design trolley on tracks

[meccanicamg]

thanks mechanicalmg, but do not have the softest wheel? is wrong or is it more convenient to replace a wheel than the tracks?

certainly, normally you prefer to replace the wheel to the tracks. not in all cases though. if the track lowers for wear in a regular way, it may also not affect if it loses the height.

 

[Mattymecc]

Thank you mechanicalmg.

 

[Marco F inox]

if the wheels of this cart are crazy, there must be a link between the cart and the rails, if then the space to be covered is double the length of the cart, the rack on the cart just is not there.
if you do not want to put anything on the ground, you could put a beautiful screw recirculation of balls, for the whole length of the rails, passing through the cart and anchored in a way shocked to a truck at the end of the rails.
you made a bunch of assumptions and friction calculations, but first you have to decide how to make the project.

 

[TETRASTORE]

If you need to stop the wagon at any point, move it any distance, can't you use a system like that of the chariot with pulse pushbutton or with potentiometer that allows you to adjust the speed up to the desired stop?

I intervene in this old discussion for completeness of information agreeing with the quotation @massivonweizen. the simplest solution, in my opinion, was to consider the motorization of the cart in question as a wagon: 4 steel wheels, with edge on two tracks, of which two motorized (with one or two motors).
before the advent of the inverters, but also now, in order to guarantee the progressive start and braking, three-phase motors were used autofrenant start and brake progressive with a flywheel and with the possibility of adjusting the brake torque (see catalog from page 62). often, the 2/8 poles were preferred in order to give more progress on the 2nd and stop at the lower speed to have greater precision in the positionings. for precise positioning it is possible to carry out, by means of a push-button, fast-tracking to the lowest speed as normally happens in the wagons without inverter. many companies place pieces on machine tools with this system.