Hi all, great forum.

Looking for someone experienced with riggers to give me some help please.

Building a Firefighter outrigger, engine will be stock Chang young F273 27cc. I read these have a little more power than a stock Zen.

Have no problem with build itself in general, more hardware and setup.

1: what size rudder, plans i bought give no guide.
2: what side should rudder be on? i read a build and builder was advised left side, my Tenshock run left side, but i see most gasers run right side?
3: Should strut be straight and on center line? or offset a degree or two?
4: Prop? 6717/3 high lift?
5: What speed can i expect?

Any help appreciated. TIA

gas_rigger

6: center of gravity

thanks

Scott has some experience with this boat, maybe he will chime in. I've never owned one so I can't be of much help.


www.modelgasboats.com

Sent from my iPhone using Tapatalk.

Help where I can ... did one from a kit being loosely based off original design.
See: www.modelgasboats.com/forum/28...rigger--exotic/
Prefer STRAIGHT blade rudders, right side mounted. My FF needed Low/No lift props and excelled with a Spoon cupped ABC 2716-20*/2 running 72-74 mph with a modified RCMK RZ rear X engine. Installed a Side X engine for a spell ( Last picture ) before selling boat.

Hope this helps ? ... need more specific just ask

Oups, seems pictures have been lost ... OK, some fresh uploads

thanks marc

cool boat scott, thanks for your time.

rudder size. looking at one that is 146mm long (measured to water fittings) i guess 160mm overall, 33.5 wide. leading edge of rudder is only 38mm from transom. your rudder looks to be 100mmm or so from transom. which way do i go?

gas_rigger

On the FF ... because rear sponsons trail so far back, unless rudder is inboard of tubs outside edge blade will interfere with inside edge of sponson.
Set mine up so lead edge of rudder was BEHIND trailing edge of sponson and very near outside edge of tub where clearance was not an issue.
** This position IMO is not optimal on a rigger feeling rudder in close to transom and prop out behind is better
Getting that relation was not very doable with the FF design so did it like I had done.
It ran and turned just fine likely because prop wash was minimal with the cupping/low lift mods done on it.

thanks scott

which size looks best

scott, got anything on cg

TIA

gas_rigger

As said ... likely first rudder assm shown.
C/G in riggers really is one of weight distribution and design of hull needing/wanting prop weight or not ?

4 point riggers such as the FF generally not as critical having what it is ... what it is
You manufacture or mount turn fin and it's brackets relative to where C/G ends up.

** IMO, the turn fin design chosen pretty much needs to get mounted so the water passing along fin at surface places hull RTR C/G @ on fins rear 1/3

Picture shown of hulls side profile has the C/G very rear the rear motor mount bolts.

thanks scott.

cg important not just for performance but needed during construction to get engine in corect location. being heaviest item in boat its influence on cg is pretty large.

i see reference to 50/50 60/40. my tenshock miniY runs 60/40. I see the jae riggers run a similar cg. mounting all gear as far forward as recommended for firefighter gives me a very forward cg. well ahead of 60/40. i also see alot if ff riggers skiping in turns as if there is not enough weight on rear sponsons. also read one report that ff does not run well on rough water

wondering if i should go 60/40,