This 20-year old Lego set has suffered a bit by having the batteries left in the controller. I created this video with the RU-vid Video Editor ( / editor ) which is now a bit flaky!
Alkaline batteries in place for 15 years. Wow. I guess we have an idea of worst case scenario. I'm glad you were able to clean up the contacts and get the scanner back to life.
I had this set (well, still do, somewhere), was a good set but history quickly forgot it when the Mindstorm RCX came out the year after. Apparently the barcodes used in this became a reused protocol in various Mindstorm systems for communication, VLL/Visual Light Link.
There are 2 types of motor used in those technic sets. the Older model (part 71427), which is the one you have. And a newer model (part 43362). The newer model is absolutely not servicable in any way, and even just opening it can make it stop working due to some bits 'pinging' out of place, and putting some extra friction on the motor preventing it from running. The older model is to a degree servicable. But it has 2 issues which is why it got replaced by a different model. 1) the sintered metal magnets have been known to disintegrate and return to powdered form. This can cause the motor to seize because it's all just a mess inside. 2) the drive gear eating into motor spindle causing it to loose it's grip. The plastic parts can then find it's way into the motor itself locking it up. You can get new parts. And you may be eligible for a free part replacement. But that depends heavily on where you bought it, and what kind of relation they have with Lego. If you do have to pay for it, bad news is that it is one of the more expensive lego parts... The batteries thing... sad panda... Using a mild acid (vinegar, citric acid) is the typical way out for alkalines (baking soda for acid leaks). The descaler might be a bit too strong. You should consider protecting the bare copper as copper will rapidly corrode on it's own. You can nickel plate this at home, though it's somewhat of a chore. www.instructables.com/id/High-Quality-and-safe-Nickel-Plating/ A thin coat of solder should help as well...
The motor has 4 pins on the 4 knobs. The is a pwm for the motor speed, 9V, Gnd and the last pin is for the encoder (for use with Mindstorms). You should try all the pins to find the correct one.
I'd suggest a little light clock oil or perhaps some spray in silicone based lubricant. I wouldn't put it on the plastic in front mind, but the rear where the commutator is might help. If you can get the rest of the motor assembly apart it might help to lube the front bearings too. I don't know as I'd go putting it on the heater though as it might warp the plastics... Still if for nostalgia's sake alone this was a great video. I used to spend hours on end playing with Lego as a kid. I had quite a few of the Technics sets and had loads of fun with them. Cheers lad...
Just bought this set from a friend, was an awesome build! Motor unfortunately doesn’t work but one is already being shipped to me. My code pilot didn’t work as the contacts were horribly corroded. I had to actually drill into the PCB and then solder wires onto it to get it to work again.
No, don't self-flagellate, Julian. Do you know of anyone who hasn't left the battery in equipment for too long? I have the cardboard tube from an Eveready 3V No.8 'Bijou' battery (Remember those? A bit fatter than an 18650.) which was left inside one of my childhood toys for over 40 years. It hadn't leaked, and what's more, it still powered the motor for a few minutes. Sometimes we strike lucky. Thanks.
Good video, great to hear that most of that kit still works after 20 years! :) Shame about the motor but great that the scanner works! Worth it just for practicing your keyboard skills :D
I was glad when you said you wernt guna build it. Dave jones "eev" murdered that one! Love your channel, i sorta feel i'm learning with you most of the time
This is the very reason I think so many companies specified alkaline batteries. They knew after a year or 2 that the batteries would leak and destroy the device hoping the parents would just go out and buy a replacement. I replaced all of the batteries in my remotes with lithium primaries in hopes to not have to deal with leaking cells.
bricklink would be better than ebay for a replacement motor. But if you haven't completely destroyed the motor the set with box is probably worth a bit, so you could sell it and buy different, working Lego instead.
I left the batteries in a big Maglite, four D size if I remember. Found it recently in the garden shed. The tube was fine, just terminals at each end destroyed so it's looking good for an 18650 and LEDs conversion.
Oven cleaner spray works wonders on rusty and corroded contacts just leave the spray on 20 mins prior to rinsing with boiling water. Finally a small coating of vasaline seals it all.
do you know how to open the electric motor from this set, I have one that doesn't run and is blocked when you try to turn it. I want to try to fix this motor but opening such a case is a tricky thing without breaking it into pieces....
Never would have thought that the motor can fail like that! Also the brush/commutator in that motor seems very delicate, unbelievably so! Those brushes are like hair-thin??
These motors have a disc shaped magnet. The magnet covering (like the shiny covering on neodymium magnets) delaminates from the actual magnet and gets stuck between the rotor, the tolerances are so small that it cannot be fixed.
Yes, I've used a glass fiber pen with good results many times in the past. As long as the metal hasn't been corroded to the point where it is so fragile that touching it breaks it (which doesn't seem to be the case here) it should be possible to restore the contacts to reasonable functionality.
Corroded Contacts: after I mechanically remove the big chunks, I use acid wash, distilled water rinse, then flux and wet with solder. Easy. Acid - not only because the batteries are alkaline, but because acids attack metal oxides. Hot acid does it better... This is how flux works to prepare a surface.
John Coops - Yeah, that was for some especially weird arrangement of contacts. Usually scotchbrite alone is enough, sometimes flux and heat as well. My iron is hot often enough anyway...
you might have to actually replace the contacts and maybe even for a long lasting solution dremel into and rework the connections between the negative battery clamps and pcb, because that looked like it rot into the copper layers, which might spread further and break connections in the future.
Hey Guys, I'm looking for some specific information about this set. Maybe someone can help me. Was this set completely made in Denmark? Does anyone know how big Lego was at this time? I heard the development time of this/such a model was about one Year. How many designers had Lego for it? Thanks in advance! Greets from Bavaria/Germany
No. These motors have a disc shaped magnet. The magnet covering (like the shiny covering on neodymium magnets) delaminates from the actual magnet and gets stuck between the rotor. It cannot be fixed.
Just get some new contacts for the batteries and you'll be all set :) I had to do this recently with a clock I bought that had its battery terminals knackered, replaced the battery connectors (and resoldered in some better wires) and all is good. edit: I see you fixed it anyway :)
I'm pretty lazy about taking batteries out and I've usually been getting away with it with alkalines, guess this unit had standby current cos I didn't see a proper power switch for disconnecting the batteries.
You could always buy a replacement motor. Brick Owl has it as a Small Technic Motor 42 Grams for a pretty reasonable cost. www.brickowl.com/catalog/lego-small-technic-motor-42-grams
No, it's "is", even though it does sound wrong. "None" is a shortening of "Not one", and so it follows "Not one of these is corroded". I prefer "are" though.
I accidentally left batteries in the rcx. Cleaned it with sandpaper and it still works. Well stick works even though I don't have a pc that can program it anymore.
If you need a motor ,I recommend Bricklink.com . Search for the set number and then inventory. Brickowl seems to be not bad too, but BL is more popular
hi Julian, can you do a little test of manually charging lithium battery with a CC/CV power supply, without a charger chip? I suspect as the battery voltage increases towards the target CV, the delta voltage between the battery and CV reduces, hence the charge current drops by a nice curve - this part (current-drop) is not controlled by the chip but a natural thing. So, it is sufficient to use any power supply with CC/CV feature to safely charge any lithium battery. Cheers.
You can almost certainly un-seize the motor by soaking the whole thing in warm very light penetrating oil (e.g. PlusGas or similar). Put some oil in a pot, heat to about 50C, then soak the motor in it.
No. These motors have a disc shaped magnet. The magnet plating (like the shiny covering on neodymium magnets) delaminates from the actual magnet and gets stuck between the rotor. It cannot be fixed.
This is a first gen motor (Lego 71427), the replacement they introduced in 2002 (Lego 43362) should be more durable. First gen suffered from cracking magnets --> locked up motor. More info: www.philohome.com/motors/motor.htm
soz J i need help i have a STC chip for my led cube i have searched the web for a way to put my own code programe in with no luck.still(love your vids ta)
You CAN NOT fix these motors are the magnets are the problem. There is a known issue where the magnets expand due to brake down of the binding material.
Julian if you ever want to sell the barcode part let me know . I have the set minus the barcode part. Havent checked to see if my motor is duff tho. :)
The plating reacted with the metal witch the core magnetic material is made of.. I would guess it was contamination I have these motors and have had 8 fail this way I build large GBC modules please open yours to see if I am correct on yours
No. These motors have a disc shaped magnet. The magnet plating (like the shiny covering on neodymium magnets) delaminates from the actual magnet and gets stuck between the rotor. It cannot be fixed.
