Has anyone successfully made motors that have the same specifications as the power functions motors?

Have a look at this thread http://www.eurobrick...howtopic=103615

Not cheap though I think

Edited December 21, 201410 yr by andythenorth

Has anyone successfully made motors that have the same specifications as the power functions motors?

Yes, TLG. They sell them from their website, and there's a large second hand market. :-)

Anything homebrew is going to necessarily have some slightly different specs, even if only in form factor.

I would hazard a guess that it's going to be worth your time to just buy the LEGO ones. Sure it might be cheaper to hack something together yourself, but unless you're a pro at it, you'll probably be working for far less than minimum wage with the time you spend vs the money you save.

Owen.

Ya, I guess your right. I am ok with making my own stuff, I just thought it would be cheaper. I am just buy the LEGO power functions

Ya, I guess your right. I am ok with making my own stuff, I just thought it would be cheaper. I am just buy the LEGO power functions

The PF motors are pretty cheap. I don't see much of any chance of making your own version any cheaper.

The PF motors are pretty cheap. I don't see much of any chance of making your own version any cheaper.

Actually, they're extremely expensive compared to the performance that even cheap RC motors can put out, you know that

Sure some include gearing but it's still very cheap plastic parts. And in the volumes TLG buyes/produces these they cost very few cents

Of course we'll never see a lowly Mabuchi/Johnson 540 in a TLG plasticshell as it would completely rip every other LEGO part to pieces (and would be priced at +50EUR even if you can pick them up for less than a buck)

I say forget about more powerfull motors, TLG better make their electronics much smarter, that's we're the customers/money is

Edited December 22, 201410 yr by 1974

I agree, they are very expense compared to a RC motor.

Actually, they're extermely expensive compared to the performance that even cheap RC motors can put out, you know that

I agree, they are very expense compared to a RC motor.

Well, yes and no. It is true that you can buy R/C motors very cheap (a couple of dollars for this size), but those motors are not comparable. To compare it to a PF motor you would have to press on a pinion gear, buy some planetary gearing, create a mounting system, solder on some connectors and wire, and then get a fuse and/or current controller. I don't think you could do all of that for any cheaper than a LEGO PF motor unless you bought everything in very high quantity. Considering what you get, I think PF motors are really cheap.

I do lots of real R/C modelling, and I know very well how much work it is to get a custom motor setup working.

Of course it would be expensive if one had to make that, but so would a simple liftarm or pin. Apples'n'oranges and that jazz

Fact is, it's a cheap motor (in any of the motors TLG ever released) and a bit of gearing does not cost a lot in the quantities we're talking about here .. 100.000 to millions

So, yeah, they're expensive

Ok, I am just going to buy the power functions. They will definitely be easier to use

Of course it would be expensive if one had to make that, but so would a simple liftarm or pin. Apples'n'oranges and that jazz

Fact is, it's a cheap motor (in any of the motors TLG ever released) and a bit of gearing does not cost a lot in the quantities we're talking about here .. 100.000 to millions

I suppose it all depends on your perspective. The original poster was asking about saving money by creating his own motor. From that point of view, I think PF motors are cheap because I don't think you could build one with the same functionality any cheaper. You are talking about a totally different question: are PF motors expensive compared with their production costs? I don't really think that is a fair question because pricing is not based primarily on production costs. I agree that the Chinese company that makes an L motor probably only gets a dollar for it and then TLG sells it for $17.99. But this is true of all their products. A 2x4 brick straight from the mold probably only costs 1/100 of a penny and sells for orders of magnitude more than that. However all of the company's overhead: legal, design, marketing, research, packaging, shipping, retail markup, and every other cost gets amortized into the final price. And don't discount liability. Tamiya can sell a loose electric motor for a dollar because in general only adults will buy it and only experienced hobbyists will be able to use it for anything. A PF motor needs to be fool proof so little kids can drop it in the sink or lick the connectors or stall the output in their hand and not get hurt. Wouldn't surprise me if the lawyers and insurance ate up 25% of that final cost.

So in summary, I'll say "LEGO PF motors provide a similar value for their cost as any other LEGO part".

ya, that wasn't really my question, but interesting to know. Kinda off topic, but want do you think about making your own LED lights?

ya, that wasn't really my question, but interesting to know. Kinda off topic, but want do you think about making your own LED lights?

You could certainly try, but in the long run, it's probably not that worth it. Working with electronics at this scale is kind of hard. Also, there is another alternative. It would be better than a DIY setup, and cheaper than a Lego one, but use a little batter powered string of LEDs. I've seen them at the craft store for only around 5-6 USD.

I was just going to go to RadioShack and pick up some LEDs and wire (possibility a switch). could I just use the LEGO battery pack, or do I need another source of power?

I was just going to go to RadioShack and pick up some LEDs and wire (possibility a switch). could I just use the LEGO battery pack, or do I need another source of power?

As long as you buy LEDs that are rated for 9V you should be able to use the LEGO battery box. Just make sure not to short any wires when making your connections.

Ok, sounds good. thanks for ur help

https://www.flickr.c...57624355112320/

Lit by bright white LEDs that cost maybe £0.30 each about 5 years ago.

The power on the bulldozer is a LifeLites brick that is no longer available (they still make other products for lighting Lego - http://www.lifelites.com). You can power LEDs from Lego battery boxes. For that you'd need to split open the wires on a Lego cable (can use one of the extension cables, they're cheap).

Unless the LEDs are rated for 9-12v, they'll need a resistor wired in series. I think there's some rule about whether the resistor has to be on +ve or -ve leg of the LED, can't remember.

Soldering is best, but you can avoid it by using screw blocks if you have space. http://www.screwfix....ack-of-10/25545

You can also cover any bare metal with heatshrink tube, which you put over the wire, then heat with hot air. Looks neater.

I forget the LED size, but I think it was 3mm. Sometimes these fit in a technic half-pin perfectly, other times they need the size reduced, which can be done with a file, turning them in a drill.

Edited December 23, 201410 yr by andythenorth

will keep all that in mind. thanks

I made a couple of (really bad) videos to show the speed of another truck. This one has 3 XL motors, so it's not especially fast. All 8 wheels driven.

It was only running on one battery box, the second set of batteries was flat. It goes a bit better on two.

Hauling the 42009 crane B-model, and 1.3Kg of children's wooden blocks. It will pull a 20Kg child, but only on dead level ground.

Videos are very low quality

Thanks for all your help!!! videos were helpful.

Unless the LEDs are rated for 9-12v, they'll need a resistor wired in series. I think there's some rule about whether the resistor has to be on +ve or -ve leg of the LED, can't remember.

Does not matter where you place the resistor, no rule

Most, but not all, LEDS are 10-20mA types. 10mA is fine, white LEDs are 3V

Ohm's Law :

R=V/A ... 9V/0.01A (<-=10mA) = 900 Ohm, standard 1k (1000 ohm) is just dandy

In fact 1k will work with just about any LED that is not a low current type (typically 2mA) at any voltage between 6 and 12 volts, no matter what colour of the LED

Cheers,

Ole

so if I have an LED with a max voltage of 2.6 do I need a resistor?

so if I have an LED with a max voltage of 2.6 do I need a resistor?

Yes

What would the resistor value have to be?

Oops, I forgot one important thing, with two motors per axle, the motors on left / right sides run in opposite directions. To solve this, connect all the motors on one side to a PF Switch, and reverse them.

I've got a prototype build of an L axle, it's too wide, but eh, haven't seen a way make it narrower yet.

Video

https://www.flickr.c...in/photostream/

The trailer has 1.3kg of wooden blocks in. The truck is fast on level ground, but pretty gutless trying to get over any kind of bump. Tandem (4 motors) or tridem (6) would have a bit more pull.

The axle is exactly one tyre width wider than the 8258 tow truck, but I think it can be slimmed down by at least 1 stud, losing some strength.

Off-topic - the axle is exactly correct width for the 42009 B-model (container stacker). It has plenty of power to move the stacker, and looks like it would drop in without major surgery (the fake engine would no longer turn mind). Full RC container stacker anyone?

Edited December 31, 201410 yr by andythenorth

Ok, I wish I knew that I when I bought the motors... Ya well