The last guide you'll need for Repairing Lego 9v wires and Mindstorms sensors

[BatteryPoweredBricks]

These videos are well over 10 years in the making.  The main thing holding me back from making a guide to repairing and testing Lego 9v / Mindstorms connectors and sensors was finding the absolute perfect wire to use.  That day has finally come.  I'm using a 6 conductor, 24 gauge wire with a thin and very flexible silicone insulation.  The problem I've always had with replacement wire was the oversized insulation thickness and inflexibility (not to mention that hideous white line down one side.  Once split into 3 pairs it works out to about 44 cents per foot if you get the 25 foot roll.

https://www.amazon.com/gp/product/B07PPT11QN/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&th=1

I know there are plenty of guides out there but I've always been frustrated by them.  I've been making my own Lego 9v wires for over a decade and soldering for over two decades.  I wanted to pass on all I have learned in a somewhat rambling video  .  I only solder the connections to the back of the sensors, everything else uses the same system Lego used.  I hope the Lego community will find these videos useful.  Any constructive feedback is welcome.

 

Edited April 25, 2022 by BatteryPoweredBricks

[1963maniac]

THANK YOU for the video and all the great know how. Thanks for sharing!!!! I have some wire that is like that. I used liquid electrical tape. But, that is only a short term fix.

Edited April 11, 2022 by 1963maniac

[BatteryPoweredBricks]

Update!

Not long after uploading these videos the price of the wire went down significantly!   The 50 foot rolls are now $30 which is what I paid for a 25 foot roll before.  Again you get three pairs so a 50ft roll nets you 150ft of 9v wire (although 50ft will have the gray markings on one side).  I ordered two 50ft rolls just in case the price changes again .

https://www.amazon.com/gp/product/B07PPSKVNN/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&th=1

I can't wait to take some of my Technic models off the shelf (like my RCX / Power Functions Code Pilot Truck) and make new wires for them!  I've also been making many custom length cables for MOCs.

[allanp]

These are excellent guide videos, and I really like the wire you found, looks better than the stuff I've been using. The issue of old wires deteriorating comes up from time to time, will definitely be sending people to your videos.

Only thing I would add (actually no, would be better as a separate video) is that the second biggest problem I have found with these cables is corrosion of the electrical contacts. Only takes a small barely noticeable amount to stop the electrical pixies flowing! Can be cleaned easy enough with contact cleaner but I'm still trying to find a way to get a nice, shiny, like new condition.

[BatteryPoweredBricks]

6 hours ago, allanp said:

These are excellent guide videos, and I really like the wire you found, looks better than the stuff I've been using. The issue of old wires deteriorating comes up from time to time, will definitely be sending people to your videos.

Only thing I would add (actually no, would be better as a separate video) is that the second biggest problem I have found with these cables is corrosion of the electrical contacts. Only takes a small barely noticeable amount to stop the electrical pixies flowing! Can be cleaned easy enough with contact cleaner but I'm still trying to find a way to get a nice, shiny, like new condition.

Thanks for the kind words, I was floored when I found this wire and had to share the news far and wide .

 

That's true, I had some connectors I threw out because they were so bad off.  Most of my connectors came from large eBay lots, some from goodwill sellers.  I wasn't sure how widespread the issue of corrosion on the actual contacts were for others.  Always on the lookout for guides to post to help out the Lego community.  I'll always have a soft spot for the 9v / RCX era of Lego electronics and it's cool to see I'm not the only one after all these years (there are dozens of us!)

[allanp]

4 hours ago, BatteryPoweredBricks said:

Thanks for the kind words, I was floored when I found this wire and had to share the news far and wide .

 

That's true, I had some connectors I threw out because they were so bad off.  Most of my connectors came from large eBay lots, some from goodwill sellers.  I wasn't sure how widespread the issue of corrosion on the actual contacts were for others.  Always on the lookout for guides to post to help out the Lego community.  I'll always have a soft spot for the 9v / RCX era of Lego electronics and it's cool to see I'm not the only one after all these years (there are dozens of us!)

Yes thank you for sharing that. And yup, the buggy motors (for their power) and 9v 5x4 ungeared motors (for the large gear reductions you get to build with a variety of belts drives and gears and so on) are my two favourite.

So far for cleaning contacts I usually just spray with contact cleaner and plug/unplug several times till I get a clean vertical stripe of metal. But I just thought of/tried a new method to get that nice new look, involving some metal polish, a dremel and a lollypop!

Tested it on one stud of an old manky electric plate. Shove lollypop with round paper stick into dremel, cut off lollypop leaving 2-3mm of paper stick sticking out, load that with metal polish and have at it. Took 5-10 seconds with the dremel and a spray with contact cleaner to rinse off the metal polish to get the above mirror like result on the contact. It's also small enough to get inside and clean the underside contact. It was also quicker and easier than plugging/unplugging many times just to get a tiny vertical stripe of clean metal. Please, if you like this method, feel free to make a video, I'll definitely be cleaning all my contacts this way 

Edited April 26, 2022 by allanp

[CP5670]

Great video, I'll have to try this on many broken 9V wires I have. The wires with the rubbery insulation are very prone to breaking over time, while the ones with the glossy insulation hold together better. The metal contacts and conductive plates have held up better for me, but they are mostly from sets I opened myself back in the day.

[BatteryPoweredBricks]

Another update:

I've been repairing tons of wires lately, making full sets for Mindstorms sets I want to review or custom length wires for projects.  Testing the wires throughout the process with a multi-meter is kind of a pain and slows things down.  So I made my own 9v wire tester and it really speeds things up!  If there ends up being enough interest I may make a guide to making one, I think It could be done more efficiently than the absolute mess of wires in this version

@allanp Thanks for the tip!  I do have many contacts that need to be cleaned, I'll have to look into that soon!

 

 

[allanp]

7 hours ago, BatteryPoweredBricks said:

Another update:

I've been repairing tons of wires lately, making full sets for Mindstorms sets I want to review or custom length wires for projects.  Testing the wires throughout the process with a multi-meter is kind of a pain and slows things down.  So I made my own 9v wire tester and it really speeds things up!  If there ends up being enough interest I may make a guide to making one, I think It could be done more efficiently than the absolute mess of wires in this version

@allanp Thanks for the tip!  I do have many contacts that need to be cleaned, I'll have to look into that soon!

 

It works great for me, but then I used to build small models using the 8x2 electric plates as regular plates and play with them in the garden, digging and such, so they've had lots of abuse from my childhood self, yours might not need such attention but the technique for cleaning them does make them like new even after my abuse, and once your set up it's really quick. Just remember to save those paper lolly sticks!

Edited June 5, 2022 by allanp

[shroomzofdoom]

Nice work fellow flux-huffer! 

A little tip for separating those little click tabs on Lego connectors, motors, and sensors: use a heat gun on low setting to soften the plastic a bit then pry apart with your little screwdriver. To avoid overheating, wave the heat source across the item for 5-10 seconds then try to 'unclip' the housing. You'll find that the item is deformed somewhat on cooling which is actually a good thing for when it comes time to reassemble. After you've made the repairs apply a little heat to the plastic housing and then hold it together for a few seconds. I've broken all the wires to my motors at least once and used 26 ga hookup wire but as you've mentioned, it's too wide for the original strain reliefs. I'm excited to try out the wire you suggested! Ordered.

 

[Fyredog]

Great Video and great find on the wire.  I tried repairing a cable last night and had no luck.  Watched the video again.  I think my issue is I wasn't tucking the wire with my driver into the pocket. It is probably allowing the wire to slip out of the prongs while pressing the connector pieces together.  I'll give it another go tonight.

[BatteryPoweredBricks]

1 minute ago, Fyredog said:

Great Video and great find on the wire.  I tried repairing a cable last night and had no luck.  Watched the video again.  I think my issue is I wasn't tucking the wire with my driver into the pocket. It is probably allowing the wire to slip out of the prongs while pressing the connector pieces together.  I'll give it another go tonight.

Yeah skipping that step could cause the wire to pull back and not meet up with the blade contacts.  Also make sure the blades are straight up and down, they tend to get bent when pulling the connector apart.  The more you do the easier it gets.  I've put on a movie and made a couple dozen at a time and only had one or two errors.  Good luck!

[Fyredog]

So Tucking the wire did the trick,  and after a few it gets easier.  The wire I found was in a single strand but a 2 pair and I basically stripped the ends and folded the wire over itself a couple times and used the pressure of the plastic to make the contact.  Have had no issues, but was not nearly as easy as this wire is.  It is somewhat flexible but not like the silicone wire.  Now I just need to find more wire - you wouldn't want to sell some of yours would you?

[BatteryPoweredBricks]

9 minutes ago, Fyredog said:

So Tucking the wire did the trick,  and after a few it gets easier.  The wire I found was in a single strand but a 2 pair and I basically stripped the ends and folded the wire over itself a couple times and used the pressure of the plastic to make the contact.  Have had no issues, but was not nearly as easy as this wire is.  It is somewhat flexible but not like the silicone wire.  Now I just need to find more wire - you wouldn't want to sell some of yours would you?

How much wire are you looking to get?  There are several options on the Amazon listing, ex. you can get a 25ft roll of 4p (2 pairs) for like 16$.  If you are just looking for a few small scrap pieces I could probably help with that as well.  Not sure if something like that could just be sent in an envelope or not.

[Fyredog]

I'm sorry, I meant the Lego Cables with the ends.  Old ones - You probably have a grip of them. 

[BatteryPoweredBricks]

1 minute ago, Fyredog said:

I'm sorry, I meant the Lego Cables with the ends.  Old ones - You probably have a grip of them. 

oohhhh I see.  Well.... I have quite a bit but at this point I'm holding on to what I have.  I recently built a display for my 10497 Galaxy Explorer and alt builds and used 60 9v connectors .  I have a lot of builds / videos planned and I don't want to run out of them.  I wish there was a good, reliable source for them but I haven't found one yet.  Even on Bricklink they can be priced high and not even state the condition they are in. 

[Fyredog]

Understandable - doesnt hurt to ask...  I had maybe 12 from a lot I had bought on ebay with a bunch of old robotics stuff, so thats what I was wanting to find them for.  I'll keep my eyes out.  Thanks again for this thread - literally a life saver.

[Fyredog]

34 minutes ago, BatteryPoweredBricks said:

oohhhh I see.  Well.... I have quite a bit but at this point I'm holding on to what I have.  I recently built a display for my 10497 Galaxy Explorer and alt builds and used 60 9v connectors .  I have a lot of builds / videos planned and I don't want to run out of them.  I wish there was a good, reliable source for them but I haven't found one yet.  Even on Bricklink they can be priced high and not even state the condition they are in. 

Do you have a thread for your 10497 Galaxy Explorer?  I have to see what 60 9V connectors looks like!

[BatteryPoweredBricks]

9 minutes ago, Fyredog said:

Do you have a thread for your 10497 Galaxy Explorer?  I have to see what 60 9V connectors looks like!

Well they are all hidden .  It's a fairly simple display, I didn't think it really justified it's own thread.  I'll post the video here since it is "on topic", look at what is possible when you make your own cables!

 

[Fyredog]

6 minutes ago, BatteryPoweredBricks said:

Well they are all hidden .  It's a fairly simple display, I didn't think it really justified it's own thread.  I'll post the video here since it is "on topic", look at what is possible when you make your own cables!

 

That is VERY Cool.  I love it.  Have you ever repaired a red micro motor?  what kind of Technic are you into?  I love the Technic stuff too.  I have recently discovered GBC.  I am pretty addicted to it even though I have not actually built one yet.  It is right up my ally.  I love to take a Technic build and fully remote control it the way it should be.  Although I have fallen behind a bit - I left off at power functions.  The new app controlled stuff is crazy.  I have older robotic stuff I would like to tinker with.  but need to get a computer built for it.  I am trying to get a laptop with a serial port and windows XP.  Sounds like your using XP correct?.  I'd like to look into the Dacta stuff too.  Your the guy with the giant train layout with all the control stuff that you somehow made talk to each other right?

[BatteryPoweredBricks]

1 minute ago, Fyredog said:

That is VERY Cool.  I love it.  Have you ever repaired a red micro motor?  what kind of Technic are you into?  I love the Technic stuff too.  I have recently discovered GBC.  I am pretty addicted to it even though I have not actually built one yet.  It is right up my ally.  I love to take a Technic build and fully remote control it the way it should be.  Although I have fallen behind a bit - I left off at power functions.  The new app controlled stuff is crazy.  I have older robotic stuff I would like to tinker with.  but need to get a computer built for it.  I am trying to get a laptop with a serial port and windows XP.  Sounds like your using XP correct?.  I'd like to look into the Dacta stuff too.  Your the guy with the giant train layout with all the control stuff that you somehow made talk to each other right?

Yep that's me .  I've never even attempted a micro motor repair, from what I've seen there isn't a non-destructive way to do it.  When it comes to Technic I think I have an affinity for the older sets.  One of my favorite projects was adding remote control capability to the old Code Pilot set using an RCX and Power Functions (so much so I did it twice ).  Yeah Windows XP is kind of a sweet spot for Lego Mindstorms / DACTA Control Lab.  I had trouble with crashes on my physical Windows 98 PC (not as much using a VM) and Vision Command didn't work at all with the camera.  With anything that needs a serial port you can always use a USB to serial adapter, and a virtual machine for older software (the serial port can be passed through).  There are many options for running the old stuff, "eventually" I will have dedicated tutorials showing the pros and cons of different solutions.

If you have any specific questions you can always DM me, just to not get too off topic in threads (I could talk about this stuff forever)

Oh and as far as GBC I had some half-hearted attempts years ago (on my other YT channel) but it's something I'm currently working on, it will take quite a while to have anything worth showing off.

[Fyredog]

46 minutes ago, BatteryPoweredBricks said:

Yep that's me .  I've never even attempted a micro motor repair, from what I've seen there isn't a non-destructive way to do it.  When it comes to Technic I think I have an affinity for the older sets.  One of my favorite projects was adding remote control capability to the old Code Pilot set using an RCX and Power Functions (so much so I did it twice ).  Yeah Windows XP is kind of a sweet spot for Lego Mindstorms / DACTA Control Lab.  I had trouble with crashes on my physical Windows 98 PC (not as much using a VM) and Vision Command didn't work at all with the camera.  With anything that needs a serial port you can always use a USB to serial adapter, and a virtual machine for older software (the serial port can be passed through).  There are many options for running the old stuff, "eventually" I will have dedicated tutorials showing the pros and cons of different solutions.

If you have any specific questions you can always DM me, just to not get too off topic in threads (I could talk about this stuff forever)

Oh and as far as GBC I had some half-hearted attempts years ago (on my other YT channel) but it's something I'm currently working on, it will take quite a while to have anything worth showing off.

I have a code Pilot.....Just fixed all the wires for it - have a fresh set of stickers for it.  I just need a new set of WHITE rims for it.  I am thinking about building it with remote controls.  I have the space shuttle - in which I fixed all the wires - and a second set which I will be selling.I also have a couple other older sets.  My son and I have alot of kits between us.  I am going to go all out on the GBC and once I get good enough I want to get into the robotics/programming side of things, so I may be hitting you up for that knowledge base you have,  BTW that wire you discovered is simply amazing!

Edited November 25, 2022 by Fyredog

[BatteryPoweredBricks]

Just a quick update on my wire tester.  I was asked to make a how-to video for it so I thought I'd share it here as well.  It's kind of interesting what you can come up with, stacking the connectors in creative ways.  The final version is quite efficient requiring 6 9v wires, still curious if I could get it any lower.  I know I could do the short circuit test with 3 connectors and a 3 way wire but I think it would be a pain to get the individual wires in, it's much easier as a pair.  Anyway if there is anyone out there making dozens of wires at a time, like me, this saves a ton of time!
 

 

[Fyredog]

THANK you for that!

 

I'm going to make one of these!

[UVAChEEngineer]

On 11/25/2022 at 2:08 AM, BatteryPoweredBricks said:

Yep that's me .  I've never even attempted a micro motor repair, from what I've seen there isn't a non-destructive way to do it.  When it comes to Technic I think I have an affinity for the older sets.  One of my favorite projects was adding remote control capability to the old Code Pilot set using an RCX and Power Functions (so much so I did it twice ).  Yeah Windows XP is kind of a sweet spot for Lego Mindstorms / DACTA Control Lab.  I had trouble with crashes on my physical Windows 98 PC (not as much using a VM) and Vision Command didn't work at all with the camera.  With anything that needs a serial port you can always use a USB to serial adapter, and a virtual machine for older software (the serial port can be passed through).  There are many options for running the old stuff, "eventually" I will have dedicated tutorials showing the pros and cons of different solutions.

If you have any specific questions you can always DM me, just to not get too off topic in threads (I could talk about this stuff forever)

Oh and as far as GBC I had some half-hearted attempts years ago (on my other YT channel) but it's something I'm currently working on, it will take quite a while to have anything worth showing off.

Just posted a comment on another, older thread.  I had the same issue but essentially found a way to install VC in English for Win98, copy the back end data files, uninstall VC in English for Win98, install VC in French for XP, and then paste over its data files with the data files from the original install.  Bit of a tedious effort but it ultimately gave me the XP version with more stable QuickCam drivers and ended up having all of the critical menus / buttons, videos, audios, and mission text in English.  Vision Command didn't work well at all in any of the Win98/XP virtual box VMs I set up.  It seems the USB passthrough severely limits data speed and the camera just stutters and stalls until it eventually crashes.  Hyper-V in Windows doesn't have a solution for USB passthrough (I think) and I did not try other VM solutions but I suspect any type of virtualization is going to have issues passing data efficiently for a USB 1.1 camera. You can find that post at: