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Old 04-06-2012, 07:00   #31
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Re: Bow Thruster

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Originally Posted by DSDman View Post
I wish there were some dang numbers on the pump...there is not. I was hoping someone on here might have had a lamborgini pump in the past or know someone who had. Talking with a couple of guys who know something about hydraulics and they say to buy a bigger pump that is variable and I can turn the flow rate and pressure up or down to maximize the motor and prop efficiency. To fast and the prop cavitates to slow and not enough thrust.

Google click on the blue Google then

Take your pick
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Old 04-06-2012, 20:37   #32
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I called a parker rep today. I'll see what he comes up with and go from there.
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Old 05-06-2012, 03:35   #33
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Re: Bow Thruster

Great I hope it goes well for you. Personally I would contact at least 3 so that I might get a general consensus.
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Old 10-07-2012, 14:12   #34
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Just an update to this thread for those pondering the bow thruster question. I have given up for the time being. I can't find one person in my area willing to come out and tell me what I actually need. Grainger has all sorts of hydraulic pumps but I still have been unable to find and expert willing to share info. Heck I cant even find another boat with a similar system I could just copy. I still refuse to pay 8000 + dollars to a vestus dealer to do it for me. Don't actually have it, so not really a choice. Hydraulics just are not that complicated and it's frustrating me that I can't solve this problem or find a boat that I can copy.
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Old 10-07-2012, 14:39   #35
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Re: Bow Thruster

Perhaps you can get a used electric snowplow pump with power up and down for real cheep. Then you can power it up and see if it works. The hoses won`t cost much to fit. If it does not work then you throw it back on Craig`s list or eBay and get your money back. I`m sure it will produce enough volume and probably draw about the same amps.
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Old 10-07-2012, 19:35   #36
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Quote:
Originally Posted by DSDman
Just an update to this thread for those pondering the bow thruster question. I have given up for the time being. I can't find one person in my area willing to come out and tell me what I actually need. Grainger has all sorts of hydraulic pumps but I still have been unable to find and expert willing to share info. Heck I cant even find another boat with a similar system I could just copy. I still refuse to pay 8000 + dollars to a vestus dealer to do it for me. Don't actually have it, so not really a choice. Hydraulics just are not that complicated and it's frustrating me that I can't solve this problem or find a boat that I can copy.
Couple of queries:
Are you driving the anticipated pump with the propulsion motor, genset or dedicated power pack? If the main motor, from the PTO or do you have or can you use a live drive off the gearbox?

Will you use hydraulics just for the thruster or for the anchor windlass also?

You want manual or electric control?

Any hoses in place at the moment?

Might be easier to plan on pulling the motor off and get it assessed commercially - would give you specs and service combined. Once you know that end then you can hunt up a pump to suit. You probably will need it serviced anyway. If too expensive you can hunt up a replacement on ebay
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Old 10-07-2012, 20:15   #37
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Re: Bow Thruster

Couple of queries:
Are you driving the anticipated pump with the propulsion motor, genset or dedicated power pack? If the main motor, from the PTO or do you have or can you use a live drive off the gearbox?
Propulsion motor, 135 hp perkins 6.354, not sure if it has a live drive or not. It looked like the pump was driven off a pully from the front of the motor. There is a pic of the front of the motor on an earlier post.

Will you use hydraulics just for the thruster or for the anchor windlass also? For now just the Thruster, windlass is electric.

You want manual or electric control? Electric probably, but not married to either idea. I actually like the idea of no electrical parts to fail.

Any hoses in place at the moment? Well, they are there but rotten.

Might be easier to plan on pulling the motor off and get it assessed commercially - would give you specs and service combined. Once you know that end then you can hunt up a pump to suit. You probably will need it serviced anyway. If too expensive you can hunt up a replacement on ebay. It was checked out and serviced two years ago according to PO. No details from them though on specifics. Good idea though and I may do that on pulling the motor and riding it around since I can't get anyone to travel out.
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Old 10-07-2012, 20:51   #38
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Quote:
Originally Posted by DSDman
Couple of queries:
Are you driving the anticipated pump with the propulsion motor, genset or dedicated power pack? If the main motor, from the PTO or do you have or can you use a live drive off the gearbox?
Propulsion motor, 135 hp perkins 6.354, not sure if it has a live drive or not. It looked like the pump was driven off a pully from the front of the motor. There is a pic of the front of the motor on an earlier post.

Will you use hydraulics just for the thruster or for the anchor windlass also? For now just the Thruster, windlass is electric.

You want manual or electric control? Electric probably, but not married to either idea. I actually like the idea of no electrical parts to fail.

Any hoses in place at the moment? Well, they are there but rotten.

Might be easier to plan on pulling the motor off and get it assessed commercially - would give you specs and service combined. Once you know that end then you can hunt up a pump to suit. You probably will need it serviced anyway. If too expensive you can hunt up a replacement on ebay. It was checked out and serviced two years ago according to PO. No details from them though on specifics. Good idea though and I may do that on pulling the motor and riding it around since I can't get anyone to travel out.
What is the internal ID of the tubing leftovers?

Yes - pull off the pump and check it out. Probably find numbers but easy to get it looked at over the counter. If it was serviced 3 years ago, find the company who did the work and get details - they probably will advise specs.

Is it an easy run from engine to helm and then to thruster? If not then solenoids will be better.
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Old 10-07-2012, 21:27   #39
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Re: Bow Thruster

There's a new type of hydraulic pumps from BoshRexroth I think that can adjust automaticly their displacement whats needed. Might take a look at those.
You better to contact some agri-maintenance mechanics, they can propably say the best quess you can get anywhere.. Just IMHO
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Old 11-07-2012, 02:20   #40
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Re: Bow Thruster

Ok DSDman, Years ago in my youth I was a hydraulics engineer and I've designed power units and mobile systems o both sides of the atlantic. Someone earlier gave youths formula for sizing the pump. You have two ways you can go
1- fixed displacement pump and then a directional valve to control the flow. This will require a suitable sized oil tank, filter and some type of power item for the pump - can be driven by an electric motor or a PTO(power take off) on you diesel engine (assuming the engine has a PTO). The benefit here is that if you size the pump correctly you can add more work options as time goes by - hydraulic winches, anchor winch etc etc etc.

2- Get a variable volume over center pump - this is a pump where you can control the amount of oil the pump produces and you also can reverse the pumping action so the suction side becomes the pressure side and vice-versa. No valving needed, just a small tank and small filter.

Which is best? Variable volume is probably more expensive - fixed volume is simpler.

I don't know if they still exist but Cessna made some inexpensive variable volume pumps back when I was in the game

Here is the link to Lamborgini in Italy. If you can get a part number off the motor they can help size a fixed volume pump

s.p.h.p. hydraulic external gear pumps lamborghini

Hydraulics are great and while the oil will eventually heat up - you can use a hydraulic thruster for much longer.

PM me if you need more help - but I've been out of the game for a lot of years now
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Old 11-07-2012, 06:39   #41
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Re: Bow Thruster

Contacting agriculture equipment mechanics was already suggested and I think is a very good idea. I would add to it a suggestion to check with lab folks at a mechanical engineering dept. of a local university - if there is one nearby to you. Often, advice in such places may be given for free, as those folks like to solve puzzles
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Old 11-07-2012, 07:04   #42
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Re: Bow Thruster

Remember that when you are most likely to use a bow thruster is when your engine is likely to be running at or near idle (when docking or leaving a dock). You will not have much hydraulic power unless you shift into neutral and rev up the engine. A complication of actions at a time when you need to be concentrating on getting the boat safely onto or off of a dock.

Most power boats that have hydraulic bow thrusters have a pump mounted on the generator so that the helmsman does not have to worry about shifting in and out of neutral, revving the engine, going back to idle, shifting again, etc. The other option is if the boat has two propulsion engines then one can be left running out of gear at high idle while docking etc. But then twin engine boats rarely require a bow thruster.

Have you determined what you will use for an alternate pump in slow speed operations?
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Old 11-07-2012, 16:38   #43
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Re: Bow Thruster

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Remember that when you are most likely to use a bow thruster is when your engine is likely to be running at or near idle (when docking or leaving a dock). You will not have much hydraulic power unless you shift into neutral and rev up the engine. A complication of actions at a time when you need to be concentrating on getting the boat safely onto or off of a dock.

Most power boats that have hydraulic bow thrusters have a pump mounted on the generator so that the helmsman does not have to worry about shifting in and out of neutral, revving the engine, going back to idle, shifting again, etc. The other option is if the boat has two propulsion engines then one can be left running out of gear at high idle while docking etc. But then twin engine boats rarely require a bow thruster.

Have you determined what you will use for an alternate pump in slow speed operations?
I agree with the above. You will need a pump which has enough capacity at idle/low revs to supply your thruster needs. With your Perkins motor you should be able to do this OK - just need a bigger pump than one which is aimed at 1500 rpm like you might have mounted on a genset.
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Old 12-07-2012, 02:07   #44
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Re: Bow Thruster

Obviously a small power unit driven by your batteries or a genset will give you more flexibility. There used to be a company called "stones" that made a small integrated power unit (pump, valve, tank ,electric motor) that was the size of a small suitcase. It was made for the truck market which means it was mass produced and therefore not horrifyingly expensive.

When you size it (or anything else) just remember that rule-of-thumb is you lose 15% of total power every time you change and 10% for friction (volumetric and mechanical energy losses) meaning if you need say 10HP at the hydraulic motor turning your thruster, add 10% for hoses, valves and fittings (now 11HP) add 15% for efficiency loss at the pump (now 13HP) and add 15% for losses you incur when going from electric motor to hydraulic pump (now 15HP).
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Old 12-07-2012, 04:23   #45
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This is good info all, thanks for helping out. I did talk to another thruster installer yesterday...he really thought electric the way to go but price on the hydraulic 13000 dollars! I have a hard time believing that. The pump info is good I will do some research on those types. Like I've said before I have options on how to mount the pump and drive it, in that I do have a 16kw generator or the engine motor.
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