Need advice on ASTRO-05 Outboard

[bearwash]

Hi,

I'm picking back up on a project that sat on a shelf for a couple of years. Have a completed but unpainted wood tunnel hull, a Lawless outdrive unit with a mount for an electric motor, and an Astroflight 5T Cobalt 05 marine motor.

Does anyone have experience in picking a set of gears for a project like this? The motor mount vendor suggested 17/21 but those gears don't even come close to meshing for some reason -- they are about 1/16" apart. So I guess I need two bigger gears. Does the ratio sound about right?

Also, I would like to hear recommendations on prop, batteries and speed controller. This doesn't have to fit a racing class but I want a good performing boat with reliable parts.

TIA,
Steve

Tri-Cities, WA

[pmpjohn]

This one uses an AF marine cobalt 05 (6 turn),twelve cells,AF 207 marine ESC,Octura X642 prop, Performance Model Products lower unit w/1-1.3 belt drive. I'm not familiar with the lawless unit but your ratio is in the ballpark for ten cell use. The 5 turn Astro is a little more power hungry than the 6 turn so if you are not racing I would recommend a larger driven gear to get your mesh and give a little more duration. If the lawless doesn't have a cavitation plate you will probably need a little more prop, X645 ?
What hull are you useing?

[bearwash]

Oh, I think it's one of those Hotshot Sprint 3.5 hulls. Certainly not state of the art nor light but won't be anything if not rugged.

I put the blue enamel on as a grain filler and have sanded it about 100 times.

I'm looking for a good speed controller I can use both for this and for an electric helicopter (both of which will use 10 cells).

Not really much to look at yet...

Any further recommendations gladly accepted and noted.

Wonder if that cowling on yours would fit mine?

[bearwash]

Should be blurry photo here

[pmpjohn]

Steve,
The cowling will not fit a Hotshot. My whole boat is only 22" and the cowl is only 15". This boat is my own design and built very light. Framed in 1/8 balsa and planked with 1/32 ply on the bottom and 1/64 ply on the top. The cowl is carved from balsa. My plans for this boat are still available from RC Boat Modeler.
Don't forget to retime your motor for reverse rotation with the gear drive. That's one of the reasons I built my outboard with a belt drive system. If you are interested and the Lawless uses the same 1.25" bolt spacing as the K&B 3.5 lower unit I may be able to dig around in the shop and find the pieces to build another belt drive.

John

[bearwash]

You know, 2-3 years ago I originally set out to get the belt drive unit I saw in the magazine, but couldn't locate the company (as I recall). I was sick for a long time and couldn't put much effort into it. Now, due to wonders of the Internet, I seem to have found the main belt drive man!

Yes, I would be interested in a belt unit if you have the parts around. Let me try to send you a PM and maybe you could get back to me with an estimated cost.

Steve

[Kris Flynn]

Hey Steve

very nice lookin tunnel you got there...the lawless is meant to be one of the better OB legs, i wish i had one. at the moment im using a kyosho ob leg on 6 cells...and will be moving to 7-8 soon :) maybe even 12
anyway just wanted to say you can get a dumas cowl that is the actual cowl for your tunnel fromDumas Sprint 3.5 Replacement Cowl (http://www.dumasproducts.com/cgi-bin/dumas.storefront/3d75fbb70d6f40f2271d40d4096806d1/Product/View/2117)

Steve or John would you happen to have any other pics of your tunnels and outboards? especially of the belt drives you talk about

Thanks
Kris

[bearwash]

Thanks Kris,

I will post a picture of my boat after it is painted and assembled.

John has the neat custom jobs, though.

Steve

[Kris Flynn]

Steve

if you want some extra help try www.rumrunnerracing.com/feforums there are many people there that can help you out
also for a good ESC for you boat try one from www.rc-hydros.com they are the best and most reliable with a good service if they are ever damaged

Kris