Dumas sk daddle 2

[adam beck]

Hello guys not sure if this is the correct place but I need some help. I originally planned to run a nitro motor but have changed my mind and want to build it with a brushless drive train. I am thinking of running a 1800kv 36x74 brushless motor.. I am looking at a submerged drive. I think I want run a wire drive set up with a three blade prop. What hardware would you guys recommend? And what size prop? Do you guys see any problems?

 

[larcor69]

I built one of them that's not complete yet I really want to run a four stroke engine in it always keep my eyes out for a decent used about a 60 or 70 size four stroke

 

[RaceMechaniX]

Hello Adam,

Are you looking for a power system that just cruises around or something a little spicier?
Do you have batteries already? or any of the other components?

 

[Jerry Dunlap]

For batteries, I would recommend 2 2S 5000 mAH packs hooked in series. This would allow you to place the batteries on each side of the motor. A transom mounted strut would allow for prop depth/angle adjustment. Hardware for a 20 deep vee would work. Personally, I'd go with flex cable drive.
JD

 

[adam beck]

For batteries, I would recommend 2 2S 5000 mAH packs hooked in series. This would allow you to place the batteries on each side of the motor. A transom mounted strut would allow for prop depth/angle adjustment. Hardware for a 20 deep vee would work. Personally, I'd go with flex cable drive.
JD

I have two 2s 5000mah packs so that works. Yes to the spicier side of things we have a large lake in the center of our town so I have plenty of room. Why the flex cable? From what I have read these have to be removed after every run. This of course could be misinformation. I have found another thread that said an actual 440 3 blade would be something to try. I have to learn how to balance and sharpen props. I also have a 150 amp 2-6s esc not motor or hardware as far as prop shaft,stuffing tube, strut,rudder or

 

[adam beck]

Hello Adam,

Are you looking for a power system that just cruises around or something a little spicier?
Do you have batteries already? or any of the other components?

Something a little spicer but not crazy I have a couple 2s batteries 2 2200 mah and two 5200mah I have a 150 a 2-6s water cooled esc but nothing elee

 

[RaceMechaniX]

So you can easily make a 4S 5200mAh setup with those cells and run the 3674 size motor with a KV in the 1500-1900 range. That will not tax the ESC beyond it's 150A limit and you can up to make it plenty fast.

Definitely go with a flex cable, .150 with Teflon tubing and a 3/16" stub shaft will work nicely.

 

[Jerry Dunlap]

I have two 2s 5000mah packs so that works. Yes to the spicier side of things we have a large lake in the center of our town so I have plenty of room. Why the flex cable? From what I have read these have to be removed after every run. This of course could be misinformation. I have found another thread that said an actual 440 3 blade would be something to try. I have to learn how to balance and sharpen props. I also have a 150 amp 2-6s esc not motor or hardware as far as prop shaft,stuffing tube, strut,rudder or

You can remove the cable after you have finished running for the day and grease/oil it at that time. A motor I have had success with is the Dynamite 2000 Kv from Horizon Hobbies.
JD

 

[adam beck]

Thanks for the info guys. You guys recommend a place for the strut and rudder? I have looked at the speed master stuff. I am gonna make a turn fin for the bottom and possibly some trim tabs. I have access to a ton of stainless strapping at work of various thickness and widths thanks again for all your help.

 

[Grimracer]

I would do a sub surface drive with a hard shaft... (maybe wire drive)

I would set the leading edge of the prop 15% from the transom and to starboard about 3/16 inch.

If your not racing the boat this is have the best FUN factor! The boat will accelerate like crazy and not blow over as easy doing it!

Grim

 

[adam beck]

Grim racer i appreciate the advice on the set up. What about center of gravity? Nothing is mounted yet so if a can set it up right the first time that would be great. Does a wire drive set up need the same maintainace as a flex cable. Hard drive you mean solid shaft in a stuffing tube with a u joint at the motor correct?

 

[Grimracer]

Adam,

Thanks for the questions.

I would start with the CG at 30% from the back.. (it might be a tick nose heavy but with FE you have GOBs of power).

Wire drive and cable are about the same to me.. I remove every 5 or so runs and re-lube

I do mean a .187" hard shaft with a coupler.. NOTE.. it has been my research that a U-JOINT typically is not designed for high RPM (I am surprised they work at all in RC boating...LOL) .. A cruciform joint is better but not by much.. I would go old school and make a HARD coupler.

Grim