point motors

philpill

point motors

Postby philpill » Wed Feb 03, 2016 11:59 am

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Last edited by philpill on Tue Feb 16, 2016 6:28 pm, edited 1 time in total.

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Jol Wilkinson
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Re: point motors

Postby Jol Wilkinson » Wed Feb 03, 2016 12:45 pm

What point motors are you using? Some types such as Cobalt and Tortoise have some built in switch capacity, although you may need that to provide the crossing feed.

philpill

Re: point motors

Postby philpill » Wed Feb 03, 2016 2:42 pm

Hi tortoise which have 4 switches i will use one for the v polarity but not sure if just use one switch to change point motor feed polarity

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grovenor-2685
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Re: point motors

Postby grovenor-2685 » Wed Feb 03, 2016 3:18 pm

Why do you want to sequence the operation? Simpler just to connect the two motors in parallel so they operate together.
The current requirements of tortoises are minimal.
If you are using a DPDT switch to operate the tortoise then you would need to use both contacts an the first tortoise to operate the second one. That leaves only the contacts of the second machine free for frog switching or indicating. Operating them in parallel leaves all 4 contacts free and keeps your options open.
If you have a significant number of tortoises then it is generally better to use a split potential power supply and SPDT switches, this is covered in the tortoise instructions.
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Keith
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philpill

Re: point motors

Postby philpill » Wed Feb 03, 2016 3:40 pm

Hi yes i will probably do that as is the easiest option i did have them moving one after the other on a layout many moons ago but cant remember how i wired them up and i thought it looked nice to have them moving seperately rather than together

Alan Turner
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Re: point motors

Postby Alan Turner » Wed Feb 03, 2016 4:43 pm

philpill wrote:Hi yes i will probably do that as is the easiest option i did have them moving one after the other on a layout many moons ago but cant remember how i wired them up and i thought it looked nice to have them moving seperately rather than together


Nice(!) but not prototypical.

regards

Alan

philpill

Re: point motors

Postby philpill » Wed Feb 03, 2016 5:48 pm

sorry but what is not protoypical the 2 sets of blades moving at same time or one after the other i not that clued up on the facts

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Will L
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Re: point motors

Postby Will L » Wed Feb 03, 2016 6:28 pm

philpill wrote:sorry but what is not protoypical the 2 sets of blades moving at same time or one after the other i not that clued up on the facts


A crossover is likely to have been operated by a single lever, and therefore both points would have moved together,

philpill

Re: point motors

Postby philpill » Wed Feb 03, 2016 6:51 pm

thanks will put both motors in parallel

philpill

Re: point motors

Postby philpill » Thu Feb 04, 2016 8:30 am

having thought on that if a single lever is used the rodding would to travel further to one crank that was furthest from the box so would one crank start moving before the other or would the timelapse be too small to notice

John Palmer
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Re: point motors

Postby John Palmer » Thu Feb 04, 2016 8:54 am

I know nothing about Tortoise motors, but assume a single motor has sufficient power to move more than one pair of switches, in which case another possibility would be to connect with rodding the switches at both ends of the crossover to a single motor.

I imagine remotely worked crossovers must have been almost always arranged so that both switch pairs were operated simultaneously. As usual the Somerset & Dorset's station at Burnham supplied the exception to prove the rule, as the turnouts forming the station's crossover were released from the box but worked by hand lever on the ground. Since we couldn't persuade a 4mm scale figure to walk from one ground lever to the other for this purpose, we adopted a cascaded switching arrangement, in which completion of the throw of one switch pair in the crossover fired the motor to operate the other switch pair. This was straightforward enough given the nature of our home-made point motor design, it being feasible to mount multiple microswitches on the motor that would operate at its end-of-travel position. In turn, that also made possible a logic circuit using microswitches that would backlock the release lever in the signal box frame whenever one of the ground-worked points was thrown.

dal-t
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Re: point motors

Postby dal-t » Thu Feb 04, 2016 9:18 am

I'll let the expert points and signals people answer on the prototype timelag, although I always understood the 'pull' went to a central splitter which ensured both sets of switches moved together (certainly I've always set model crossovers up that way). However, my arrangements, both for wire-in-tube and point motor operation, were based on helpful diagrams that used to be around showing the best set-up for different track formations. I have had a quick 'websearch' for these (by which I mean a simple Google and a look at the on-line GOG manual) but can't find them, which makes me wonder whether they were in the EMGS Manual, which I only ever had in paper copy. Maybe a current EMGS member could advise on that, and if there are no copyright issues perhaps share some of the content? Interest declared, I'm about to build a simple facing crossover for mechanical operation (hovering between being brave with 'proper' scale rodding*, or falling back on good old wire-in-tube with cranks and omega loops).

*La Poste has just brought me a stores order containing point rodding stools (in place of fishplates!), guess that determines which way I am going to have to go. But Spooky, or what?
Last edited by dal-t on Thu Feb 04, 2016 10:08 am, edited 1 time in total.
David L-T

philpill

Re: point motors

Postby philpill » Thu Feb 04, 2016 9:55 am

hi thanks for reply nothing on my emgs disc about subject

Alan Turner
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Re: point motors

Postby Alan Turner » Thu Feb 04, 2016 9:57 am

Digest 23.6.5 if you are interested.

regards

Alan

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steamraiser
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Re: point motors

Postby steamraiser » Thu Feb 04, 2016 10:25 am

Both sets of point blades will move at the same time if operated from a single lever.
There is no time lag, unless there is a number of joints that are a sloppy fit, which is most unlikely.
If you move any long solid object one end moves at the same time as the other in a push pull scenario.

Gordon A

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grovenor-2685
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Re: point motors

Postby grovenor-2685 » Thu Feb 04, 2016 12:16 pm

philpill wrote:having thought on that if a single lever is used the rodding would to travel further to one crank that was furthest from the box so would one crank start moving before the other or would the timelapse be too small to notice

My original answer seems to have been lost and now others have answered, definitely to small to notice!
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Keith
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steamraiser
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Re: point motors

Postby steamraiser » Sun Dec 09, 2018 12:58 am

Yard points would be operated independently at a different time as each point would have its own lever.
Using DCC route selection on my sidings I noticed that each point changes at differing times in the sequence that you programme them.


Gordon A

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grovenor-2685
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Re: point motors

Postby grovenor-2685 » Sun Dec 09, 2018 8:18 am

Monty wrote:Nobody has given an answer on this?

Monty,
What question are you looking for an answer on?
The original question was answered long ago, even though the question has since been edited out leaving the question to be deduced from the answers.
I can't see any other unanswered questions.
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Regards
Keith
Grovenor Sidings


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