propping a Mega Midi 3

[CM007]

My second boat is a 32" JetStream 800 that's geared 1.4:1.
FDM surface drive, with a Mega midi 3 on 12 cells.
This is for sport running...
I have an X438 and an X442?

Run time and heat Hmmm?

pictures soon

CM

[CM007]

If this was a question about propping a Lehner, I'd probably get 20 responses. I still hear the crickets chirping.

But anyway, If anyone is interested, I used the X442 and got just about three minutes of run time. Nothing too hot. I was pleasantly surprised with the speed, even geared 1.4:1.

It ran really well, but It definitely needs a turn fin and trim tabs.

CM

[Andrewg]

This is the Lehner USA site after all

However, with this motor running a 442 is pretty mild I would try an x642 at least and perhaps 1.2:1 or 1.3:1 ratio

The motor will run hot once its running hard - it was designed a amp monster for 7 cell competition gliders and will cope with - likes - big amps - that is why it suits boats - big power big torque - still a good sprint motor particularly at club level

if the speed suits you - keep it that setup - the motor will last for ever

However there is more there

Watercool the brushes and can of course

[CM007]

Andrew

My brushes are watercooled. I would like a little more speed. 1.2:1 or 1.3:1 you say? It was petty quick, but quicker would be a plus.

Also, for a stepped El Lobo? For now, I have the X438 & X442. Eventually ABC though.

Thanks

CM

[Andrewg]

the octura 642 or prather 215 is the way to go for props

the 442 is good on a direct drive

[Paul]

Hello CM,

For a sprint setup I used a x450 at 1.2 to 1 and the boat (a Titan) flat out screamed. On my setup it didn't much care for the x6 props. With the 1.4 ratio go with the x445/47 and you should be pretty happy with the results.

Paul.

[CM007]

Is the X438 too small for the El Lobo?

What difference could I expect with the X438 as opposed to the X442?

CM

[CM007]

Thanks Paul

CM

[CM007]

I ran my El Lobo with the X442 today. Smokin'

It was real windy here today (15-20 mph), and I flipped it twice. I was running with a friend with his Miss Bud hydro (RTR Horizon hobby). I easily out accelarted him in the strightaways, but with the wind he had me in the turns. For $299.00 that hydro is pretty neat (for a nitro).

Man, can that Mega produce some heat!

CM

[Andrewg]

If the timing is not adanced wind some in - remmber to loosen the end nuts hold the enplate and turn the magnet housing clockwise - this seems opposite to a 05 but you are turn the endbell in the same way relative to the magnets - the correct advance will be somewhere between 1/8 and full advance - just keep that cold water up to it and it should be fine

[MR truckpull]

CM007
propping a Mega Midi 3

I may be asking the same type question,although mine is for a direct drive rigger.
Are you asking about Mega Midi 6 3 turn ?

[Andrewg]

Start with a X642 and work up - try higher pitch first then more diameter.

However a rigger should run very light compared to a mono and will not need the same diam as the above boats.

[CM007]

MR truckpull

Yep...

CM007

[K.R.Joye]

CM007, What cells are you using to get 3 mins runtime? If your using 2400's thats great! But you still need another minute if you plan on competing in NAMBA 4 min enduros. You may have to upgrade to 3000hvs or better yet GP3300's. I'd like to see some pics of that Jet Stream running!
I'm just finishing a lightweight cutdown Jet Stream for Mi Cup Unlimited Offshore. My set-up uses the 14.4 800BBX motor D/D on (20) 3300's. This set-up should give 5 mins runtime with a x645-6 prop.

[CM007]

K.R Joye,

I'm in the process of adding some trim tabs and a turn fin to the JetStream. With the Mega in there it barely touched the water. Once I'm back on the water I'll send some pics.

For my El Lobo yes I'm running 2400's. My brush hoods are water cooled, and I really think that I could get four minutes, but I've been a bit conservative. Lastly, I think if I go with an ABC or Prather prop I might be close to that time (4 min.).

I am also going to try my Neo in the JetStream on a 1.1:1 or 1.2:1 gear.

CM

[CM007]

ABC 42/55 or Prather (size uncertain) for my Mega/El Lobo combo?

CM