Mean Machine Reliable vs Top Speed

[Raceprep79]

Thinking about building or purchasing a partially rigged MM hull from Kintec. I have read in many threads that if you want a reliable setup to stay around 30,000rpms max loaded to keep from killing the drive line. Trying to decide if setting up 4s or 6s is the correct way to go. I do not plan to race and would like something that scares the crap out of me (seems like I need this to have fun) I currently have a UL-1 with a swordfish 220+, leopard 2200, X642 prop, running 4S 2p 3200mah packs.

Does anyone have experience with a reliable setup that goes somewhere around 65mph?

Looking at loaded prop speeds looks like anything over 55mph will start sacrificing drive line reliability. Is this correct?

I have been looking at the Mean machine so I would have a boat that can do rougher water than the UL-1. Seemed pretty good bang for the buck. Does anyone have any suggestions on that decision or could recommend something different for the $?

Thanks in advance for the help. New to this site and really enjoy everyone being so helpful with technical data.

[Raceprep79]

Anyone? 1st post and no bites. Any feedback?

[tlandauer]

It is on the small side for 6s. I run mine with a Neu 1515 1y (2200kv) with a m445 prop. I know people have run that motor on 5s with a smallish prop(m440) ,
I run 4s2p and is a reliable set up.

[Chilli]

The MM is a great boat but IMO 65mph out of that hull may be asking a bit too much for sport running. If you go 3/16 flex shaft, the drive line will not be an issue. The 30K suggestion is to keep heat down in the motor and esc so you can run longer and not stress the gear. Keep the set up close to what Tim is running as far as motor size and KV, get some 4S 5000 packs and you'll have a fun reliable boat. Can a 6S set up work? Sure it can but the 4S2P set up has been run successfully in that hull many times over so why reinvent the wheel. Throw the Leo 2200 in her with a Turnigy 180 ESC (or larger). Try a 442 on her for starters, keep the rudder long and go have some fun.

[champion221elite]

I have a 29" Sprint Cat which is nearly the same hull (if not the same) as a Mean Machine if memory serves me correctly. I'm running a Leopard 4082 rated at 1600 kv on 6s with a SK 180 ESC. Depending on prop selection, my Sprint Cat runs low to mid 60's with an X448 and mid to upper 60's with my Y547 prop. I'm running a .187" driveline and keep my runs timed to 3 minutes.

[Raceprep79]

Thanks a ton for the feedback. I have some 4 cells for my UL-1 I will try for shakedown runs. Maybe later can try 5s if I get bored with the speed.

On the rudder does anyone know if the boat with hardware version that Kintec sells is the adequate length? If not what length I would need minimum?

[gsbuickman]

I agree with Tim's setup . The 2200kv / 4s / m445 is a reliable effective combination. I was running a slight variation with 4s (2sx2 series), AQ 3656 (2030kv) and the m445 prop. It was a reliable sportboat setup.

I recently reoutfitted it & changed the motor to a 2350kv 3674 with two 3850mah 4s cells in parallel on the m445 prop. I just finished it last night and I haven't had a chance to get it in the water yet for testing. with the way the wind is blowing today, The boat holes are all white capped.

[tlandauer]

Thanks a ton for the feedback. I have some 4 cells for my UL-1 I will try for shakedown runs. Maybe later can try 5s if I get bored with the speed.

On the rudder does anyone know if the boat with hardware version that Kintec sells is the adequate length? If not what length I would need minimum?

A good question. Looks like Kintec is using Chinese hardware and I couldn't tell the length of the rudder. it maybe OK. I can tell you from personal experience with the MM hull a longer rudder is preferred. I bought both of these to test:
http://www.offshoreelectrics.com/pro...d=ros-spdr-005
http://www.offshoreelectrics.com/pro...d=ros-spdr-001
I can tell you with certainty that the shorter Speed Master rudder didn't work so well, any rudder input and the boat would spin out. You can shorten the longer one somewhat but not by much.

[Chilli]

I shortened the Speedmaster .21 rudder about 3/4". I maybe could of gone a little shorter but didn't feel comfortable taking the chance.

[78MaicoRider]

I have a 29" Sprint Cat which is nearly the same hull (if not the same) as a Mean Machine if memory serves me correctly. I'm running a Leopard 4082 rated at 1600 kv on 6s with a SK 180 ESC. Depending on prop selection, my Sprint Cat runs low to mid 60's with an X448 and mid to upper 60's with my Y547 prop. I'm running a .187" driveline and keep my runs timed to 3 minutes.

I am putting together the same setup now. A brand new (no holes drilled) 12 year old nitro Sprint Cat picked up with hardware for $60. What pack config are you running for 3 mins? I am planning to run 2 3S 5200 mah 45C packs in series. I have both 1600kv and 1800kv 4082 leopards I can put in it. Are you running a cap bank on the SK 180?

[champion221elite]

I run Nanotech 5000 mah packs rated at 40c. My SK180 v2 has an external cap bank.

[Raceprep79]

Ok, so I am thinking pretty seriously about rigging my own bare hull Mean Machine. I am a machinist and capable of making a lot of things, but I have never rigged an RC boat. I have these questions. I know they are a lot, but sure could use the help
What is the ideal angle to set the motor at? Is that set by the mount itself?
What is the best method to secure the motor mount? Carbon fiber epoxy or just epoxy?
What dimension works best to put the stuffing box along the boats length?
What is the traditional way to secure the rudder assembly on the back of the boat? I am assuming it is just thru bolted, but my UL-1 has inserts?

Sorry for the lame newbie questions. My only RC boat experience is my UL-1.

[tlandauer]

1, depending on what motor mount you get, mine was fixed at 15*
2, Two-part epoxy ( 30 min. variety is better than 5 min. epoxy which cures fast but extremely brittle). Another great adhesive is JB Weld. I am unaware of any carbon fiber epoxy, unless you mean epoxy mixed with carbon fiber.
3a,You need to find the correct COG, you need to determine what kind of hardware to use, i.e., Speed Master or other suitable hardware, order them and wait for them to arrive, use double sided tape to "hang" them where they will be mounted, put motor, batteries, battety trays and servo ( radio receiver is light weight so I don't bother sometimes) in and find the correct spot for the motor ( with mount), you need to also install the collet on the motor shaft and insert a short piece of metal rod( correct sized drill bit would do but may be too long) , I used .187 cable so I cut a piece of 3/16" rod, it will help you to "project" where to drill the stuffing tube hole on the floor.
b, If you have decided where to drill, next is really to mount your strut in the correct place, this will help you to determine the profile of your stuffing tube.
4, There is a transom doubler in the hull, drill thru and bolt.
For your reference, here is my build thread:http://forums.offshoreelectrics.com/...+machine+build
Note, other people have other or better procedure, this just my $.02
Cheers and good luck on your build!

[gsbuickman]

Alright. I got out Saturday and got a video of my mean machine, with the new setup.

Ez-run 3674 2350kv mill, m445 prop, on 2 thunder power 3850mah 30/60c 4s1p cells in parallel ....

It would have been a bit longer, but the battery in my radio died. the beeping you hear when I pull my boat out of the water is the alarm on my radio going off.
Overall once I started getting the hang of how it handled with the upgrade in power, she started moving right along pretty good

http://m.youtube.com/watch?v=-6yap7jL2Rg

[78MaicoRider]

Are you sure you are running your packs in series? That would be 8S a high voltage setup. Typically requiring a high voltage ESC.