I have a fair number of MTL F7's in my stockpile of locomotives. They all (as for as I can recall) have a black plastic main drive gear in each truck assembly. I recently scored a black and silver NYC unit via an EBay auction, and based on the road # 3501, this little gem was most likely built in 1986. No jewel case mind you and Marklin crab claw couplers. An initial power check on my test track yielded nothing, and prompted me to tear down the chassis and take a look-see - which I do regardless. Needed brushes, lube, etc., but was surprisingly clean and seemed to be unmolested. Well, what surprised me was the main gears in each of the trucks. As you can see by the photos, they are metallic in nature, most likely aluminum, with one side of each having what appears to being tan carbon fiber side, and the other side, just being the base metal. Has anyone seen these before and could it possibly be that MICRO TRAINS was experimenting with different gears to see if they could keep the “coffee grinder noise” down? The carbon fiber material may be nothing more than a sticker of sorts, but it does have a carbon fiber appearance. I have yet to reassemble and test this unit to see if it’s any louder or quieter than any of the other F7’s I have. Just wanted to see if anybody had seen these before.
I bought some dummy F7 chassis off Epay along time ago, and they had similar trucks like that, just no gears. I thought it was weird too, never did do anything with them though.
That is an interesting find. I have not seen that before but I didn't start playing with Z until 2005. My guess is that the textured sticker is just there to electrically insulate the two frame halves. Maybe it's a genuine Nelson Gray F7? Are their any makers marks on the bottom, frame or inside of the shell? Gray, Kadee, MTL marks?
Although the attached picture is probably not even worthy to send, the frame is stamped MICRO TRAINS and then below that the KADEE logo and then USA. No other markings otherwise. I’m rather anxious to get this one put back together and see how it runs. Will be interesting to see if it’s quieter as compared to the standard F7. Doubtful, as I am really thinking the metal on metal gear lash would be a little bit louder. But if it runs like “White Lightning” and is quieter, then these may very well be worthy of being copied and printed using a 3-D metal printer. And there just happens to be several in use at a business a few miles from my house!!
OK, I finally got around to reassembling the NYC F7 with the metal main gears. Below is a video I shot of it running at yes, full speed. I do this to actually test what the average lap time is for the any unit on this little oval. It gives me a good idea if it’s faster or slower than others. You’ll notice one thing about the sound, and that is the higher pitched whine. This may be a reason why further development of the metal gear was not considered. https://youtube.com/shorts/Q_RdQ7CF4b0?si=AaPUjY515sDv6qA7 Oh, and the average lab time of this F7 with metal gears was about 5.5 seconds Now this next video is of a standard NYC F7 with plastic main gears. You can clearly see there is not near the high-pitched “angry mosquito” whine that the metal gears produce. https://youtube.com/shorts/zhX71a1fuCo?si=63VA7knPEkIbUYvS The average laptop of this unit was actually about 5.0 seconds. Quieter and a tad faster. Now granted the difference in sound is barely discernible via the videos. Although, as we know, all of these MTL F7’s are noisy little rascals anyway. Still a mystery though, as to where these metal gears originated from. I may actually give a call to MICRO TRAINS, just for the fun of it. Maybe they can share some history.
I purchased some as well... Rather disappointing to me. These dummies have terrible rolling characteristics (ideed the mule-like towing MTL F7s nearly spin with one of these in tow). Dom
So are you saying the dummy locos had a metal main gear, or no gear whatsoever? What I’m curious of is if anyone has seen this metal gear as well. The NYC unit I stumbled upon with these metal main gears is powered obviously, but no original jewel case (box). But we know based on the road number, at least on the body, this is an early production unit.
No, sorry, that's not what I was saying. Maybe I'm a little bit out of subject here. What I say is that these dummy F7 have the same axles as powered ones, with the same axle gearing, but of course no other mechanism like what we find on powered locomotives. And I was saying that on another hand these dummy F7s have very bad rolling characteristics as their metal axles simply lie in the trucks' metal cradle, thus implying a lot of friction. Dom
I never did use mine, they're still in a drawer. The wheels are kinda' hard to turn, you can feel the drag, and they wobble as well when "dragged" down the track!
Ohhhhhh, I am all too familiar with the dummy locos that do not roll. I'm going to pull out a few of my Dummy B's and revisit their rolling ability. Like I don't have enough to do already. I believe Others have attempted to put a high polish finish on the cradle where the axle sits. I’ve tried this myself and then attempted to put a degree of lubricant in there to see if it helped. It did a bit, but not as much as one would expect. Here's a link from the AZL forum that might be useful for those of you suffering with "Draggin' B's": https://azlforum.com/thread/603/micro-trains-f7-units?page=1
Lance, Kurt and all, quite a few years ago MTL made these shims to address the problem. They go on under the sideframe assembly.
Ahhhhh yep, I recall seeing those before on a few frames, F7B's obviously. I can see this lifting the frame up just enough such that the axles are not fully engaging the upper portion of the frame -- or journal if you will. I need to go back and tear apart a few F7B's to see if they are in place and if they do work as planned. I am thinking I have a few F7B's that do not have this spacer.
It was explained to me that the side frames made slight contact with the axels to maintain proper engagement of the gears. This then caused the drag in the dummies. The shim eliminates contact with the side frame. Burnishing the journals with graphite using a soft pencil really helped mine.
Thanks Vern, first I've heard of this! Now, where do you find them-IF I ever wanna' drag them back out, lol!! Nice "Ribsiders" in the background, btw!
