BBB XL drivers and PF train motor

[someguy]

Alright so a while back I built myself a lego big boy steam locomotive and that was a lot of fun. Now I am making my own custom designed lego steam engine and have some questions.

I plan on using Big Ben's Bricks extra large flanged drivers, will these fit on a lego PF train motor? The motor on the right is what I plan on using. I simply want to put 4 XL drivers on it with custom connecting rods I plan on buying.

Are the axles far enough apart to fit two XL drivers on there? I checked measurements and im just not sure.

Also, if the above works, I just might end up putting FOUR PF train motors on my engine. Two sets of driving wheels and 2 under the tender. Is that overkill (will I ever need that much power?)

Traction should not be an issue. I plan on placing two battery boxes directly above the driving wheels plus I will buy steel/lead weights if needed.

What is the best way to apply white walls to BBB XL drivers?

Edited August 28, 2015 by someguy

[Daedalus304]

They will fit, but it`s probably the worst way to power XL drivers. Using Large or XL drivers, the pf train motor has incredibly abysmal power. With Large drivers you can't pull than 2 or so cars without running into problems. This would be even worse with XL drivers - although you would have a ridiculously fast engine. I'd suggest either powering the drivers with an XL or L motor, or use a pair of train motors in the tender with the small wheels. It`s practically impossible to synchronize speeds between different size wheels - so you can't really do both.

Edited August 28, 2015 by Daedalus304

[jtlan]

Even if the XL drivers fit, you probably don't want to mount them on the PF train motor. The PF train motor turns very quickly, and the XL drivers don't have much traction (no tires), so basically the wheels will just slip immediately and the locomotive won't go anywhere.

If you're building a locomotive with XL drivers, the best way to power it is probably to power the small wheels in the tender with a Power Functions M, L, or XL motor. This makes it easier to concentrate weight on the driven wheels.

It`s practically impossible to synchronize speeds between different size wheels - so you can't really do both.

See this thread for some of the trouble you'd be in for.

[someguy]

I totally forgot about syncing the wheel speeds up! So either tender or the boiler now. As for the motor not being strong enough and spinning too fast I think I'll do some testing. Reason being is I built a big boy which is powered by 4 lego medium PF motors in the boiler which power the drivers and it has E P I C wheel slip. So I am weary of something similar in my next engine.

Do you think it would be a good test to configure my big boy tender with a PF train motor in the front with regular lego size drivers and lowering the rear axles down to the track?

Here's why I think this would be a good test:

- big boy tender definitly will weigh less than my finished engine.

- comparable amount of total axles I would be using (for friction)

- I will see how many of my lego cars it can pull.

- I will get an idea of how much wheel slip will be a problem.

Also, I know I basically want to do the opposite of what you both mentioned and suggested, and I appreciate your input, I just want to research and educate myself before I make a descision.

(prolly going to be another $500 dollar engine lol)

Edited August 28, 2015 by someguy

[CrispyBassist]

They will fit, but it`s probably the worst way to power XL drivers. Even with the Large drivers, the pf train motor has incredibly abysmal power. You cant pull than 2 or so cars without running into problems. This would be even worse with XL drivers...

I've actually been quite successful with train motors. My GP9 has two of them and can run happily with 8 cars (see here), and move a line of even more short distances. I haven't tried the motors with larger wheels than the normal ones though, but I have been considering it for future projects. Is that where the power issue comes in? Edited August 28, 2015 by CrispyBassist

[Daedalus304]

I've actually been quite successful with train motors. My GP9 has two of them and can run happily with 8 cars (see here), and move a line of even more short distances. I haven't tried the motors with larger wheels than the normal ones though, but I have been considering it for future projects. Is that where the power issue comes in?

Yes, with the normal "small" wheels the PF train motor is great, especially when you have two of them in tandem. I definitely did not mean to make it seem like the motor itself was bad - it's only when you put the Large drivers or bigger on it. The large drivers end up giving you a little less than half the torque, which makes starting a train tough and corners are bad too. My first PF train MOC was originally using Large drivers on a PF train motor and after 6-10 minutes with a single EN coach and a caboose it was throwing the overheat switch. Even using two of the Train Motors with Large drivers still won't get you the same amount of power.

From what I've tried, the BBB Medium drivers fare much better, but you are still dealing with a loss of strength; just not nearly as bad as you'd get dealing with L drivers.

I totally forgot about syncing the wheel speeds up! So either tender or the boiler now. As for the motor not being strong enough and spinning too fast I think I'll do some testing. Reason being is I built a big boy which is powered by 4 lego medium PF motors in the boiler which power the drivers and it has E P I C wheel slip. So I am weary of something similar in my next engine.

Do you think it would be a good test to configure my big boy tender with a PF train motor in the front with regular lego size drivers and lowering the rear axles down to the track?

Here's why I think this would be a good test:

- big boy tender definitly will weigh less than my finished engine.

- comparable amount of total axles I would be using (for friction)

- I will see how many of my lego cars it can pull.

- I will get an idea of how much wheel slip will be a problem.

Also, I know I basically want to do the opposite of what you both mentioned and suggested, and I appreciate your input, I just want to research and educate myself before I make a descision.

(prolly going to be another $500 dollar engine lol)

Well, if you go the Train Motor route for a big boy you're going to want more than one, and you're probably going to want to get some better o-rings on the wheels for improved traction. 4 Medium PF motors should be giving you a decent amount of strength, so if traction is your big concern I would suggest you try some traction bands like the EN had and see if that improves your performance. I would only put them on one axle per engine, though, if you put too many traction bands on you're going to run into other issues. If you really want to avoid traction bands because the bright gaudy red is an eyesore - I'd suggest you look into something called Bullfrog Snot which basically lets you create a tire that ends up drying almost completely clear and is really, really easy to remove.

EDIT AGAIN: Just saw your question about the white walls. I use white acrylic paint with a very small brush to paint them on, then after it dries you can use a hobby knife very carefully to scrape off anything that got where it shouldn't. It's hard to do with unsteady hands like mine, but it may be easier for others. I've been thinking of trying putting a decent layer of paint on a piece of paper on a flat surface and trying to sort of reverse-stamp the driver on it, but I haven't got around to giving it a go. The nice thing with acrylic paint is that it stays on pretty well under normal use, but if you need to touch it up or redo it entirely it's really easy to remove and doesn't damage your parts.

Edited August 28, 2015 by Daedalus304

[dr_spock]

I think not using the PF train motor will also give you more gearing options. You can gear your drive train for speed or pull.

[someguy]

Ok so I tested a single train motor under my big boy tender by itself (no big boy engine in front) and it had serious trouble moving, will not be using train motors for my next build.

I use 4 of these motors in my big boy and it goes pretty good,

but I would like to get some more speed and power out of my next build so I am considering using 4 of the large motor at the bottom.

.

Last, my next build will be a 4-4-4-4 (not a T1) wheel arrangement using BBB XL drivers and custom drive rods I have seen advertised on here. I plan on having 2 sets of drivers with 2 large motors powering each set.

Now a question of 'power.' I can fit 2 battery packs into the tender with 2 IR sensors. I plan on connecting the batteries just so the engine stays powered longer and the drop off from the bateries discharging is not as noticable. Two IR sensors because I heard this helps improve responsivness and help with using 4 motors.

Is it a good idea to use two batery packs?

Is it a good idea to use two IR sensors?

[LoneBrickerSG]

Is it a good idea to use two IR sensors?

I can't figure a reason why you would need more than one....

[Daedalus304]

If you use 4 L-Motors, you will need two receivers and two battery packs, but even then; running two L-Motors together doesn't give you their full power unless you use the V2 Receiver or an SBrick, both of which are 3 times as expensive or higher. I would reccomend you use a pair XL motors, geared up 2:1 with a 24t and a 12t gear. A single XL should still be stronger than two L Motors, though not quite as fast.

Two XL motors without any gearing changes has an insane amount of power, so even gearing them to be faster still gives an incredibly strong engine. XL motors can be paired without any special requirement, so you get more for your money if you can fit them. If you're just really looking to be crazy you could try going 2 Batteries, 2 IR Receivers, and 4 XL Motors, but that's overkill. 2 XLs will break magnetic connections long before they so much as slow down, so 4... it would be nuts, really, and you'd have to hard connect everything to use that power.

Edited August 29, 2015 by Daedalus304

[someguy]

name='LoneBrickerSG' timestamp='1440831339' post='2314575']

I can't figure a reason why you would need more than one....[/b]

Somehwere a while back I read where someone used two in a MOC, but I cannot find it anymore. I remember it was something about reducing the PF whine noise by making the signal stronger to the motors, or perhaps that was done by using two batery packs.

For now though I will stick with one ir sensor, I can always add another later.

I went and uncovered my big boy engine from the layout and got it all together and working. (I had been modifying it like crazy trying to get to move!) I did not realise too many tires would make it bind up and I removed 4 tires. (Not lego tires because I was not paying $4 a piece for black ones, went to Lowes and bought toilet O-rings) Now it runs great! I got some silicon from the garage that drys and keeps surfaces slick. I also, finally, took the driving wheels off and rotated them all 90 deg apart and put drive rods on. The engine now runs smoothly and I can even control a nice slow acceleration to start moving on turns instead of a sudden lurch! I do know that my next engine WILL be geared for faster running. The big boy cannot run very fast, but it can easily pull my friends full train of Santa Fe cars around with ease. (6-8 or something)

name='Daedalus304' timestamp='1440862558' post='2314930']

If you use 4 L-Motors, you will need two receivers and two battery packs, but even then; running two L-Motors together doesn't give you their full power unless you use the V2 Receiver or an SBrick, both of which are 3 times as expensive or higher. I would reccomend you use a pair XL motors, geared up 2:1 with a 24t and a 12t gear. A single XL should still be stronger than two L Motors, though not quite as fast.

Two XL motors without any gearing changes has an insane amount of power, so even gearing them to be faster still gives an incredibly strong engine. XL motors can be paired without any special requirement, so you get more for your money if you can fit them. If you're just really looking to be crazy you could try going 2 Batteries, 2 IR Receivers, and 4 XL Motors, but that's overkill. 2 XLs will break magnetic connections long before they so much as slow down, so 4... it would be nuts, really, and you'd have to hard connect everything to use that power.[/b]

Why does it not give me their full power without a V2 reciever?

Edited August 29, 2015 by someguy

[Daedalus304]

Why does it not give me their full power without a V2 reciever?

The L-Motors are a little more power hungry than the M or XL motors. Just one is fine, but a V1 receiver can't deliver enough for two and so they won't run to their full potential. The V2 receiver can deliver three times as much current to them, but is still limited by the battery box.

http://philohome.com/pfrec/pfrec.htm has more info

[someguy]

The L-Motors are a little more power hungry than the M or XL motors. Just one is fine, but a V1 receiver can't deliver enough for two and so they won't run to their full potential. The V2 receiver can deliver three times as much current to them, but is still limited by the battery box.

http://philohome.com/pfrec/pfrec.htm has more info

Ok now I understand better. Untill I found out about these 2 ir recivers I thought my research was done! Now I have even more questions!

I figure before I start asking questions I should start by stating what I want my engine to be capable of doing.

Goals:

- 2 battery packs

- 1 or 2 ir recivers (v2)

- 4 L motors or 2 XL motors

- no quick reversing

- no quick acclerations

- quick decelerations

- High speed

- capable of pulling at least 10 normal lego designed cars

- capable of pulling at least 6 MOC cars aprox. dimensions: 6x40 studs

Questions:

- Which could be built to be faster and has more power, 4 L motors or 2 XL motors?

- Would you use 2 V2 ir sensors with 4 L motors?

[Daedalus304]

Well, Flickr user Shuppiluliumis recently built an excellent Challenger Locomotive using 4 L-motors, and that engine has a really good balance of speed and strength.

4 L-Motors will be quick and strong without needing to worry too much about gearing, but will be more than twice as expensive

2 XL motors will be incredibly powerful and can be geared to go faster if need be, and can both be run off a single battery box and a standard IR receiver

To be honest, though, for what you've listed that you want to pull you can probably just use 2 L-motors. My Mallet uses two L-Motors geared down and it's insanely powerful, more powerful than it has the tractive effort to make use of some times. If you're using XL Drivers, you're going to get a lot better speed than my mallet (2.5 times faster or so?), so you may want to try to design your engine so that it can use four, but start off with just two and see if that's good enough.

[someguy]

Well, Flickr user Shuppiluliumis recently built an excellent Challenger Locomotive using 4 L-motors, and that engine has a really good balance of speed and strength.

4 L-Motors will be quick and strong without needing to worry too much about gearing, but will be more than twice as expensive

2 XL motors will be incredibly powerful and can be geared to go faster if need be, and can both be run off a single battery box and a standard IR receiver

To be honest, though, for what you've listed that you want to pull you can probably just use 2 L-motors. My Mallet uses two L-Motors geared down and it's insanely powerful, more powerful than it has the tractive effort to make use of some times. If you're using XL Drivers, you're going to get a lot better speed than my mallet (2.5 times faster or so?), so you may want to try to design your engine so that it can use four, but start off with just two and see if that's good enough.

Thanks! I have some thinking to do and some more design to do to see what I will use.

Edited August 30, 2015 by someguy

[zephyr1934]

EDIT AGAIN: Just saw your question about the white walls. I use white acrylic paint with a very small brush to paint them on, then after it dries you can use a hobby knife very carefully to scrape off anything that got where it shouldn't. It's hard to do with unsteady hands like mine, but it may be easier for others. I've been thinking of trying putting a decent layer of paint on a piece of paper on a flat surface and trying to sort of reverse-stamp the driver on it, but I haven't got around to giving it a go. The nice thing with acrylic paint is that it stays on pretty well under normal use, but if you need to touch it up or redo it entirely it's really easy to remove and doesn't damage your parts.

A long time ago I used to build and paint plastic model sets. My preferred brush for detail work was actually a toothpick. I also found that as the paint was drying (very tacky but not yet solid) I could scrape off many "overpaint" splotches with a clean toothpick. I'd suggest practicing on some scrap bricks to perfect your style (e.g., the bottom edge of a 2x4 plate).

Two XL motors without any gearing changes has an insane amount of power, so even gearing them to be faster still gives an incredibly strong engine. XL motors can be paired without any special requirement, so you get more for your money if you can fit them. If you're just really looking to be crazy you could try going 2 Batteries, 2 IR Receivers, and 4 XL Motors, but that's overkill. 2 XLs will break magnetic connections long before they so much as slow down, so 4... it would be nuts, really, and you'd have to hard connect everything to use that power.

Just one XL motor has the power to pulverize lego gears and snap axles. You are going to be limited by weight on the drivers before you are limited by the power of an XL motor.

If you can avoid using two IR receivers and two battery boxes it would be for the best: saves a lot of money, it can be tricky to sync the two IR receiver speeds (one motor could easily be running a notch or two off from the other... still doable, just an extra challenge), also you might run into trouble if the batteries run down at different rates.

In any event, you'll likely want to build several "sketches" with the wheels in place and different propulsion ideas before settling on the final design of the actual locomotive, e.g., this.

[someguy]

Thanks zephyr, the tooth pick idea sounds really good! For now I plan on using either 4 L motors with a v2 sensor and 2 battery boxes or 2 to 4 XL motors with 1 v2 sensor and 2 battery boxes. Im still working out how im going to get the look I want for the engine and how to make a sturdy chassis.

[zephyr1934]

No problem, meanwhile, I haven't built anything with L motors yet, but I can tell you that a pair of XL, a single "v1" sensor and a single battery box should be sufficient for anything that will stay on lego tracks. That example in my last post pulled a 50+ car train and could do more if it were not for the fact that the weight of the train would pull the lead cars off the track on curves. Of course it is also important to have enough weight on the (actual) drive wheels.