Kato F7 truck changes

[spookshow]

I've heard various rumblings over the years about truck/pickup changes to Kato's early (pre-DCC) F7's, but never really understood what they were. Can anyone elaborate on what said changes might have been? Pictures would be great.

Thanks!
-Mark
 

[mplsjct]

Going by memory, as I don't own an original Kato F unit anymore, but they originally used a truck design similar to the original run of the Atlas RS3, where pick up from the truck was transferred to the chassis by friction of the two similar metal surfaces, as opposed to small wipers, as is the case with most Kato designs of today (as you are well aware).

The original run, was a little noisier than later issues, from what I recall, and, they were quite hefty, with plenty of pulling power.

Not a complete answer to your question, but some days you just feel a little more chatty than others.

[spookshow]

So they went from metal / split-frame trucks that contacted the chassis directly to plastic trucks with metal sideframe inserts with axle-cups and chassis-wipers?

Thanks,
-Mark

[peteski]

The original trucks were very similar to ones used on Kato/Atlas RS-3/RS-11 and on Kato GP38-2.  The later versions used the very relaibel low-friction needle-axle-point pickups trucks similar to what is used on all current Kato locos (introduced in Kato U30C). I don't knwo if there was anything other used on those locos between the 2 types mentioned above.

[spookshow]

It sounds like there have been three different truck versions. I've never owned a Kato F with the earliest version, but the second version (introduced with the 1996 F7 production run) had "low-friction" axle-cup style pickup and wipers that contacted the bottom of the chassis directly -



The current trucks are essentially the same as the second version, although the wipers are now longer in order to reach the contact strips on the top of the chassis -



If anybody can provide pictures of that first verson, I'd be most appreciative.

Thanks,
-Mark

[randgust]

Mark, I've got four of the DC's.   I'll confirm that they have no pickup wipers, do have end cup pickups, contact the frame directly, weigh a ton, and are somewhat noisier than any other Kato I own.   I thought they were originals, but they may be second run.

In order to get the shell off, you have to take apart the front coupler, which in my case are MT's with the springs.  So, nope, not doing that today.  I also equipped mine with Richmond Controls lighting and added the mars light, so they are packed full of wire.

Other than the noise, outstanding power.  Four of them are what I call the 'rail grinding train' that I use to clean track in the hidden yard. They will break through crud and polish railtops that nothing else will touch.

[u18b]

Hi Mark,

Here is the low-down.

Original- like the RS-3.  Frame full and heavy.  Blue label box.

Revised, made the trucks low friction- but kept the frame the same.  Imagine Atlas GP38 low friction EMD trucks.  All they did was bend the tabs that reach up outward.  The frame actually rides on the bent tabs (like the old RS-3 trucks).  Green label.

DCC friendly version.  New truck totally redesigned.  Fits new DCC friendly frame.

The revised trucks can be used to place on other early locos.  For example I placed these trucks under my GP50 and it GREATLY increased the performance of the loco.  It sat too heavy on the drive gear, so I bent the tabs up a TINY amount and they worked great.

Ron

[u18b]

Mark, yes, good simple way to put it.
Yes, there have been THREE truck variations and TWO frame variations.

Actually, the old heavy frames have TWO truck variations.
Should be able to tell apart from the color of the box label (blue is earliest original).
Assuming of course no one has changed boxes!.

[u18b]

Kato delineates the versions with the words:
Original
Revised
DCC Friendly

They are almost out of the revised trucks.
Here is their shot-  http://www.katousa.com/images/929122.jpg

Note the tabs bent down (frame rides on them).  Also note the larger "head" (flattened with lips) to the top part of the geartower.
 

[u18b]

A clarification to your post above.

You said current version is essentially the same as the second.

That's not the best way to put it.  They are very different.  In fact, everything is different except the wheels.

[wm3798]

The first generation is as described above.  The truck itself was a split metal frame.  These were problematic because the frame metal tended to oxidize and make contact spotty.
Second generation was a plastic frame with PB wipers that contacted the split frame directly.  These were problematic because there was no allowance for uneveness in the track, again, making contact spotty.
Not sure what the most recent iteration looks like.
Lee

[u18b]

Hmmmm.

Topic has already been covered with photos.
Check this thread out on the Model RRder discussion board.
http://cs.trains.com/TRCCS/forums/p/193066/2107222.aspx

[spookshow]

Hmmmm.

Topic has already been covered with photos.
Check this thread out on the Model RRder discussion board.
http://cs.trains.com/TRCCS/forums/p/193066/2107222.aspx

Excellent, just what I needed. Thanks, Ron (and everyone else) 

Cheers,
-Mark