Elevator for upper/lower deck

[nkalanaga]

Would the Nelevator handle two N scale tracks?  If so, you could "double the hill" and almost fit your normal train on it.

[voldemort]

Sorry, I've been on the road and haven't been able to get back on this.

I looked at, and am on the waiting list for the Nelevator.  When last I heard, he was having some staffing problems and had a waiting list of several years.

There are some excellent ideas in here.  As usual, I'll let them bounce around in my head for a bit as I figure out how to do it.  It certainly looks like it can be done.   One idea I had was to have some kind of a projecting piece under the elevator 'floor', sticking out at the connecting end.  When its at the top, it would engage in a similar shaped and matching thickness recess to limit the upward motion to exactly where the arriving track level is.  When its lowered, there would be a deeper recess in the bottom of the receiving track that it would nest in to set the maximum downward travel to match the outgoing rails. 

Some really excellent input from everyone

[voldemort]

I don't want to push any once source or another, but these look like they'd work great- one on each corner (four corners) and bob's your uncle.  IF they can be set to turn an exact amount, accuracy might be enough that it just needs to be set by the arduino (eg, turn 112.2 rotations in the sketch to arrive at the top location) and not need any travel limiters otherwise

https://www.amazon.ca/Actuator-Sliding-Stepper-Automation-Industries/dp/B083BW7L56/ref=sr_1_102?dchild=1&keywords=stepper+motor+linear+slide&qid=1598292864&sr=8-102

[CRL]

You could get by with just 2 if you’re only lifting one track.

[freedj]

https://www.therailwire.net/forum/index.php?topic=44543.msg664696#msg664696

I am working on an arduino driven elevator using steppers, linear slides and end stops which should allow for decks at different separations.  I’m currently building out the scenic top deck and then I’ll go back to the lift  mechanism and code.

My plan is to have each end be independent so that if my deck separation heights are not perfect from end to end the steppers will skew slightly to keep the railheads level.  I am also planning on using home switches so that if steps are ever lost (they will be) it can self correct.

[NtheBasement]

I was surprised to see DC motors used.  Two reasons; hard to get two of them to move at the same speed, forcing you to use a single motor and something mechanical to lift both ends, and they have momentum which makes precise positioning difficult.  For example on my dumper I had to get a microswitch with an extra long lever arm because the gearmotor kept turning and slammed the switch long after the switch killed the power.  Two stepper motors would eliminate both those issues.

Something to watch for: when you power the Arduino up it doesn't "know" where the elevator is.  It could be up, down, or some place in between when the power was last cut off.  So you have to start the program by sending the elevator toward a "home" location until a limit switch is hit.  But... what if a train is half on/half off the elevator when you turn on the power?  Ouch.

[freedj]

The power loss problem is a fun one to think about. You could Store the last level in EEPROM and possibly if it is between  levels, and put in a interlock so that track power is disabled when the elevator is moving.

Put your home switches where you normally want the main deck to be. 

If you loose power while it’s between levels trains won’t be able to move until you re home the elevator.

If you loose power while the elevator is stationary everything knows where it is and trains can move.

Or if you’re using resistive block detection And don’t want to cycle your EEPROM you could put in a short block on either side of the elevator so the elevator can know that a train in spanning the edge.

Apparently the eeprom is good for 100000 writes.

[CRL]

Since I don’t understand EEPROM, Arudino devices, programming issues, etc, etc, blah blah blather, but I do understand nuts, bolts, screws, wood, glue, screws (I like screws), then it looks like a helix is my best option to change levels.

[voldemort]

That losing power/initialization of the motors was exactly the problem that hit my brain as I was about to go to sleep last night. 

[CRL]

That losing power/initialization of the motors was exactly the problem that hit my brain as I was about to go to sleep last night.

Don’t ya just hate it when that happens?

[mark dance]

Since I don’t understand EEPROM, Arudino devices, programming issues, etc, etc, blah blah blather, but I do understand nuts, bolts, screws, wood, glue, screws (I like screws), then it looks like a helix is my best option to change levels.

Hi "CRL"...John Geddes' approach uses drawer slides and off the shelf linear drive components including the controller for what appears so far to be precise/repeatable elevator operation.  So no need to learn any of the stuff you mention...He listed all the benefits in his application vs a helix.

md [jumping off the soapbox now]

[CRL]

Except... you still need to:

Have the elevator stop at exactly the right height, whether up or down...

Have a circuit that prevents the train from entering elevator when it’s occupied, moving, not in position...

Have detector & circuit to position the train on the elevator...

Have a method of getting power to track on elevator without interruption...

The attraction of the Nelevator is this has already been done in a mostly assembled unit with all the logic circuits included. If you have the skill set required... go for it. I know my limitations (and interests), so I won’t.

[Kentuckian]

This solves a ton of design issues for the layout I am planning. What about using drawer slides with a TV lift mechanism?

[MDW]

This is a great solution for multi-level layouts where small locomotives are going to be run - think short lines running 2-6-0’s or 44 toners.  You could model realistic train lengths and still be able to make it between levels - something probably impossible to accomplish with tiny locomotives and a a helix.   

Michel

[voldemort]

With regards to what to do with an inevitable loss of power (or simply buggering it up somehow), my early thinking is to have have a reset program that has all 4 motors go down until the elevator hits a microswitch  below the bottom level on each.  The microswitch would then interrupt that screw's motor.  When all 4 are down (I'd just give it say 10 seconds of time), reset the counter to 0 for all of them, then restart.   

Just a before bed idea