Power Functions question

[Darth Legolas]

Here's the list:

1. Can the regular battery box power 1. The lights 2. Two M-motors 3. A switch and 4. an IR receiver all at the same time?

2. How does the IR remote work with the receiver and motors? Do you just hook the receiver to the battery box, and the motors to the receiver, and then it works?

3. How many things in general can the battery box power?

4. How do you get wheels with suspension, for example the ones in 8297, to work with a motor?

Thanks!

[Sergiu]

1. I think a Power Functions Battery Box will power the lights, two M motors, a switch and an IR receiver without any problem.

2. It is just like said, very simple.

3. I think the Battery Box can power 2 XL motors or 4 M motors, this is what is said on the LEGO site, but I used it a couple of times with 2 Xl motors and 2 M motors and it worked quite well, although if you need really high torque it may not work so well.

4. That shouldn't be too hard, you just connect the motor to the axle that turns the differential and the rest is already done, because the set already has the u-joints and cv joints, although it may be a little difficult to find space for a motor. Be sure the transmission can handle the motor's torque, or the u-joints might break.

I hope the information helped you.

[Darth Legolas]

1. I think a Power Functions Battery Box will power the lights, two M motors, a switch and an IR receiver without any problem.

2. It is just like said, very simple.

3. I think the Battery Box can power 2 XL motors or 4 M motors, this is what is said on the LEGO site, but I used it a couple of times with 2 Xl motors and 2 M motors and it worked quite well, although if you need really high torque it may not work so well.

4. That shouldn't be too hard, you just connect the motor to the axle that turns the differential and the rest is already done, because the set already has the u-joints and cv joints, although it may be a little difficult to find space for a motor. Be sure the transmission can handle the motor's torque, or the u-joints might break.

I hope the information helped you.

Thanks for the answers! I don't want it to go fast at all, I just want it to move and steer by my control, with working lights, and not die every two minutes. I don't know where I'm going to go with the suspension, seeing as I don't understand anything about U and CV joints, I just want it to be bouncy.

Seeing as I'm not a complex or technical guy, I think I'll go my way with trial and error once the rest of my PF order has shipped. As long as all of the electronics work, I'm more than fine.

[Milan]

I don't know where I'm going to go with the suspension, seeing as I don't understand anything about U and CV joints, I just want it to be bouncy.

Just explain what you want to do and we will help you step by step!

[soc399]

Seeing as I'm not a complex or technical guy, I think I'll go my way with trial and error once the rest of my PF order has shipped. As long as all of the electronics work, I'm more than fine.

I've had a lot of fun lately building PF trains with the trial and error method. The power functions components are very easy to work with, but designing working drivetrains and the like is harder. Good luck!

[Darth Legolas]

Thanks for the help! I've got a couple of new questions!

1. Will a six wheeler with four in the back motorized, and two steerable but non-powered in the front turn well? As in, the back wheels are pushed by a motor, and the front are loose moving, but the axle is connected to an M-motor facing down, so it can turn the axle left and right?

2. Are there any wheel sizes that match up with the ones from the Off Roader and the Dirt Bike?

Thanks!

[Ralph_S]

Thanks for the help! I've got a couple of new questions!

1. Will a six wheeler with four in the back motorized, and two steerable but non-powered in the front turn well? As in, the back wheels are pushed by a motor, and the front are loose moving, but the axle is connected to an M-motor facing down, so it can turn the axle left and right?

2. Are there any wheel sizes that match up with the ones from the Off Roader and the Dirt Bike?

Thanks!

I can answer the questions under 1.

I have a six-wheeled fire engine with PF remote control. You can see a short video on youtube of the thing in action. Only one of the rear axles is powered, but it drives fine. Ed Diment -a friend of mine- and myself also built a six-wheeled Power Functions space vehicle called L.U.R.C.H. I did al the technic bits for it. I have a video on flickr. It has steering and drive on the front wheels.

In short it can be done!

You'll have to think of a better way of doing the steering than what you describe now. You really don't want the whole axle to rotate. It'll be a complete bastard to control and will probably look terrible. You'll need to build a more conventional steering set-up and drive that using a motor -an regular one will do the trick fine. I'd also recommend either using a torque gear or a spring from a hockey set. The fomer will prevent the system from wrecking itself once the steering reaches its maximum angle. The latter bit self-centres the steering set-up. It's not my idea, unfortunately, but I did it on L.U.R.C.H. and it made the vehicle far more controllable. Somebody has put a little graphic of it on brickshelf. I still intend to modify the fire engine accordingly.

I'm not a particularly experienced technic builder myself and both of these were pretty complicated projects. L.U.R.C.H. took about three rebuilds to get right. The drive on the fire engine was also rebuilt a few times. The truck is heavy and the XL motor gives so much torque that when driving it would break apart the gearing I built for it. I finally did solve the issue, but not without a few headaches. Be prepared for some trial and error.

Cheers,

Ralph

Edited December 6, 2009 by Ralph_S

[Darth Legolas]

I can answer the questions under 1.

I have a six-wheeled fire engine with PF remote control. You can see a short video on youtube of the thing in action. Only one of the rear axles is powered, but it drives fine. Ed Diment -a friend of mine- and myself also built a six-wheeled Power Functions space vehicle called L.U.R.C.H. I did al the technic bits for it. I have a video on flickr. It has steering and drive on the front wheels.

In short it can be done!

You'll have to think of a better way of doing the steering than what you describe now. You really don't want the whole axle to rotate. It'll be a complete bastard to control and will probably look terrible. You'll need to build a more conventional steering set-up and drive that using a motor -an regular one will do the trick fine. I'd also recommend either using a torque gear or a spring from a hockey set. The fomer will prevent the system from wrecking itself once the steering reaches its maximum angle. The latter bit self-centres the steering set-up. It's not my idea, unfortunately, but I did it on L.U.R.C.H. and it made the vehicle far more controllable. Somebody has put a little graphic of it on brickshelf. I still intend to modify the fire engine accordingly.

I'm not a particularly experienced technic builder myself and both of these were pretty complicated projects. L.U.R.C.H. took about three rebuilds to get right. The drive on the fire engine was also rebuilt a few times. The truck is heavy and the XL motor gives so much torque that when driving it would break apart the gearing I built for it. I finally did solve the issue, but not without a few headaches. Be prepared for some trial and error.

Cheers,

Ralph

I've got ll of those pieces. I have no idea how that thingie is supposed to work, but I'll take your advice. I was digging through my collection and picked up a bunch of those spring boxes, they looked useful.

Thanks!

[Ralph_S]

I've got ll of those pieces. I have no idea how that thingie is supposed to work, but I'll take your advice. I was digging through my collection and picked up a bunch of those spring boxes, they looked useful.

Thanks!

I'll try to explain it. A steering system that works well is one where if you have the motor that drives it go in one direction that car goes to the left, if you have it going in the other direction the car goes to the right and if the motor is off it drives in a straight line. That's what this 'thingy' makes possible, because if you mount it to the axle connected to the motor the spring inside it will centre the axle when the motor is off, centring the steering. I suggest you try building the arrangement in the diagram on brickshelf and try it out yourself. It probably makes more sense if you can see it in action.

Cheers,

Ralph

[Darth Legolas]

I'll try to explain it. A steering system that works well is one where if you have the motor that drives it go in one direction that car goes to the left, if you have it going in the other direction the car goes to the right and if the motor is off it drives in a straight line. That's what this 'thingy' makes possible, because if you mount it to the axle connected to the motor the spring inside it will centre the axle when the motor is off, centring the steering. I suggest you try building the arrangement in the diagram on brickshelf and try it out yourself. It probably makes more sense if you can see it in action.

Cheers,

Ralph

The video was really helpful to me in the final planning stages before I start my project over the weekend. Now I understand the centering, I still don't know what the great part does, but I understand the whole functioning! Just two final questions:

1. Do all motors have enough power to push the gear in the spring box? It seemed pretty resistant manually. I only have M-motors, by the way.

2. Does it hurt the motor to be turned by something other than itself?

Thanks again!

[Ralph_S]

The video was really helpful to me in the final planning stages before I start my project over the weekend. Now I understand the centering, I still don't know what the great part does, but I understand the whole functioning! Just two final questions:

1. Do all motors have enough power to push the gear in the spring box? It seemed pretty resistant manually. I only have M-motors, by the way.

2. Does it hurt the motor to be turned by something other than itself?

Thanks again!

No problem. On LURCH we used a regular motor and it has enough oomph to do it, so I'm pretty sure one of those big boys will have no trouble whatsoever. I don't know for certain whether it hurts the motor to be turned by an outside force, but from what I know about electric motors I can't come up with any reason why it should be a problem. Ed and I put some serious mileage on LURCH (driving it through a room at a Brickish meeting) and it just kept going.

Cheers,

Ralph

[Darth Legolas]

No problem. On LURCH we used a regular motor and it has enough oomph to do it, so I'm pretty sure one of those big boys will have no trouble whatsoever. I don't know for certain whether it hurts the motor to be turned by an outside force, but from what I know about electric motors I can't come up with any reason why it should be a problem. Ed and I put some serious mileage on LURCH (driving it through a room at a Brickish meeting) and it just kept going.

Cheers,

Ralph

Okay! I'll be sure to get back to you when I've built the first stage of it!

[DLuders]

My 17-year-old son and I have been learning about Lego Power Functions steering geometry via trial-and-error. If you just want to see how the PF elements work in a simple "drifter" car, check out the step-by-step photo instructions on http://www.brickinside.com/NeoView.php?Db=...amp;Number=1798 . It's a fun car that is FAST and doesn't bother with differentials! I too struggled with understanding how Lego Power Functions elements interfaced with each other when they were first introduced. Perhaps the best explanation is contained in the "Power Functions Presentation" PowerPoint file that can be downloaded from Philo's website http://philohome.com/tech.htm . For ideas on how to power wheels with suspension, check out Sariel's website http://sariel.pl/ . He has many links to other Lego Technic builders at the bottom of his webpage. Those builders have photographs on Brickshelf.com that show how to use various Technic elements to make a driveable Power Functions vehicle with steering and suspension.

Edited December 10, 2009 by dluders

[Darth Legolas]

My 17-year-old son and I have been learning about Lego Power Functions steering geometry via trial-and-error. If you just want to see how the PF elements work in a simple "drifter" car, check out the step-by-step photo instructions on http://www.brickinside.com/NeoView.php?Db=...amp;Number=1798 . It's a fun car that is FAST and doesn't bother with differentials! I too struggled with understanding how Lego Power Functions elements interfaced with each other when they were first introduced. Perhaps the best explanation is contained in the "Power Functions Presentation" PowerPoint file that can be downloaded from Philo's website http://philohome.com/tech.htm . For ideas on how to power wheels with suspension, check out Sariel's website http://sariel.pl/ . He has many links to other Lego Technic builders at the bottom of his webpage. Those builders have photographs on Brickshelf.com that show how to use various Technic elements to make a driveable Power Functions vehicle with steering and suspension.

Thanks for the tip! I'm going to base my car off of some of these designs, but the way you went through trial and error, I really want to figure things out myself, even if that'll take forever!

It'll be hard to compete with all of these amazing designers out there!