lash up questions?

[Anonymous]

Yes Walt:

You are quite right, but once again i would caution that it isn't as simple as that; if you can go back over all the trouble i had with my Stainz, powered tender combo, derailing you will get a better idea. My Stainz is older and has done more klicks than my tender and when i set them up to start they run for months without any trouble. Then it started to derail in the same spot all the time but only in one direction and it took much to find out the problem.

I looked at everything from track camber to coupling but in the end it was an MTS problem, or more correctly an MTS solution. It seems the tender had run itslef in and its speed had improved slightly and it was getting to go faster then the Stains and it was causing it to jackknif e on a right hand curve and where it was derailing all thetime was a tough right hand curve. It would actually pu***he rear of the Satinz to the left.

I could run it around the track for as long as you like anticlockwise and no trouble. But the other way where there is all right curves it would derail more and more and i just slowed the tender down fractionally and i fixed the problem. I am still trying to work out why right hand curves and i have only a glimmer of a reason.


rgds ian

[grandpopswalt]

Ian, I agree that setting up double heading can be tricky. What we're trying to accomplish is equal load sharing. But once it’s set it should maintain itself. For instance, if the lead engine of a train starts to go up a grade or curve, it will slow down a bit. This will cause the trailing engine to have to pick up more load because it is still trying to travel at the original speed. The increased load current will cause it to also slow down, thus restoring the load balance. In both cases the engines slowed down due to increased IR drop. And if the lead engine starts to go downhill, the reverse scenario will occur.

Walt

[Anonymous]

Even so Wal, it can be a problem in that they must go round the track as advised with a minimum of variance at about the speed you wi***o run them. and they should go at just about the same speed as each other. then i have had to adjust the speed of the rear unit so that is is slightly slower (Very very) slightly. If the rear ones gets to pu***he front one, it may tend to pu***he rear of the front unit off the track on a right hand curve and cause unexpected derailments.

Using DCC or for me the MTS this can be easily done by adjusting register 2. There are two ways to double head on DCC. One is the give both units the same address, ie my ICE train has front and back engines both set to 5. Or there is function called double heading and you just enter the addresses of the two units in and they will do evry thing as a single unit; ie lights on and off whistles go off together as well as direction and speed.


Thjis is quite a big subjectand their is a lot in it.


Rds Ian

[grandpopswalt]

This discussion gives us even more reasons to go to DCC or Battery/RC. With either system the speed/torque of each engine can be set to share the load equally.

Walt

[gvdobler]

Put two locos on the track about 6-8 inches apart. Run them a few laps and see if they stay about the same distance apart, if they do you have a good match. Run them at different sppeds and with one backwards. If they change more than a couple inches in a lap, then I would say don't la***hem up.

[cabbage]

I am sorry, I speak very poor American -but I think I understand your questions.

1: is it possible to couple up two locomotives from diverse manufacturers?

The answer depends on the type and height of coupling used -but it is possible to fit the Kaydee couplers to both locomotives -so the answer is yes.

2: how damaging is it to couple up two locomotives that are not quite in synchronisation?

This depends on how far the axial rotation differs. At a steady state eg: both locomotives doing 10 cps, then if the difference is less than 5% then it should not tax the motors too much. Your main problem will result from accelerational differences. If one locomotive is highly geared then it will accelerate slower than one with higher gearing. This will be seen by the higher geared one as a dynamo action and the lower geared one as a brake action. Thus the current used and the heating effect on the locomotives will be far higher.

3: Can you pull more when you have locomotives coupled together?

The answer to that is yes -but you have to remember that this depends on the mass of the carriages and wagons that you are pulling and their rolling characteristics. For example: In my youth It was quite common for 3 type 15A garrett to pull 2Km long coal trains from Wanke to Victoria Falls. There would be one locomotive at the front and two at the back. Once the coal train had reached speed 55kph the rear two locomotives would disconnect and the coal train would proceed at speed until Victoria Falls where tthe single loco would brake the train over a distance of about 10km... So, if your carriages and wagons have good rolling characteristics then you could pull more of these with a single locomotive than you could ones with poor characteristics using more than one.

4. Do DC motors heat up more when rulling in coupled mode?

There should actually be no difference as (in theory) the current running through multiple motors is lower than that running through a single motor. I build my own locomotives and normally power each axle -the biggest is the ACE6000G with eight motors. I have found that initial draw is around 10 amps but this tails off to a static draw of around 5 amps when running. All my motors have internal fans at the rear before the commutators.

An AC motor would use less current -but the torque curve would be very unpredictable in my application.

I hope this has helped?

regards

ralph

[faricelli]

1. Is lashing up two different manufacters possible?

2. How damaging is it to lash up engines that are not quite in sync?

3. Can you pull more when lashed up?

4. Do the DC engines heat up more when lashed up?


Thanks, Rob