Jul 21, 2013
Thank you guys for the report. Can't wait to have mine!
If the driving wheels are in the locomotive wouln't adding more weight in the locomotive increase the pulling power? Can it be done? I want a simple fix for an old man. Me.
Have a look here and you can see this engine opened up.
The only place you can add weight is in the cab. and do not remove weight from the tender and that weight is basically there to keep the torque of the motor from turning the tender over rand putting it on the ground at start up.
If you have someone who can cast pewter then you could use lost was technique to produce tender shell in pewter and that would definitely increase the weight. There is a weight under the plastic boiler shell so if you could create a brass shell to replace the weight and plastic shell you could increase the tractive effort that way. I am not sure just how much tractive effort would be increased by these changes. I know from NN3 modeling that replacing a Marklin motor with a Faulhaber coreless one and adding a brass fly wheel plus pewter boiler shell and cab makes a remarkable change in the pulling power of Marklin chassis used in K28 conversions in Nn3.
for internal pictures have a llok here http://www.elmassian.com/z-scale-trains/z-motive-power/azl-mikado
when i said tender shell that should have been boiler shell
I removed the shell from the chassis and added 2 grams of powdered Tungsten to the smokebox. That increased the pulling power on my 2% grade with compound curves from 6 AZL passenger cars to 9 passenger cars. Starting on the grade produced no slippage. Thanks to all. Jim Thomas
Jim, good idea, you're on the "right track" to improving pulling performance. And.....decreasing a bit of "chatter" when you power up the loco, especially under a load. I went a step further and created a small donut that goes in behind the headlight. I mix some thinned epoxy with tungsten powder and created the insert-able weight. Another tip is to take a small weight (made up the same way as above with TP) and glue it on the top side of the leading truck. Add's weight, improves tracking.
I ran the Mikado on the Golden BLackhawk and Central City layout in Atlanta for 4 hours. the engine runs fine on rough track and there is no need to add weight to leading truck, in fact you may make the weight so high on the truck frame that going through a dip, you lift the front driver off the track causing slippage and poor performance. My take, is if the front truck is coming off the track your track work is at fault not the leading truck on this engine. Yes i add weight to Marklin leading trucks myself but I won't be on this engine. If there is any place I would add weight it is in the cab so it is behind the rear driver where the traction tire is located. If you can stuff some into the boiler I would do that but I would not remove weight from the tender as that is needed to counter the starting torque of the motor. With the weight removed from the tender it has inclination to roll over if power is applied too fast and the engine ends up on the ground. With the weight in place you can see the tender rock with a quick injection of power but iti stayed put on the track.
I recon from my experience with Nn3 and Pewter boiler shells that if you were to use the lost was technique you could cast the boiler shell in pewter and gain a considerable weight advantage in doing so, while sacrificing some of the crisp detail and added detail parts.
On the flat This engine was able to pull 16 AZL heavy weights including straight and 180 degree turns.
After seeing the torque lift the front of the engine off the track on an upgrade, I have steered clear of adding weight to the cab over the traction tire. The torque associated with the tender also applies to the engine. I was impressed with the impact of 2 grams added to the smokebox. I would add more if there was room. I will keep looking for more ways to add weight. Thanks to all. Jim
Tungsten is more dense than lead, but lead is more dense than tungsten powder. So if you put lead in the same place as tungsten powder it will weigh more. You can form lead with pliers and a hammer, even cut it with scissors. Just saying if you are trying to maximize weight...
Now if you can find 99% tungsten welding rod the is the same dia. as the inside of the boiler, that is the way to go.
Density is measured in grams per cubic centimeter so:
Lead 11.34 g/cc
Tungsten powder 11.25 g/cc (someone packed it as much as they could and only got 10.42 g/cc, poured in loose it was only 8.45 g/cc!)
Tungsten 19.25 g/cc
With all this talk about adding weight for more traction it leads me to ask the question....'about' what is the normal number of heavy weights you would expect to see in a passenger train? I know freight would be a considerably higher number of cars pulled, but thus far no one seems interested in testing freight cars. ''Are the heavy weights much heavier than the average box car from MTL or AZL?
The AZL passenger cars are a given weight and don't change. Where as MTL cars with the original plastic wheels don't roll as good as the Fox Valley metal wheels. And AZL wheels IMO don't roll as well as the Fox Valley either. Have not tried Uncle Will's metal wheels yet.
But I do agree that we need to see how many MTL freight cars with metal wheels one engine can pull.
The point to all the weight issue is related to a new design; motor in the tender-drive wheels in the engine. Torque has not been an issue before. Balancing the weight to increase effeciency is the issue. An AZL passenger car weighs about 3 times as much as a 40 ft MT boxcar.
We inquired about making the locomotive weight out of cast tungsten, but it is a difficult metal to work with. Our manufacturing partners were not willing to work with it.
I believe a tungsten locomotive weight would make an excellent 3rd party after market item. It might be possible to authorize known service providers to install a tungsten weight without voiding the warranty.
I would not expect tungsten in a stock loco. Was just passing on the info. I'm waiting for the heavies!
You're thinking in the wrong direction...think platinum: 20% denser than Tungsten and much easier to work with. You could probably even cast the shell in it. And at today's going rate, you could sell the Mikado for about the same price as the Big Boy
Rob, glad that you guy's gave it some thought with your vendor to consider tungsten on the weighting. As I get to doing a few more decoder installations and further testing with this new loco, I plan to mold some tungsten replacement weights and make a side by side comparison to the standard issued brass and zinc.
It should be re-stated that this loco is perfectly fine right out of the box. Sometimes our personal needs to further perfect what is already a good thing can cloud your mind to think that there is something wrong with a product. When all we are really trying to do is maximize performance and reliability.
I am definitely looking forward to the additional issues that are coming to us all shortly. Rob & Hans, Thanks for building us a great new product that we in Z-Scale are happy to finally receive. Maybe someday we'll have some Northers and Consolidations
Here is a link to some additional close-up pictures from my installation; http://www.elmassian.com/z-scale-trains/z-motive-power/azl-mikado
Platinum is heavier, but not by much:
Plutonium looks promising...
BTW. Bismuth is listed at 9.8 g/cc That is what Walthers LoTemp is.
I would recommend taking the worm out of the locomotive and getting it to roll as smoothly as possible. Any slight bind would try to twist the loco with tender drive.
I'm looking forward to see how many single sheated boxcars and drop bottom gondolas they can pull
Trying to understand your train of thought here. The added weight is to simply increase tractive effort in both the boiler as well in the tender. More weight forward keeps pressure on the drivers and since one of the drivers has a traction tire, the mechanism moves flawlessly powered by the tender installed motor. The little beast is "torque-happy" and responds better in my opinion to DCC than in DC. There is no real operating issues with this loco. And there is no problem with any resistance or binding on the worm or drive shaft that I have seen anyway. For those of us who have a slight grade on our module or layout, the extra traction adding weights is a welcome plus to a steam engine that handles 10-14 Pullmans. I think most of us are happy to pull 6-8 cars including a baggage plus maybe an overnight box car.
Double head this baby and she'll probably pull 40 era box cars.
This idea of adding weight to the tender won't increase the traction of this engine it will do the opposite, and while some have talked about removing weight, I found it has the right balance of weight to counter the motor torque if you open the throttle too fast, but with DCC and DC with programmed acceleration, there is not need to worry about torque. I used the Rokuhan C002 and Joeger throttles on this beast and booth controlled the engine well and could make it creep. The Joeger could get it creeping a bit slower than the C002 but not by much. The advantage of the C002 with Constant lighting the moment you turn the controller on at lowest setting the headlight is on full bright.