Howdy, We are in the final stages of testing and evaluating out SD40-2 chassis. Nice to see all those wheels creap around the layout! I wanted to show as reference the different sizes...the SD40-2 on top the GP chassis lengthened for my GP40p-2's, a standard GP chassis and the GP Chassis modified to fit a MP-15. The MP15 chassis was the most challenging because I had to shorten everything. It only has one flywheel but will work 4-6 cars really well. It's only a rough mock up right now, I have to do some noodling and come up with a modified chassis that I can duplicate and hold two flywheels. I was thinking about making the flywheel and worm gear one part with the flywheel on the outside. this way I can get the trucks closer to the center and still keep the performance level you all demand of me ) I'm going to bring in my other camera and shoot some video to post later of all this stuff running. But...don't get your tightie whities in a bunch right now, we don't have a switcher scheduled, I'm just trying to do some advance work...scouting the beaches for obsticles (I watched the movie Frogmen last night) and try and pave the way here. Ok, I beat that to death. Anyway, back to work, must create. ) Cheers Joe MTL
nice work, joe, it's good to see the line-up. the switcher mod: is that a second one? it looks different than i remember your first picture of it looking (a long time ago). can't wait to see the new chassis running. dave f.
Joe, Is it possible to test this. Can you remove the flywheels of one of the loco and keep it on the loco elsewhere to maintain the weight and check the performance difference with a similar loco with flywheel. The reason I am asking this is the flywheel is needed mostly at low speeds and having it on the motor that spins so slow at low speeds may not be effective. So if there is no flywheel and still have the same performance you have more space to play with. I have broken the shaft trying to remove the flywheel so I am reluctant to try this experiment. Kim
The first go-around it worked well without a flywheel and Chris, your right about not needing it at slow speeds since your not going fast enough to need to coast over dead spots in the track. I have a couple of motors without the flywheels and have drilled a hole in the worm gear shaft to fit over the motor shaft with good effect. I even had the company send me two 6mm motors thinking they would be shorter, but they are the same length. Joe
Joe, I am curious about the pulling power of the SD40. Does it have more pulling power then the GP35, and is it significant. My theory is that extra pair of power axle will pull more cars, and the heavier chassis will help also.
i'm glad you asked the question, john. i know that often times 6 axle units are used on light track, because they distribute the weight better (whereas 4 axles have more traction because of the proportionate concentration of weight over each axle). so i've wondered: do 6 axles pull more, because more AXLES are powered? or do they pull LESS because there is less weight on each axle due to the distribution? of course all this may be moot, because of the low weight of our model engines, compared to the "big boys." still, i've wondered how it works out. i'll be interested to hear the views. dave f.
Not sure yet, but I suspect you should be able to pull more cars. If I were shewed, I'd make it pull less so you'd have to buy more than one unit to pull a consist )...but I'm not!
I'm not sure if the SD40 would pull more because it has more weight than the others. I'd like to know if any would fit under a PA or F unit shell? Then you could fill the remaining space with whatever material that will fit? In N scale, the top pullers tend to be the cab units that have all that extra space to put metal, making the locos heavier. For comparison, be sure to check out a set of your own FT's. MTL does have a fine power train there. The cool part would be a mech to put under the old FA's & FB's. A cool track test would be to see how many MTL 2bay hoppers you could pull.
i believe joe said that the same mechanism with different sideframes will be under their new three axle E units (replacing the two axle F units). A PA might be doable if the E frame/mechanism can be shortened appropriately. we shall see! dave f.
More axles will have no effect on pulling power (theoretically), the pulling power here is only due to friction and having more axles will just distribute the friction which is due to weight and surface which is the same. Adding more power will also not help because the loco is already over powered, if you can make the wheels easily slip it is over powered. In real life too there is just enough wheels to take the load. The most effective solution is friction (traction tires) and weight. Joe, Imagine if you could make the chassis out of tungsten. The metal injection process or powder injection can make molded parts out of many metals including Tungsten. They use finely powdered metal mixed with a polymer which allows them to inject the metal in the mold. Once heated and sintered the polymer is evaporated and the metal bonds by melting . The ratio of metal to void is very high up to 98%. All info is on the net..... I guess it might boil down to cost. Then the Z scale loco could pull G scale cars with ease and weigh more than gold. Kim
MTL Z Chassis Joe An idea for the 6mm motor. You could create a bell or cylinder shaped fly wheel that fits over the end of the motor where there are no power leads. The design would be 8mm od by 10mm long and then bored out 8.5mm deep by 6.1mm diameter for a clearance fit over the 6mm motor shell. The energy of the fly wheel is the mass at the outer circumference. While a flywheel does noto create the coast effect that a high rpm flywheel produces it deffinitely does have an effect at low speeds with pulse power smoothing it out and reducing the strain on the drive train of the sudden pulse of power it is acting like a capacitor and it still stores energy even at slow speeds just not as much as at high PRM. I have used them on 8mm motors in Nn3 engines and it a space saver and really enhance the performance and also helps in this case over come any high friction points in the valve gear operation. I first saw this in operation in the LOK14 K27's. It save space in the length of the drive train if you have the extra width available. Really looking forward to getting my hands on one of the SD40's. It is ammazing what an FP7a on the GP chassis can do when you cast the extra weight on the side. It will out do the F7a. Now need to shorten the chassis to go into the F7b shell. Would be nice to purchase the GP locomotive as a kit of parts so we do not have to risk killing a motor to get the flywheel off of the motor shaft. cheers Garth
Joe I just want to know one thing. When is the SD40-2 supposed to be released? I thought it was to be June 1.
Now it's advertised as beeing released in "summer 2008". So I guess it'll be a little later than june. Dom
Hi Harold, Right now we are working through the final design issues with the chassis, our vendor has been testing out diffferent gear ratios to get the performance I want and I think we are close. The sample I got on Thursday runs really well even through the switches and will maintain about the same speed as our most recent GP chassis. Marketing is holding off on the actual release dates until we have approved units in our hands. So, later in the Summer is a good bet right now. The upshot on this delay is we are able to devote more capacity to the paint scheme and go with the CSX overall Blue scheme as the first release instead of the rather bland NW. Again, things are always in flux, so until I show you a photo, don't get too excited. Cheers Joe MTL
good for you ... not so good for me. i was hoping for the less costly and less complicated paint job to strip! ha ha ha! dave f.
