Hod Carrier

Some dumb PU questions

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Now that it appears that the remaining PF elements have been retired I guess that I shall have to now consider getting with the new tech and adopting PU. Unfortunately this means that I haven't really been paying attention to the discussions so far. Also I just like to build and drive trains and am no engineer, so I'm afraid that a lot of the discussion about Powered Up is way beyond my comprehension. So forgive me if these questions seem a little simplistic or if they've already been answered elsewhere.

1) Did we ever get to the bottom about whether or not Powered Up could handle a twin-motor set-up without having to dismantle or modify any parts?

2) Has anyone else tried using the new Technic motors (e.g. 88013) for loco propulsion? How do these compare with the outgoing PF motors in terms of power and speed (I already know how they compare for price :angry:)?

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Posted (edited)

Hi,

15 minutes ago, Hod Carrier said:

1) Did we ever get to the bottom about whether or not Powered Up could handle a twin-motor set-up without having to dismantle or modify any parts? 

 

Yes, connect one motor to Port A and the other one to Port B. Or - for a long train with engines on each end - use two hubs, one motor each.

15 minutes ago, Hod Carrier said:

2) Has anyone else tried using the new Technic motors (e.g. 88013) for loco propulsion? How do these compare with the outgoing PF motors in terms of power and speed (I already know how they compare for price :angry:)?

You find these values here:

https://www.philohome.com/motors/motorcomp.htm

Edited by Lok24

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Regarding the price: you can find the technic motors much cheaper on bricklink (below 20USD). Make sure to check both, the "part" and the "set" (that contains only the motor and is sold by lego)

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32 minutes ago, Hod Carrier said:

 (I already know how they compare for price :angry:)?

Yes, train motor PF 13,99 $  train motor PU 13,99 $ :wink:

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26 minutes ago, Lok24 said:

Yes, connect one motor to Port A and the other one to Port B. Or - for a long train with engines on each end - use two hubs, one motor each.

Oh, it really is as simple as that? That's good. As I say, I haven't been paying a huge amount of attention to the PU discussions, but I seem to recall that this had been an issue. I guess I must have read it wrong. Many thanks.

27 minutes ago, Lok24 said:

He's a quick worker. I had a feeling that I should have probably checked there first. So the new L-motor is a tad more powerful than the old PF version but at the cost of lower RPM.

12 minutes ago, Tcm0 said:

Regarding the price: you can find the technic motors much cheaper on bricklink (below 20USD). Make sure to check both, the "part" and the "set" (that contains only the motor and is sold by lego)

Good tip. Many thanks.

Just now, Lok24 said:

Yes, train motor PF 13,99 $  train motor PU 13,99 $ :wink:

That parity wasn't evident with the L-motors, though. TLG were shifting the outgoing PF L-motors at @12-15GBP before Christmas (assuming I've remembered the figures correctly) but the new L-motor is @30GBP.

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Posted (edited)
11 minutes ago, Hod Carrier said:

LG were shifting the outgoing PF L-motors at @12-15GBP before Christmas (assuming I've remembered the figures correctly) but the new L-motor is @30GBP.

Yes, and it contains electronic to give feedback of speed and angle to the hub. This enables you to turn for 90°, it can be used as a servo.
Or for speed regulation....

So it's quite a different technique. But I agree, the prince is to high.

Edited by Lok24

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4 hours ago, Lok24 said:

Yes, train motor PF 13,99 $  train motor PU 13,99 $ :wink:

HA! But the PF motor package contained wheels and axles, and the PU motor does not. So the PU train motor ends up being more expensive if you need the wheels.

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Thanks. I heard both versions: included and not included.

But if not you are right.

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1 hour ago, Phil B said:

HA! But the PF motor package contained wheels and axles, and the PU motor does not. So the PU train motor ends up being more expensive if you need the wheels.

They have began to cut the parts of train motors a long time ago. Back then all of them included the "side panels". I think that they got removed sometime during PF.

Current PF train motors only contain axles and wheels. According to bricklink the current PUP train motor contains the same.

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9 hours ago, Lok24 said:

Or for speed regulation....

I really, really like to emphasize on this.

To be quite honest, this has bothered me from day one running trains across a "curvy" track. Back then, I had 16 curves and some straights. And then all that grew. Nevertheless: Using plain vanilla 9V motors OR PF train motors and some longer train, it always turned out to be almost stalling in tight curves and running pretty fast on straights.

There are two approaches for resolving that issue: a) Provide power. Add PF XL's - as many as "needed" to overcome the problem. b) Provide a brain. Here is the reasoning: At full speed (i.e., apply full controller voltage to >train motors< with no PWM) - at least for me - resulted in flying off the track. Particularly when approaching the curve from a stretch of straight track. Everything in between: Slow - fast - slow - fast ... This means that train motors can do it, but need control. Problem: Train motors (even PU) have no rotation sensors. Solution: Use an RCX, a rotation sensor, and train motors, load RobotC into RCX, program a PID algorithm, and off you go. Lot of work. Lot of fiddling. But fun.

Solution two: Use the PU L motor and a PU hub of choice. You just need the "Set speed" (not "Set power") command - and full-blown PID speed control is invoked. Without noticing. When your train is really too heavy: Use two. But: The PID algorithm in the Hub is really cool. 

There is even one more: You can select acceleration/deceleration profiles: Starting speed (lets say "0%"), final speed (lets say "60%"), time to go from start to final, press "start" and the train slowly and steadily, regardless of "obstacles" like curves, does that. Or: Set speed (not power) to 5%. Your train will move around your layout with exactly that speed.

I honestly believe that all that is at least compensating for a little of the price tag of PU motors with rotation sensor and feedback electronics.

Best
Thorsten       

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10 hours ago, Toastie said:

I really, really like to emphasize on this.

To be quite honest, this has bothered me from day one running trains across a "curvy" track. Back then, I had 16 curves and some straights. And then all that grew. Nevertheless: Using plain vanilla 9V motors OR PF train motors and some longer train, it always turned out to be almost stalling in tight curves and running pretty fast on straights.

-snip-

Solution two: Use the PU L motor and a PU hub of choice. You just need the "Set speed" (not "Set power") command - and full-blown PID speed control is invoked. Without noticing. When your train is really too heavy: Use two. But: The PID algorithm in the Hub is really cool. 

There is even one more: You can select acceleration/deceleration profiles: Starting speed (lets say "0%"), final speed (lets say "60%"), time to go from start to final, press "start" and the train slowly and steadily, regardless of "obstacles" like curves, does that. Or: Set speed (not power) to 5%. Your train will move around your layout with exactly that speed.

I honestly believe that all that is at least compensating for a little of the price tag of PU motors with rotation sensor and feedback electronics.

Best
Thorsten       

This sounds very interesting. I am still hesitant to equip my old 9v trains with PU (let alone how to fit the hub...) but this possibility - among the others regarding automation - intrigues me. When you say PF L Motor, does this mean it won't work with a train motor? The 10277 is my only train driven without a train motor. 

@TuffTuffTuff

Small amendments as a workaround (haven't done this myself though) 

If both motors are attached to one hub (a+b), you could turn one set of buttons upside down on the remote and control both simultaneously. 

If they are attached to two hubs you would still have to choose different ports and then quickly switch between channels (=hubs) before controlling the second motor. 

13 hours ago, TuffTuffTuff said:

You will have to use the app for a twin motor setup. 

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3 minutes ago, Sunil766 said:

When you say PF L Motor, does this mean it won't work with a train motor? The 10277 is my only train driven without a train motor.

 

PU L
No, it dosnt't work with the train motor.

 

4 minutes ago, Sunil766 said:

If both motors are attached to one hub (a+b), you could turn one set of buttons upside down on the remote and control both simultaneously. If they are attached to two hubs you would still have to choose different ports and then quickly switch between channels (=hubs) before controlling the second motor. 

Yes, I showed that a while ago:

10457-1594120800.jpg

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1 hour ago, Sunil766 said:

The 10277 is my only train driven without a train motor

Is the Croc driven with the PoweredUp L motor + 2I/O Hub? Then you are all set.

And as @Lok24said: This is all for PoweredUp only, and in this case specifically for the PoweredUp L motor. The PoweredUp train motor does not have any other extra in it (as compared to 9V and PF train motors) other than a resistor telling the hub what it is, when you connect the PU train motor to a PU hub. The PU L motor has a "rotation sensor" and some signal shaping etc. electronics in it, which is recognized by a PU hub when you attach the motor. All PU devices identify themselves in one way or the other (but unequivocally) when you connect them to a PU hub. The PU train motor does nothing actively - it just passively pulls a one of the connection lines down (or up, don't remember), telling the PU hub "I am a dumb motor". BTW using this wiring scheme you can hook up any motor to a hub - but you won't have any speed regulation (etc.) means, as you signal "dumb motor" to the hub.

Best
Thorsten   

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2 hours ago, Lok24 said:

PU L
No, it dosnt't work with the train motor.

 

Yes, I showed that a while ago:

10457-1594120800.jpg

Clever, I like it! 

1 hour ago, Toastie said:

Is the Croc driven with the PoweredUp L motor + 2I/O Hub? Then you are all set.

And as @Lok24said: This is all for PoweredUp only, and in this case specifically for the PoweredUp L motor.

 

- snip-.

Best
Thorsten   

Yes I am, but only with the crocodile. Don't know if it's due to the transmission, but the Croc never seemed to drastically lose speed in corners, even when pulling 5+ (standard) cars without the red traction bands. 

 

I know that I will want to step the game up with automation and track section control (maybe with (magnetic) proximity sensors) at some point. Just not sure which system to base this on:

- use my existing 9v equipment (4 transformers, 110 straights, 5 or 6 pairs of switches) and be limited to "x loops = on/off" 

- upgrade to more PU equipment (so far only Croc and 2x60197) and be able to control trains individually. 

I assume the latter provides more flexibility in what can be achieved. Would be very helpful to see an overview of use cases incl. required Equipment... Might have to do some research in that direction first, YouTube is offering a lot in that regard. 

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30 minutes ago, Sunil766 said:

Would be very helpful to see an overview of use cases incl. required Equipment... 

I for one am working on a turnkey software using color sensors mounted in the locomotive. Would mean you'd need Hub + sensor + motor per loco (78€ S@H), plus motor + hub for switches if you go purist.

Look at other solutions, though, I'm a horrible procrastinator and been working on this since September 2019.

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PID control?  Where is the fun in that?  Kids like seeing train crashes at LUG events especially when the AFOL train driver was too busy chatting with the kids' moms to notice the curve of death at the bottom of the hill.  :laugh:

I experimented with PU color sensor to indicate slow and fast sections with different color plates/tiles on the tracks.

colorsensor.jpg

 

 

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22 hours ago, Phil B said:

HA! But the PF motor package contained wheels and axles, and the PU motor does not. So the PU train motor ends up being more expensive if you need the wheels.

 

20 hours ago, Tcm0 said:

Current PF train motors only contain axles and wheels. According to bricklink the current PUP train motor contains the same.

I can confirm, I bought one of the PU train motors to get over a "free set" price point last month and I was surprised that it came with wheels when the photo does not show them. Maybe Lego is keeping their options open to drop the wheels in the future.

 

 

 

16 hours ago, Toastie said:

I honestly believe that all that is at least compensating for a little of the price tag of PU motors with rotation sensor and feedback electronics.

The motor feedback is really cool, but lego needs to also make dumb motors (which fortunately we have in the train motors) and dumb battery boxes so that simple projects do not cost $75. That said, what you can do with the sophisticated system is amazing, e.g., color sensors. Another drawback of the (unmodified?) PU system is that you need a phone or tablet to be connect to the hubs at all times. It would be great if your automated train could just do its thing without regard for being connected to a phone. I understand why it is not the default option, but for the cost of the system, we should be able to select it.

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1 hour ago, zephyr1934 said:

The motor feedback is really cool, but lego needs to also make dumb motors (which fortunately we have in the train motors) and dumb battery boxes so that simple projects do not cost $75. That said, what you can do with the sophisticated system is amazing, e.g., color sensors. Another drawback of the (unmodified?) PU system is that you need a phone or tablet to be connect to the hubs at all times. It would be great if your automated train could just do its thing without regard for being connected to a phone. I understand why it is not the default option, but for the cost of the system, we should be able to select it.

I'm pretty sure that we will see the dumb battery box this year again that was used in the canceled osprey set. But that's a technic battery box.

The ability to download programs/routines to the hubs should be added to the PUP app this year. It's already possible with pybricks. Also, in theory the large technic hub from mindstorms/spike prime can control other pup hubs.

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Just now, Tcm0 said:

The ability to download programs/routines to the hubs should be added to the PUP app this year. It's already possible with pybricks.

Yes, pyBrick works fine, but yet no connection to other hubs (which is on the roadmap)

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On 1/4/2021 at 1:12 PM, Hod Carrier said:

2) Has anyone else tried using the new Technic motors (e.g. 88013) for loco propulsion? How do these compare with the outgoing PF motors in terms of power and speed (I already know how they compare for price :angry:)?

I tried the M-Motor on this 1:22.5 locomotive and it works fine (with a  3:1 final gear ratio) - same results as PF M-motor. It's not fast nor extremely powerful - but it can haul three/four small G scale wagons pretty easily on plain track. But it works only using the Tablet/Phone app. No way to use it with standard controller. Even battery, considered the weight of such a big model, is pretty durable.

 

Lego G Scale Toy Train -  night run in the garden

The really good thing with PuP app is that you can emulate smooth acceleration and stops by creating some easy code and add additional controls with a color sensor (it could be useful for your tilting train experiments - for example).

It's another way to think and play, even if I prefer the old PF motors, until they are available.:wub:

Ciao!

Davide

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On 1/4/2021 at 11:19 PM, Toastie said:

...it always turned out to be almost stalling in tight curves and running pretty fast on straights.

a) Provide power. Add PF XL's - as many as "needed" to overcome the problem.

b) Provide a brain.

c) Remove rubber bands on one side of your engine. Won't completely cure the slowing down in corners but at zero cost it makes a big difference.

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On 1/5/2021 at 9:36 AM, dr_spock said:

PID control?  Where is the fun in that?  Kids like seeing train crashes at LUG events especially when the AFOL train driver was too busy chatting with the kids' moms to notice the curve of death at the bottom of the hill.  :laugh:

I experimented with PU color sensor to indicate slow and fast sections with different color plates/tiles on the tracks.

colorsensor.jpg

 

 

First generation PTC for Lego trains.

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On 1/5/2021 at 12:19 AM, Toastie said:

b) Provide a brain. Here is the reasoning: At full speed (i.e., apply full controller voltage to >train motors< with no PWM) - at least for me - resulted in flying off the track.

"c) Remove rubber bands on one side" Oh yes! But b) was referring to the build with >train motors<. Taking off the rubber bands from train motors is less efficient. Taking them off from the LEGO or BBB drivers: Definitely!

Best
Thorsten

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