Power Functions in 60's and 70's Train Sets

[retrotecchie]

Love my new 7939 Cargo Train, and love the Power Functions RC system. I have a 7740 replica I assembled from odd elements, thanks to an instruction scan downloaded from Peeron. I don't have any of the 12v track conductors, controller or running gear but managed to adapt a new 9v train motor from the LEGO shop to work on the loco. This 9v train motor has the older style stud connections, like the old Sound and Light stuff, but there is a Power Functions cable that adapts the motor to the new system.

So, a new motor, borrowed battery box and IR receiver from the 7939 and my 7740 ex-12v loco is now motoring round my old blue track under PWM speed control...lovely.

Then I got to thinking...I have twenty original LEGO locos spanning 1968 to 1985 all motorised with the old 4.5v classic 4x12x3 1/3 4.5v motor units.

The 7722 train set used the 4.5v motor and a 4.5v battery tender, but one of the pages in the instructions shows how a later 9v motor can be adapted to replace the 4.5v unit. Figuring that the 4.5v motor was the de facto standard for 30 years, I concluded that exactly the same adaptation would work for any train using the old motor.

http://www.peeron.com/scans/7722-1/30 for the scan

So I took my beloved 171 loco from 1972, did the motor conversion and hooked up an old train base with the PF battery box and IR receiver as a temporary tender.

Result. A Power Functions 1972 171 Train set! I then built a replica 182 style battery tender, and incorporated the receiver and battery box, tweaking the design a little to clear the IR sensor and the battery box connector. It did take some tweaking but the whole battery and reciever pack does fit into the same size as the old 4.5v tender.

Downside....the new train motor weighs 220g less than the old 4.5v block. 120g as opposed to 340g, which is why the 7740 modification shows the inclusion of the 2x6x2 black train weights. Can't fit those into the design of the 171 so the loco is a little too light to get the best traction.

But then I thought...the old 4.5v motor has the same two stud contacts as the 9v train motor, so in theory, the Power Functions cable SHOULD fit the 4.5v motor and make an electrical contact. Perhaps I could retain the old motor and red train wheels (with rubber drive rims), keep the look and the weight of the loco exactly right, and still run it under remote control using power functions.

The 9v motor is never driven directly across the 9v supply using PF, unless you connect it directly to the battery box and bypass the receiver. Instead, the motor is driven from the C1 and C2 terminals of the PF using PWM. So, in theory, driving the 4.5v motor using the slower speeds and PWM shouldn't do too much harm to the motor. In practice, I found this to be the case and now my old 171 is happily motoring round the track using PF control. When my new battery boxes cables and IR receivers arrive from the LEGO shop, I will then be able to run all my trains using PF!

Replace the 6 AAA 1.5v batteries with NiMH 1700mAh rechargeables at 1.2v each (for less each than the price of a decent Duracell), making a 7.2v pack, PF runs like a dream and the 4.5v motor is much happier - a bit more torque and not so much overvoltage! And rechargeable to boot.

Photos to follow :)

[LEGO Guy Bri]

Can't wait to see them! Are you going to keep the original bogies no the rest of the train, or replace with the 9v style bogies?

[johanby]

So, a new motor, borrowed battery box and IR receiver from the 7939 and my 7740 ex-12v loco is now motoring round my old blue track under PWM speed control...lovely.

I have tried the same, but find that the new wheels with technic axle connection (e.g. http://www.bricklink.com/catalogItem.asp?P=55423 ) have trouble staying on the blue track, especially on switch points. I wish there were similar wheels like http://www.bricklink.com/catalogItem.asp?P=wheel2a but with technic cross axle connection instead.

Then I got to thinking...I have twenty original LEGO locos spanning 1968 to 1985 all motorised with the old 4.5v classic 4x12x3 1/3 4.5v motor units.

The 7722 train set used the 4.5v motor and a 4.5v battery tender, but one of the pages in the instructions shows how a later 9v motor can be adapted to replace the 4.5v unit. Figuring that the 4.5v motor was the de facto standard for 30 years, I concluded that exactly the same adaptation would work for any train using the old motor.

http://www.peeron.com/scans/7722-1/30 for the scan

Actually, the adapted motor you refer to as a 9V motor is the newer 12V type motor http://www.bricklink.com/catalogItem.asp?P=bb12v . However, this does not change any of your conclusions. I really like what you have done and will try it myself.

[retrotecchie]

Can't wait to see them! Are you going to keep the original bogies no the rest of the train, or replace with the 9v style bogies?

I have to confess to being a bit of a purist with the older trains, so I shall keep the rest of the rolling stock as original as possible. I am rather fond of the old 70's train bases, but all my new 'recreations' use the current train wheels, bogeys and axle blocks available from PAB unless I find an old retro train lot here and there on ebay!

Next trick....convert my 1968 116 loco to Power Functions, but that will probably mean building the IR receiver and battery pack into one of the carriages (probably the cargo waggon) as there is no easy way of redesigning the old style hand-held battery box type tender to take PF: http://www.peeron.com/scans/116-1/5

The original tender will then be just a dummy replica and I'll need a longer cable that goes from the loco, through the dummy tender and into the next carriage!

[Toastie]

Love my new 7939 Cargo Train, and love the Power Functions RC system.

Then I got to thinking...I have twenty original LEGO locos spanning 1968 to 1985 all motorised with the old 4.5v classic 4x12x3 1/3 4.5v motor units.

The 9v motor is never driven directly across the 9v supply using PF, unless you connect it directly to the battery box and bypass the receiver. Instead, the motor is driven from the C1 and C2 terminals of the PF using PWM. So, in theory, driving the 4.5v motor using the slower speeds and PWM shouldn't do too much harm to the motor. In practice, I found this to be the case and now my old 171 is happily motoring round the track using PF control. When my new battery boxes cables and IR receivers arrive from the LEGO shop, I will then be able to run all my trains using PF!

Replace the 6 AAA 1.5v batteries with NiMH 1700mAh rechargeables at 1.2v each (for less each than the price of a decent Duracell), making a 7.2v pack, PF runs like a dream and the 4.5v motor is much happier - a bit more torque and not so much overvoltage! And rechargeable to boot.

Hi retrotecchie,

nice! But why aren't you using the 4.5V battery directly as the PF receivers power supply? The receiver runs smoothly on 4.5V, just tested it again. I may have dropped that somewhere around this forum, forgot.

It actually does correct PWM control down to 2.8V, which means that it will flush the 4.5V entirely without malfunctioning, I bet. I don't have 4.5V motors, used the PF motor for this little test. BTW the receiver also operates on 12V like a charm. So regardless what "retro-train type" you are using, 4.5V, old 9V, 12V: The PF receiver does them all. When hooked up to the proper LEGO electric stuff (4.5V supply -> PF receiver -> 4.5V motors or 12V supply -> PF receiver -> 12V motor you naturally won't have any overvoltage issues at all ...

There is a discussion over at the Technic Forum regarding higher than 9V supplies on PF stuff. Rien is running some of his PF driven LEGO equipment on 11.1 V using a custom LiPo. Works like a charm as well. People are concerned a bit about the 11.1V with regard to the motors - but no one is having problems with the receiver. Seeing what Rien has been doing with his PF stuff, the PF receiver is a really nice piece of equipment TLC has made for us!

All you need is a custom PF extension cable (The 9V -> PF converter cable works perfectly well). Cut that in two pieces and connect the 9V terminal C1/C2 lines to the 9V/0V line at the PF terminal which then snaps onto the receiver's PF supply terminal. The 9V terminal may go to any 3V ... 12V supply you see fit and the receiver will happily drive the matching LEGO electric stuff (motors, lamps ...)

Have fun!

Thorsten

[retrotecchie]

Great stuff! My 4.5v battery boxes have already been converted by changing 3 x 1.5v alkaline 'C' cells to 4 x 1.2v 1700mAh NiMH AA cells at a cost of a few Euro/£ a box, so I am already using 4.8v rechargeable as a 'standard' for my old retro trains. I didn't think of trying the 4.8v boxes as a power source. That would indeed mean I could keep my original tenders, but would then be lost for somewhere to fit the IR receivers....unless I can squeeze them into the cabs somewheres!

The only downside, is that to 'hack' a PF extension cable to plug in on the old battery boxes you will need to add a silicon diode in series with one of the leads to make sure you don't accidentally reverse the polarity from the battery box...the new PF snap on connectors are polarised, whereas none of the old 4.5v or even the 9v stuff was, strictly speaking. Unless of course the electronics Gurus at TLG have already added a bridge rectifier or something into the PF reciever....

[Toastie]

The only downside, is that to 'hack' a PF extension cable to plug in on the old battery boxes you will need to add a silicon diode in series with one of the leads to make sure you don't accidentally reverse the polarity from the battery box...the new PF snap on connectors are polarised, whereas none of the old 4.5v or even the 9v stuff was, strictly speaking. Unless of course the electronics Gurus at TLG have already added a bridge rectifier or something into the PF reciever....

Hehe,

the Guru's knew about the creativity of brickers - there is a 4001 protecting the receiver electronics. Oh well, I guess this is more or less good design practice, particularly when the leads are exposed and somebody could accidentally get metal stripes from C1/C2 to 9V/0V as I did a second ago ... - 0.7 V is all that is left on the supply line and all the current through die diode is transferred to heat ...

So no harm again other than the shorting. But that is no problem with batteries.

Regards,

Thorsten

[Dan-147]

Sweet!

I've been wanting to convert all my old 4.5volt trains to Power Functions, actually any kind of wireless remote, for some time. Power Functions is great because it makes it an all-LEGO solution with minimal conversion. My biggist hurdle, apart from not having any Power Functions for the time being, was that Power Functions uses 9volt while the motor wants 4.5volt. But if I read this quote correctly;

nice! But why aren't you using the 4.5V battery directly as the PF receivers power supply? The receiver runs smoothly on 4.5V, just tested it again. I may have dropped that somewhere around this forum, forgot.

...

Thorsten

the Power Functions receiver could work on 4.5volt. Please confirm if I got it right or if I'm totally out in left field...

Thanks!

[retrotecchie]

Sweet!

I've been wanting to convert all my old 4.5volt trains to Power Functions, actually any kind of wireless remote, for some time. Power Functions is great because it makes it an all-LEGO solution with minimal conversion. My biggist hurdle, apart from not having any Power Functions for the time being, was that Power Functions uses 9volt while the motor wants 4.5volt. But if I read this quote correctly;

the Power Functions receiver could work on 4.5volt. Please confirm if I got it right or if I'm totally out in left field...

Thanks!

Aha! Bingo!! I can indeed confirm that 4.5v motors, with a PF IR reciever and a 4.5v Alkaline or 4.8v NiMH supply do indeed work like a dream...exactly what I was after!

The downside is that the really early locos (116, 120, 171, 182, 183 etc) really don't have the space to fit the receiver in the cab. But....with a little imagination, an old 6x12 carriage base and some black bricks and blue plates, you can build a reasonable 182 style battery tender and incorporate all the gubbins in that. Have some photos...

Oversized Image 1

171 with 4.5v motor, PF reciever in 182 style tender, 7.2v NiMH battery pack using 7939 battery box

Oversized Image 2

Power Functions to 9v cable just snaps straight on to 4.5v motor power studs - simple!

Oversized Image 3

The IR reciever protrudes forward of the 6x12 carriage base by one stud, but this then gives enough space to curl up the surplus cable between the receiver and the battery box.

Incidentally, 6 x AAA NiMH cells soldered into a pack to give 7.2v is exactly six FLU's long, or two studs shorter than the 8 stud long battery box, so if you make up a rechargeable pack, you can fit everything into the footprint of the 6x12 carriage base, and hide the front of the receiver...you just need the sensor sticking out of the top of the tender.

Apologies for the image quality.....very low light levels in my attic and the camera on my phone is, er, not good!

Edited January 26, 2011 by TheBrickster
Please adhere to EB's image posting guidelines, 800x600 max, usually 640x480 works just fine.

[Toastie]

Sweet!

the Power Functions receiver could work on 4.5volt. Please confirm if I got it right or if I'm totally out in left field...

Hi there,

you are absolutely in the field. The PF receiver works down to about 2.8V maybe even further down and all the way up to 12V.

Regards,

Thorsten

[retrotecchie]

Hi there,

you are absolutely in the field. The PF receiver works down to about 2.8V maybe even further down and all the way up to 12V.

Regards,

Thorsten

Indeed Toastie! Thanks for the info on the voltage range. I'm an electronics engineer by trade and used to 'butchering' various devices...overdriving things and generally mucking about to see what limits I can push! As I only had one PF IR reciever (ten more coming in a day or so) I didn't want to 'experiment' and risk frying it until I was sure I'd not be left 'trainless' for a few days

[Toastie]

I'm an electronics engineer by trade and used to 'butchering' various devices...overdriving things and generally mucking about to see what limits I can push! As I only had one PF IR reciever ...

Why am I not surprised ...

Well, I guess this forum will learn a lot in the time to come from your input. When Teddy has the already announced new index operative (see top of train forum, message from TheBrickster) - that may take some considerable time though, it's a shipload of work, I believe - then you entries will be most welcome!

All the best,

Thorsten

[retrotecchie]

Ah.....my goodies arrived from LEGO so out with the soldering iron last night!

Decided to use a 4 AAA battery pack (4.8v) with 1000mAh NiMH cells for my 4.5v Trains. A sub miniature toggle switch on the top of the tender (fitted to a 2x4 blue plate) and a PP3 battery snap....job done. The whole shooting match goes nicely in a replica 182 style tender (black with the blue roof, hence the blue plate to mount the switch).

I could have drilled a hole in the bottom of the carriage base for the wires and mounted the switch unobtrusively on the side of the base between two wheels, but I figured modifying the plate was less drastic than brutalising a vintage carriage base! I was also thinking of fitting a 2.5mm DC power socket as I have on my modified 4.5v tenders so I can simply plug in a NiMH charger rather than have to drop the cells out and charge them individually, but I made up a load of spare packs so some can be charging while I'm playing with the others.

Now I have my 1968 '116 Deluxe Train Set', the 1970 '120 loco and tender', three 1972 '171' train sets, later 7710 and 7725 and my new 7939 Cargo Train all making their way around the attic now using one PF controller.....result!!

[Dan-147]

Ah.....my goodies arrived from LEGO so out with the soldering iron last night!

Decided to use a 4 AAA battery pack (4.8v) with 1000mAh NiMH cells for my 4.5v Trains. A sub miniature toggle switch on the top of the tender (fitted to a 2x4 blue plate) and a PP3 battery snap....job done. The whole shooting match goes nicely in a replica 182 style tender (black with the blue roof, hence the blue plate to mount the switch).

I could have drilled a hole in the bottom of the carriage base for the wires and mounted the switch unobtrusively on the side of the base between two wheels, but I figured modifying the plate was less drastic than brutalising a vintage carriage base! I was also thinking of fitting a 2.5mm DC power socket as I have on my modified 4.5v tenders so I can simply plug in a NiMH charger rather than have to drop the cells out and charge them individually, but I made up a load of spare packs so some can be charging while I'm playing with the others.

Now I have my 1968 '116 Deluxe Train Set', the 1970 '120 loco and tender', three 1972 '171' train sets, later 7710 and 7725 and my new 7939 Cargo Train all making their way around the attic now using one PF controller.....result!!

I agree with your choice of mounting the switch on an ordinary 2x4 plate instead of modifying an out-of-production and rare train base. Recently, I've also become less of a purist since the LEGO company doesn't always give us what we need. However, I try not to modify the bricks themselves. In this case, I would have tried to find a micro-switch that would have fitted in a 2x4 technic plate. But sometimes you don't have them on hand...

Your work is of great interest for me because I have a 7720 and a 7760 "clone" powered with 4,5volt motors that I've wanted to remotely control for some time. I was just curious about how you fitted the PF receiver (8884) into your train. Do you think you could post a picture of your set-up?

Thanks and keep up the inovations!

P.S. Any chance of a few pictures of your modified 4.5volt tenders?

Edited January 25, 2011 by Dan-147

[retrotecchie]

I agree with your choice of mounting the switch on an ordinary 2x4 plate instead of modifying an out-of-production and rare train base. Recently, I've also become less of a purist since the LEGO company doesn't always give us what we need. However, I try not to modify the bricks themselves. In this case, I would have tried to find a micro-switch that would have fitted in a 2x4 technic plate. But sometimes you don't have them on hand...

Your work is of great interest for me because I have a 7720 and a 7760 "clone" powered with 4,5volt motors that I've wanted to remotely control for some time. I was just curious about how you fitted the PF receiver (8884) into your train. Do you think you could post a picture of your set-up?

Thanks and keep up the inovations!

P.S. Any chance of a few pictures of your modified 4.5volt tenders?

Will upload a few shots tomorrow for you. Actually, a 2x4 technic plate (in blue) would have been perfect. I think the holes in Technic are 4.9mm and the hole I drilled to take my switch was 5mm.

As I have to take the top off the tender to swap out the 4 AAA pack, I could have just dropped the switch inside and not bothered about mounting it. The top mounted switch was a 'nice to have' rather than a necessity.

Edited January 25, 2011 by retrotecchie

[retrotecchie]

Right.....as promised. Again, apologies for the crap camera, but I hope you get the gist!

Take a standard 6x12 carriage base from the 70's

Build up as shown, leaving the front open...the IR receiver sticks out by one stud. You need to pack the base with two 4x1 plates and two 4x2 plates, building it up to the required height and allowing a one plate gap for the cable to emerge.

Fit the reciever, and the battery pack sits nicely behind it.

Make up the lid using blue plates, and finally, tuck in the switch wiring and fit the switch plate.

Shown here, my 120 Loco (1970) with the whole assembly fitted.

[SqueebsMcGee]

Hi All,

Back a few posts (and a few months ago now) you guys had a brief discussion about polarity issues powering the old 4.5v motors off the battery tenders - with the PF IR receiver in between. My knowledge of electronics doesn't quite have me 100% sure of the end result of that discussion.

I've got my old 7722 set from when I was young and I've recently been inspired to get back into the lego train world. I would love to be able to run it via power functions, however the motor car that came with my set does not have the raised stud power connections as retroteccie mentions in his example. In my case, the power studs are below the "surface" level of the brick.. According to bricklink I am using a x469bopen motor, vs what I belive you guys are using/talking about the bb06 motor. I've read enough other posts that I have been considering hacking some of the power functions cables so that I could run a motor directly off a 9v battery, but I would like to stay original if I can. My question is: if I just wire up either of the powered wires from the PF cable (specifically the 9v and 0v, leaving the c1 and c2 wires to be capped) to the standard issued electrical cable that came with the train set, then I should not have polarity issues from what I can gather and should not run the risk of damaging my 4.5v motor? Polarity issues don't seem to mater in these train set between when you trip the switch on the side of the battery tender, from what I have visually understood from looking at the battery tender, the switch seems to change the output polarity which I assume then changes the motor from running forwards to backwards...

I suppose the other option is to simply buy the power functions train motor, but I cann't find anything about it's brick dimensions and I have a feeling it is not 12x4x3 1/3 like my original motor (seems to be at least 2 studs shorter.. perhaps 10x4x3 1/3 or so). Also, I am keen to get this working sooner rather then waiting until september when the train motors may be off of backorder according to the lego website. And if I can run my train just by buying a PF cable and an IR receiver then I am able to save a couple bucks too..

Thanks for any help you guys can give me,

[peterab]

Hi SqueebsMcGee,

You shouldn't have polarity issues with any motor, as reversing the polarity will simply reverse the direction. You should also not be able to damage the motor if you use the original voltage (ie 4.5V) which the original battery cars supply.

I've just re-read your post and it seems you want to run your 4.5V motor with a 9V battery. That's not a good idea unless you have another load in series with it. You don't want to run it with all 9V across the motor. Use 4.5V as the input to the receiver and all should be fine.

I think you'll need to use the C1 and C2 outputs since the 0 and 9V outputs are uncontrolled by the remote. Using the controlled outputs will allow you to control the speed and direction.

You should be able to adapt a PF cable to the plugs that fit your motor. All the 4.5V train motors were pretty similar despite some small external differences.

Edited June 27, 2011 by peterab

[hoeij]

I've just re-read your post and it seems you want to run your 4.5V motor with a 9V battery. That's not a good idea unless you have another load in series with it. You don't want to run it with all 9V across the motor. Use 4.5V as the input to the receiver and all should be fine.

If you avoid the highest speed settings then there is little risk of damaging the 4.5V motor.

Even the highest speed setting, which I would avoid, will do little damage to the motor. At the highest setting, there would be more than 4.5V on the motor, but it would still be well below 9V because a small 9V battery simply won't be able to produce 9V under this load.

To really kill the motor, you need to pull a 10 feet long train with this one motor, under 9V, and do that non-stop for a whole day (yes, I tried that, and I did kill a 4.5V motor that way. Note that a replacement motor costs only $4). The 9V battery won't be able to deliver the current to kill the motor. I don't see any risk here.

[Locutis]

I have the 7722 Train Set. I was just thinking I could power the Loco using the 88002 PF Motor.

I would build a new red battery car out of bricks, and house the AAA battery box inside to power the PF motor.

Any thoughts on this?

My original train motor stopped working decades ago.

Locutis

[JopieK]

I have the 7722 Train Set. I was just thinking I could power the Loco using the 88002 PF Motor.

I would build a new red battery car out of bricks, and house the AAA battery box inside to power the PF motor.

Any thoughts on this?

My original train motor stopped working decades ago.

Locutis

7722 is quite simple I think, just use that PF 9V Train motor indeed.