Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[Rob47]

Anyone any suggestions on the best way to approach making the side lift of CVA-01 a working item?


Bob

[Leaky]

Could a scissor lift type arrangement do it I've no photos to post but a servo doing a push pull arrangement could operate the legs.

[derekwarner]

Rob....there is certainly extensive trial & error work here in the MBM archives on scissor lifts .....in one of the aircraft carrier build threads .......... Derek

[Rob47]

It’s for a side lift so scissors is no good. I know about the info I put some of it up 😄


Bob

[Leaky]

I'm not too sure from the photos I've looked at because I'm quite drunk but it looks like it moves up side rails with a lifting chain arrangement so could this be replicated by using sail winches pulling it up and down. Or an internal (hidden) scissor lift/lift arms pulling it up and down via chains?

[tigertiger]

Not an expert speaking here.
My thoughts.
Any kind of cable lift would need the platform to have a lot of weight to run smoothly.
Rack an pinion, using a stepper motor (or one at each end) using Arduino to control the end positions would do it.
I have also seen simple circuits with a micro-switch at each end. Have a look at what the aero boys are doing with retractable undercarriages might also throw up some ideas.

[johnv]

Hi Bob it's John V what I have used in the past is a one and a half turn sail winch and made a wooden cam wheel for the end of the sail winch  also use guide rails cheers John V

[Leaky]

The guide fails could also hide a relatively weak return spring to aid either lifting of lowering negating the need to weight the lift

[steamboat66]

if a scissor lift is proven, then put one inside. the lift platform is then mounted on an extension of the top part.

[warspite]

the scissor could be on the inside edge between the guide rails, the bottom centre pivot pin fixed with the other pivot pins allowed to run in a guide rail, as the bottom ends are pulled together the scissors close and extend up, the top ends are in the end of the lift and slide towards the middle.


Another thought is a bike brake cable attached to the underside and as the servo moves through the 90°, extended arms on the servo match the distance needed to travel the lift up and down, the connection to the lift is central between the guide rails to have an equal effect on the lift.

[Rob47]

Scissors is a no go as when lift is down the mech would be seen
Instead of clear access to hangar. Think it will be two winches on Y lead
with the lift supports hanging bearings at each end to aid smooth running in the guides


Bob

[littoralcombat]

My Mate, who is building the USS Constellation at 1/72nd (approx 4.5 metres long), has four of these mechanisms to make operational.
 

He is planning on using two lead-screws for each, located just inside the hull. The cables fore & aft on the outboard corners will be mostly for decoration, being black cotton/twine that will run through multiple sheeves/pullies, but is kept tensioned using longish light springs inside the hull. I am unsure what type of motors he is going to use, or indeed how he is going to keep them synchronised, but will discuss with him this coming Sunday at our Club Sailday......Connie will also be in attendance!
Nige

[gingyer]

See if you can find model boats mag with Paul Bannnons carrier
Builds it may help.

[john44]

I should think a fork lift type of arrangement would work running up and down side rails with
either one central pull rope or a pull rope running over pulleys on top of the rails worked by a
sail winch. The bottom rail will have to be weighted or Spring tensioned to help the slide.
I built this type and fitted it to my rescue boat.
I don,t own the boat any more so can,t post any photo,s but Google images helped a lot.


John

[Rob47]

See if you can find model boats mag with Paul Bannnons carrier
Builds it may help.

Gingyer any idea what period?


Bob

[Brian60]

A leadscrew arrangement using 3mm threaded rod and captured nuts on the platforms. The ends of the rods can be either mounted directly to a sail winch or if space is tight a pulley on sailwinch and end of rod and a small drive belt. Micro lever switches to use as end point stops should do it.

[Rob47]

A leadscrew arrangement using 3mm threaded rod and captured nuts on the platforms. The ends of the rods can be either mounted directly to a sail winch or if space is tight a pulley on sailwinch and end of rod and a small drive belt. Micro lever switches to use as end point stops should do it.

Like it, and yes space is very tight


Bob

[justboatonic]

A leadscrew arrangement using 3mm threaded rod and captured nuts on the platforms. The ends of the rods can be either mounted directly to a sail winch or if space is tight a pulley on sailwinch and end of rod and a small drive belt. Micro lever switches to use as end point stops should do it.

My dear dad used something similar to make a floor lift in a 2 storey garage he made for me as a kid. He only used one threaded bar as the driver and 3 guide bars in the other corners. Powered by a motor with a rubber drive belt. Simple and effective.

[littoralcombat]

Hi Rob,


Not sure if you have seen this on the Carrier Builders site (or if the link will work, as the site appears to have had little input for a long time).


https://www.carrierbuilders.net/element/element.php?id=734


FNS Charles De Gaulle with working deck edge Aircraft Lifts. Unfortunately, the links to the videos do not function, but this CHAP APPEARS TO HAVE COME UP WITH A WORKABLE SOLUTION....IN 1/150th!


Nige

[Rob47]

Nice one nige, thanks for that


Bob

[Akira]

Take a look over at this site. There have been several builds with working elevators(side lifts). Click on the Message Board.
http://wmunderway.mysite.com/home/home.htm