The Lego Railway Series

How strong does my motor setup need to be for this train??

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I don't have the luxury of being able to test things with physical bricks too often, and I'm trying to figure out how powerful my motor setup should be to be able to move this particular train easily at a decent speed.

The locomotive itself is powered by 2 PU M motors in the boiler that moves the drive wheels (I know this isn't enough for the whole train)

52019300473_57e09a8e0e_c.jpgGordon_2 by The Lego Railway Series, on Flickr

 

I was going to use something like this with two XL motors above each bogie, 4 XL motors in total (final mounting design is TBD) I'm mostly worried about strength and speed of the overall train. is it strong enough? overkill taking into account the locomotive?

52478040008_01bdabb5b9_c.jpgexpress wip 5 by The Lego Railway Series, on Flickr

52477955630_41624dba08_c.jpgexpress wip 6 by The Lego Railway Series, on Flickr

 

This is the full intended train I wish to run.

52476984187_9da45b1fc9_h.jpgexpress WIP by The Lego Railway Series, on Flickr

52477486316_da5fe797e4_b.jpgexpress wip 2 by The Lego Railway Series, on Flickr

52478035438_b09c440917_b.jpgexpress wip 3 by The Lego Railway Series, on Flickr

52478035948_290c0b5cbc_b.jpgexpress wip 4 by The Lego Railway Series, on Flickr

 

Edited by The Lego Railway Series

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Looks like a fantastic train with a nice steam engine in unusual colors. It will be worth it making a real brick build train out of it.

I would recommend standard train motors as bodies for the "powered coach". The XL motor has a lot of torque but the train won't be fast.

And add ball bearings to all non powered wheels.

The video shows my BR 10 with two train motors in the tender and wagons without ball bearings.

LEGO BR 10 custom steam engine on R88/R104 curves

 

Edited by HoMa

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16 hours ago, HoMa said:

Looks like a fantastic train with a nice steam engine in unusual colors. It will be worth it making a real brick build train out of it.

I would recommend standard train motors as bodies for the "powered coach". The XL motor has a lot of torque but the train won't be fast.

And add ball bearings to all non powered wheels.

The video shows my BR 10 with two train motors in the tender and wagons without ball bearings.

LEGO BR 10 custom steam engine on R88/R104 curves

 

Thanks! the colors are bright because I build Thomas characters.

The normal train motors are too short for my scale, and I cant build the detail on them that I want. hence actual motors. I'm gonna gear them differently to increase speed. I just wasn't sure of w would be overkill or not or if maybe 2 was enough. I'm not familiar with what they are capable of. or maybe 4 smaller motors instead of XLs? I duno.

I absolutely plan on adding bearings. I know that will help a *ton*

that's a nice pace for what you've got, Im looking for something similar. granted my train is also much longer and my coaches/engine are bigger and heavier.

I also have R88 and R104. I know the wider radius will help in general.

7 hours ago, Duq said:

4 XL motors will also need multiple battery packs...

If you do decide to go with XL motors I would suggest bracing the gears with this piece for example:

87408.png

(https://www.bricklink.com/v2/catalog/catalogitem.page?P=87408#T=C&C=11)

yeah, there is plenty of room in the coach for two battery packs. I figure one battery per 2 motors would be sufficient?  im more worried about the number and strength of the motors themselves. is 4 overkill? would 2 XLs/4 L motors work just as well maybe?

how exactly would i mount this particular piece? im not familiar with this piece.

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image.png.fa41539e91361749a43691e0f6a4ddf4.png

It prevents the gears from skipping (or the powerful XL motors from pulling the whole thing apart ;- )

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If I'm looking at this correctly, this set up will not work.  One motor will have to be turn in the opposite direction of the other and they cannot be cross linked.  I've not used PU motors, but a PF motor is powerful enough to damage gears if there is a bind.  Traction is the biggest problem with plastic wheels on plastic track.

 

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40 minutes ago, Karle said:

If I'm looking at this correctly, this set up will not work.  One motor will have to be turn in the opposite direction of the other and they cannot be cross linked.  I've not used PU motors, but a PF motor is powerful enough to damage gears if there is a bind.  Traction is the biggest problem with plastic wheels on plastic track.

 

Correct. The motors cannot share a pin. There need to be 2 pins that meet in the middle. They can run counter to each other and brush against one another, but they cannot be on the same pin.

Really fancy locomotive, btw, OP - is it supposed to be something specific?

With a boiler that size, I bet you could fit 2-3 motors into it - I do it all the time. Dunno if it's worth it to you, or not, but sometimes it is nice to have the locomotive power the train.

Edited by LordsofMedieval

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they don't share a pin, they have their own independent pin. i am aware how gears work.

 

if anyone actually read what i asked. im not asking HOW to motorize it. im asking if 4 XL motors is powerful enough/not powerful enough or totally overkill based on the size of the train i wish to move. i just want to know if the train would be able to actually move easily enough, not how to move it.

In total the whole thing is about 12k parts, i will be using roller bearings and R104 tracks.

the locomotive has 2 PU M motors in the boiler attached to the drive wheels.

all i want to know is how many motors i should put into my motor coach and/or what size should they be in order to supplement the 2 PU motors in the boiler because i know that those two aren't enough alone.

31 minutes ago, LordsofMedieval said:

Really fancy locomotive, btw, OP - is it supposed to be something specific?

With a boiler that size, I bet you could fit 2-3 motors into it - I do it all the time. Dunno if it's worth it to you, or not, but sometimes it is nice to have the locomotive power the train.

Gordon from the Railway Series (Thomas the Tank Engine)

the loco already has 2 PU M motors in the boiler. only ones i could fit unless there is a technique i am unaware of to fit larger and still have the construction be stable.

Edited by The Lego Railway Series

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41 minutes ago, The Lego Railway Series said:

the loco already has 2 PU M motors in the boiler. only ones i could fit unless there is a technique i am unaware of to fit larger and still have the construction be stable.

If that's the case, don't mix motor sizes - it's best to go with all large or all medium or whatever. The hulking PF can motors you have in that coach will offer very different speed-to-torque ratios than the PoweredUp Mediums.  

Also, having a bunch of medium motors power the big driving wheels of the engine, and another set of motors power the much smaller wheels of the car could be an issue.

My advice is to focus putting the most power possible into one wheel size/type, all feeding off a single IR unit. That way you only have to tote around one controller, and all wheels will spin exactly the same speed at all times, and all your battery packs will drain at the same rate. If that necessitates shortening the train slightly... well... those Isle of Sodor trains were never very big, anyway. Or you could build a second locomotive (like James) to help.

Edited by LordsofMedieval

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21 hours ago, The Lego Railway Series said:

in order to supplement the 2 PU motors in the boiler because i know that those two aren't enough alone.

I assume the wheels are slipping due to lack of traction, rather than the motors stalling. If so, you'll need to add more weight to the driven wheels, or increase the number of driven wheels. 4XLs is way overkill and won't help with lack of traction, other than by adding their weight to the driven wheels.

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1 hour ago, jtlan said:

I assume the wheels are slipping due to lack of traction, rather than the motors stalling. If so, you'll need to add more weight to the driven wheels, or increase the number of driven wheels. 4XLs is way overkill and won't help with lack of traction, other than by adding their weight to the driven wheels.

well I've not actually built any of this physically yet. but given the length and weight of the train I just assumed that the 2 M motors wouldn't be nearly enough. the issue possibly turning out to be wheel slipping over motor stalling does make logical sense though. I mean if the loco can pull this all on its own that would be absolutely fantastic. maybe I'm just underestimating the power of the LEGO motors, I've never worked with them before. I was just building the motor coach as a kind of backup because I didn't know if this will actually work physically (i know the builds themselves are solid. i mean the actually motorization/running part) I was just covering all my bases if you will. i would rather not have to do extensive redesigning once I've build the model's physically.

though going by what some of you have said. just using M motor's in the motor coach should probably be enough considering the loco already has 2 as well and then that way the RPM's of the motors will be the same. 4 M's would likely move all of this with little problem.

the only issue is the different wheel sizes then i guess. the larger XXL drivers of the loco, and the standard small for the coach bogies. though this issue can probably solved with some fancy gear work to make sure the small wheels of the coach are moving at the same pace as the drivers.

i guess all that i need to do would be to figure out what those gear ratios are in order to do that.

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9 hours ago, The Lego Railway Series said:

the only issue is the different wheel sizes then i guess. the larger XXL drivers of the loco, and the standard small for the coach bogies. though this issue can probably solved with some fancy gear work to make sure the small wheels of the coach are moving at the same pace as the drivers.

You can avoid this using alls other PU motors, where you cat set rotations/sec , with pybricks you can enter the "gear" in the commands

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