This is going to be a 3 part or more series. The install is done and the engine runs but I don't have all the documentation done so will put it up as I finish it. ============================================================== I'm trying to get most of UP's locos from '40's into the early '70's. I couldn't find any FM H-10-44's but did find some Minitrix FM H-12-44's so bought them as they are suppose to be close to each other in looks. Then I found there is a pretty major difference in the cab's top at the back and found a nice FM H-10-44 shell on Shapeways so bought it and put it on an Atlas VO-1000 chassis with a decoder. You can find that info ( HERE ). So what to do with the two non-UP FM H-12-44's I'd bought? I sold one to a person who needed parts and I decided to go ahead and put a decoder in the other just for the heck of it. I might see if I can print an extension I could add to the back of the cab to make it more like a FM H-10-44 even though it is shorter than the shell I bought. Above is a photo of the loco blown apart. It has a different pickup than I've seen before. Both trucks have axle/wheel wipers on the same side of the truck that conduct power from the track on the loco's right side to an electrical contact pad at the center bottom of the frame. That pad is insulated from the rest of the frame. There is a contact wiper on the pad that contacts the bottom motor cap. Also a wire from it goes to the only light, a forward light. The wheels on the other side of the two trucks transmit track power on that side to the truck's frame and gear tower. There is a pin that holds the whole truck assembly in the frame and the frame rests on the pin and power is transmitted from the truck to the frame via that pin as far as I can tell. The end result is the whole frame except for the insulated pad at the bottom is connected to left side track current. To insulate the motor from track power we have to remove the tab on the bottom insulated pad that contacts the bottom of the motor there. We also have to bend down or remove the bent tab at the top of the motor that contacts the frame at the top. Doing that insulates the motor and we can now attach the orange and gray wires to the motor as will be shown below. Next up is milling the frame and more wiring. Link to this info on my site ( HERE ). Sumner
FM H-12-44 Decoder Install Pt. 2.... ======================================================= I don't use my mill on very many decoder installs but felt this was a good one to use it on. One problem I have is making sure I don't crush the frame in the vise on the mill. Since this wasn't a spit frame it made that job easier. As you can see from the picture above the frame is dwarfed once in the vise on the mill. I have another smaller mill but the table doesn't raise/lower in the 'Z' axis. You can run the spindle up and down but I feel I have more control in the 'Z' axis with this mill and use very shallow cuts when doing this to keep the tool from grabbing the frame and pulling on it. You honestly don't need to have a mill to do these installs and I could of not used one following the steps ( HERE ). Also watch the video above or ( HERE ) for more ideas. The mill did do a nicer looking job vs. if I would of done it by hand but the results would have been the same and looked the same once the shell was on. You don't need to use the flexible PCB strip but it is sure nice for this application and other applications where you want to move electricity from one place to another with needing virtually no height room to do it. I saw them used first on nscale.net by SteamPower4ever (Jens) in one of his decoder installs ( See different options for them ). I couldn't find a source in the States for them or any source that would ship to the States from Europe. He was so kind to order some and then ship them himself (thanks again Jens). Later I found a source on eBay that would ship and ordered more so now have probably a life-time supply for about $20 total. ( HERE ) is the current link to the eBay site. On the next page the LED light strip will be finished along with the rest of the wiring and decoder install and we will run the loco. A link to the info on my site ( HERE ) Sumner
FM H-12-44 Decoder Install Pt. 3.... ======================================================= First thing is to finish up the rear LED light. Soldering the small LED and resistor can be intimidating. The flex PCB helps with this as it lays flat. I put a weight on it and leave the strip long at this point as it is easier to hold. With the strip pre-tinned you can pick up the LED or resistor and hold it by one end and place it on top of the tinned section. Put a very small drop of solder on the end of your iron (first) and then just touch the iron to the LED/Resistor and the strip at the same time and remove it quickly as soon as you see the solder flow onto the LED/Resistor. With one end soldered on move to the other end and solder it. It will be easier as it is in place held by the other end. With the components soldered on I test across the resistor with an ohm meter to make sure it is soldered to both sides. I also use a LED tester I have to test across the LED to make sure it is working. Remember that the LED is polarity sensitive so you need positive going to the anode side and negative to the cathode side. If it doesn't light swap the leads and see if it does. You can check the whole assembly by running the current through both the resistor and LED. I think if I was to run the common blue wires again I would of gone from the decoder with a very short wire to a short strip of the flexible PCB and off of it to the front and rear LED's. The above did work as there was the former light pocket at the front where I could tuck the connection of the three wires into. Above one can see where the connection of the three wires got placed. As mentioned earlier the LED is polarity sensitive so you should look at the markings on it and place it in the short circuit in a way that suits you. However if you mistakenly soldered it into the circuit backwards that is no problem. Just swap the blue wire and the other decoder wire (white or yellow) around and the LED should work fine. It doesn't matter if the current flows through the resistor before or after the LED. One thing I'm using the test track for is to also test out some of my different turnout controls. I'm using three of the 'Hidden Switchers' (one shown above) and four of my 'Gravity Switches' for the turnouts on the test layout. Above moving the stack of 'culverts' back and forth activates the one turnout and also changes the polarity of the frog. More about the Hidden Switcher and the Gravity Switcher ( HERE ). Want to see this guy run on the test track? Click ( HERE ) or above. Overall I'm happy with the decoder install in the FM H-12-44. It doesn't have the really slow speed running capabilities of most of my other older DC loco's I've converted to DCC but it is also a much older design coming out in the '70's vs. the '90's or newer. It does navigate the ME code 55 track and my code 55 hand-laid turnouts for the most part despite having 'cookie cutters' for wheels. I doubt I'll try to turn them down as I probably won't use this loco much since UP didn't have any FM H-12-44's only the H-10-44'S and some other FM locos. Link to this info on my site ( HERE ). Sumner
