Answers.Body: <p>In my case, the gear next to the slipping clutch was cracked. Since it is only pressed on, it can no longer transmit large forces and the slipping clutch slips in the wrong place.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2021-12-26T13:13:15.243Z
Answers.LastActivityDate: 2021-12-26T13:13:15.243Z
Answers.UserDisplayName: LegoTechniker
Answers.Body: <p>I'm currently in the throes of repairing one very similar - directly above the driven wheels are two alloy blocks.  It looks like mine were originally glued, but over time and with use, that glue has deteriorated and I think the blocks tend to drop onto the wheels slightly, creating drag. I have used contact cleaner to remove dirt and grime collected over the years from carpets. etc - then applied a little &quot;liquid insulation&quot; (i.e.; liquid rubber that sets fully in 24 hours to make sure they stay snug inside their bespoke compartments when cured. I've also used the contact cleaner on the circuit board and electrical connections. It's still apart, so this is just a suggestion at the moment - time will tell as to its success.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-12-22T18:02:58.973Z
Answers.LastActivityDate: 2024-12-22T18:02:58.973Z
Answers.UserDisplayName: Ian N
Body: <p>I've recovered my old LEGO Duplo set from the attic, and tried to get the electric train working again. After inserting fully charged batteries, the train does start, but it's unable to pull even a single wagon.</p>
  <p>I've also tried using Duracell batteries, but that gives the same result. I've already opened up the train and my dad says he can see a little crack in one of the gears, but the train still runs when using Hameg PS and even with the batteries.</p>
  <p>Can I get this thing working again somehow?</p>
  <p><a href="https://mintplayer.com/Uploads/duplo-train.mp4" rel="nofollow noreferrer">Here is a video of the train with a single wagon</a></p>
  <h2>Edit</h2>
  <p>I tried hooking up power.</p>
  <p>And at first it started to drive smoother, but after like 5 seconds it got to a halt again. When lifting the train, the wheels spin again, but when putting it down again it just stops. The wires are not in the way for sure.</p>
  <p><a href="https://mintplayer.com/Uploads/20210929_141609.mp4" rel="nofollow noreferrer">Here is the video of the train wired to the power</a>.</p>
  <p>Currents are:</p>
  <ul>
  <li>75 mA while driving</li>
  <li>120 mA when stuck</li>
  </ul>
  <p><a href="https://i.sstatic.net/WpUvR.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/WpUvR.jpg" alt="Duplo train wired to power source" /></a></p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-09-29T08:26:14.333Z
Comments.Text: Hi Pieterjan, and welcome to Bricks! Does it also fail to pull a wagon when using the Hameg PS as well? From the sound in that video, I'd hazard a guess that there's a an issue with the clutch mechanism - to reduce the chance of damaging either the motor or small train drivers fingers the wheels have a clutch mechanism to stop them turning if there's something blocking them. Have you seen [this question on stripping down the drive wheels](https://bricks.stackexchange.com/q/13425/56)?
Comments.UserDisplayName: Zhaph - Ben Duguid
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-09-29T12:32:04.150Z
Comments.Text: Hi, thanks for the response. I did try your suggestion, and updated the question.
Comments.UserDisplayName: Pieterjan
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-09-30T11:37:49.727Z
Comments.Text: Can you get a good look at the battery contacts? Corrosion (especially from leaked batteries) can cause a high resistance.  OTOH from the video, the motor is still turning, so it's getting power and we're looking for a mechanical fault.  If you turn it on upside down, do the wheels turn? How easy are they to stop with a finger, and does this stop the motor noise?
Comments.UserDisplayName: Chris H
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-09-30T12:01:32.247Z
Comments.Text: Thanks. Upside-down the wheels are able to turn but still with the clicking noise twice a second. Gently pushing against the wheels doesn't stop them from turning yet, but pushing slightly harder does block the wheels. The clicking noise still persists though
Comments.UserDisplayName: Pieterjan
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-09-30T12:09:29.503Z
Comments.Text: And I would consider buying a new train set, but that would render the special tracks useless. Although [this](https://i.ebayimg.com/thumbs/images/g/2-oAAOSwF3VgjAZC/s-l300.jpg) is probably the only part that will not be usable...
Comments.UserDisplayName: Pieterjan
Tags: <trains><duplo>
Title: Old LEGO Duplo train not working on batteries
UserDisplayName: Pieterjan
ThreadText: # Old LEGO Duplo train not working on batteries
  
  (Asked by: username_0 on 2021-09-29)
  
  I've recovered my old LEGO Duplo set from the attic, and tried to get the electric train working again. After inserting fully charged batteries, the train does start, but it's unable to pull even a single wagon.
  
  I've also tried using Duracell batteries, but that gives the same result. I've already opened up the train and my dad says he can see a little crack in one of the gears, but the train still runs when using Hameg PS and even with the batteries.
  
  Can I get this thing working again somehow?
  
  [Here is a video of the train with a single wagon](https://mintplayer.com/Uploads/duplo-train.mp4)
  
  ## Edit
  
  I tried hooking up power.
  
  And at first it started to drive smoother, but after like 5 seconds it got to a halt again. When lifting the train, the wheels spin again, but when putting it down again it just stops. The wires are not in the way for sure.
  
  [Here is the video of the train wired to the power](https://mintplayer.com/Uploads/20210929_141609.mp4).
  
  Currents are:
  
  * 75 mA while driving
  * 120 mA when stuck
  
  [![Duplo train wired to power source](https://i.sstatic.net/WpUvR.jpg)](https://i.sstatic.net/WpUvR.jpg)
  
  **Tags:** trains, duplo
  
  > **Comments:**
  > **username_1**: Hi username_0, and welcome to Bricks! Does it also fail to pull a wagon when using the Hameg PS as well? From the sound in that video, I'd hazard a guess that there's a an issue with the clutch mechanism - to reduce the chance of damaging either the motor or small train drivers fingers the wheels have a clutch mechanism to stop them turning if there's something blocking them. Have you seen [this question on stripping down the drive wheels](https://bricks.stackexchange.com/q/13425/56)?  
  > **username_0**: Hi, thanks for the response. I did try your suggestion, and updated the question.  
  > **username_2**: Can you get a good look at the battery contacts? Corrosion (especially from leaked batteries) can cause a high resistance.  OTOH from the video, the motor is still turning, so it's getting power and we're looking for a mechanical fault.  If you turn it on upside down, do the wheels turn? How easy are they to stop with a finger, and does this stop the motor noise?  
  > **username_0**: Thanks. Upside-down the wheels are able to turn but still with the clicking noise twice a second. Gently pushing against the wheels doesn't stop them from turning yet, but pushing slightly harder does block the wheels. The clicking noise still persists though  
  > **username_0**: And I would consider buying a new train set, but that would render the special tracks useless. Although [this](https://i.ebayimg.com/thumbs/images/g/2-oAAOSwF3VgjAZC/s-l300.jpg) is probably the only part that will not be usable...  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_3 on 2021-12-26. Score: 1
  
  In my case, the gear next to the slipping clutch was cracked. Since it is only pressed on, it can no longer transmit large forces and the slipping clutch slips in the wrong place.
  
  
  ---
  
  ### Answer by username_4 on 2024-12-22. Score: 1
  
  I'm currently in the throes of repairing one very similar - directly above the driven wheels are two alloy blocks. It looks like mine were originally glued, but over time and with use, that glue has deteriorated and I think the blocks tend to drop onto the wheels slightly, creating drag. I have used contact cleaner to remove dirt and grime collected over the years from carpets. etc - then applied a little "liquid insulation" (i.e.; liquid rubber that sets fully in 24 hours to make sure they stay snug inside their bespoke compartments when cured. I've also used the contact cleaner on the circuit board and electrical connections. It's still apart, so this is just a suggestion at the moment - time will tell as to its success.
  
  
  ---
  
  