I recently aquired a third party 9V motor and I've decided to try and implement it into Lego for making RC vehicles. I have started this topic to document my progress so that even if it doesn't work out then I hope some of you can learn from my mistakes. The motor is currently running at about 7.75V and spins at either 18 or 20,000rpm (I can't remember which ) and also works with the powerfuncions Infrared system. Here is a video:

There are some things I would like to know though:

Have any of you ever tried anything like this before? If so, how did it go?

Do you have any hints or advice?

Do you know of any problems that might come up and/or how I can overcome them?

I'll try to post regular progress and I hope you'll all find this as interesting as me and maybe learn something from it. Feel free to discuss anything realated too!

[edit]: no bricks have or will be modified/cut. I want to be as purist as possible!

Edited January 28, 201411 yr by MrNumbskull13

Have you tried running motor with gears for longer time? I would worry about gear overheating due to friction, as motor spins really fast.

Have you tried running motor with gears for longer time? I would worry about gear overheating due to friction, as motor spins really fast.

Not yet, but once I solder the wires and machine up a metal connector i will see how it goes, that was another thing I was worried about. Would some sort of lubricant help?

Edited January 28, 201411 yr by MrNumbskull13

Maybe, even though I think it could be prone to slipping or lack of power. Good Luck.

.

Even lego XL motors can grind axles to dust, place it on a dark towel or black piece of card and run it for a while then tap it after to see if there is powder coming off from the parts.

Edited January 28, 201411 yr by JM1971

Have you tried running motor with gears for longer time? I would worry about gear overheating due to friction, as motor spins really fast.

I once made following experiment: typical axle in liftarm hole was loaded with ~1 kg and spun @ 5000 RPM for 30 seconds. It has marks of heavy wear when I tried this without lubrication and looked ok when greased. 1 kg is rather high load, however I did not tried it without applying any load or at smaller loads and longer times.

Photo:

http://img.osudim.org/221/axle-damaged-1.jpg

http://img.osudim.org/221/axle-damaged-2.jpg

full size:

http://img.osudim.org/gal/221/9/Original_axle-damaged-1.jpg

http://img.osudim.org/gal/221/9/Original_axle-damaged-2.jpg

Hmm, it seems wear & tear is the main issue here. The gears should be ok if I brace them well enough, but the axles might be an issue... I'll see how it goes.

Do you know of any problems that might come up and/or how I can overcome them?

Once I built a similar motor in a Lego moc, and the holes of the axles, and the axles too, were melted after a while because of the high rpm and load. So the loaded parts will be melted, if it runs enough long. Nowadays, I got some ball bearings, and when I will use again a strong/high rpm non Lego motor, the bearings will have the load. If you need, I can show some pictures about the placing of the bearings in the Lego structure.

Once I built a similar motor in a Lego moc, and the holes of the axles, and the axles too, were melted after a while because of the high rpm and load. So the loaded parts will be melted, if it runs enough long. Nowadays, I got some ball bearings, and when I will use again a strong/high rpm non Lego motor, the bearings will have the load. If you need, I can show some pictures about the placing of the bearings in the Lego structure.

That would be very helpful actually....

Nice work. This is how it starts. Do you have any technical data on the motor?

Nice work. This is how it starts. Do you have any technical data on the motor?

Sadly all I know is that it's a 9V motor that spins at either 18 or 20,000rpm. There isn't and numbers or letters printed on the motor either :/

This looks like a great find because the motor looks like it fits perfectly inside a 3 stud length. The motor sounds very fast in the video. Did you buy this motor off the web or did you salvage it out of something? I prefer buying the motors over salvaging them. The big problem with salvaging motors out of old power drills and printers and other stuff is going out and getting another one also there is the risk of the motor being worn down enough where it is on the verge of breaking.

It was from the Internet I think! My grandad actually sent me them and this was the fastest one so I've decided to try it out first. I thought about taking a motor from a drill before I done this actually. I'll make another video once I get the gear connector made, maybe before I solder the wires. I'm glad you've taken interest in my project. :)

Ps. I can find out where the motors came from if you like?

That Is awesome! Find out everything you can about the motor. Having that technical data sheet will help in figuring out how much the expected power output of the motor is and how well the Lego Ir receiver can handle the motors load. I am very interested here and what you plan to do with the motor. Will the motor have a fixed gear on its shaft?

I'm thinking about putting a Dewalt drill motor in Lego. My dad works at Dewalt, and he can easily get free tools.

I'm thinking about putting a Dewalt drill motor in Lego. My dad works at Dewalt, and he can easily get free tools.

I thought about using a drill motor, they can spin very fast and the must have a lot of torque to be able to drill. My only concern would be that it might destroy your lego. Let me know how it goes! :'D

I thought about using a drill motor, they can spin very fast and the must have a lot of torque to be able to drill. My only concern would be that it might destroy your lego. Let me know how it goes! :'D

I said I thought about it. I still am not sure about it though. You know, you can still run higher power motors at the standard current from a Lego battery box. The current and voltage rating is just a maximum.

I said I thought about it. I still am not sure about it though. You know, you can still run higher power motors at the standard current from a Lego battery box. The current and voltage rating is just a maximum.

What is the current rating for the AA battery box? If I removed the current limiter would my motors have more power?

What is the current rating for the AA battery box? If I removed the current limiter would my motors have more power?

I don't know the current rating. It probably depends on what type of AA batteries you use. I haven't experrimented with the current limiter, but I'll give it a try, since I have some extra battery boxes.

I don't know the current rating. It probably depends on what type of AA batteries you use. I haven't experrimented with the current limiter, but I'll give it a try, since I have some extra battery boxes.

Don't go destroying battery boxes just for me hahah! I would rather keep mine the way they are tbh, I'm new to electronics and wiring a motor is complex enough for me! :P

Don't go destroying battery boxes just for me hahah! I would rather keep mine the way they are tbh, I'm new to electronics and wiring a motor is complex enough for me! :P

I was probably going to do it sometime anyway... I somehow have more battery boxes than working motors.

There is going to be wear and tear due to using a drill motor. But you in order to minimize that wear your going haft to contain that power flow because the motor will expose all the weak areas in your build.

But first there are some problems that must be solved before tying to use the drill motor.

When I first started testing my drill motor, I quickly found out that the motor needs way more power from the PF battery box and PF receiver than it will handle. So I decided it would be best to power it from an DC adapter.

Here is a quick

of this test run.

I think your link goes to the wrong video...

But I did find one of your videos with a 12V drill motor, it goes really fast but how did you connect it's driveshaft to lego?

That Is awesome! Find out everything you can about the motor. Having that technical data sheet will help in figuring out how much the expected power output of the motor is and how well the Lego Ir receiver can handle the motors load. I am very interested here and what you plan to do with the motor. Will the motor have a fixed gear on its shaft?

I'll try my best to find out more about the motor. I think I'll make a trophy truck with it and yes the gear will be fixed.

I think your link goes to the wrong video...

Its the right video. The drill motor video part starts around at 4:07. I tried to make the video link begin at that time frame.

I'll try my best to find out more about the motor. I think I'll make a trophy truck with it and yes the gear will be fixed.

Let me tell you a story.

Awhile back I put two custom motors on the 9398 crawler to see how the v2 receiver handles them. It worked fine, just like if it was powered by the L motor, but because of the planetary gear train is not there on the custom motor, the gear ratio is no where near the L motor design. With the number of limitations going on with the setup I was surprised at the speed that was achieved.

Edit:

But I did find one of your videos with a 12V drill motor, it goes really fast but how did you connect it's driveshaft to lego?

With JB weld.

Edited February 12, 201411 yr by Boxerlego