16 teeth gears and other questions of technic concern

[Darth Legolas]

Referring to this handy image from Sariel:

What are 16 teeth gears good for besides connecting to themselves? I can't find any gear (and I have all teeth counts besides the 12 teeth gears) that links to them besides another one of them.

Also, I'm planning on buying the Tractor with log loader sooner or later, and all I've heard about it from our handy review by Blakbird is that it needs more logs. How well does the power functions compressor work? Is it a good buy? Is that tractor worth it? How ugly is the loader?

Now, one last question. I recently purchased the latest three technic mini sets, the Tractor, the Bulldozer, and the Mini Telehandler. Unfortunately, they all do pretty much the same thing, you twist the worm/spiral gear and the arms lift up and down. That also means, unfortunately, they all have the same problem. Because of gravity, when you twist the arms up, they have a smooth steady pace upwards, but when you twist them down they move shakily and pause a lot. When turned upside down, the reverse happens. I assume this is because when moving down, the force of the outwards arm is pushing down, so when you move it the way it wants to go, it will go down fast and skipping, in a way. When you move it up, it's your force against its, so it goes smoothly with an equal balance. Is there any way to fix this?

Thank you!

[Siegfried]

What are 16 teeth gears good for besides connecting to themselves? I can't find any gear (and I have all teeth counts besides the 12 teeth gears) that links to them besides another one of them.

I could be missing your meaning, but it's OK to link 8 teeth gears to 24, and 16 to 8... In any case, the first 16 is a axeled one, and the second isn't thus it can be used differently. It's also used in transmissions. Similarly, the first 24 is normal, the second is torque limited, and the third is a "Crown" gear that's used for 90 degree connections. (Not as useful as it used to be since most gears are now bevelled and can do 90 degree connections too!)

When you move it up, it's your force against its, so it goes smoothly with an equal balance. Is there any way to fix this?

Not to my knowledge, but I've never seen it as a big problem. But there are loads of Technic experts here...

[CP5670]

What are 16 teeth gears good for besides connecting to themselves? I can't find any gear (and I have all teeth counts besides the 12 teeth gears) that links to them besides another one of them.

I think I see what you're saying. You can connect that gear to most of the others by using holes spaced at non-integer distances. Here is an example with the 8t gear.

I assume this is because when moving down, the force of the outwards arm is pushing down, so when you move it the way it wants to go, it will go down fast and skipping, in a way.

That generally indicates that some axle in the geartrain is encountering friction. Make sure all the axles are spinning freely without any resistance. I only have the bulldozer but it has no problem with this.

[Darth Legolas]

I think I see what you're saying. You can connect that gear to most of the others by using holes spaced at non-integer distances. Here is an example with the 8t gear.

That generally indicates that some axle in the geartrain is encountering friction. Make sure all the axles are spinning freely without any resistance. I only have the bulldozer but it has no problem with this.

Thanks (I actually understood what you were saying about the teeth!), but now you proposed to more questions!

1. What do driving rings do? I have been looking for pictures but so far, the only use I've found is the one in the picture you just posted, and I still don't see the purpose, though there obviously must be.

2. A. My PF truck that I made, still kind of a WIP, goes extremely slowly. The driving is an M-motor going through a gearbox like the one in the X-wing, pulling one axle. I know that's not a lot of detail, but here's more information:

B. The drive motor is linked to a 2 cylinder engine (that's all I have ), and for some reason, when I tried gearing it down, it went even slower! How did that happen?

I'm assuming that the weight the motor has to pull and the gears it has to turn is what makes the thing crawl, but why did my engine slow down when I geared it down? Shouldn't it have gone faster?

Thanks!

[grepin]

1. What do driving rings do? I have been looking for pictures but so far, the only use I've found is the one in the picture you just posted, and I still don't see the purpose, though there obviously must be.

This should enlighten you

You can see more here (in Technical Functions -> Transmission).

[allanp]

The 16t gear can be meshed with a 20t gear when it is off-set to one side or the other by one hole distance as seen here:

http://www.peeron.com/scans/8419-1/34/

Incidentally the same distancing of axles allows you to mesh a 12t double bevel gear (or even two 12t bevels back to back facing each other) with a 24t gear, as seen here:

http://www.peeron.com/scans/8436-1/7

Here we can see a pattern. If you add the number of teeth in the first combination of gears (16+20) and the number of teeth in the second combination of gears (12+24) you get 36 both times. So if you want to use two different gears in this same spacing, as long a the teeth add up to 36 it will work in that spacing. For example:

The first differencial Lego released had 28 teeth. This means using the same spacing, we can drive it with an 8t gear, as 28+8=36.

[Jetro]

Although the 16 tooth gear is most frequently used to translate movement sideways, there are many ways in which you can use a 16 tooth gear in combination with other gear sizes. I have a little contraption on my desk that meshes 16 tooth gears (z16 for short) with z20 and with z24. You can also make it mesh with a turntable (z56) or a wormgear (z1) to mention just a few other possibilities.

To get some ideas on how to make gears work together have a look at this excellent resource: Tora no Maki

[Darth Legolas]

Okay, my gear troubles are over... I think I got that now... X3. Thank you all! So can anyone enlighten me on the forest tractor, my slow-moving RC, and it's engine?

Thanks again!

[freakwave]

The 16t gear can be meshed with a 20t gear when it is off-set to one side or the other by one hole distance as seen here:

have a look at this adder-subtractor, in my Brickshelf folder, the 16 tooth gear was perfect for this application!

Edit: now the link should work!

Edited January 30, 2010 by freakwave

[Jetro]

hmm, that link doesn't work

[Darth Legolas]

have a look at this adder-subtractor, in my Brickshelf folder, the 16 tooth gear was perfect for this application!

The link doesn't work... but thanks really. I'd kind of like someone to answer my non 16-tooth gear questions though... please?

[allanp]

The link doesn't work... but thanks really. I'd kind of like someone to answer my non 16-tooth gear questions though... please?

Well I don't have the tractor YET, i'm on the lookout for it, I can't seem to find it in the shops but I would say that it is deffinately worth it, will buy it as soon as I see it. By loader do you mean the tractors B-model? Many have said that it is in fact better than the A-model. I'm not sure about that but I must admit, 90% of what attracts me to the tractor and trailer is the trailer itself. Whilst the tractor unit has some good new parts, on the whole it's very boring, like most tractors from technic I find. Honestly all a tractor does is move forwards, backwards and steer. So unless it's got a gearbox or pneumatic steering or something what else can a tractor do?

As for your worm gear question you can try adding a rubber band to whatever it is that the worm gear raises in a manner as to try to pull it back down. This should prevent any juddering as it comes down.

As for your slow moving motor, this is strange. Gearing it down should put less strain on the motor enabling it to turn faster. I assume that you have checked that you have geared it down and not up by mistake and that all your axles are spinning freely and that your 2 cylinder engine comes before the added gearing down and not after am I right? If so then posting a picture of the problem would assist us in giving you a better answer.

Edited January 31, 2010 by allanp

[Darth Legolas]

Well I don't have the tractor YET, i'm on the lookout for it, I can't seem to find it in the shops but I would say that it is deffinately worth it, will buy it as soon as I see it. By loader do you mean the tractors B-model? Many have said that it is in fact better than the A-model. I'm not sure about that but I must admit, 90% of what attracts me to the tractor and trailer is the trailer itself. Whilst the tractor unit has some good new parts, on the whole it's very boring, like most tractors from technic I find. Honestly all a tractor does is move forwards, backwards and steer. So unless it's got a gearbox or pneumatic steering or something what else can a tractor do?

As for your worm gear question you can try adding a rubber band to whatever it is that the worm gear raises in a manner as to try to pull it back down. This should prevent any juddering as it comes down.

As for your slow moving motor, this is strange. Gearing it down should put less strain on the motor enabling it to turn faster. I assume that you have checked that you have geared it down and not up by mistake and that all your axles are spinning freely and that your 2 cylinder engine comes before the added gearing down and not after am I right? If so then posting a picture of the problem would assist us in giving you a better answer.

It's odd how my system works. First, a motor turns a worm gear, which turns a 24 tooth gear which turns both wheels. Then the axle turning both wheels is connected to two 40 teeth gears. One is connected to a chain which pulls the manual setup winch, while the other 40 tooth gear turns a system of smaller gears which finally ends with a 12 tooth gear turning another 12 tooth gear which turns the crank and pulls the two cylinders.

Then, I tried to attach an 8-tooth gear to the axle, replacing the 40-teeth gear, and have the gears it turns get gradually larger, and I thought it would make the cylinders turn faster, but instead it slowed everything down... it was quite confusing.

Maybe I did it entirely wrong... no clue though.

Edited January 31, 2010 by Darth Legolas

[Jetro]

it's quite obvious (supposing you mean you changed the 40t gear that turns the chain) in one turn the 40t gear advances... 40 teeth so 40 chain links. If you replace that with an 8t gear it will advance only 8 chain links per turn...

[Shompis]

Well correct me if I am wrong, the motor not spinning fast enough can have several reasons. For one thing you mention a gear box, I guess it has input and output gear right? What is the gear ratio of those? And what is the gear ratio between the spur gear and the pinion (the one the motor if it is a pinion one) gear? I think your goal is to lower the gear ratio for increased speed. Or easiest is to get a motor with higher rpm per voltage :D

Edited February 1, 2010 by Shompis

[Darth Legolas]

Well correct me if I am wrong, the motor not spinning fast enough can have several reasons. For one thing you mention a gear box, I guess it has input and output gear right? What is the gear ratio of those? And what is the gear ratio between the spur gear and the pinion (the one the motor if it is a pinion one) gear? I think your goal is to lower the gear ratio for increased speed. Or easiest is to get a motor with higher rpm per voltage :D

I'm not smart, can you run that by me again? All the box has is a worm gear and a 24 tooth gear. I'm not very advanced, as this is my first try, but I'm learning!

I don't know what a pinion or a spur is... sorry...

[allanp]

I'm not smart, can you run that by me again? All the box has is a worm gear and a 24 tooth gear. I'm not very advanced, as this is my first try, but I'm learning!

I don't know what a pinion or a spur is... sorry...

A spur gear is a standard gear. http://www.peeron.com/inv/parts/3648a

A bevel gear is a gear that changes the direction of rotation along the same axis. http://www.peeron.com/inv/parts/6589

This gear is a combination of a spur and bevel gear http://www.peeron.com/inv/parts/32269

A pinion gear is the smaller of two different sized gears meshed together. The pinion can drive the larger one or be driven by it. You may have heard of rack and pinion steering, the pinion is the small gear driving the rack side to side.

Your worm gear is the pinion driving the 24t spur gear in this case (in real life it would drive a worm wheel, which is like a spur gear but whose teeth are at an angle matching that of the worm gear).