Point motor availability

Started by Too old to die young, January 08, 2020, 08:12:38 AM

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geoffc

Quote from: Biggy on January 09, 2020, 09:45:10 AM
QuoteServo based point motors are worth a look; There are several off-the-shelf systems including one produced by Peco.

A search for Servo point motor will give you plenty to look at.

Steven B

The attraction for me of the cobalts is the simple wiring and the built in frog power and polarity reversing which can be done with three wires all of which are clip fit.
How does this compare with the servo motors?  I genuinely don't know but would be interested in The answer
Many thanks

As for costing to control 4 servos using MERG kits a Servo4 kit costs £6.80 and a servo setter will cost £16.07 plus the servos, mountings and 4 on/off switches. To switch the frog polarity a pcb can be bought (servoxing) but you will need to source the components, this is wired in series between the servo4 output and the servo and comes out at approx £4 per servo.
As @kirky has said the Ezybus system works out cheaper and will control up to 128 servos, relays or leds using one master, 8 input modules and 16 output modules on one bus. It has cost me £4.64 for the master and about £3.50 per module including all the components, plus the relays and on/off switches.

Geoff

Ted

#16
Quote from: Biggy on January 09, 2020, 09:45:10 AM
QuoteServo based point motors are worth a look; There are several off-the-shelf systems including one produced by Peco.

A search for Servo point motor will give you plenty to look at.

Steven B

The attraction for me of the cobalts is the simple wiring and the built in frog power and polarity reversing which can be done with three wires all of which are clip fit.
How does this compare with the servo motors?  I genuinely don’t know but would be interested in The answer
Many thanks

The C in Cobalt is for convenience!  :D

I have the Megapoints system and there is quite a bit of wiring involved, it's all a bit fiddly, but I got it working.

I'm not actually sure if I've saved any money using their system over say, Cobalt or Tortoise though?

The MERG stuff to me - a novice in electronics - just sounds like hard work. Personally, I'm happy to pay for the simpler, more convenient DCC and/or Megapoints systems.

edit: for ref, over 12 turnouts, the Megapoints system works out at about £25 per point (that's everything included; servos, wires, boards, power etc).
Just call me Ted, or Edward... or Ed.

Just not Eddie.

Layout & Updates > Midlands Coal & Freight, Late 1980's


LASteve

I'm not sure if anyone has updated you on the Cobalt IP's, but they're back in stock, you can order directly from DCC Concepts or a distributor. I had 2 12-packs on back order for a while, but the supply problems have been resolved and I got them delivered towards the end of January.

They are definitely the most convenient option for DCC, especially if you're wiring the frog.

Ted

Quote from: LASteve on February 24, 2020, 07:25:55 PM
I'm not sure if anyone has updated you on the Cobalt IP's, but they're back in stock, you can order directly from DCC Concepts or a distributor. I had 2 12-packs on back order for a while, but the supply problems have been resolved and I got them delivered towards the end of January.

They are definitely the most convenient option for DCC, especially if you're wiring the frog.

To be honest it makes me wonder why I spent all that time and energy learning Megapoints, when the Cobalts are an all-in-one solution!?  :doh:
Just call me Ted, or Edward... or Ed.

Just not Eddie.

Layout & Updates > Midlands Coal & Freight, Late 1980's


LASteve

Quote from: Ted on February 24, 2020, 07:32:29 PM
To be honest it makes me wonder why I spent all that time and energy learning Megapoints, when the Cobalts are an all-in-one solution!?  :doh:
At least you know you made the right choice, whichever direction you chose in the end :) Knowledge is power!

Izzy

I think the big advantage of such as servos are the smaller size and footprint needed compared to Tortoise and Cobalt. When you have points closely located it can get difficult fitting them in place, impossible sometimes. This is not the case with the Peco/Seep motors nor servos.

You pays your money .......

Izzy

njee20

Quote from: Ted on February 24, 2020, 11:54:37 AM
edit: for ref, over 12 turnouts, the Megapoints system works out at about £25 per point (that's everything included; servos, wires, boards, power etc).

Crikey, that sounds a lot. I admit I went for Megapoints as it was cheap, and then by the time you add the multiprocessor board, DCC module etc etc it gets more expensive, but nothing like £25 per point. 12 points is surely one board, one DCC module (if needed), then servos/wires/switches which are all dirt cheap? Id have thought it would be less than £10 per point?

Ted

Quote from: njee20 on February 26, 2020, 08:56:32 AM
Quote from: Ted on February 24, 2020, 11:54:37 AM
edit: for ref, over 12 turnouts, the Megapoints system works out at about £25 per point (that's everything included; servos, wires, boards, power etc).

Crikey, that sounds a lot. I admit I went for Megapoints as it was cheap, and then by the time you add the multiprocessor board, DCC module etc etc it gets more expensive, but nothing like £25 per point. 12 points is surely one board, one DCC module (if needed), then servos/wires/switches which are all dirt cheap? Id have thought it would be less than £10 per point?

Hmmm, I added it up quickly but here's what I have:

Servo Controller £63
Regulated Power supply £24
Remote setup panel £10
DCC Module £30
4 x Relay / Frog Board (4-way) £12
Relay / Frog Driver module £36.00
Servo Mounts £12
Misc cables and connectors £40
Servos £25


So that's £23 per point.

I wasn't far off?

Same price as a Cobalt which is zero fuss and self-contained! However, @Izzy makes a great point - the smaller footprint, in tight spaces, could be the winning argument here for Servos vs other.

I have 2 triples back-to-back and looking at it, I'm not sure I would have squeezed the bigger Cobalt or Tortoise in to that area without issue!
Just call me Ted, or Edward... or Ed.

Just not Eddie.

Layout & Updates > Midlands Coal & Freight, Late 1980's


njee20

Yep, fair enough!

I don't use the frog/relay modules, their servo mounts or the remote panel set up, plus I paid less than £1/servo, likewise for leads, so I think mine is more like:

4x boards: £240
1x multiprocessor board: £90
1x DCC module: £30
48x servos: £40
leads etc: £30
microswitches: £30
mounting channel: £20

Which amazingly (and genuinely not a fudge, although admittedly some rounded numbers!), comes to £10 a point.

The problems I have with them I think are mainly of my own making, most notably having the length of the actuation rod change over the length of the stroke, such that it can protrude too much and catch passing stock. I think I needed to be more accurate with centring the servos so as not to be using the extremes of the movement.

I can't decide what to use on my next layout, I sort of feel I'm too invested in Megapoints to change, and I do like the servos, at least conceptually. I think having access to the bottom of the board would make things easier for alignment (as would being less slapdash!), as I did all of it upside down, which definitely doesn't help!

Two other failings with Megapoints I've not resolved while we're talking about different systems: when you get a short the servos all cycle in unison, even using a PSX circuit breaker, clearly it doesn't feed enough power downstream to the servos. I have got another accessory booster to try and resolve that, but haven't got around to it. Tends to mean a minor incident immediately gets far worse, as anything that happens to be stopped over a point gets derailed and causes a series of subsequent shorts!

I also find the initial twitch on start up a bit violent, and it can snap tie bars on my (badly built) handbuilt track. Not sure how to resolve that! It concerns me if I were to use more rigid servo mounts for sure.

I'm a member of MERG, so perhaps I should consider their new set up.


Izzy


I'm afraid it was the current needed at startup and the twitching which persuaded me to change over to hacked servos. They can then be run off very low current, a single AA can be the power source if desired as around 1.5v is all that is required. A much cheaper setup but perhaps not best suited to larger layouts with lots of points.

They are still very powerful given the high gearing they have but will 'stall' at the end of the travel. I use momentary switches with them and fine piano wire (for the actuator) which will bend when meeting too much resistance but doesn't 'give' over time and loose it's strength.

Izzy

Ted

Quote from: njee20 on February 26, 2020, 12:30:09 PM
The problems I have with them I think are mainly of my own making, most notably having the length of the actuation rod change over the length of the stroke, such that it can protrude too much and catch passing stock. I think I needed to be more accurate with centring the servos so as not to be using the extremes of the movement.

I know what you mean, I had to fiddle around to really line them up and then cut the wire at the very tip of tiebar. Otherwise as you say, the wire would easily clip stock as it passed.

QuoteI can't decide what to use on my next layout, I sort of feel I'm too invested in Megapoints to change, and I do like the servos, at least conceptually. I think having access to the bottom of the board would make things easier for alignment (as would being less slapdash!), as I did all of it upside down, which definitely doesn't help!

Two other failings with Megapoints I've not resolved while we're talking about different systems: when you get a short the servos all cycle in unison, even using a PSX circuit breaker, clearly it doesn't feed enough power downstream to the servos. I have got another accessory booster to try and resolve that, but haven't got around to it. Tends to mean a minor incident immediately gets far worse, as anything that happens to be stopped over a point gets derailed and causes a series of subsequent shorts!

I also find the initial twitch on start up a bit violent, and it can snap tie bars on my (badly built) handbuilt track. Not sure how to resolve that! It concerns me if I were to use more rigid servo mounts for sure.

I've got a dedicated power supply for the servos and megapoints setup, so they 'remember' where they were when powering on/off, a short doesn't take out the megapoints system. Or if it does, I don't recall it creating a problem like you say? Perhaps that's the solution, isolated power.

The way I have the throw (wire runs the length of the servo 'face' or cap/head), there's no chance of tiebars being ripped out or snapped. The extreme throw from side-to-side isn't stressing them, there's still a little give left.

I'm a novice, but even so I think I've got it all setup right, and it did take a lot of patience to get there!
Just call me Ted, or Edward... or Ed.

Just not Eddie.

Layout & Updates > Midlands Coal & Freight, Late 1980's


njee20

Yep, I've got a dedicated power supply, still happens. It doesn't matter that they remember their positions, upon start up they all go to their "home" position, and then return to their remembered state after a couple of seconds, but that initial twitch is pretty aggressive.

The tie bars breaking is only on handbuilt track - and actually more common is the rail pulls off the tie bar (because the servo has moved the closure rail hard against the stock rail), rather than the PCB timber itself breaking. No such issues with Peco points.

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