Reply
 
Thread Tools Search this Thread Display Modes
 
Old 09-18-2020, 11:16 AM   #1
Veteran Member
 
Turtle Blues's Avatar
 
City: Chesapeake Bay
Country: USA
Vessel Name: High Noon V / SV Evelyn
Vessel Model: Golden Star 42 / Ericson 30 / Yard full of trailer boats
Join Date: Mar 2020
Posts: 37
Proper Sizing for Octopus Pump

Need some help on choosing the right size Auto Helm Pump.

So my steering ram size 17.7ci /290 cc puts me at the high end of the AF1212 and starting range of the AF2012 piston pump.
Thinking the 14.5 second hard over calc for the 1212 does not leave much in reserve. The calc for the 2012 would put me at 8.7 seconds at full volume however the application chart says adjustable to 15 seconds which would be ideal.
Leaning toward the 2012 but want to make sure this is not oversizing.
Would like to hear from anyone that has done this. Thanks
__________________
Advertisement

Turtle Blues is offline   Reply With Quote
Old 09-21-2020, 09:02 PM   #2
Veteran Member
 
Turtle Blues's Avatar
 
City: Chesapeake Bay
Country: USA
Vessel Name: High Noon V / SV Evelyn
Vessel Model: Golden Star 42 / Ericson 30 / Yard full of trailer boats
Join Date: Mar 2020
Posts: 37
Maybe an easier question to ask.
For a twin engine heavy trawler in the 40 to 45 foot range what size pump do you have?
__________________

Turtle Blues is offline   Reply With Quote
Old 09-21-2020, 10:44 PM   #3
Moderator Emeritus
 
ksanders's Avatar
 
City: SEWARD ALASKA
Country: USA
Vessel Name: LISAS WAY
Vessel Model: BAYLINER 4788
Join Date: Feb 2011
Posts: 4,705
First lets think how the pump works, as that will help you decide, since either pump will do the job.

A Autopilot pump is simply a 12 volt pump that changes direction by reversing polarity of the power.

There is no variable power here. The pump is either off, or pumping.

If you go with a slower pump, you will simply get slower corrections. This can feel smoother but it can also be slow to react in situations where you would want quicker reactions, for example in a heavy quartering sea.

If you go with the faster pump you will get the faster reactions you would want in a heavy sea, but you will get faster reactions in a calm sea as well.

The good thing is that your autopilot computer will learn how your boat reacts to overcome the tendency to overshoot that a fast pump would provide.

On my boat with my steering ram I was near he upper end of the smaller pump and went that way. Like you I could have went with the higher capacity pump and would have been just fine as well.
__________________
Kevin Sanders
Bayliner 4788
Seward, Alaska
ksanders is offline   Reply With Quote
Old 09-21-2020, 11:00 PM   #4
Guru
 
Comodave's Avatar
 
City: Au Gres, MI
Country: US
Vessel Name: Never Say Never
Vessel Model: President 41 DC
Join Date: Jul 2015
Posts: 9,409
Have you contacted the manufacturer and get their recommendations. That is where I would start. They should be the experts...
__________________
Boat Nut:
If you are one there is no explanation necessary.
If you arenít one, there is no explanation possible.
Comodave is online now   Reply With Quote
Old 09-22-2020, 07:28 AM   #5
Veteran Member
 
Turtle Blues's Avatar
 
City: Chesapeake Bay
Country: USA
Vessel Name: High Noon V / SV Evelyn
Vessel Model: Golden Star 42 / Ericson 30 / Yard full of trailer boats
Join Date: Mar 2020
Posts: 37
Guys,
Thanks for the assist.
Yes, the reaction time is the critical factor. The 15 seconds that the manufacturers literature says to calculate for seems a little lethargic, but appears to be the standard.
Yes, have sent the question to Octopus through their website but no response to date. Probably should repeat.
Turtle Blues is offline   Reply With Quote
Old 09-22-2020, 09:15 AM   #6
Guru
 
OldDan1943's Avatar
 
City: Aventura FL
Country: USA
Vessel Name: Kinja
Vessel Model: American Tug 34 #116
Join Date: Oct 2017
Posts: 6,101
Can the steering reaction be adjusted within the autopilot control unit?
__________________
The meek will inherit the earth but, the brave will inherit the seas.
OldDan1943 is online now   Reply With Quote
Old 09-22-2020, 10:01 AM   #7
Veteran Member
 
City: Seattle
Country: US
Vessel Name: Antares
Vessel Model: Canoe Cove 42 Sedan
Join Date: Dec 2015
Posts: 34
I installed an Octopus pump on our last sailboat. It was an adjustable model. I set the response time as suggested. That worked great for what we needed. It was not too difficult to reset if we found the response too slow or fast. I thought the Octopus pump was one of the best things we added to that boat.
Antares is online now   Reply With Quote
Old 09-22-2020, 08:10 PM   #8
Veteran Member
 
Turtle Blues's Avatar
 
City: Chesapeake Bay
Country: USA
Vessel Name: High Noon V / SV Evelyn
Vessel Model: Golden Star 42 / Ericson 30 / Yard full of trailer boats
Join Date: Mar 2020
Posts: 37
Dan,
Yes,I am driving the pump with a Raymarine SPX 30 and ST70 Autopilot so the system has a learn program and 9 sensitivity settings for most functions.
Antares,
Thanks for the . seems that anyone who has one is happy with it so that's a definite plus.
Turtle Blues is offline   Reply With Quote
Old 09-23-2020, 08:41 AM   #9
Veteran Member
 
Turtle Blues's Avatar
 
City: Chesapeake Bay
Country: USA
Vessel Name: High Noon V / SV Evelyn
Vessel Model: Golden Star 42 / Ericson 30 / Yard full of trailer boats
Join Date: Mar 2020
Posts: 37
Received factory confirmation to go with the larger pump this AM.
Will update with commissioning results.
Thanks to all
__________________

Turtle Blues is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 07:48 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012
×