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View Full Version : Hydraulic steering question from a dummy...



Lenny
06-08-2006, 08:06 PM
What limits the travel on a single/dual system? I am putting two rams (external) on my 280 Volvo. Obviously there is a lock-to-lock point, but knowing (what little) I do about hydraulic rams on anything, what is stopping the ram from, be it one pushing and one pulling, just snapping off the drive from the gimbal due to their own power? Is it the actual "compression/expansion" limit of the ram itself or does it quit (or want to) once at "lock" and the gimbal resistance?

Or, is this a function of the length of the ram itself and its' available throw?

Do you measure the distance from (in this case) the wingplate, and how far it travels from full left to full right, calculate this distance, then allow for the angle of attack due to transom location, and buy rams that suffice the lengths required?

Mechanical apptitude in it's infancy,... Lenny :D

Mr X
06-08-2006, 08:21 PM
Do you measure the distance from (in this case) the wingplate, and how far it travels from full left to full right, calculate this distance, then allow for the angle of attack due to transom location, and buy rams that suffice the lengths required?


Yes, exactly.

You "aint" no dummy in my book! :biggrin.:

DonCig
06-08-2006, 10:29 PM
Ted, I have not known Lenny for a long time, but if I had a need to put a man on the moon, have him drive a boat around the moon, have him make a phone call to B.C. that he was coming home for dinner, and have him show up 5 minutes early fashionably late for dinner.
This man would be on the short list of available candidates!

Don

yeller
06-09-2006, 12:00 AM
Maybe you didn't think so, but that was a good question Lenny. I'll be installing hydraulic soon myself and I never even thought about snapping the gimbal with too long of a ram. :bonk:
Rick's bringing my sytem to Powell for me. :yes:

BTW: we gonna get pics of this project. You promised us detailed documention. :D

BigGrizzly
06-09-2006, 11:21 PM
Lenny there are no stupid questions just stupid answers. A dome question is one that is asked that you already know the answer to. The answer to the question is Don't make the throw of the ram longer than the travel of the outdrive. The rams stop at the end of their respective travel either single or dual ram. The only time you get into trouble is if the rams are not centered. In all ram systems I have encountered the push overides the pull. Hope this helps.

smoothie
06-11-2006, 08:46 PM
Lenny,I would first find out where I could mount my transom brackets so they dont interfere with anything inside the transom with the standard length rams, you only have a 7" to 10" stroke to choose from,and keep em on the centerline of the drive shaft.I made one closed and one opened out of cardboard to see if I cleared my stringers,trim taps and exhaust tips...

MOP
06-11-2006, 10:00 PM
Lenny you have brought up an interesting point, but I would bet that many systems push the drives to the stops. The only time you will hit the stops is at low maneuvering speeds, when you feel it hit the stops whether it be the rams or the drive stops you will stop turning the wheel. Even if you did hang heavy on the wheel I doubt like hell you would damage anything. I can see the dual setup guys checking to see if theirs hit the stops, I bet a bunch of you do and it is pretty much irrelevant!! What I have done in the past is to install the drive cap plate then chock the drive in the center position, collapse the ram and mark the the exposed rod right where it goes into the ram then extend it measure from that mark to the housing to find center of travel. Move the ram to that mark hook it to the drive cap plate and mark the transom, now to give you peace of mind remove the drive chocks and swing the drive full over and extend the ram if it falls short of the marks that will tell you the ram is stopping internally and the drive will not hit its stops. You can always move the marks out board a tad to accomplish this.

Phil

maddad
06-12-2006, 09:14 AM
Lenny, great thread, I'm following it closely because I'll be doing the same thing shortly. If you can, please add as many photos and tips as possible. I'd like to add one question. Big grizz said push will over ride pull. Since dual rams are for safety, what happens when one side fails due to a leak or broken hose? Will the other side maintain control, or will it be affected by the leak or failure in the system? Is there valving in the helm to keep the 2 sides isolated while they work together?
Thanks for helping me better understand this stuff.
:wavey: