I have created a video of this switcher operating at 13.5 mph. These switchers were speed limited to 15 or 20 mph. http://youtu.be/1NA-52nNEPs Z-Scale speed table prepared by Garth Hamilton May 23/2014 Col A Col B Col C Col D Col E to convert MPH to KPH mph to ft/sec ft/sec to scale in/sec in/sec to sec /ft math mph x1.609 A X 5280 in./(60min*60sec) C*12in / 220 scale 12/D MPH KPH FT/SEC z in/sec SEC/FT(30.5 cm)* 60 96.5 88.00 4.80 2.50 45 72.4 66.00 3.60 3.33 30 48.3 44.00 2.40 5.00 25 40.2 36.67 2.00 6.00 20 32.2 29.33 1.60 7.50 15 24.1 22.00 1.20 10.00 10 16.1 14.67 0.80 15.00 5 8.0 7.33 0.40 30.00 *note 1 ft = 30.5 CM regards Garth
Hi Garth, How smoothly did the power max motor start and stop or did it need a little nudging to get going sometimes? Do you think it would work well in a locomotive that had two trucks but only one of the trucks was powered by the power max motor? Or do you think there might be some weight distribution/traction problems because there is just not enough power?
Depends on what you are using to control it. A good PWM controller like Joeger or Medvend can make them crawl but no all straight DC controllers have fine voltage control so it tends to jump start if you are ham fisted. I works well with decoder on DCC. Weight is the key to smooth operation. Searails has a brass casting of a doodlebug or rail diesel car that is powered with the power max and front truck is non powered, and it can pull a trailer. Nudging if required is due to dirty track or dirty wheels or a combination of both. IF both are clean then no nudging is required. Everything I have that uses a power max or its predecessor R18 form Lajos Thek has a cast cast brass body on it so there is some weight on the wheels. They run fine on their own with no five finger assist.
Excellent! Thank you Garth, I really appreciate all your knowledge. I'm contemplating building a switcher with two trucks. I have a model already designed in CAD. But there is only room for one truck to be powered. I was also contemplating making it a cow/calf configuration so I can then have the power of two motors (maybe a better idea or not...). But I am worried about getting enough extra weight over the drive wheels as there is not a lot of room... I'm also worried about getting a spare wheel set that exactly matches the ones used in the power max for the non powered trucks. I'll have to inquire if I can buy a set from them separately if they are using them on their doodlebug. Otherwise I dont think this will work....
shapeways can print polished brass see Stonysmith designs in Z, his shell for power max worked well for weight. That is if you are going to use an RP printer for your design.
I am going to use RP. I have tried a test piece with one of my booms for my Z scale 250 ton Brownhoist crane in brass. I was hoping the wax printing process they use to make the master for the lost wax casting process would be better then FUD printing. Unfortunately I was not impressed at all with the final surface quality. It might be different if you could dictate to shapeways how they orient the part when printed, but they do not let you do that...If they did, I would split the body shell in half right down the middle and have the sides of the shell be facing up when its printed. That way I would get the best surface quality where the most detail is and have the least amount of finishing work to do in highly detailed areas. Add to that, brass is a lot harder to finish then acrylic material used for FUD which can easily be scraped instead of sanded. But I do have a vendor that does FUD and will let me dictate how the part is printed. I also use Tungsten putty for adding weight. It lets me mold it and shape it so I can stick it just about anywhere there's space in the body shell. That being said, I have not ruled out making the lower chassis from shapeways brass. But its just so darn expensive and I dont think just the lower and internal chassis in brass will add that much weight compared to the tungsten putty. I really need to assign a brass material to the lower chassis in my CAD model so I can do some mass calculations to see if the weight is worth the money...
