Motor Selection 30" Balsa Cat

[ezhitz]

Hi
I've built the hull now I need to select a motor.Running on 4S I was thinking either 8XL or 9XL but also wondered if there is any advantage to using the UL1
motor the boat is for sport running not racing. It's built from 1/8 and 1/16 balsa with the transom and middle bulkhead from 1/8 ply.the whole boat is covered in 3/4 oz. cloth and west system inside and out.I was going to use the inline strut & rudder sold here on OSE ,on less its better to seperate them.
Thanks for your input Jack

[HYDROJERRY]

Nice looking build man, im going to use the inline drive system in my 32'',, i see lots of guys here using them seems they work well for single setups.... im not crazy about the heatshreink at the front of the strut covering the stuffing box thow... makes it look kinda cheap.

[ezhitz]

Hey HydroJerry thanks, i noticed the heatshrink too but as long as it does the job thats ok.

[HYDROJERRY]

an ebay seller has one that looks exactly like it and the front of the strut has a nose peice looks more arrowdynamic, a complete kit think im going to get one when im ready.....

[Fluid]

IME - twenty years worth - inline prop/rudder setups have no advantages over placing the rudder to the right of the prop. On the extremely narrow German hull designs they might help a little in keeping the boat from rolling over, but those hulls simply have to slow down to turn anyway. The disadvantages of inline rudders are twitchy running on the straights due to aerated water hitting the rudder, difficult prop removal, and high sensitivity to rudder input.

Boaters with limited experience seem to think that an inline setup is required to turn well in both directions. Nothing could be further from the truth. All the cat hulls I've played with (none of the narrow German designs) turn plenty well enough to the left when the rudder is mounted to the right of the prop and closer to the transom.

The main positive to the inline setups are a closer-to-scale appearance and the ability to mount on tiny transoms. The former is important to many boaters and that's fine - just don't believe anyone who says that is the only way to successfully rig most cats.


.

[ezhitz]

Fluid thanks for your input I thought i read that before about inline being more sensitve.Years back i ran a old dumas hotshot tunnel converted to inboard 3.5 nitro and turned either way great with offset rudder.

[Jesse J]

Hey Jay -
I found one advantage - if your drive line fails you have a safeguard to losing your stub/drivedog/prop/propnut. I have broken several wire drives in my 27" cat before I smoothed out the bend in the stuffing tube. Since, I have thought about switching to offset rudder. I have experienced that twitching you are talking about and it is a little unnerving at speed. I have the black inline one I got from OFE, but will be converting to offset. I guess the advantage would only be in effect during the trials but in the end, off set rudder is the way to go.