the setup as run for the 2 lap record. Your motor at 8 1/2" and being larger (heavier)means you may want to move your battery weight back a bit to get the balance you need. Address flex angles as already discussed.
Mic

IMG_0436.JPGIMG_0437.JPGIMG_0438.JPG

[Brothers 1718]

I took out the stuffing tube last night but I don't have any spare 9/32 sized brass tube at hand so I'll hopefully order a few new ones before the end of the week.