[PSUBS-MAILIST] Manipulators
Alan James
alanlindsayjames at yahoo.com
Thu Jan 23 21:27:25 EST 2014
Jim,
I had a lot of discussion with a previous member, Frank Dalgleish, about using linear
actuators underwater. Frank has since passed on.
I ended up with about 8 actuators & pulled a few to bits to try & compensate them.
One of the problems I encountered was that the small motors didn't like the compensating
oil & had what Phil describes as a "herky jerky" movement caused by the brushes being
flung off the commutator by the centrifugal force of the oil. On bigger motors it wouldn't be
such a problem & the spring tension can be changed to compensate, but the small motors
are generally a sealed unit. I had to drill the motor casing to inject oil in to them.
Aside from that; with the piston moving in & out, it is displacing the compensating oil, &
you need a flexible external bag for both this & to maintain the internal pressure at ambient.
Obviously someone has got it right by the link you posted. (posted a link to that a few years back)
You could perfect it, but I think it would be more trouble than its worth as you end up with
something like a hydraulic cylinder anyway except with a hydraulic system you have one motor
for all the cylinders, whereas with linear actuators you have one motor per cylinder.
Cliff replaced his hydraulic cylinders with actuators but they caused him grief at conference.
He may want to comment.
Hope that saved you 200 hrs of research.
Alan
________________________________
From: "jimtoddpsub at aol.com" <jimtoddpsub at aol.com>
To: personal_submersibles at psubs.org
Sent: Friday, January 24, 2014 2:17 PM
Subject: [PSUBS-MAILIST] Manipulators
Vance, Hank,
Moving the thread title back to Manipulators: My intention has been to buy or build an all-electric manipulator instead of hydraulic or pneumatic. Do you have any thoughts on that? Here's one I found online last year:
http://www.youtube.com/watch?v=uY0Qz-CxkBE
Thanks,
Jim
-----Original Message-----
From: Land N Sea <landnsea1 at hawaiiantel.net>
To: Personal Submersibles General Discussion <personal_submersibles at psubs.org>
Sent: Thu, Jan 23, 2014 6:54 pm
Subject: Re: [PSUBS-MAILIST] I am not a dork
Hank,
I was under the impression that pneumatics loose their punch with depth and
that is why people usually go with hydraulics?
Rick
From: hank pronk
Sent: Thursday, January 23, 2014 2:43 PM
To: Personal Submersibles General
Discussion
Subject: Re: [PSUBS-MAILIST] I am not a dork
Rick,
The cylinders are pneumatic but you can use hydraulic if they use an
o-ring for the shaft seal.
Hank
On Thursday, January 23, 2014 5:36:58 PM,
Land N Sea <landnsea1 at hawaiiantel.net> wrote:
Hank,
Do you have any data on the rams that you have and they are hydraulic and
not pneumatic correct?
Rick
From: hank pronk
Sent: Thursday, January 23, 2014 2:12 PM
To: Personal
Submersibles General Discussion
Subject: Re: [PSUBS-MAILIST] I am not a dork
Rick,
The nice thing about a manipulator for a sub is, you want it to be
slow and slow is cheap. Go with big cylinders and a small pump with a
restrictor. It will be so easy to operate it you won't believe
it.
Hank
On Thursday, January 23, 2014 4:57:21 PM,
Land N Sea <landnsea1 at hawaiiantel.net> wrote:
Most of what I plan to use the arm for is for gathering all the gold
doubloons that fell out of Captain Cooks pockets while he was here in Kealakekua
bay wind surfing, but I would settle for an old bottle or two off his ship if I
had to. I was more wondering if I came across an abandoned small anchor or
something else that weighed around 50 Lb.'s or so if it would up end the boat
much? I would rather not use the forward MBT to keep the trim because of having
to dump air at the proper rate while ascending. Tagging it with a line and
letting the guys in the support boat lift it also sounds good but I would have
to master the manip technique.
Rick
From: Vance
Bradley
Sent: Thursday, January 23, 2014 11:20 AM
To: Personal
Submersibles General Discussion
Subject: Re: [PSUBS-MAILIST] I am not a dork
Manips are for manipulating, not lifting. Most light arms can do 50-60#.
for lifting you could hook on a (releasable) cables and lift with the MBTs.
Better yet, take a line down to attach and let your surface crew haul away, or
do what we fit at HBOI and in the North Sea. Take a lift bag down rolled into a
PVC tube with a blow and go hose from your air banks. Hook up, back away to
deploy the bag, inflate and run away (to get out from under the load)
Vance
Sent from my iPhone
On Jan 23, 2014, at 2:27 PM, "Land N Sea" <landnsea1 at hawaiiantel.net>
wrote:
I am planning on fabricating my own manipulator for my K-350 that will be hydraulic and was wondering if anybody that had experience using one on a boat that size would be able to let me know about how much an arm would be able to pick fully extended and if a VBT up forward was mandatory to keep the trim.
>I am planning on making the manipulator out of two sections, each about 2’ long giving me a 4’ reach fully extended which will get me out just past my forward MBT.
>I realize that the lifting capacity is based on a number of things like the rated capacity of the rams and where they are attached to the arms so if you know that as well that would be great. It’s freezing here on the big Island! I woke up to a chilling 54 degrees and had to put on a sweat shirt just to walk up to my shop.<wlEmoticon-sadsmile[1].png>
>
>Rick
>
>From: hank pronk
>Sent: Wednesday, January 22, 2014 1:43 PM
>To: Personal Submersibles General Discussion
>Subject: Re: [PSUBS-MAILIST] I am not a dork
>
>Alan,
>Yes I could spring load it, It does take some effort to pull the fingers open. The oil has to travel through a pretty small line and all I have here is a pail of 5/30 and that is a bit heavy. I don't heat my shop at night so it gets chilly by morning.
>Hank
>
>
>
>On Wednesday, January 22, 2014 4:34:35 PM, Alan James <alanlindsayjames at yahoo.com> wrote:
>
>Hank,
>can you mount a wedge somewhere so you can push the manipulator grippers up against
>it to wedge them open? Or have a compression spring temporarily mounted across the grippers?
> You could hang some plastic fish from the garage roof to add a bit of realism.
>Alan
>
>
>
>
>
>From: "vbra676539 at aol.com" <vbra676539 at aol.com>
>To: personal_submersibles at psubs.org
>Sent: Thursday, January 23, 2014 11:09 AM
>Subject: Re: [PSUBS-MAILIST] I am not a dork
>
>
>Hey, she's a banker. It's all black or white with them. Except for the ones with mad manibubators in the shop out back, one supposes.
>
>
>
>-----Original Message-----
>From: hank pronk <hanker_20032000 at yahoo.ca>
>To: Personal Submersibles General Discussion <personal_submersibles at psubs.org>
>Sent: Wed, Jan 22, 2014 4:37 pm
>Subject: Re:
[PSUBS-MAILIST] I am not a dork
>
>
>The only problem is, Gamma's manipulator has a power only to close gripper. The gripper opens with outside water pressure pushing against it. So I have to jump out of the sub to open the gripper each time. I was trying to explain this to my wife and she replied "can't you just put it in a pail of water" I am still laughing inside of coarse :-)
>Hank
>
>
>
>On Wednesday, January 22, 2014 2:03:46 PM, Michael Holt <mholt at ohiohills.com> wrote:
>
>On 1/22/2014 2:57 PM, Alec Smyth wrote:
>> That is indeed a very necessary practice, but for it
to work properly
>> you also have to make loud "AOUUUUUGAH"
klaxon sounds every so often,
>> to indicate diving and
surfacing!
>You're right: you gotta have the right sounds.
I have a friend who used
>to sit in the incomplete fuselage of
his biplane in his garage, making
>airplane-engine noises.
>
>
>M
>
>---
>This email is free from viruses and malware because avast!
Antivirus protection is active.
>http://www.avast.com/
>
>
>_______________________________________________
>Personal_Submersibles mailing list
>Personal_Submersibles at psubs.org
>http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>
>
>
>_______________________________________________
Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>
>_______________________________________________
>Personal_Submersibles mailing list
>Personal_Submersibles at psubs.org
>http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>
>
>
>
>_______________________________________________
>Personal_Submersibles mailing list
>Personal_Submersibles at psubs.org
>http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>
>
>
_______________________________________________
>Personal_Submersibles mailing list
>Personal_Submersibles at psubs.org
>http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>
_______________________________________________
>Personal_Submersibles mailing list
>Personal_Submersibles at psubs.org
>http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>
_______________________________________________
Personal_Submersibles mailing list
Personal_Submersibles at psubs.org
http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
_______________________________________________
Personal_Submersibles mailing list
Personal_Submersibles at psubs.org
http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
_______________________________________________
Personal_Submersibles mailing list
Personal_Submersibles at psubs.org
http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
_______________________________________________
Personal_Submersibles mailing list
Personal_Submersibles at psubs.org
http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
________________________________
_______________________________________________
Personal_Submersibles mailing
list
Personal_Submersibles at psubs.org
http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
_______________________________________________
Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
_______________________________________________
Personal_Submersibles mailing list
Personal_Submersibles at psubs.org
http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.whoweb.com/pipermail/personal_submersibles/attachments/20140123/169a9a0c/attachment-0001.html>
More information about the Personal_Submersibles
mailing list