Andromeda

It is not just you, the links have been refreshed. I used the same forum link code as before... Maybe it was a forum or image hosting glitch, it's working now anyhow. Thanks for all of your positive comments.

My broken flasher unit arrived today. Contrary to the sellers listing, it did not light the lights at all. After dissassembly, 4 alternate holes(top and bottom) need gently depressing and pulling apart, I started to test. Using my DVM I tested all but two of the resistors in cct, they were both the 4M7's. Those I lifted a leg so to speak, with a soldering iron to test. My MPSA13 resistor was reading 12pF(out of range on all ranges with DVM) when it should have read 12R - yes 12ohms brown red black. OgeL have now used three different rated resistors for this unit, and I have seen two different signal diodes too. The two diodes can be tested in cct too, they should read 0.5-0.7V. Similarly the two transistors can be tested in cct. You should get 0.5-0.6V between middle and one edge pin, and around 1.5v between middle and the opposite edge pin for the Darlington(MPSA13). And around 0.7V each way for the same pins on the BC547. Both of my transistors were toast. Don't be afraid to reverse your DVM test probes when testing diodes/transistors, make sure you are in Diode mode. The two large pink looking 1/2W resistors are in fact the 22nF capacitors. They can be difficult to test unless you have a decent DVM. I had to purchase a separate meter for this - see previous post. Looking at the cct diagram that Mark provided, IMHO the most likely failures are the two transistors, the 1N4148 diode and the 12/15/18R resistor. I will however see how this proves out as I have another two broken flashers on their way to me for fixing as I type.

Yes the 7740 was very much coveted by boys of the time, and I dare say quite a few adults too. I have seen these for sale and they are still very popular today. I was never fortunate enough to own one when I was a boy, but I do own one now! I managed to scoop it up for £102 from fleabay with track and transformer - which still had it's 13VAC cover in place. I imagine a set of repro sticker from JopieK's ministickers.nlwill be in order to finish this fantastic train. You will also be able to get repro stickers to make the 7815/9 sets to go with this, the stickers are very good. He's got a new printer and when I visited a few days ago they were rebuilding their shop.

Indeed I wish I had one at times! My PEAK testers and DVM are my trusty companions. This is a very simple circuit, and made simpler my Mark’s disassembly. There were a few red herrings though! Thanks. It’s good to keep information flowing! I have seen so many times in threads that someone fixes something, but omits to give any detail. Plus I have had my fair share of just ‘taking’ when it comes to forum threads…

Hi, have a look at this post that I would have gotten round to, but your questions have sped up the process ! http://www.eurobricks.com/forum/index.php?showtopic=88329&hl And this one for the lamp. http://www.eurobrick...wtopic=78487

I have decided to put together this thread for those of you who are wondering how to get inside and potentially fix your old 12V signal switch. This I think was the first incarnation of the switch, with coil like wiring and round sockets - not the later triangular The hardest part is removing the 2 x 8 studded piece from the top of the unit. You have to break the chemical welds that are in the six places shown in the picture. There is a slight groove around the whole outside edge of the 2 x 8, in the part that looks similar to a 2 x 8 plate. I was 12 when I did this so finesse was not high priority. I would suggest using a sharp blade and running it around the groove, then trying to pries it off. I haven’t tried this, but maybe drill a hole in each top corner of the bottom of the unit and use a tool to push the top off. I’d drill in the center of each of the stud locking corner circle(see blue circles on underneath photo and bear in mind that the circles are just off pic) With that done you need to flip it over and insert a small screwdriver into each of the three rectangular holes to un-clip the buttons. Don’t lose the springs! Operation: When the red ‘stop’ button(S2) is pressed, S2.1 is raised to connect with the negative(P-) rail. S1.3 remains connected to the positive(P+) rail, giving + on C3 and – on C2 to power the red LED. C4 and 5 are open circuit at this time – stopping the train, and C1 is not used. When the green ‘go’ button(S1.1&1.2), S1.3 is raised to connect with the negative(P-) rail. S2 remain connected to the positive(P+) rail, giving - on C3 and + on C2 to power the green LED. With S1.1 depressed, C4 & 5 are connected and the train moves! If you break any of the button clips then you can MEK/melt or glue another piece of plastic to repair it – see pictures. I have some other good tutorials here at Eurobricks on using MEK to solvent weld ogeL. If your button does not stay down then the little plastic nipple has come off of the bottom of the tube that the button spring sits in. A piece of wire twisted around and partially melted in at the sides was my 12 year old minds idea of a fix. Today I would use MEK to weld a new piece on. If you have any broken coils, if they are only in one place per coil, then place both ends side by side overlapping the coils by around 4-5 turns of the coil and press together. Good luck!

Indeed a headache. I should have tested the component before ordering a half dozen 22mH chokes... ! I have a couple of broken flasher units on their way to me now. I think at least one of them exhibits the same symptoms as yours, I will let you know the out come. Due to these fun and games I have recreated the circuit on stripboard, I won't hijack your thread though, I will start another ! If you don't mind I could put a link in here at a later date, and link your page from mine...?

Right, I've cracked it! The two ‘inductors’ in the circuit are actually capacitors, 22nF to be precise. Confirmed by my newly purchased PEAK LCR meter, and by fishing out two Mylar 22nF caps out of the junk, and connecting them to a working Lego circuit. Happy days! Just to set the record straight: Mark’s online picture (http://www.brickshel...y.cgi?i=4448290) shows an 18R resistor, my circuit has a 15R. Edit: And without Mark's inspiration, things would have been a lot harder. Edit II: hopefully corrected images!

How did you get on Heppeng? I have been having a play with this circuit recently, and although Mark has done some excellent work in reversing this, there may be a couple of omissions. The 18R resistor is actually a 15R (Brown,Green,Black). The signal diode (LHS) is a 1N4148, and the (RHS) diode is a 1N4007. I have tried to recreate this circuit and found that the 22mH inductors that I purchased are the cause of the fault. Confirmed by connecting my 22mH’s to a working flasher cct and got the same results. I am going to investigate further and let you know.

This was what my mind was picturing when I wrote this: http://www.amazon.co...g/dp/B006B3PRL2 Having seen the home-made version, it looks more precise! The 'jaws' of the one above are prone to initially moving. I imagine Alain would prefer your suggestion ! As the days grow short and the nights grow long, the Lego comes out to play !

Nice work Alainneke, this tek should inspire many others! Did you use a threaded claw type puller? Maybe they used some anaerobic adhesive, I use it to lock screws in laptop repairs?

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....

Absolutely awesome detail with this MOC Cpt. K. I especially like the electric pickup, and both repair booms! Not to mention the material supply waggon!

Thanks Guys! I also use MEK to repair any broken element. It's a bit like solvent weld waste pipe, once you've coated both sides and push together, a very slight twisting helps them bond better. If you've lost the rivet head, just mix more 'donor' plastic into the MEK to make more of 'liquid plastic', this should harden into just plastic! Using a DVM, or two! I only checked the resistance because the continuity alarm crackled when the point was moved/probed. I've opened the RH points, pictured very top right, and have found a similar weak connection. Being as these have had less abuse, their welds are quite sturdy. So I may be looking for a less destructive way of better electrical contact under the center old dark grey - perhaps silver conductive paint.... Edit: I did prise the rails off, they were easier than my original point. I'll be looking at them later... Anyway, these are pics of a straight off connection to the faulty rail on the RH points. Sanity check second DVM Applying pressure one way, almost normal readings. After applying pressure the other way. Testing the straight through route.

Anyone been setting up a track and found that they had two left feet? I did the other day, and managed to break my 30 year old points! Lots of swearing ensued, but not all is lost... The candidates for this topic are my very first set of points(left), and a set that I aquired from 3bay: In addition to the break, the left set have a poor pass through electrical connection. First off we need to flip the points over and locate the six plastic rivets. For half of them I just cropped the top off with a pair of wire cutters, The remaining rivets were 'teased' back into a pillar shape using the wire cutters and a pair of pliers - small electrical ones! On the first picture above, there is what looks like a 7th rivet that perhaps was made too short, larger circled item. It has been chemically welded. Once the first six are free, slip a small screw driver in between where the 7th joins, and gently prise it open. You should hear a snap! Hear are some pictures of what you get. For the feint hearted, and those of you who donot have electrical connection issues, the next part can be skipped. All of the ends of my conductor rails had become unwelded from the end braces. If you are feint hearted and do have electrical connection issues, the following two pics try and show you where the contacts are. Because my points were so old and abused, I continued to prise the central join with a screwdriver like soldering tool. The point is composite, and has been chemically welded during manufacture. Here you can see the weld breaking. How did this get here? Well now it is, I might as well explain that the melted plastic between the rails was caused by a very bored and destructive 8 year old, exploding button cells! Here it is, looks remarkably like the 4.5V version! Clever ogeL using the same parts! These are the broken welds that I mentioned earlier. You can see the welded middle point. The weld is strong enough to hold while the plastic tears I checked the continuity and resistance of the conductor rails. One bad connection racked up 15 ohms, whilst most were less than 1 or 2ohms in the picture pairs 1 and 2 are visible without these last few steps, pair 3 can just be accessed with a screwdriver, without total disassembly. My trouble was mainly with pair 2, as you can see in the pic they have a little arcing evidence. A small pair of pliers were used to press each metal tab, whilst being pushed/supported from the rail side. Now to weld the broken base plate. You will need some Methyl ethyl ketone (MEK), a chemical proof crucible/dish and stirrer/applicator, and maybe some broken donor ogeL element of the same colour. I chose to dissolve a very small amount of plastic shavings. Because the break was very clean, I did not really need to additional material. Add a few drops of MEK and mix with your shavings to your desired consitancy, here it is weak and thin. Apply sparingly but evenly to the edge of the element to be welded, wait a few seconds then press together. Sometimes applying to both edges. It's best use a flat surface to work on, one prepared with non stick properties, like a strip of kapton tape! In this example I trimmed the excess too soon, the excess smeared a little. Once it is bonded sufficiently to handle, place on a radiator or somewhere warm to set fully. Now we are ready to reassemble the points. Get your welding kit together and the parts lined up. We don't need any extra plastic material this time, just a few drops of pure MEK in the crucible. First off we're going to weld the rails in place. Apply MEK as shown and press together, leaving to dry in a warm place again. Next assemble the base plate and slider. Remember that half rivet that we snapped earlier? Put a spot of MEK on it before lowering the rails onto the base. Try not to push it fully together yet. Flip the whole unit over and if you have snipped the rivets, place a spot of MEK in each hole, as you've not pushed it fully together right? If you 'teased' the rivets straight, then press together and put a spot of MEK on each, using the end of the pliers press and work the rivet flat. For my snipped rivets, I kept the heads and welded them ontop. The red circles show the snipped rivets, blue the formed ones. Both methods work. That's it, you've just saved yourself a small fortune! I'll come back and post about the the RH points later...

Wicked and really informative tech Guys... Which is why I asked for, and wanted this to have it's own life... ! Thanks Shadows. @Shazam I think you only need 10 posts(don't quote me) to PM. The repies by B n B and Alainneke are both worth following up on. Your original link won't work straight off the bat as it uses two independant solenoids to switch the points from the same polarity supply, where as the ogeL point switch uses reverse polarity. @ Bricks n Bolts, Alainneke I did follow up on your suggestions as I have come across the polarity headache before, and have found a wealth of knowledge, thanks. How to adapt this for the old 12V, I imagine modified power rails or the rarer signal rails...

It's funny what you find along the way! http://www.ebay.de/itm/Lego-12V-Eisenbahn-Signale-7860-/271157349645?pt=DE_Allesf%C3%BCrdKind_Spielzeug_Lego&hash=item3f223ccd0d

Evening All, I had a transformer that was only outputting around +/- 7.5V from the speed controller output. I had a dig around online and found conflicting information on how to open the unit up, includung an old 2011 post here on Eurobricks. One person said to drill them out, another said to push them in, and another said not to pull them, I pulled them! They are round pegs with two plastic barbs at the end, well after pulling them the barbs were fairly non existant. I have left an entry mark down the side of each hole and the pegs have a dent were my 120 degree desoldering tool was pushed in and pulled them out, not ideal for reselling! Not sure how drilling would go as the pegs seemed easy to rotate in their holes, but If you were to drill in 2mm with a 3.7mm bit then you would be able to push them in. I tested both caps for ESR and correct value, ok, and both 1K resistors were fine. Outputs from Tx itself on full tilt gave 16.89 A.C. All of the diodes rectifying the speed output tested as conducting, but when the voltage was measured across each, one was dropping 6V. I relaced all four (located top right when you lift the cct) and they are 1N4003's. Edit: The caps are 2.2uF, 400v @ 85 deg.C. Here are a few pics to give you an idea: These were the fellows: Any questions or comments welcome.

Nice idea Alianneke! I do like to look of the old steel tracked 9V rails, I'm still stuck in the 12V era! I see that you are putting your lathe to good use...

Thanks! I'll have dig through my ogeL and see what I find in the way of 3062's... Thanks again! You have a lathe, I'm jealous! I know that MEK won't bond delrin but neither does it bond the heat-shrink I used. If the MEK has some black ABS plastic dissolved into it, it does 'hold' the heat shrink in place, so it should work. If you try it, let us know how you get on?

I have made a few pictures of what is really going on with this modification build: The magnets I will cover again soon...!!!

Indeed! I tried contacting them three or four days ago. I imagine it was all made under licence/contract... So any unused parts were probably destroyed or returned to ogeL. Fair enough, but I’m not convinced. The flat motors could be modded for the older 12V 14 studs long. If these: have three coils on the armature then Roamingstudio could ‘steal’ the commutator, esp. if they weren’t expensive, but you would need a ‘puller’ to remove it. The spindles are of a comparative size, 2.01 on my 12V(my calliper is only two DP). So it is a question of tools, expense, 3 coil armature and W/r.p.m. Even so if you are thinking of removing the commutator from the new motor, and it has a 4 coil armature, you might as well remove the armature as well… My opened original motor pulls 140mA no load, and varying 200mA plus under load.

After I bit of poking around online I found the following article, which showed exactly what I failed to explain above. The Guy fixes a 30+year old motor! http://www.instructa...mmutator/#step1 If it was an older 12v, with studs and no bogie, I would source from these guys as they are the orignal company commissioned by ogeL - Bühler: http://www.buehlermo...EN/DC_EC_Motors

@ Roamingstudio That's an F'er! I looked at mine and the ceramic piece that has 'migrated' on yours, is only a solder point for the commutator. Your main issue is that the commutators' contact/s have now become un-glued from the spindle/insulator. I have successfully used brass tube to 'upgrade' 12v switch point motors, maybe you could use something similar to repair your motors' pickup? A larger Dia. would be needed of course...

Kudos where it is deserved ! I run lights from both the switch 'end' connection and the above mentioned a.c.; you can run 800mA from each... Already have! Now I know why I have so much competition on 3bay for the old ogeL 12v track !