Bill Shields wrote: ↑Fri Sep 23, 2022 8:21 am
this is one of those iterative engineering processes:
you have to calculate mass / moment of what is moving, then pick a motor and see if it will work and fit.
If not -> start over...
there is a very good reason for all of the gears inside these units....
Yup, an iterative process for sure Bill, and, gets more challenging as the scale gets smaller ...
Any gearing must be carefully selected to still allow the motor to be 'back driven' to allow it to return to Stop when power is removed ... or ... another creative method used to achieve the same thing (drop on power loss)
Regards,
Chuck Hackett, UP Northern 844, Mich-Cal Shay #2
Owner, MiniRail Solutions, LLC, RR Signal Systems (http://www.MiniRailSolutions.com)
"By the work, One knows the workman"
Hi Chuck,
We have working semaphores on the Comanche and Indian Gap. I believe Richard Day designed and built them. They don’t model a prototype but work great. Nothing more cool than watching that blade drop as you roll past.
I know the prototypes are/were counterweighted. One in particular that comes to mind has a big “dumbbell” that hangs off one end.
Does the weight counterbalance the arm and all “sprung” parts so it is balanced? To do so reduces a great deal of the need for energy to move the spectacle and blade assembly.
One then needs to take into account the desire for “fail to stop.” You need just enough weight to drop the assembly with no power, but not so much the motor needs a lot of power to lift it.
Yikes ... and I thought I had a lot of 'stuff' hanging around here!
Regards,
Chuck Hackett, UP Northern 844, Mich-Cal Shay #2
Owner, MiniRail Solutions, LLC, RR Signal Systems (http://www.MiniRailSolutions.com)
"By the work, One knows the workman"