More pulling power for Maersk Engine

ecmo47

I just powered my Maersk engine (#10219) with the Power Functions Train Motor (#88002) as described in the instructions. Turns out that it's not a very powerful motor and can barely pull another unpowered engine + 4 cars around the track. My Emerald Night has much better pulling power with the #8882 XL Motor. Anyway, has anybody tried powering the other truck (front set) on the engine? Will one battery box (rechargable) support 2 motors? Any tips on syncing the motors? Thanks.

oldtodd33

Personally, I would buy another #88002 and battery box for the other engine and set the frequency on both the same. There is no need to synchronize the motors. I haven't tried putting 2 PF motors on 1 engine before but I can't imagine it would do the 1 battery box any good at all. It might even overheat the box or wires depending on how you hook them up.

iancam33

LEGO just needs to produce a better, more powerful motor. One full horsepower should do it. Calling Tim Taylor, where are you?

ecmo47

^^ That is what I will probably do. 2 motors might be a pretty heavy pull for 1 battery box although 1 battery box powers 4 motors in the Motorized Excavator. I wonder if I could power the truck with an XL motor?

graphite

Two motors on one battery box shouldn't be a problem. Two motors would lessen the strain on one and reduce its average current draw, and the IR receiver wires have to be designed to handle the power of whatever is hooked up so each port can handle the draw of a motor and the wire to the battery box has to be able to handle the full power of the battery otherwise it is unlikely to pass UL testing (or I would assume). You'll reduce the run time you can get on a battery charge but other than that it should be more than fine.

oldtodd33

I'm no electrician here but, the voltage is constant at 9V, the IR controls current. That's why 2 motors on one battery would drain it faster and cause lower run time. Running two motors on one battery box would DOUBLE the current draw and possibly burn up the IR unit or lessen it's life time.

graphite

^ The IR units have two ports, so while it is possible that putting two motors on one port *might* burn up one channel, it is unlikely that it is designed with current limits that are LESS than the total current capacity of the battery box. So no matter how much you hook up to either port on a single IR receiver it is probably able to handle the max draw that 6 AA batteries or the rechargeable battery is capable of putting out. Pretty sure UL tests would require that safety component.

But if you put a motor on each channel, and the IR receiver can't handle that from one battery box, then LEGO designed a completely piss poor product and that is not really likely in my opinion.

oldtodd33

^ I understand what you are saying but we are thinking opposite of each other. If you think of this in relation to the old 9V system, the 9V controller is basically the IR receiver in this system. If you put too many 9V motors on the track or short the system in some way. The controller shuts down to cool off. I am thinking with the two motors drawing their top capacity, they could pull more current from the battery box than the IR receiver can handle and damage the IR.

aap

According to the information on Philo's comprehensive website about LEGO motors it is no problem to use two PF train motors on one IR channel, because each consumes 0,38A, the internal protection of the IR receiver V1 can handle 0,9A on one channel and the internal protection of the AA battery box or the rechargeable battery is nominal 0,75A.
In the Rock Crawler set (9398) LEGO uses two PF large motors (0,49A) on one IR channel.

Paperballpark

From what I've read elsewhere, I'd use a V2 IR receiver if you want to have two motors from one IR channel. These are easily distinguishable from the V1 version by the addition of 'V2' on the front of it :)

oldtodd33

@aap Thank you, that's a handy website to be able to look at in the future.

flecski

The cargo set #7939 can have two train motors put into it and it works very well. I would think Maersk would also take this setup. Note, the second motor needs to have the power set in reverse, using either the switch or soldering up the wire.
Where @graphite‌ says the average draw would be less, I think he means that because a second motor is helping, the first motor doesnt need to do as much work to get the train moving. Yes, the overall current draw will be more, but as @aap‌ points out with the specs, its still within tolerance.
I have run one #7939 with its rolling stock, and added on #7938 at the front and back and also the toy story carriages. It pulls everything with no problem. In fact the main problem is the strength of the magnets between carriages. If there is too much weight then it can detach.

Flec

oldtodd33

^ With a longer train, I use one motor in front and 1 in back to avoid that problem. I have only noticed that particular problem with the newer magnets though.

Paperballpark

The newer magnets can 'flip' inside the casing though. if the connection seems particularly weak, try moving the magnets up and down against each other, and you should hear them 'click' into the stronger position. I've never had a problem with them in the stronger position.

flecski

^ as long as both IR units receive the same signals then this does make for an easier setup.

I suspect that this would drain power faster though, as there is more weight being pulled round with two battery packs. Of course, it would seem like it lasted longer because that extra drain is split between both packs. If you are limited to just recharging 6/8 cells at a time then this may make a difference. Having said that, rechargeable AAAs are not too expensive so you just need to keep loads charged up.

flecski

flecski said:

. . . the main problem is the strength of the magnets between carriages. If there is too much weight then it can detach.

Flec

Thinking about it, we have had more problems when the boys have put a lightweight stock (eg, car transporter) in the middle, that gets pushed against heavier carriages. If you accelerate at full chat, then the lightweight unit can lift a bit and derail. I guess because the weight in front is too high,
The method @oldtodd33‌ uses should stop this. (But I still like having just one powerful engine. Must be the Clarkson effect)

Flec

ecmo47

Paperballpark said:

From what I've read elsewhere, I'd use a V2 IR receiver if you want to have two motors from one IR channel. These are easily distinguishable from the V1 version by the addition of 'V2' on the front of it :)

Any idea why it would make a difference?

graphite

If you don't care about being able to pull the cars apart really easily you can always pull the magnet part out of the buffer and connect cars with like a 1x3 technic beam and pins into the hole in the buffer where the magnet goes. Would also probably help fix the "lifting" of light cars since it wont have as much vertical movement like the magnet does.

ecmo47

flecski said:

I have run one #7939 with its rolling stock, and added on #7938 at the front and back and also the toy story carriages. It pulls everything with no problem. In fact the main problem is the strength of the magnets between carriages. If there is too much weight then it can detach.

Flec

I knew that this would be the next issue with a long train. I wonder how easy it would be swap the Lego magnets for rare-earth magnets.

ecmo47

...or I could just do what Graphite says. Thanks!

oldtodd33

@graphite and @ecmo47 I think I saw on Dr. Daves blog a picture of a 1 x 3 plate mounted on top of the magnets to hold them together.

graphite

^ Yeah you can do that as well with the newer magnets because the plastic casing has a stud on top and bottom. But if you're going to do that I think the technic pieces will still hold better in the long run. Enough bumping and turning and the plate might pop off but the technic should hold up to more abuse.

ecmo47

I did several combinations with a second motor tonight. In the end, I just ended up powering 2 separate locomotives, both facing the same direction. I had hoped to be able to hook them up back-to-back but I could never achieve smooth operation that way. 2 locomotive would pull a seven Maersk flats loaded with 11 Lego containers so it is a pretty heavy train. I did have issue with couplers pulling apart especially on curves.

I tried 2 configurations on a single locomotive:

1. 2 Lego motors on one locomotive with the front powered truck facing backward. I started here since it was the easier modification. The wire easily went up the hole in the middle of the engine. I attached the plug to the second port on the IR receive so I could control it separately. I had a very hard time getting the motors synced for smooth operation, since they wanted to run in opposite directions.

2. 2 Lego motors on one locomotive with the front powered truck facing forward. Power wire would have to come over the front of the baseplate and through the cab to reach the IR receiver. You could cut a hole in the base plate to let the wire through but I did not do this yet. The plug was stacked on top of the other motor plug so they would both on the same channel. This configuration showed a lot of promise, except that it would require extensive remodeling of the front end of the locomotive. Had good pulling power.

Bottom line is that it is very hard to operate 2 motors if they are not facing the same way either on one locomotive or two.

I just had a thought that I might try. To achieve the back-to-back operation that I wanted, I could put the powered truck on the front of the back locomotive. Since its facing backward it would push the locomotive in the right direction and I would not have to make major structural modifications.

ecmo47

Next issue to investigate is durability. I need to see if motors and battery boxes can run for hours on end. Im prepping for a weekend show so this is important. Also, I wonder about lubrication for the axles. Of special concern is the unpowered truck on the locomotive. It is just a simple axle shoved through technic beam hole. I would think that would wear quickly. Puff of graphite like we did for our pinewood derby cars? WD-40? Suggestions would be helpful.

oldtodd33

I don't know about the graphite but WD-40 is NOT a lubricant, it is intended to be a penetrant, it will evaporate. I have used silicone spray on the battery box of my 7722 4.5V train and that seems to work. What ever you use, make sure it's intended to lubricate. Maybe a small amount of grease would do.