Motor Upgrade

[Boxerlego]

@ Boxerlego: Hey, with that fast-running, modified Lego Power Functions XL motor, one may be able to achieve helicopter flight! Several questions:

1) How hot does the motor become when you run it for an extended period of time?

2) What is the cost of the Neodymium magnets, and do you The Lego Group ever adopting your idea to produce an "XXL" motor someday?

3) Did you modify the PF Battery Box to short-circuit its internal fuse?

@Dluders: Thanks! That sound like something I could maybe attempt, I have a propeller that are 170mm tip to tip in size. Something could be done to them to connect up with out any separation.

Answers:

1) With out the magnets, the motor runs at a moderate temperature and gets warm with prolong use just like any motor. With the neodymium magnet on the motor I suppose that it would get warmer slightly faster and run a little warmer.

2) I've had these magnets for a couple of years now. It cost me somewhere around $4-$5 for 10 neodymium magnets.

3) No. Nothing was done to the PF Battery Box. I thought about using a DC adapter to power the motor but I don't have one at 9v.

The magnets is an interesting idea. You might get better performance if you could arrange them in a cylinder shape, maybe around the inside of the plastic casing?

Apologies if I'm stating the obvious, but applying a current through the wires means they want to move perpendicular to the magnetic field, so you will get a stronger, more efficient effect at the top and bottom of the motor. At the sides (90degrees), the wire is moving parallel to the magnetic field and so there will be no effect, with various, decreasing effect between the two points.

Maybe some of those smaller neodymium magnets (http://www.amazon.co...m magnets cubes or http://www.amazon.co...odymium magnets could be placed around the inside of the casing to give a more regular, smoother magnetic field for the wires to move through? You'd want to ensure that your added magnets' field was aligned with the existing magnets inside the motor (no point in having N-N cancel out) so some trial and error would be required.

p.s. I heard a rumour that small neo magnets might be being withdrawn from sale in the US after some were eaten by a child so grab 'em quick of you're in the US.

Hi chorlton, Thanks for the very interesting suggestions and thoughts. The bar magnet looks good and strong to use if you have a long motor considering that the polarity of the bar is on the top and bottom and not end to end like a conventional bar magnet. I think they would work great on the motor. The case would haft to be modified slightly to allow the bar magnets to stick out with the motor. I want to say that having the magnets closer to the motors armature produces the better torque and RPM. As the distance between the armature and magnet expands it reduces the magnets effect on the torque and RPM.

The motor has a north pole magnet on the right side and a south pole magnet on the left side (180degrees). The motor is small, 25mm from left to right to be exact, and the motor magnets come very close together in the center,roughly 8mm apart, so the motor magnets are not completely surrounding the armature like you see in the XL motor. The neodymium magnet are placed on the motor like this, the motors north pole magnet has the neodymium north pole magnet facing to the motor on top and on bottom and the motors south pole magnet has neodymium south pole magnet facing to the motor on top and on bottom. Basically the neodymium magnets are adding to the already presented magnet field that is in the motor.The neodymium magnets sit slightly behind the magnets in the motor due to the compact design. The magnet don't sit directly over the armature. I've tested a number of possible combinations of the magnets that can be on the motor. I tested two magnets on the motor then to four magnets to keep the field balanced. The arrangement of the four neodymium magnets proved to me to produce the most RPM on the motor. Now if you add more magnets on to the magnet you will have more magnetic field effect. Using small neodymium magnets would be probably be the better option to get some extra RPM and torque with out overdoing the motor and battery on Amps. I've got some really small disc magnets that are able to fit inside the axle/pin hole on the Technic parts. However, using magnet this small will probably have a little effect on improving RPM and torque if used.

[Doc_Brown]

This is a awesome thread! I was thinking of doing the same. Well done, and keep up the great work.

Edit: I forgot to add a capacitor. I should have connected the capacitor up before the JB weld part.

What does a capacitor do? Seen it a few times on motors.

[legomuppet9]

This is a awesome thread! I was thinking of doing the same. Well done, and keep up the great work.

What does a capacitor do? Seen it a few times on motors.

Capacitors store electrical power till they are full and then release it. I think...

[Doc_Brown]

Capacitors store electrical power till they are full and then release it. I think...

LOL, What I meant was what does a capacitor do in respect of connected between the the motor terminals? Is it in case it stalls?

[Boxerlego]

This is a awesome thread! I was thinking of doing the same. Well done, and keep up the great work.

What does a capacitor do? Seen it a few times on motors.

Thanks! I've put up a picture of the Capacitor on the motor wire.

The capacitor in this setup is known as a decoupling capacitor. The capacitor has many effects here. One efffect that having this capacitor will do is increase the commutator and brush life on the motor.

Capacitors store electrical power till they are full and then release it. I think...

LOL, What I meant was what does a capacitor do in respect of connected between the the motor terminals? Is it in case it stalls?

Legomuppet9 has the right idea. See another effect for the capacitor is when you switch motor direction. When you switch the motor direction the capacitor is a reservoir of instantaneous supply of electrical power to the motor to run in the opposite direction...because the capacitor is right next to the motor it is the fastest at delivering the change of current to the motor.

Edited April 21, 2013 by Boxerlego

[Boxerlego]

I took apart the L-motor and the first thing I do is set the L-motor next to the motor in the XL MOD to compare sizes. Both the motors are identical in design alone. However, the L-motor is short in length by a couple of mm compared to the XL MOD motor.

There was another goal on opening up the L-motor and that was to check out the planetary gear box, I've been powering my L-motor is with a 8-cell battery boat 10.7 volts. I've been making a second upgraded XL motor and I wanted to take another direction in building it. I intend to use to the gear box as a guide to build a motor case for connecting and centering the motor up with the XL gear box. Nothing is going to be done to the L-motor and the gear box on it.

-BL

[Doc_Brown]

Thanks! I've put up a picture of the Capacitor on the motor wire.

The capacitor in this setup is known as a decoupling capacitor. The capacitor has many effects here. One efffect that having this capacitor will do is increase the commutator and brush life on the motor.

Legomuppet9 has the right idea. See another effect for the capacitor is when you switch motor direction. When you switch the motor direction the capacitor is a reservoir of instantaneous supply of electrical power to the motor to run in the opposite direction...because the capacitor is right next to the motor it is the fastest at delivering the change of current to the motor.

Wow thanks for all the info guys. Makes a lot of sense now.

I took apart the L-motor and the first thing I do is set the L-motor next to the motor in the XL MOD to compare sizes. Both the motors are identical in design alone. However, the L-motor is short in length by a couple of mm compared to the XL MOD motor.

There was another goal on opening up the L-motor and that was to check out the planetary gear box, I've been powering my L-motor is with a 8-cell battery boat 10.7 volts. I've been making a second upgraded XL motor and I wanted to take another direction in building it. I intend to use to the gear box as a guide to build a motor case for connecting and centering the motor up with the XL gear box. Nothing is going to be done to the L-motor and the gear box on it.

-BL

I'm pretty sure Tamiya do a "racing" version of that motor with a blue plastic part. this if memory serves was much higher quality motor, and would be a easy straight swap. Just an idea.

[Boxerlego]

Interesting! Be careful about using JB Weld epoxy around electric motors -- it has magnetic properties and may affect the motor's performance. See this Eurobricks post for details. Perhaps a non-magnetic epoxy would work adequately, so as not to affect the motor's magnetic field.

I just tested the effect JB weld has on motors by completing my second upgraded XL motor with no JB weld this time around and it spins around 420 Rpm. Compare that to the JB weld motor which spins around 260 Rpm. Now understand that the JB welded motor Rpm was tested during two development stages during the constriction and which both stages tests produced the similar Rpm, first stage was with the liftarms around the motor

, and then the completed design

.

-BL

[Boxerlego]

I just tested the effect JB weld has on motors by completing my second upgraded XL motor with no JB weld this time around and it spins around 420 Rpm. Compare that to the JB weld motor which spins around 260 Rpm. Now understand that the JB welded motor Rpm was tested during two development stages during the constriction and which both stages tests produced the similar Rpm, first stage was with the liftarms around the motor

, and then the completed design

.

-BL

I removed all the JB-weld off the motor and tested it with the second design and the Rpm and it is still the Same 260 Rpm I get some pictures up of what I've done and the second motor too.

-BL

[Boxerlego]

Here is some picture of the second motor design. The first pic is of the motor that had the JB weld job on it. Can you tell which motor it is, top or bottom? The second motor design is able to use any motor that fits inside this shape (see the second picture). I used the original super glue to connect everythingtogether here. Making the plastic part was a very quick process and didn't require much glue to do either compared to the epoxy. All the plastic that made up this part came off the same item and making it was like writing a book. That book started as this. The plastic spool had the right size circle that was able to fit around the motor and the flat end were right for the flat plastic sides that lock the motor in place. Making the parts from the spool is a very precise and critical part and is one part of the key part in making it work. Each plastic part must fit around the motor to form a secure and also removable connection with the motor and must sit straight and level on the planetary gear box as well.

Edited May 11, 2013 by Boxerlego

[Doc_Brown]

Great work! You have inspired me to try some motor modding. :thumbup:

[Boxerlego]

Great work! You have inspired me to try some motor modding. :thumbup:

That is awesome. I cant wait to see your take on this. Will you be improving upon the XL motor also?

Motor upgrade Update: Strengthen the Permanent Magnet on the motor with out removing the magnet in the motor.

I have recently figure out why two identical motors are able to run at different RPM and it involves magnets. Here is a basic How to for you to understand what basically happen to the motor. Now understand that I had bought two motors, I used one motor for the upgrade and I stored the other motor on a neodymium magnet under a metal desk and it was attached to that magnet for several months since like this . There was no intended thought on using the neodymium magnet to strengthen the motors permanent magnets. I was something that was unknowling done. Now I have consider the possibility that there are duplicate version of the motor that spin at different RPM but I've eliminated this possibility out by buying 4 more motors and just by judging by the hum of the motors they sounds just like the motor that spins at 260 RPM. Also just by doing some math and taking the Motor Rpm and multiplying that by the XL planetary gear box 1:36 you get 260rpm*36=9360rpm on the motor shaft @ 9 volts. The technical data sheet for the motor says it spins 12500 rpm @12 volts and that not a big jump from the motor runing @ 9 volts. Now lets grab the motor that spins at 420 rpm @ 9 volts and figure out how fast the motor shaft is and compare to the technical data sheet .... 420rpm*36=15120rpm @ 9 volts. @ 12 volts the motor is rated for 12500rpm. How did this extra rpm appear in the motor especially at 9 volts. It is insane for the motor to run that fast especially @9V which is why I know that the neodymium magnet is the reason for this increase.

Now this is the project. Here is the motor that had the JB weld on it and I am using the 6 powerful n50 neodymium magnet field to strengthen the permanent magnet on this motor. I am going to leave that magnets on this motor to sit there for a couple of months to strengthen the motors magnet field. Current rpm is 260.

Edit : instead of waiting a couple of months I decided to put the motor with the magnets in the freezer suggested by the How to and wait 24 Hours.

Edited May 16, 2013 by Boxerlego

[Doc_Brown]

That is soooo cool!!! Nice trick with the magnets. Does it really work? Can you turn on the motor with the magnets there??

I just got a $9 motor from China, which is rated at 12V 80ma 1000rpm. Well I was very disappointed! From 6v to 12v there is no Rpm increase what so ever! It feels lifeless, SO maybe the magnet trick will work. :)

[Boxerlego]

That is soooo cool!!! Nice trick with the magnets. Does it really work? Can you turn on the motor with the magnets there??

I just got a $9 motor from China, which is rated at 12V 80ma 1000rpm. Well I was very disappointed! From 6v to 12v there is no Rpm increase what so ever! It feels lifeless, SO maybe the magnet trick will work. :)

Well it has been a week and a couple of days since the neodymium magnet has not been on the motor and the motor is still spinning around 400-420 rpm@ 9volts and I've ran this motor pretty long the other day testing out the pneumatic pump regulator. I believe it works. I see that cold temperature is key here for strengthening the magnet field because the opposite is true when you heat the magnet up.

I can turn the motor on no problem with the magnet there. When you have the Neodymium magnets on the motor it appears to make way to much current come from the battery than a permanent magnet would require. You can see this here in the video

Your motor appears a little slow, 1000rpm in not much compared to the XL motor that spins around 8000 rpm, even with the addition of strengthening the permanent magnet on the motor it might come up to speed with the PF motor.My first motor was from a 18 volt cordless drill found in the trash can. That motor took way to much current to run off the battery box 800ma fuse and would only run for a second. The FC-280PC motor that is used in the XL motor upgrade can possibly be found in car door. Here is a technical data sheet of this motor.

Edited May 16, 2013 by Boxerlego

[Doc_Brown]

This is what I brought, my mistake $15! Urgh

http://www.ebay.com....984.m1439.l2649

I was under the impression that it would be higher Rpm then geared down to 1000 after the lil gearbox. I guess the motor actually does 1000rpm, or it is a dud.

Are you sure that FC-280PC is used in XL motor? I thought

FC-280PC was used in M and L motors.

Are you sure that it is 800ma cutoff? I thought it was 2A?

Edited May 16, 2013 by Doc_Brown

[Boxerlego]

This is what I brought, my mistake $15! Urgh

http://www.ebay.com....984.m1439.l2649

I was under the impression that it would be higher Rpm then geared down to 1000 after the lil gearbox. I guess the motor actually does 1000rpm, or it is a dud.

That gear box is not a mistake, maybe the motor is a dud but the gear box is not. That gear box can connect to any motor that will fit. 15$ for that gear box is not bad, one XL motor cost around that price so you did well.

Are you sure that FC-280PC is used in XL motor? I thought

FC-280PC was used in M and L motors.

The L-motor is slightly smaller than the FC-280PC motor. And the M-motor is smaller than the L-motor, However, the "planteary gears" in the gear box on the M and L motor are exactly the same. I will get some pictures up of this along with the m-motor as well.

Are you sure that it is 800ma cutoff? I thought it was 2A?

Here is a link to the 8881 batter box. Check it out, see it for yourself.

[Doc_Brown]

OK cool 800ma it is. So if you want 2 of the most powerful motors per battery box you really can't exceed 280ma per motor.

Yeh my motor is a dud, i can see the magnets inside are not alighted, obviously not glued in correctly. and its making a screechy sound now. hahaha

My local electronic store sells good motors, I will post there data sheet soon.

trying to get one that's 27mm dia, so will fit in a 4 x 8 battery box (old one)

Thanks for the info

[Boxerlego]

Update: 48 hour test

I've tested the motor that was in the freezer (for about 2 days) with the n50 Neodymium magnets and the motor still runs around 260 RPM . I am starting to see that the problem with that test was that the motor with neodymium magnets was not stuck to a metal mass like how the first motor was stuck underneath the metal desk. Before I start doing more test on strengthening the permanent magnet on the motor. My next test is to figure out if the faster motor magnets are at equal level of strength or if one is stronger than the other. If one of the magnets are stronger then the other that could be a result from the strengthening of the permanent magnet with a stronger magnet. If the magnets are at equal level of strength, then that would possibly show that the motor came from the manufacturer with the stronger magnets. When I can determine a test on how to measure the strength of the magnet is on the motor then I will be able to compare and proving that a magnet is indeed stronger than another.

-BL

[Boxerlego]

The L-motor is slightly smaller than the FC-280PC motor. And the M-motor is smaller than the L-motor, However, the "planteary gears" in the gear box on the M and L motor are exactly the same. I will get some pictures up of this along with the m-motor as well.

Here is a deeplink of the M-motor along with a comparison picture of the two planetary gear boxes for the M and L motor.

I've open up one of the motor I recently got. To have some to compare against when I open up the motor that spins 420 rpm.

My next test is to figure out if the faster motor magnets are at equal level of strength or if one is stronger than the other.

I've just done a simple test to determine if the magnet is stronger than the other on the motor that spins 420 rpm. Well it appear that one of the magnets is in fact stronger than the other magnet. In fact the weak magnet on the motor barley showed any attraction in the simple test; Also the magnets that are on the all motors that spin around 260 rpm are stronger than the magnets in the motor that spins faster than them. I will get a video of this simple test showing strength of the magnets on the motors along with the speed of the fast motor.

-BL

[Doc_Brown]

Heres the motors that are available of the shelf here in OZ.

Im thinking the ym-2716 as it is 27mm dia, so will fit inside 4x8x4 studs, and has a draw of .28a so 2 could be powered by a battery box and still be almost twice teh power of the RC motors.

Edited May 19, 2013 by Doc_Brown

[Boxerlego]

Heres the motors that are available of the shelf here in OZ.

Im thinking the ym-2716 as it is 27mm dia, so will fit inside 4x8x4 studs, and has a draw of .28a so 2 could be powered by a battery box and still be almost twice teh power of the RC motors.

Nice! That is a good motor, the only problem with the motor is the 2.3mm driveshaft size. Now this does not mean you cant use the motor with the XL gear planetary gear box. The pinion gear is the major problem here because the pinion gear that is in the XL motor fits on the 2mm driveshaft. There is probably a pinion gear that can fit with the 2.3mm driveshaft and inside the XL gear box as well, finding it is the problem. I will get a detailed picture up of the pinion gear.

[Boxerlego]

[Doc_Brown]

WOW. that's a really interesting test, so the weaker magnets equal higher RPM?

I'm hoping that with a bit of "force" it will fit 2mm, hahaha.

[Boxerlego]

Be careful with putting the pinion gear on. I thought about doing that but I was afraid that the pinion gear would crack if I put it on the 2.3mm driveshaft. I've been searching for pinion gear with a 2.3mm hole that would be identical match to the pinion gear for the 2mm driveshaft from the time I started this topic.

Yea, I've seen many people think the same thing. weaker magnet faster motor I am going to show more test of this motor and get the multi-meter on it because it does everything better and some other interesting stuff like so... In the video you can see that the one side of the faster motor was able to pick up some ball bearings. Well the motor that spins faster only spins 420 rpm clockwise. In fact when you power the motor in the other direction it spins around 380 rpm counter clockwise. Basically, I am starting to understanding that the unused part of magnetic field is now being used resulting in faster RPM and more power.

[Boxerlego]

Edit: I am remaking this video.

Edited May 24, 2013 by Boxerlego