Question MTL F7 issues

I have an MTL F7 that has been a beast to get running from the start. After all the tweeking, I have gotten it going, but it sounds like a wood chipper. Are they just loud all the time? What kind of experience have y'all had with these F7's? Glen Chenier has been a great help, but is not doing much, if any work on them anymore. Does anyone have any other contacts thatwork with these?

Thanks for any insight.
Enjoy the coming New Year.

 

Mine has always been loud, and once a year I tear it down completely and spray it down with Buggy blast or Nitro. These are RC car motor cleaners in an aerosol can that dry quickly and degrease. I then relube and reassemble and it runs well. Loud, but well. I have not done this this year with mine and it is very sluggish I think that will be something I have to get done.

 

I have a few F7's that run ok, Most growl and sound like Wood Chippers.
I took 2 of them completely apart Cleaned, deburred, lubed, and added TCS Z2 decoders which helped some.
I don't know if it was the tearing down and cleaning, The fine tuning, The addition of the decoder, Or the combination of it all,
But the 2 with the decoders do run better than any of my other MTL F7's.

 

I say you have done well with your F7's the only other improvement that can be made is to replace the complete chassis with a shortened Micro Trains Geep chassis. Then you have an F unit that will MU with any MTL Geep and you can used the TCS decoder fore the Geep as well. With all the Shapeways designs if someone were to do an FP7A it would drop onto ta GEEP chassis without modification to to the chassis. I made my changes when geep chassis were readily available.

 

I want to DCC my F7 fleet. Got any pictures showing the inside after installation? Do you have to mill some of the frame?
And why did you go with TCS Z2 decoders over something else?

 

Garth
I didn't know the Geep chasse's could be made to fit the F7's I will have to give it a try. Maybe I can get a couple of the A units running and turn the B units into non powered rolling stock.
Had I known how bad the F7's ran I wouldn't have bought so many of them (16) At Least my A,B,B,A sets Look pretty good hanging on the wall.

 

Loren
I will post some pictures a little later. Yes you have to mill the frame. I used a dermal type rotary tool to mill / cut / grind off the top/back of the frame. A lot of grind a little and test fit to get it right.
I chose the TCS Z2 for 2 reasons, one; I had a couple sitting here in my parts box, two; it looked like it might fit.

 

Thanks for the replies. I guess I have done what I can. Might give the the GEEP frame a shot.



Trey

 

I milled off one half at a time, test fitting the decoder often as I went.
After getting both sides close I screwed the 2 half's back together using a popsicle stick in place of the plastic insulating shims and finished fitting grinding with both half's together as a assembled unit. I used a popsicle stick because the frames got rather hot when milling and I didn't want to take a chance on melting the plastic shims/spacers.
Be careful as the area where the decoder rest will be paper thin. At this point I also cleaned up some burrs on the inside and made a small grove for the wire to fit into on the underside above the motor. Then I placed some krypton tape over the milled area as well as inside the motor housing area to prevent shorts when soldering wires to the motor itself.



After some more test fitting and filing I cut some groves for the wires to fit into along the outside to the wiper contact springs on each side. later came back and cut a grove for the light wires along the top sides as well. Once I got everything to fit like I wanted it. I re assembled and made sure everything turned free before soldering all the wires. I folded each wire along the side of the board and back to give some slack so I could disassemble for cleaning or repairs with out having to un-solder everything. I did the same with the orange and gray wires to the motor, You can see them in the pic folded around the sides of the brush housing and tucked in out of the way.


I have more pic's if you want to see something from a different angle just ask and I will see what I can do.

 

Thank you. Exactly what I needed to see. Good explanation and tutorial. Appreciate your efforts.

 

Loren,
Glen Chenier posted a document in 2007 describing the installation in great detail. Don't remember where I downloaded it from, but you might want to search for it.

Mark

 

Thank you Mark.

Will go a hunting for it.

 

Loren, hunting for wabbits?


://www.wiringfordcc.com/zmtf7.htm

 

Glen emailed me that very info a while back. It is in MS word format. I can email it or whatever if anyone wants it. Don't know if I can post it.

On another note, I had picked up a nonworking chassis for cheap and found that the bronze whiskers didn't have a good fit in the frame, so I worked with them and that chassis now runs better than the original one I was trying to fix. Looks like a likely trouble spot.

Trey

 

WOW ! ! ! -- A lot of good info there.
I wish I had known about this website /write up before I put the decoders in mine.
I might have done a few things differently.

 

Just joined the board. I am just realising the shortcomings of the MTL F7. I returned the first one as defective and the replacement is not much better. I agree about Glen Chenier, he has helped with lots of advice. How do these compare with Marklin's F7? I would imagine that Marklin are a lot better but do not know? I am not terribly impressed with MTL, so how are American Z in build quality compared with MTL.
I might have a shot at the wiper installation once I convince myself to keep this one and not return it for a store credit.

 

I was going to do the wiper install, but never got to it. I found the biggest problem, for me at least, was the pickup whiskers in the frame halves were loose. I removed them and flattened the ends that are pressed into the frame and re-inserted them. Also they are very finicky about re-assembly. You have to get the whiskers to contact the truck tower correctly. After that, they ram quite well. They pull like a bulldozer, but sound like a meat grinder. I also have 2 MTL sd-40-2's and have not been that impressed with them either. One hade a broken tab on the lightboard frame mount and has never run. MTL will repair for a $50/hr fee + parts, but I have not ponyed up the cash as yet. I have a few different AZL locos, F59, GP-38-2, RDC and Mikado and all have run nicely. The GP-38 is a bit finicky about the light board being loose, but mostly works well. That said, I think the MTL F7 is worth the effort if you can manage the repairs which are onlt tricky because of the small size. Hope this was helpful.

 

OK I finally took apart my MTL F7…not to difficult really. I cleaned the brass contactor strips and the bogie towers to ensure best possible contact. I found that all the gears and worm gear were BONE DRY..no lubrication at all. Hmmm perhaps this might explain some of the problems. I very carefully put a hint of lubrication on the big bogie gear and the worm gear of the motor. After a bit of a fiddly job I got the two halves back together with the bogies in place..nice a free movement of each one VOILA!! A dramatic improvement. Much better at the high end and for the first time it run quite nicely at slow speeds. I am not going to say its perfect and I am sure Glenn’s wipers would make it better…but honestly this is a HELL OF A LOT better than it was when I first got it.

Bottom line…MTL..I don’t think you put this together very well…not lubrication at all. The big gear wheel in the center of the bogie had NADA!!! Both of them. Runs nicely at 6.3 volts..before it would not be moving at this voltage.
It may need this again sometime..but this is it…I’m very sure this was the majority of the problem.

 

I had a look at installing the windows from the plastic spur. Forget it! They aren't even the right size, too big. Any one done this?