14 replies to this topic

[DLuders]

On Flickr, Duq (Ronald Vallenduuk) posted this picture of his Power Functions Points Motor for switching Lego rails (click on the image below to enlarge).  



He wrote, "I started building this when I needed remote control for our display in Blackrock. Then I remembered the Reverse Engineering Challenge in RailBricks 9 so I used that as a starting point. Looking for inspiration I found this idea by Chris Alano which looked promising. I didn't like the little lever to hold down the Technic steering connector. I then remembered the mechanism in 8052 Container truck and realised I could replace 32068 with 42003 [shown below] for a much stronger solution.
It all worked well and it's smaller than the design in RailBricks..."

  

[Duq]

Oops... Looks like I'm too late to post My Own Creation...

[peterab]

 Duq, on 25 March 2012 - 12:01 AM, said:

Oops... Looks like I'm too late to post My Own Creation...

I'd take that as a compliment, this is a good looking design (from a technical as well as asthetic viewpoint), and something the rest of the community was bound to find interesting  

[Duq]

Don't worry, I do see it as a compliment. I was just surprised at how quickly it had been posted here.

[roamingstudio]

Over in the technic forum DLuders is know as being faster than a silver bullet... you wont be the first or last to be beaten to your own posts...

[skaako]

This is a really good design however when I built it I realized the two extra liftarms rub against the studs on the switch and causes a bit of flexing of the switch itself.  So I started again with a similar design and this is what I came up with..




You can view the set of instructions here.

It's slightly smaller in design and there is no flexing of the switch and causes very little pressure on the bottom cover of the switch.

Edited by skaako, 15 April 2012 - 10:54 AM.

[brickie]

Looks good.

DLuders, how did you connect the wire from the motor to your control point on a large table?  

[MetroiD]

 brickie, on 15 April 2012 - 11:11 AM, said:

DLuders, how did you connect the wire from the motor to your control point on a large table?  

Perhaps Duq would be in a better position to answer that question...

Duq - great idea, as usual! The lack of enough PF motors suggests that I won't be implementing it anytime soon, but that doesn't make it any less useful... I can totally imagine large-scale layouts using these PF switches!

[Tearloch]

 MetroiD, on 17 April 2012 - 09:30 AM, said:

Perhaps Duq would be in a better position to answer that question...

Duq - great idea, as usual! The lack of enough PF motors suggests that I won't be implementing it anytime soon, but that doesn't make it any less useful... I can totally imagine large-scale layouts using these PF switches!

So does the box around the mechanism limit its travel sufficiently to prevent snapping off the little nubs (where lever meets the slider attached to point)?

I really wish Lego had some smaller motors for this.

Also, how do you handle multiple switches?  Power supplies?  I would imagine an elaborate set up would quickly run out of PF channels (without even considering channels for the trains themselves).

[skaako]

 Tearloch, on 17 April 2012 - 01:46 PM, said:

So does the box around the mechanism limit its travel sufficiently to prevent snapping off the little nubs (where lever meets the slider attached to point)?

For Duq's design the liftarms limit the travel as they rotate.  With my design i added the headlight bricks with 1 x 1 tiles to limit the travel in this direction as it did cause a slight amount of stress on the bottom cover of the switch.  In my newer design the tiles at the top of the housing limit the travel too.

[Duq]

 brickie, on 15 April 2012 - 11:11 AM, said:

Looks good.

DLuders, how did you connect the wire from the motor to your control point on a large table?  

I used the PF to 9V cable, then a long 9V cable and then the old pole switcher:

A friend of mine used the same cables but with the old battery box:

The advantage of using the battery box is that the motor can't stay on accidentally.
My plan for next time is an all-PF solution using the simple PF remote, again so I can't accidentally leave the motor on.

[skaako]

Here is my smaller PF points motor.. I finally had the time to make instructions and take a few photo's  

[Pet-Lego]

 skaako, on 09 June 2012 - 02:50 AM, said:

Here is my smaller PF points motor.. I finally had the time to make instructions and take a few photo's  

Looks quite nice, do you need to make any changes to the switch to make it work?

[skaako]

 Pet-Lego, on 09 June 2012 - 08:19 AM, said:

Looks quite nice, do you need to make any changes to the switch to make it work?

Thanks.. No changes are required at all to the switch.  And i have tested it with various switches old and new and works fine with all.

[Mark Bellis]

You might find that after repeated operations the mechanism begins to lift off the points.
My rack mechanism uses the gantry feet to lock the points piece to the mechanism and prevent detachment.
I used a white clutch gear to prevent motor strain at the end stops, since at a show it is difficult to hear the mechanisms reaching full travel, especially if they are underneath other tracks, in the fiddle yard.  I might see if using a second white clutch gear can help overcome a sticky point mechanism.  My mechanism is designed for maximum reliability so I can use it in out-of-reach places for a 2-day show.

Mark