7996 Modifications howto?!

[JopieK]

When we read this topic, http://www.eurobrick...showtopic=33819 the question is asked (actually to me, but I didn't notice it back then), how to modify the switch so it gets more possibilities.

My boss asked me about it too (actually not my direct boss, but his boss ;) quite interesting to see AFOLs in all layers of organizations) and also for myself of course:

I did some research:

Normal switch:

http://www.brickshel...ery.cgi?f=25276

Cross switch:

http://www.brickshel...ry.cgi?f=425176

http://www.brickshel...y.cgi?i=4399207

Here is the guy with the solution, but I don't really get the exact instructions:

http://www.brickshel...ry.cgi?f=147934

His instructions with my comments:

Motorized Crossover Pointsby Mark J E Bellis June 20081.

Remove the Switch Rails and modify the springs.Take care in removal - you do it at your own risk.

I used a screwdriver under the switch rail next to its pivot.

[JK: Uh, where exactly is that supposed to be? Does he mean the small moving part of the switch,

so "Let the entire switch face upwards, then put a screwdriver under the switching part of the switch]

A small scratch on the crossover may not be noticed as it is under the switch rail.

Gradually and carefully bend the ends of the spring in order to alter the defaultposition of each

switch rail relative to the slider lug that is underneath it.Remember to bend left and right switch rail springs in opposite directions!

[JK: so we want all 4 switching rail parts to stand in a straight position, so that is quite logical]

They should be in mirror image positions when you have finished.

With springs in correct positions, both switch rails will be half way between thetwo end positions when the crossover slider is in the middle of its travel.

[Yups, so don't forget the start with that in step 1!!!]

In this position a train will go down the straight path from the toe end of the point.

It is possible to test the spring position before clicking the pivot back into place.

Do not remove a switch rail too many times or you might damage thepivot catch that holds it in place.

When you have finished, trains will go down the straight paths on both sides ofthe crossover when the slider is in the middle.

2. Remove the lever frame.Take care in removal - you do it at your own risk.I used a thin modelling saw to begin the cuts,

a Stanley knife to complete them andneedle files to smooth the remaining part of the lever frame.

[JK: so that sounds scary, where do I cut, what exactly do I cut...]

Be careful not to scratch other parts of the crossover.Be careful to avoid cutting the slider lugs (that the lever usually moves).

When removed successfully, the middle should be flat apart from the 2 slider lugs.3.

A 3M axle and 2 toggle joints will be used to move the slider.The middle of the axle moves the slider.

4. Pneumatic cylinders will move each end of the actuating axle.I used only the bottom nozzles because the top ones sometimes leak.

Better to have reliability for long-term use at public exhibitions.Therefore I used 8 pneumatic cylinders.

This design is best where the track is raised up and built into modules.

You will need 8 plates height below the rail pieces to mount your crossover.

5. On the real railway, both ends of a crossover are usually actuated together.

UK signal box levers and diagrams show evidence of this.

Therefore, connect up the pneumatic hoses to just 2 valve switches with T-junctions.

Arrange the hoses so that the crossover is straight with both switches away from you.

This means one set of pneumatics up and one down at each end of the crossover.

When the left lever is moved down, the crossover should move to bottom left to top right.

The crossover should return to staight when the left lever is moved up again.

When the right lever is moved down, the crossover should move to top left to bottom right.

The crossover should return to staight when the left lever is moved up again.

If both levers are moved down, the crossover will be straight, but this is not proper practice!

Therefore you may wish to use levers to block such action on your control panel.

6. Place suitable parts around the motorized crossover to ballast it for your layout.

The crossover has fewer studs than the 9V points, so you can use clip parts to vary the colors.

I chose black for sleepers and black/dark grey mix for the ballast.

This is because on my layout the crossover will be in the yard, where more ash and oil are dropped.

You might like to use lighter grey ballast if your crossover is on the main line.

I kept some of the dark bley crossover colour in the ballast where it was convenient.

I surrounded the actuation lever with ballast to the same height.

The height of the ballast allows any rail vehicle of any scale to go over the crossover because

the height is limited to 1 stud height (1.6mm) above the rail.

Have fun!Mark

[mostlytechnic]

I modified a regular switch to move easier for easier motorization. I was able to get the bottom plate off without needing to drill (like the one brickset gallery shows) - just pried the plate off. Then I filed down the bumps on the sliding piece like it shows. I left a bit, so it still "clicks" each way, but it's much easier to switch.

I'm all PF, so I have no idea about the (very nicely done!) metal foil job to make the switches 9V compatible.

[JopieK]

I did one with alu foil, was quite successful, but I moved also to PF so no real need for that for me too.

Automating the switch is however one of my plans.

[JopieK]

Deejay made a modified controlled version:

http://www.youtube.c...h?v=mIq081MEZnI

I have good hopes of doing it using a servo or memory wire instead.

[Lister]

On 12/6/2011 at 6:29 PM, JopieK said:

I did one with alu foil, was quite successful, but I moved also to PF so no real need for that for me too.

Automating the switch is however one of my plans.

How do you get on? I'm at the point now where I've taken the back off (a 9v switch) to see the insides and try and figure out where I might need tape (to convert a PF switch to 9V)

[JopieK]

Well don't open the switch, it basically destroys it. Use the spring and tongue to your advantage. I use L-shaped tiles with 92593 on the opposite site of the normal switch knob. Works like a charm. I can't show it IRL as my LEGO is still in a warehouse waiting on the builder to finish my new LEGO basement. 

Also, it is a rather old topic so keep that in mind (for future topics, it is often better to open a new topic and quote the old one).

[FGMatt]

21 hours ago, JopieK said:

Also, it is a rather old topic so keep that in mind (for future topics, it is often better to open a new topic and quote the old one).

I do wonder if there's scope for a sticky topic about making "ghetto" track though; it's quite a handy thing for L-gauge and until a few weeks ago isn't something I'd ever even realised existed.

[JopieK]

6 hours ago, FGMatt said:

I do wonder if there's scope for a sticky topic about making "ghetto" track though; it's quite a handy thing for L-gauge and until a few weeks ago isn't something I'd ever even realised existed.

That isn't a bad idea at all. Also adding 3D printed parts to solve certain issues...