[PSUBS-MAILIST] actuators

Thu Jul 5 19:14:34 EDT 2018

 Cliff, thank you, my wife and I enjoyed meeting you as well and the tandem dive was a once in a lifetime event .  I will not make the mistake of flashing my lights at you at depth again .  Or at least I will bring welding goggles next time lol.I am going to experiment with the actuators and I think I will make an oil passage way past the acme nut.Gamma's trailer is also getting a modification.  I can add a pullout hitch extension of 10 feet without any trouble.  I am spoiled here with steep ramps, so a pull out extension will be nice when I am faced with less steep ramps when I am out of town.I will give up on my coms and buy an OTS system.I plan to add a low pressure compressor to blow ballast at the surface to conserve HP air.After the entanglement  problem David had, I want to add 1\4 inch screen to the bottom side of my vertical thrusters.Other than what I mentioned I think Gamma is perfect, it was reliable and handled passenger changes in waves quite nicely.On to the next project.Hank
    On Thursday, July 5, 2018, 7:49:56 AM MDT, Cliff Redus via Personal_Submersibles <personal_submersibles at psubs.org> wrote:  

 Hank, it has been awhile since I played with the Lenco trim actuators but to the best of my memory, it was uniformly slower both when extending and retracting.  If the tear down was as I remember, the DC motor was high speed with a significant set of reduction gears.  On the motor was a fan with lots of small blades to cool the motor.  My working hypothesis is that this fan was designed for air not light oil.  As such, even with the low viscosity oil I was using, the drag caused by this fan operating in oil would be dramatically higher than for air.  I think this caused the motor to consistently spin slower than with oil, this the reduced stroke speed by extending or extracting.  I never tried this but if this was indeed the cause of reduced speed and not oil lifting the brushes off, then an easy fix would be to remove the fan or fan blades.  I think the cooling would be adequate given the low duty cycle particularly while submerged. With the fan removed you would have to limit use out of surface to keep from overheating the motor.   
OAS, I enjoyed meeting you and your wife and learned some things that I will implement on my boat.  I particularly like the your trailer setup for launch and retrieval.  My new goal is to launch and retrieve by boat like Hank!  This will entail two trailer mods.  The first is I am going to weld a 4x4 by 10 extension just aft of my hitch.  Maxi has a boat we use for a tender so I don't need the dingy and as such don't need a wide platform.  The second modification is that I am going to install two Lenco trim liner actuators on my "Y" yoke at the stern end of my trailer and run these of the trailer emergency brake battery.  This will enable me to lock in the stern of the boat without having to fiddle around in the water with straps.  After the boat has been cradled and pulled out of the water and away from ramp, I can then attach straps.  These changes should dramatically reduce my launch and retrieval time.  I may end up using a larger trailer 12V battery than what comes with the electric brakes.  I am also going to permanently attach a kit box on the extension that I can stow straps, chocks, tire tools, small floor jack plus miscellaneous spare parts.   Given that my new trailer brakes failed about an hour out of Lake Tahoe, I am going to look into adding electric brakes to the second axle.
On the negative side this new arrangement will impose a minimum boat ramp angle that I can launch from.
One of the highlights of the trip for me was the dive we made on Tuesday together.  I got a kick out of seeing your boat as we descended.  I got one little video clip from Alec of us at about 100 ft.  Hoping to get more.
Best Regards
Captain Redus

On Thu, Jul 5, 2018 at 6:33 AM, hank pronk via Personal_Submersibles <personal_submersibles at psubs.org> wrote:

 Cliff,Was the reduced speed of stroke in both directions?Hank
    On Wednesday, July 4, 2018, 7:29:46 PM MDT, Cliff Redus via Personal_Submersibles <personal_submersibles at psubs. org> wrote:  

 I used small plastic accordion shaped reservoirs, one per actuator.  Worked ok but oil seemed to make them stroke slower.  I had them place on control surfaces for first Islamorada psub convention.  Dives were shallow.

Sent from my iPhone
On Jul 4, 2018, at 3:42 PM, hank pronk via Personal_Submersibles <personal_submersibles at psubs. org> wrote:

Hi Cliff,At Lake Tahoe, you mentioned that you oil compensated your Lecno actuator.  Did you use a bladder reservoir?  Did you have any time in the water with the actuator under pressure?  thanks'Hank

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