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Author Topic: Request for minecart speed assistance  (Read 1157 times)

WanderingKid

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Request for minecart speed assistance
« on: September 13, 2013, 04:45:24 am »

Hey guys,

I know some of you have seem my 'holding pattern' loop I like to use on some of my cart systems as a spacer for multiple carts on a single line.  What I haven't been able to figure out is a way to make sure that it does the following:

- leaves with the same speed it came in at after dropping a ramp, doing something, then coming up a ramp and returning to the main line.
- Spends ~100 tics in the holding loop.

I'm wondering what you guys would recommend?  I'm not sure how I can control the cart speed exactly without a wall crash reverse, and that can dump the goods I'm trying not to lose.  Is there a way to put highspeed brakes over a roller (or something similar) that you can change to exactly the speed you want without a wall crash?

JAFANZ

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Re: Request for minecart speed assistance
« Reply #1 on: September 13, 2013, 05:39:06 am »

Track stops?
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Talion

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Re: Request for minecart speed assistance
« Reply #2 on: September 13, 2013, 06:49:31 am »

Track stops do seem like the best bet. You wish to use multiple stops with only light breaking applied. It be possible to control how many stops the cart goes through with a derail or activated bridge.
In the case of the derail you might need to derail first to determine the entry speed.

Alternatively you could pump water onto the track. If the amount of water pumped was based on how fast the cart came in it might allow you to get a predictable speed out. You would need to account for random water flow however, as well as track clean-up afterwards.
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Larix

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Re: Request for minecart speed assistance
« Reply #3 on: September 13, 2013, 08:23:32 am »

If you have power, rollers are perfect for speed regulation, since they _set_ speed of affected carts to a certain value. A cart slower than the roller's specified speed will gain the roller's speed, a cart going into a roller in reverse is sent back at the roller's speed. For this purpose, a switch-like construction usually works best:
x
L--
|
|

Cart comes from south at random speed (but less than 1 tile/step), encounters a N->S roller on the NE track corner 'L', and continues east at the roller's set speed (roughly 10.000 units for every 'level' of speed, ~10 000 at lowest, ~50 000 at highest). If you put a wall on the 'x' tile, the cart will even stop and wait for the roller to reactivate when it's off. With a pressure plate linked to the roller's own power supply just south of the corner, you can even use the cart's own passage to enforce a 100-step waiting period.

I rarely use carts for transportation, but to the best of my knowledge, getting returned by rollers or bumping into walls at non-derail speeds doesn't hurt riders or lose cargo.
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WanderingKid

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Re: Request for minecart speed assistance
« Reply #4 on: September 13, 2013, 12:28:35 pm »

x
L--
|
|

Cart comes from south at random speed (but less than 1 tile/step), encounters a N->S roller on the NE track corner 'L', and continues east at the roller's set speed (roughly 10.000 units for every 'level' of speed, ~10 000 at lowest, ~50 000 at highest). If you put a wall on the 'x' tile, the cart will even stop and wait for the roller to reactivate when it's off. With a pressure plate linked to the roller's own power supply just south of the corner, you can even use the cart's own passage to enforce a 100-step waiting period.

This might be just what I need.  Now I just need to figure out how to get a 100 step wait out of a short run. :) 

Thanks all.

Snaake

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Re: Request for minecart speed assistance
« Reply #5 on: September 14, 2013, 02:10:35 pm »

If you have power, rollers are perfect for speed regulation, since they _set_ speed of affected carts to a certain value. A cart slower than the roller's specified speed will gain the roller's speed, a cart going into a roller in reverse is sent back at the roller's speed. For this purpose, a switch-like construction usually works best:
x
L--
|
|

Cart comes from south at random speed (but less than 1 tile/step), encounters a N->S roller on the NE track corner 'L', and continues east at the roller's set speed (roughly 10.000 units for every 'level' of speed, ~10 000 at lowest, ~50 000 at highest). If you put a wall on the 'x' tile, the cart will even stop and wait for the roller to reactivate when it's off. With a pressure plate linked to the roller's own power supply just south of the corner, you can even use the cart's own passage to enforce a 100-step waiting period.

I rarely use carts for transportation, but to the best of my knowledge, getting returned by rollers or bumping into walls at non-derail speeds doesn't hurt riders or lose cargo.

I was just going to say that if power is acceptable, rollers are the obvious answer. Rollers setting the speed of carts (instead of adding to it) is an older discovery than impulse ramps, don't forget rollers!

Larix: Shouldn't your text either say "W->E roller" or "continues South"? I fail at seeing the logic where a N->S roller would redirect the cart east (unless _maybe_ if the cart had derailed and was on a NE heading, then hit the N->S roller that negated it's northward momentum but kept the eastern and rerailed it). I've run into a statement similar to that one a couple of times before as well, so I started wondering if something's really buggy with roller directions... haven't really used rollers much since my minecart science thread last summer.
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WanderingKid

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Re: Request for minecart speed assistance
« Reply #6 on: September 14, 2013, 02:28:20 pm »

I was just going to say that if power is acceptable, rollers are the obvious answer. Rollers setting the speed of carts (instead of adding to it) is an older discovery than impulse ramps, don't forget rollers!

Snaake, my concern was for carts already going faster than the roller.  You can speed up a cart, but you can't slow it with rollers.

jcochran

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Re: Request for minecart speed assistance
« Reply #7 on: September 14, 2013, 03:27:01 pm »

I was just going to say that if power is acceptable, rollers are the obvious answer. Rollers setting the speed of carts (instead of adding to it) is an older discovery than impulse ramps, don't forget rollers!

Snaake, my concern was for carts already going faster than the roller.  You can speed up a cart, but you can't slow it with rollers.

Hmmm... Have your speed regulated in two stages. Yes, carts moving faster than the roller are unaffected if they're moving in the same direction as the roller. But if they're moving in the opposite direction of the roller they're reversed and sent back at the roller's speed unless they're moving really fast (derailment speed).  Perhaps something like this

Code: [Select]
------+
      |

      +------
      |
      |
Cart enters from west, takes a turn to the south and derails onto roller track.
Rollers catch and reverse cart so it's now heading north, cart then takes turn to the east at constant speed regardless of speed upon original entry.
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Larix

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Re: Request for minecart speed assistance
« Reply #8 on: September 14, 2013, 04:53:27 pm »

For this purpose, a switch-like construction usually works best:
x
L--
|
|

Cart comes from south at random speed (but less than 1 tile/step), encounters a N->S roller on the NE track corner 'L', and continues east at the roller's set speed (roughly 10.000 units for every 'level' of speed, ~10 000 at lowest, ~50 000 at highest). If you put a wall on the 'x' tile, the cart will even stop and wait for the roller to reactivate when it's off. With a pressure plate linked to the roller's own power supply just south of the corner, you can even use the cart's own passage to enforce a 100-step waiting period.

I rarely use carts for transportation, but to the best of my knowledge, getting returned by rollers or bumping into walls at non-derail speeds doesn't hurt riders or lose cargo.

I was just going to say that if power is acceptable, rollers are the obvious answer. Rollers setting the speed of carts (instead of adding to it) is an older discovery than impulse ramps, don't forget rollers!

Larix: Shouldn't your text either say "W->E roller" or "continues South"? I fail at seeing the logic where a N->S roller would redirect the cart east

I don't know about logic, i'm just reporting how rollers behave in the game. Just build the construction like this and you'll see.
The heart of the matter is that a 'reversed' cart behaves as though it _entered_ the tile with the roller from the direction the roller is pushing from, i.e. the cart here turns from a cart moving from south to north into a cart moving from north to south; because it's on a corner tile, it also takes the corner and heads off east.

You can believe me, i've built dozens of varying roller-switched cart circuits, and this is the roller switch configuration that works best, without requiring constricting walls to prevent carts from flying off on diagonals and similar nonsense.

Quoting myself with an example using exactly this design doctrine quite casually:

[begin quote]
Thus, the delayed NOT:

paths: rollers and pressure plates:
[end quote]

All three rollers here are installed on top of corners, those to the right work N->S, the one in the bottom left S->N, against the direction of the incoming cart. If all rollers are on, the cart will circulate in a 2x2 cycle between the southern and central roller - the central one receives the cart from the south and sends it out west, the southern one receives it from the north and sends it out to the east.
« Last Edit: September 14, 2013, 04:56:37 pm by Larix »
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Snaake

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Re: Request for minecart speed assistance
« Reply #9 on: September 14, 2013, 08:12:01 pm »

I was just going to say that if power is acceptable, rollers are the obvious answer. Rollers setting the speed of carts (instead of adding to it) is an older discovery than impulse ramps, don't forget rollers!

Snaake, my concern was for carts already going faster than the roller.  You can speed up a cart, but you can't slow it with rollers.

Hmmm... Have your speed regulated in two stages. Yes, carts moving faster than the roller are unaffected if they're moving in the same direction as the roller. But if they're moving in the opposite direction of the roller they're reversed and sent back at the roller's speed unless they're moving really fast (derailment speed).  Perhaps something like this

Code: [Select]
------+
      |

      +------
      |
      |
Cart enters from west, takes a turn to the south and derails onto roller track.
Rollers catch and reverse cart so it's now heading north, cart then takes turn to the east at constant speed regardless of speed upon original entry.

Yea, I missed out on the fact (and might've done this before too) that it was a NE track, was assuming SE. Probably since I assumed the cart was just rolling onto the track corner/roller spot normally, instead of derailing onto it (wasn't mentioned in the initial explanation). My solution would probably just be to have carts enter that phase at speeds below where wall crashes empty them (by using track stops or less impulse ramps).
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