Why do Power Functions motors need internal gearing

[N-4K0]

How is the Mindstorms-white different from the Technic-white? Is it more bright?

[allanp]

Mindstoms white is more of a very light bley.

[LiamM32]

To the nylon idea: can it be painted just like ABS? I would vomit of pale-white, or just slighty off color gears all around inside a Technic model.

Maybe that's the main reason for ABS

Take apart an m-motor and you'll see. It would look gross in a technic model.

I was also initially wondering about how easy it would be to colour nylon gears, but I deleted it from my post. I assume that you are referring to unpainted nylon, which is most common as colour is not an issue for most non-Lego applications. I have found a few images of painted nylon gears on Google images, and I think I accidentally found a black one in my house just over a week ago. Lego pieces are already produced in various plastics for opaque colours, which reflect slightly differently but overall match-up in colours. This should also apply to painted nylon. There used to be a colour in the palette called "Nature" (on BL "milky white") which was unpainted ABS. It was a translucent-opaque white, similar to nylon, but I think that they should continuse to make this colour only in ABS because other plastics would look too different. Unpainted polycarbonate is given a different title; "Transparent" (still common today). To see for yourself; Here is a photograph from the internet of paint-molded nylon gears;

The blue gears here appear mediocre quality. The black gear better represents the precise Lego molds, and has a fully opaque colour suitable for Lego. If you are still unhappy with the look, than TLG might be able to add gloss to look more like ABS. I personally wouldn't mind it without surface treatments though.

Edited August 31, 2013 by LiamM32

[LiamM32]

Dissapointed that I got no replies to my previous post. I though that it was quite relevent to what others were wondering.

About the nylon; I was thinking that Technic pins might be made of this already. I found an old topic discussing the materials used for Technic, which I was curious about. They were unsure about the pins. But Technic pins are slightly flexible, low friction but sensitive to pressure. Seems like nylon.

Again; What do you think of nylon gears after seeing the image? Should I post to the embassy?

[Junpei]

I don't know, I think pins are made of something other than the liftarms, but not nylon. Sorry, I didn't see the topic. Also, I think any of those gears look like the same quality as lego, maybe it's just the picture but they look really malleable.

[allanp]

I think there are many different formulations and grades of ABS, all suitable for different things such as gears, pins, beams and so on. As well as nylon, some types pf delrin (spelling?) plastic could be useful. It machines great in my iModela! Need to buy some smaller tooling before I can make gears tho. The size of the teeth may also be an issue with fast spinning motors. They can be very noisey and inefficient. That's why they used to use belts and in the planetary gearing of the pf motors the teeth are much smaller. This is one reason why I think a separate pre-built reduction unit with the same gears as you would find inside the current motors would be a better option for ungeared motors than nylon or delrin gears.

Edited September 2, 2013 by allanp

[Junpei]

Ahh yes, that's why my planetary reduction box makes so much noise. At very high (something like 2400 RPM, I think) speeds, it sounds like nails on a chalkboard.

[clarkdef]

Ha just out of the blue, another reason why I think they have gear reduction is because of the melting axles issue. I had this issue when using a non lego motor, the axle went smooth and smelt NICEEE

Also what if kids got their fingers pinched in the cogs, ouch!.. Well it could happen anyway, but it would be more painful.

[Junpei]

Really, I've never had an axle melt before. I have gotten my finger stuck between two 24t gears on an XL though, it was painful.

[LiamM32]

Ha just out of the blue, another reason why I think they have gear reduction is because of the melting axles issue. I had this issue when using a non Lego motor, the axle went smooth and smelt NICEEE

Also what if kids got their fingers pinched in the cogs, ouch!.. Well it could happen anyway, but it would be more painful.

I have not experienced an axle melt either, as I am not as experienced with Technic building as most of you probably are, and never used a high-RPM motor. They could just reduce the internal gearing from 2 lairs of planetary gears to one lair, but the problem with that is that there would be less precision with external worm-gearing.

About the finger pinching; I actually think that it would be less painful if not geared down. I don't think that it would be strong enough to effectively hurt fingers, even though it would spin fast on its own. For extra safety, the motor could have a built-in clutch.

@AllanP: If you could ever make nylon versions of Technic gears yourself, I would love to see a demonstration video. About the size of the gears; That is unfortunate but they should have done it from the beginning of Technic. I think that it is now too late to change it for compatibility purposes, but switching from ABS to nylon would be a big improvement in efficiency. The benefits would not be limited to ungeared motors.

Edited September 27, 2013 by LiamM32

[1974]

RPM is not important, torque is. You do _not_ want your fingers between an XL and some gears

[allanp]

The only times i've had some wear on an axle is when i've geared up an ungeared motor.

RPM is not important, torque is. You do _not_ want your fingers between an XL and some gears

True.

[Blakbird]

There are no Technic parts currently made of Nylon (Polyamide 6/6) that I can think of. It would be obvious. Nylon is much softer than ABS. You can put a permanent dent in a part with your fingernail. However, it is very good for very small gears because of its relatively high strength and the fact that the softness means it will absorb impact without breaking and run quietly. The ABS used for Technic gears is actually much stronger but less resilient.

[weavil]

But they would have to change their machines, because doesn't nylon have a different heating and cooling during molding?

[LiamM32]

There are no Technic parts currently made of Nylon (Polyamide 6/6) that I can think of. It would be obvious. Nylon is much softer than ABS. You can put a permanent dent in a part with your fingernail.[ /u] However, it is very good for very small gears because of its relatively high strength and the fact that the softness means it will absorb impact without breaking and run quietly. The ABS used for Technic gears is actually much stronger but less resilient.

Hmm. The ease to puncture nylon could be a problem blocking it from Lego's quality standards. That is unfortunate, because just about every other property of nylon is about perfect.

Could it be mixed with a small amount of ABS to be made stronger (without raising costs too-much)? Are there higher grades of nylon that are more durable?

I have some more reading to do.

Edit: I found something about mixing nylon with ABS. The article is a decade old. http://www.ptonline.com/articles/new-generation-nylon-abs-alloystarget-automobile-interiors

But they would have to change their machines, because doesn't nylon have a different heating and cooling during molding?

I think so. Nylon has a higher melting point, but it is a thermoplastic like ABS.

Edited September 4, 2013 by LiamM32

[weavil]

I also read on Wikipedia that ABS can have a different hardness depending on the temperature and the time till it's cooled, if I remember right. Its hard to put a link in a post on my phone.

[weavil]

Why couldn't lego do a modular planitary gear set...

somethin like this could work. right? Have a way to connect 0 to 6 or more. Also have it so it could be stand alone as well. Like the motor has 1 set on it and 1 at the wheel.

[Blakbird]

Why couldn't lego do a modular planitary gear set...

They did. This is 20:1 inline gearbox that you could put right onto the 4.5V motor. Of course, you could put more in series.

[allanp]

Well why didn't I think of that! :laugh: :laugh:

But yeah that's the best way, you get ungeared motors that are easily converted to geared motors, so everyone is happy and you get more options as well as a gear unit that can be used anywhere and stacked many times if you like.

Edited September 20, 2013 by allanp

[weavil]

@ Blakbird...

I know they did, but I was thing of something for studless and thinner. It would have 4 mounting points on each section instead of 3 like in the picture.

[LiamM32]

They did. This is 20:1 inline gearbox that you could put right onto the 4.5V motor. Of course, you could put more in series.

Thanks for showing it. I think that someone referenced this part in the first page of the thread, but we couldn't find it on BrickLink.

@ Blakbird...

I know they did, but I was thing of something for studless and thinner. It would have 4 mounting points on each section instead of 3 like in the picture.

I don't think that it should be completely studless. It could be designed for both System and Technic, but I think that it's more important for system models because it's harder to fit Technic gears. Maybe it would be nice if it was designed to fit with the M-motor with 1.5L pins. It should be 1 or 2L long, not 3.

Alternately, they could make a naked planetary gearset.

[Junpei]

Yes, that piece is what I was talking about, it makes an infernal screeching noise when at high speeds. Maybe an updated version of that and an ungeared motor would be beneficial.

[weavil]

I know they did, but I was thing of something for studless and thinner. It would have 4 mounting points on each section instead of 3 like in the picture.

I was referring to the picture I posted. It showed long bolts in 3 mounting points. I was saying have more than 3 around the outside of the housing.

@LiamM32

The idea was to have an XL or Large motor gears on the outside in a housing like in the picture I posted.

[Boxerlego]

The 4.5V motor is ungeared and has a 1:20 gear block attachment, and ends up just being 1 stud longer than the m-motor because of the plugs which lego can now get rid of.

What? The 4.5V motor is being deleted from bricklink?

I actually like being able to plug the electrical connection in to the motors; however, it is understandable that keeping up with the electrical connection and motor separately can be quite the effort.

[Junpei]

I was referring to the picture I posted. It showed long bolts in 3 mounting points. I was saying have more than 3 around the outside of the housing.

I don't think the 3-pin arrangement will work very well, I was thinking the old gear block, but with pinholes arranged like on the front of the l-motor on both sides. That also means that you can keep the studs and anti-studs for system and train builds.