Repairing 12V point switch, Modding manual to remote

[Andromeda]

I recently bought an electronic point control from 3bay knowing it’s vertical axel was snapped off at the box level. I thought it was fixable by bonding an old axel piece to it…. The box already had a small nail inserted, which I thought to remove, whoops I sheered another piece of black plastic from the spindle. But a separate part of the spindle is a magnet…

I had also opened a manual switch to see the difference. The same part of the spindle as above was just a plastic, and AIO. I got to thinking that maybe I could modify the manual spindle….

Checking with another magnet on the original remote spindle, showed that each end was opposed, i.e left top was north, right top was south.

I had some magnets from some dismantled hard drives so…

I dremel’d two bits to fit, and voila….

Edit:

I have since Modified a manual point to be automatic, please read below if you are interested....

Edited July 12, 2019 by Andromeda
Refreshing photo links

[alainneke]

Nice solution! I always wondered what to do with those hard drive magnets :) How did you open the electric point motor?

[JopieK]

with a sharp knife like a scalple I would say. You can also buy magnets e.g. at supermagnete.de

[Andromeda]

From underneath I run a thin blade around the join to break any ‘side’ weld, it sinks in about 4-5mm, careful not to lever or push too hard as you’ll leave a line visible in the outer plastic.

Then I use a right angled tool in one of the four holes to ‘carefully’ prise it open, and work around the other holes too.

There are four weld points each side, and two at each end. With a remote switch you have to be careful not to cut any of the turns of copper that make up the electromagnet(plug end), or to break the soft magnetic part on the spindle at the other end. With the manual point motor you can be a little less careful!

Edited July 13, 2019 by Andromeda

[LEGO Train 12 Volts]

Amazing work!

[Andromeda]

Thanks!

I got a little bored last night and decided to go the whole hog! I retrofitted an electromagnet to a manual point switch:

And managed to get the holes nearly right, in the outer box(Right box is real):

Edited July 12, 2019 by Andromeda
update photo links

[alainneke]

That looks really good! Great job!

[bricks n bolts]

Fantastic, great resource for the rest of us 12v heads!

[Shazam12]

Wow that is great! Did you make the coils from scratch, or is it a standard part from somewhere?

[Andromeda]

I wish it was a part to be bought! I couldn't even find a suitable sized coil former, so that was made by welding ABS plastic with MEK. The 'horseshoe' was hand cut and folded, and the coil was also hand wound...

I'm awaiting some larger gauge(smaller dia) enameled copper wire. The wire shown in the pic is only an ohm per meter, and therefore draws 400mA from the supply. My electromagnet measures 27ohms, the original is 52. The new wire coming is 2ohms/m, so in theory should produce a higher resistance, and less current draw!

[Shazam12]

Ok interesting! Do you have a picture of the coil former, before being wound? For the connector tubes where the plugs are inserted you used the 3mm brass rod?

[Andromeda]

Sorry Shazam, I did not take any pictures, I am modeling it in AutoCAD when I have time so I will let you know.

My new wire arrived yesterday ! I have re-wound the unit that I made above, it now has an impedance of 53.3 ohms (original ogeL part=52ohms) and runs at 216mA, much better than 400!!

I now have 6 more manual point motors open and I have 2 metal sheet pieces cut and ready to bend. Looks like I have a busy weekend ahead!

I will try and remember to take pics throughout the build and post them later...

[Andromeda]

I forgot to mention that I made an ogeL holder for the switch whilst you open it. I got sore hands after opening three units so I made this:

The 2 x 8 sticking out is to prise the top off, you can then push the switch motor top out of the holder. I also run the blade around whilst in the holder

I would have uploaded the instructions but they are too big to attach, so I uploaded the LDD file instead !

.

12v Switch motor holder.lxf

Edited July 12, 2019 by Andromeda

[Shazam12]

Hi Andromeda,

if I would buy some magnets from supermagnete.de, which ones would I need to order for application in this switch motor application? Can't see what size or sort would fit.

[Andromeda]

Hi Andromeda,

if I would buy some magnets from supermagnete.de, which ones would I need to order for application in this switch motor application? Can't see what size or sort would fit.

I am using recycled HDD magnets, Neodymium(about1-1.2mm), they are one of the strongest... I also had to dremel them to fit. The original ogeL magnet is very much like the fridge magnets in material!

I have had a look, and by thickness the Neo's come out best for size... I found maybe this one, Q-07-06-1.2-G, might be suitable.

Don't forget that by size, this seemed to be the best solution, and that you may need to 'whittle' it down! Have a look at the size within the manual switch rotary plastic, I used a digital caliper.

[Shazam12]

Ok, I was concerned with the + and - side of the magnet. With the ones you pointed out the poles will be on top and bottom when glueing the magnet in. Is that ok, thought the poles should come out front to back. Kinda cool, gold plated magnets. Lego gettin´ some bling on.

[Andromeda]

@Shazam12

I think as long as you make sure that each side is opposing you will be ok. i.e. I use another magnet in the same position, held in hand, to make sure that one side attracts; the other to oppose - tested from above. When the electrical polarity is changed, so does the magnetic pole, hence the mechanical motion...

I did however cut some magnets and left them 'stuck' to my vice, when I came to remove them they seemed weaker... I then remembered a vague memory from my Grandad's teachings, and had to brush the dust off, about magnets needing a 'keeper'. This is usually a piece of iron/steel placed accross the poles to 'keep' the magnet, the magnetism flows...

So I have revised my modded spindle to include a 'keep', bearing in mind that the original ogeL spindle magnets are AIO(all-in-one). I have included a length of paperclip bridging the magnets at either end. The result was a stronger magnetic field, strangely enough, even when just using it manually!

[Andromeda]

I have made a few pictures of what is really going on with this modification build:

 

 

 

 

 

 

 

 

 

 

 

The magnets I will cover again soon...!!!

Edited July 13, 2019 by Andromeda

[Andromeda]

I forgot to mention the winding wire is 40 SWG/0.125mm enamelled copper wire. At nearly 2ohms per meter, after 27 of them you will know....

[DET]

Pardon for bumping an old thread!

I am in need of a helping hand with no insight found anywhere!

I have aquired a 12v manual switch, like the one Andromeda aquired in the first post, that has already been opened and I believe is missing some pieces:

-There is only the case and the totally plastic black piece with axle mentioned earlier, nothing else:

How does the mecanism that´s missing work; spring or something else?

Could anyone explain or post a photo?

Any idea is appreciated!

[Dread Pirate Rob]

Pardon for bumping an old thread!

I am in need of a helping hand with no insight found anywhere!

I have aquired a 12v manual switch, like the one Andromeda aquired in the first post, that has already been opened and I believe is missing some pieces:

-There is only the case and the totally plastic black piece with axle mentioned earlier, nothing else:

How does the mecanism that´s missing work; spring or something else?

Could anyone explain or post a photo?

Any idea is appreciated!

I have some photos showing how to open and then conduct a basic repair on a 12v point switch motor here:

The trick with opening them is to start levering at the end with the plug and go slowly with a good quality screw driver.

Unfortunately from your description it sounds like someone has replaced the internal components with those from a manual switch. I hope this helps.

[DET]

Thanks for the reply, Rob.

The info that I was looking for though, IS for the manual version 12v switch.

I think I´ll just keep it for spares in the end.

Regards

[Andromeda]

A good quality screw driver! EEEEEEEK!

A thin blade between the join first to break any vertical chemical weld, then a hook through the holes to pull the bottom piece carefully away:-).

The piece missing from your manual DET is a piece of shaped spring wire. If I come across one I will let you know.

[DET]

Andromeda, yes I have it open, and that was the problem. It is empty save the plastic spindle!

Confirmed from you then it is a spring, as I expected.

I you were to come across one and post a photo, that would be great. For me to be able to make a copy of one (now the spindle just moves freely).

Thanks for the reply

[Andromeda]

Here you go DET:

Edited July 13, 2019 by Andromeda