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Thanks, I appreciate all of your inputs. I will play around with all the inputs Ive got and post the results here at some point! I can source generic parts from China with reasonable (not cheap) prices, but 60 days delivery time. My local currency is very weak, buying original parts here is prohibitive, all my original sets are from when I lived overseas. Nice! Awesome model and a creative workaround!

No worries. Thanks for all the help you have given me here and in the other topic. Really appreciated. I have an arduino with bluetooth controler and a raspberry pi somewhere, I plan to do some lego experimenting with them and lego at some point in the future. The servo will come handy then. For now I will give it a go with the a return to center system using shock absorbers and a PF L Motor (I have only 1 L and 1 XL). https://rebrickable.com/mocs/MOC-0514/Driva00sCreations/lego-return-to-center-steering/#details Hopefully the RC receiver + the L Motor protection systems will be able to protect the motor while still letting things work properly. Otherwise I will try feeding the motor with 6.8V with some relays. Cheers! Thats a good idea. I didn´t think of adding more of them together. I actually might need to buy some. I will give it a go, thanks!

Impressive! It took me a while to digest it all, but I really need backward steering and I am not sure how the system would behave at high speeds.

Very nice, it is the first time I hear about GeekServo. Do you have any suggestions on how to control it? I assume I need a receiver board + controller.

Can the servo motor actually work reliably? I have two here, both of them generic and new, both started to glitch in the second day of use. I have opened them, inspected the contacts, clenned (although they were not dirty).... one burned after I insisted on using it despite the glitches The idea of having a custom made battery pack sounds awesome. Both my power back and my relay box end up being much bulkier than needed. I am switching all the high current circuit lego electrical connections to the ones you can below, to avoid melting more lego connectors.

Thanks for the detailed reply. I will try two motors in the same axle and see where that takes me. At first I thought I was going to need two battery packs, but in the end it worked well with just one. The power pack has two outputs, one for the IR receiver and one for the buggy. The IR receiver controls the relays that switch power to the buggy. This way the high current that is drawn by the buggy motor dont pass through the IR receiver. Originally I had the servo motor connected directly to the IR receiver, but it started glitching too much, and it eventually burned. Having 11 V connected to it certainly did not help, but the current was kept low by the IR receiver, so I don't believe the 11 V was the root cause of the failure. I see that you repplied to my thread asking for help with a steering solution, I will repply to you there about this part. That is awesome! And you actually have two separate power packs! Lots of inspiration from your setup, thanks for the detailed description! You might be able to get power from two 18650 for the steering stuff, saving the need for the secondary power pack.

Nice! Yes, I have experienced that problem with my PF plugs, I think 2 or 3 melted already. Changing them for more robust connectors is in my to-do list. Why did you decide to go with an independent motor per wheel? How are you controlling the motors? I am using 4 relays to isolate the control signal (low current) that comes from the IR sensor to the power signal (high corrent) that goes to the buggy. Drive train wise, here are the desing options I can think of, but I am not sure on the (dis)advantages of each of them: 4WD - one buggy motor for each differential (front and rear). 2WD - one buggy per rear wheel 2WD - two buggy connected on the axle that goes to the rear or front differential Appreciate any thoughts you have on it, Thanks!

Hey all, I am looking for suggestions on how to make my car go very very fast. I am currently using a buggy motor connected directly to the rear differential, to reduce loses. I am powering it with 3 x 3.7V, 3400 mAH, 18650 li ion, rechargeable batteries to give it some extra juice, and controlling it with an IR RC. Without any load the wheels go very fast, but once I put it in the ground, it slows quite a bit because of the weight of the power pack - and that is also why I think a gear box is to the solution to make it go faster. I feel the only path is to add more motors, but I am a bit lost on how to do that. Would adding two buggy motors in the same axle be a good idea? Thanks a lot!

Hello all, I am building a medium car model using an infrared remote control and a buggy motor, all generic. To give a bit more juice I am using 3 x 3.7V, 3400 mAH, 18650 li ion, rechargeable batteries. The two servo mottors I have are giving me all sorts of trouble. From my experience and from the topics I have seen here, it seems they are a big source of headache. It seems to me that an alternative for the servo motor is to use a return to center mechanism with a normal motor and shock absorbers or rubber-bands, like to ones seen here: https://brickshelf.com/cgi-bin/gallery.cgi?f=468843 My understanding is that these designs will stall the motor, which might result on high currents and a potential motor failure - I am considering that my generic PF M motor does not have a reliable protection system that will prevent it from frying, especially as my power pack is already over tha standard specs. I found more info on motors stalling here: https://philohome.com/motors/motorcomp.htm. Therefore I am looking for ideas on how to have a good steering system for a medium sized car without a servo, and without stalling the motor. Thanks! I have found this similar question from some 12 years ago, but many of its references are dead, and hopefully some new ideas came up since then.