porpoising

Aircraft powered airboat discussion.
Post Reply
arbtmn
Southern Airboat Member
Posts: 49
Joined: Wed Jun 10, 2015 6:18 pm
Location: slidell louisiana

porpoising

Post by arbtmn » Sat Dec 05, 2015 7:55 am

Hello Everyone. I recently pick up my boat from alumitech and I love it. It is powered by a lycoming 360 and is presently at the aircraft shop getting rigged up with cables, etc. Can someone tell me what makes for a good throttle set up? I want to use a boat type throttle and not the foot. Also can someone explain the bolts under the main frame that are used to adjust porpoising? I don't understand how they work. I was told to snug them up before I put the boat in the water. If it porpoises I was told to first snug up the ones in the front about have turn and do the same for the other three bolts in the rear.
Marty

Gary S
Site Supporter - I
Site Supporter - I
Posts: 1646
Joined: Wed Mar 03, 2010 3:30 pm
Location: Redlands

Re: porpoising

Post by Gary S » Sun Dec 06, 2015 7:04 am

Why do you want a hand throttle? I take it this is your first boat. You are constantly going to have to make engine adjustments from just a little up or down to full stop to wide open. you are also already using your left hand to steer, in a emergency when you need to adjust the throttle, (like wide open} turn and hang on, what are you going to use to hang on with
You need to find someone close to you to help you learn about your boat. I don't want to sound like I am putting you down because everyone has to start somewhere. But you have a boat that has the potential to kill you and others. Find someone close by. You didn't fill in your profile so no one knows where you are, but there are a lot of good people on these pages that can make this safer for you and your passengers
Which brings me to my next rant. Please don't invite all your friends and family to go airboating until you go solo for a few trips to get the hang of it. A airboat is different and little things can screw you up. So you don't need extra people on the boat helping you to screw it up.
The jacks in the bottom of the boat change the shape of the bottom. They also can just keep it from changing. So do like you said and snug them up and go try it. And be safe and have fun.

User avatar
Planeguy
Southern Airboat Member
Posts: 179
Joined: Sun Sep 06, 2015 4:49 pm
Location: OK

Re: porpoising

Post by Planeguy » Tue Dec 08, 2015 8:48 am

Gary has outlined some very good reasons not to run a standard motorboat throttle. If you want to control power with your hand you might consider connecting it to the steering stick. Forward to go, back to stop, left to turn left and right to turn right. My father swears that is the best setup he has ever used. All he has ever done is river running in Nebraska and most of his boats you sat down in the hull instead of 2-4 feet above it. If I remember correctly (it's been over 40 years), his first airboat had a steering wheel with a standard motorboat throttle and it was not a popular option for him.

Another option would be a squeeze lever or twist throttle on the stick but I think if the ride got a little too interesting a person might tighten their grip instead of letting go. A thumb lever like on an ATV or snowmobile might work okay though.

arbtmn
Southern Airboat Member
Posts: 49
Joined: Wed Jun 10, 2015 6:18 pm
Location: slidell louisiana

Re: porpoising

Post by arbtmn » Sat Dec 12, 2015 8:48 am

good points. I thought I could hang on easily since my throttle would have some sort of friction lock (cruise control) for longer distances. I could easily and rapidly bring the throttle back to 0 and hold on. Anybody know of a good aluminum welder in the slidell area? I would like a couple of additions to my boat like trolling motor mount, some handles in the front, etc. Thanks
Marty

User avatar
goldhunter_2
Site Supporter - III
Site Supporter - III
Posts: 8953
Joined: Mon May 23, 2005 7:17 pm
Location: Port Saint Lucie Fl

Re: porpoising

Post by goldhunter_2 » Sat Dec 12, 2015 1:32 pm

a regular boat throttle will get someone hurt as already mentioned

I have used a jetski throttle on top the stick it worked very well, The only limitation was I couldn't rig a front & back drivers seats only rear because of cable lengths

http://southernairboat.com/photopost/da ... _1_jpg.JPG
Image
.


Support our future , get a kid involved in the outdoors!!

:rebel:



.

User avatar
jopete
Site Supporter - II
Site Supporter - II
Posts: 977
Joined: Mon Mar 30, 2009 8:07 am
Location: loreauville, la

Re: porpoising

Post by jopete » Sat Dec 12, 2015 2:24 pm

if you run the ground or the woods, a boat style throttle will have that new boat broke up in a short time. the boat will go from left to right while sliding over roots/trees in a instant, and if u don't lift off the gas immediately, u gonna have to get out the chainsaw and possibly a new set of drawers. lol

best of luck with the boat!!!!

User avatar
glades cat
Site Supporter - III
Site Supporter - III
Posts: 3039
Joined: Mon Jan 22, 2007 2:36 pm
Location: Miami, Fl

Re: porpoising

Post by glades cat » Sat Dec 12, 2015 8:50 pm

Airboat throttles should be a dead-man type that is automatically closed by springs. In the event the operator is separated from the craft the throttles will close automatically. The most familiar and widely used are foot operated because it has become an instinctive control method to most everyone who drives a vehicle. More than one spring should be used to close the throttles.
Gary made good suggestions to becoming proficient with the airboat before loading up the SS Minnow on a 3 hr cruise with family and friends. Be safe and the fun will follow.
"Leave a legacy...Preserve the irreplaceable"
12' x 7' sled built by Scorpion, Cont. O-470-K, 72" Whisper Tip
Rigged by Gladescat & sons in 2009

JohnnyBravo
Site Supporter - V
Site Supporter - V
Posts: 212
Joined: Sun Mar 28, 2010 5:28 pm
Location: Ocala, Florida

Re: porpoising

Post by JohnnyBravo » Sat Dec 19, 2015 3:39 pm

Everybody's different but I would not recommend that set up. Heck it's hard enough to run with the dang
regular gas pedal sometimes with my fat butt bouncing around the seat running dry.
Lol! Good luck with your build.

JohnnyBravo
Site Supporter - V
Site Supporter - V
Posts: 212
Joined: Sun Mar 28, 2010 5:28 pm
Location: Ocala, Florida

Re: porpoising

Post by JohnnyBravo » Sat Dec 19, 2015 3:48 pm

Everybody's different but I would not recommend that set up. Heck it's hard enough to run with the dang
regular gas pedal sometimes with my fat butt bouncing around the seat running dry.
Lol! Good luck with your build.

User avatar
Southern Style
Site Supporter - IV
Site Supporter - IV
Posts: 5239
Joined: Mon Oct 06, 2008 3:34 pm
Location: Sarno marsh

Re: porpoising

Post by Southern Style » Thu Jan 14, 2016 7:40 pm

I was actually sitting here on the couch trying to pretend driving with hand throttle... WOW, brave man... I could not get the concept down.. LOL.. I agree, running dry, between trees, bouncing off things you cant see under tall grass, and that stick is gonna be going crazy.. Foot throttle has been basic since learning to drive a car.. I will stick with foot controls.. I would understand if you were disabled and a hand throttle was all you could operate, I would say have at it !!! But man, thats awkward, at least to me. to each his own.. Good luck, let us know how the build goes.. Be safe..
DONT ARGUE WITH STUPIDITY...THEY WILL JUST DRAG YOU DOWN TO THEIR LEVEL, AND BEAT YOU WITH EXPERIENCE.....
KRVSA Member
SJRAA Member
KCCO

AceNtheHole
Southern Airboat Member
Posts: 82
Joined: Wed Feb 25, 2015 7:36 pm

Re: porpoising

Post by AceNtheHole » Thu Jan 14, 2016 8:09 pm

Sympathetic reaction! Whatever your left arm and hand do in an emergency situation, it's likely your right arm and hand will follow. That's not good for an airboat application. Stay with a foot throttle.

User avatar
Waggs
Site Supporter - II
Site Supporter - II
Posts: 899
Joined: Mon Jul 21, 2008 5:50 pm
Location: Clermont, FL

Re: porpoising

Post by Waggs » Thu Jan 14, 2016 10:19 pm

One big observation I made from your comments OP, was you said you could pull the throttle back to "0" and hold on. There is absolutely "0" steering with the throttle at "0". This is one of the most important safety items to keep in mind. No air across the rudders equals no steering.

My opinion would be to sell it, there's already too many airboats out there. As Yogi Berra said "nobody goes there anymore, it's too crowded..."
12.5' Predator, O320H2AD, 72" Whisper Tip Narrow

Liberty Mechanical Services
Performing all commercial and residential HVAC services
321-689-7709
Making America Cool Again!

KCCO

Doug Murdock
Southern Airboat Member
Posts: 19
Joined: Sun May 26, 2013 6:08 pm
Location: Lake Arenal, Costa Rica.

Re: porpoising

Post by Doug Murdock » Sun Jan 17, 2016 7:14 am

Put a motorcycle throttle on the rudder stick. Problem solved.

User avatar
kwanjangnihm
Site Supporter - IV
Site Supporter - IV
Posts: 1983
Joined: Sat Mar 30, 2013 8:23 pm
Location: Bartow FL

Re: porpoising

Post by kwanjangnihm » Sun Jan 17, 2016 8:07 am

a rudder stick throttle device is subject to branches or limbs impairing control and typically snatching it to a wide open throttle situation

definitely read the above posts and make a sound decision for you, your family and other airboaters

I think billybob uses a hand throttle device - maybe he can chime in :rebel:

Image
" I don't care who you are back in the world, you give away our position one more time, I'll bleed ya, real quiet. Leave ya here. Got that? "

billybob
Southern Airboat Member
Posts: 1424
Joined: Wed Nov 25, 2009 7:34 pm
Location: Lake Alfred, Fl.

Re: porpoising

Post by billybob » Mon Jan 18, 2016 11:24 am

kwanjangnihm wrote:a rudder stick throttle device is subject to branches or limbs impairing control and typically snatching it to a wide open throttle situation

definitely read the above posts and make a sound decision for you, your family and other airboaters

I think billybob uses a hand throttle device - maybe he can chime in :rebel:

Image
Yes I do and because I have to do to paralysis. It is very functional and I have never had any issues with tree limbs or vines hanging it wide open. Easy to do. I will see if I can post a pic later.
I do all my own stunts!!!!!!

Post Reply

Return to “Aircraft Power Only”