LEGOTrainBuilderSG Posted October 23, 2021 (edited) Hi everyone, the PF L-Motor in my MR 20 Class was running well up until today.. It appears that the motor got 'weaker' as it can longer crawl at 'Speed 1' but starts moving only at 'Speed 2'. I thought maybe the battery was low? So I changed them to 6x brand new energzier 1.5v AAA but the L-motor was still problematic with stuttering at low speeds. Also, from the video, you can see that the L-motor needs a little nudge on the gear connecting to the axle for it start moving. Upon change in direction, the motor would freeze up. You can hear the PF motor trying to move and you can see a little twitch in the gears but nothing happens.. interestingly, you can hear the rev up sound from the PFx brick suggesting that the motor should have been moving. I don't think the axle and gears through to the bogies are a problem because my other locomotive, 24 Class, uses the same technique and it runs well with a different L-motor. Furthermore, without the L-motor, the axle and gear mechanisms appear to run smoothly when pushed along the track. So, based on all these information and video, do you think this L-motor is faulty? or about to burn out? Have any of you experienced this with your PF L-motor? Times like this made me wish there was a narrow gauge train bogie.. Appreciate all the help and feedback! https://www.flickr.com/photos/108174470@N03/51622438094/in/dateposted-public/ Edited October 24, 2021 by LEGOTrainBuilderSG Share this post Link to post Share on other sites
zephyr1934 Posted October 24, 2021 I'm not a motor expert, but it could be that your motor is burning out. It could also be that the drive mechanism (and other trucks on the engine if using technic axle wheels) are just building up more friction. Even if the motor turns out to be fine right now, eventually it will wear out so you might want buy a couple of L motors or make sure you can upgrade to a PUP L motor (via some adapter or splicing the right wires) when the day comes. If PF L are more expensive than PUP L at this point, I'd just start planning for the PUP path. Share this post Link to post Share on other sites
AlexxInc Posted October 24, 2021 (edited) You might have been running it through multiple gears over a significant period of time causing the motor to lose it's strength. You may want to buy new motors as @zephyr1934 stated. If this option is too expensive, there are some companies who make replicas/alternative in which can perform better under certain circumstances. I hope this helps you. Edited October 24, 2021 by AlexxInc Share this post Link to post Share on other sites
LEGOTrainBuilderSG Posted October 25, 2021 14 hours ago, zephyr1934 said: I'm not a motor expert, but it could be that your motor is burning out. It could also be that the drive mechanism (and other trucks on the engine if using technic axle wheels) are just building up more friction. Even if the motor turns out to be fine right now, eventually it will wear out so you might want buy a couple of L motors or make sure you can upgrade to a PUP L motor (via some adapter or splicing the right wires) when the day comes. If PF L are more expensive than PUP L at this point, I'd just start planning for the PUP path. Ahh thanks for your feedback. I think it might be burning out too.. not sure why. I am using technic axles on the wheels but without a motor attached, the train rolls nicely with some inertia rolling after a push. Just checked Bricklink and as of now, the PF L and PUP L motor costs roughly around the same price. I think I'll probably get 5 - 6 L - motors. I hope I don't have to switch over to PUP. No idea where to get the adaptor to plug into the PFx brick. 6 hours ago, AlexxInc said: You might have been running it through multiple gears over a significant period of time causing the motor to lose it's strength. You may want to buy new motors as @zephyr1934 stated. If this option is too expensive, there are some companies who make replicas/alternative in which can perform better under certain circumstances. I hope this helps you. I see! Do you have any recommendations for these alternatives? (want to know that I have alternatives in the future!) Share this post Link to post Share on other sites
dr_spock Posted October 25, 2021 Your motor is showing signs of wearing out. They do that sooner or later depending on the load conditions placed upon them. There are ways to connect a PU motor to PF. You can wire pin 1 & 2 of the PU connector to the C1/C2 pins on the PF connector. Some PU motors have rotation sensors but Power Functions have no support for that feature. PF cable from burned out motors makes a good adapter. Share this post Link to post Share on other sites
AlexxInc Posted October 25, 2021 (edited) 9 hours ago, LEGOTrainBuilderSG said: I see! Do you have any recommendations for these alternatives? (want to know that I have alternatives in the future!) One alternative is Green Gecko Workshop. It is still on the pricey side but there are some YouTube videos showing the performance. If this is still a bit much you could settle for Ali-Express off brand motors, I'm not too sure how their quality and durability is thought. Another option could possibly be to find used lots of LEGO motors on eBay or another online marketplace. Edited October 25, 2021 by AlexxInc Share this post Link to post Share on other sites
