Can the Atlas H16-44 frame be swapped out for some other loco frame?

[thomasjmdavis]

My first run Kato F3-  136g

Atlas "Classic" (early run) GP-7 -  76g

Atlas H16-44 -   63g

total weight per my reasonably accurate kitchen scale

[mmagliaro]

My first run Kato F3-  136g

Atlas "Classic" (early run) GP-7 -  76g

Atlas H16-44 -   63g

total weight per my reasonably accurate kitchen scale

Heh... I think we can all see why those old F units pull like a team of oxen!  LOL!  I've always been curious to see if I could
mill out enough little rectangular areas and replace them tungsten cubes to raise the modern-era F units up to the weight of the old ones, but it's always on my "low priority" list.

[peteski]

This frame looks really "wimpy".  It is is probably made from the same alloy Atlas uses for other frames.

I suppose that one could figure out whether it's the same alloy or not.  First find out the volume of the H16-44 and another Atlas frame by fully immersing each  in a graduated glass partially filled with water, noting how much water the frame displaced.  Then it is all math to figure out the differences in volume, and using the known weight of each, figuring out whether it is the same alloy or not.

The Kato F-units are heave because the frame pretty much fills the most of the wide body.  I don't' think they used a lead alloy. I think the only Kato loco which used a lead alloy was GP38-2.  Those were heavy!  Too bad that lead got banned.

[thomasjmdavis]

Looking at a "decoder ready" GP-7/9 frame, it looks stronger, in that it only has 1 "step" rather than 2, but depending on what needed to be cut away, I could see similar problems.  I wonder if the amount of metal that would need removal was the reason the most recent release of RS-1s, a couple years ago, did not have a DCC ready frame.  It was a major complaint at the time, IIRC.  Kept me from buying one, as I was just beginning my project to install decoders.

[peteski]

Reading all  this makes me wonder why someone has not started making lead, or even just pewter copies of the common loco frames.  I seem to recall that NSN (N scale of Nevada) used to make those.   Or even better, make them out of brass. They would be almost as dense as lead, with no inherent dangers of lead.

[randgust]

The only NSN frame I had was the one that was made to correct the wheelbase on the second Atlas GP7.   I ended up putting it under a heavily redone Rapido GP30 shell and it ran that way for about 15 years.   Thing weighed a ton, pickup was a little spotty as the interior truck frames had to contact the frame directly - no wipers.   It literally was soft enough that you could bend it with your fingers at the thin spots.   That frame wasn't developed for weight, it was to fix the truck spacing problem, and it really worked.   John Coots background with Scale Structures Lltd (some guys called their details "little lumps of Lead Limited") made him comfortable spin-casting N frames in what was either lead or pewter.

I can't imagine what it must be like in HO to have plenty of space for all the electronic gadgets and room left over for weight.    It's tough enough in N to squeeze in a lot of decoders; then add lighting, and now a speaker for sound. And take the lead out of frames.   Now we have to coolest stuff ever that won't pull and has pickup issues.

Nobody in their right mind is going to commercially sell a product with known lead content, so we can let that go, but I still think that Kato has a secret sauce for their frames that is significantly heavier than many Atlas, and their wheel metallurgy has proven to me that it gets a better grip.  I'll give Atlas all the points you want on paint, detail, availability of roadnames, etc.   but the last unit of theirs that really pulled above it's class was probably the Trainmaster.   Some of the recent product has had a noticeable improvement on the wheel adhesion, I've been harping on that for years, but overall it's pretty sad if you compare it to 'legacy' N here.    I ran into this on trying to use a stretched RSD4/5 chassis to rebuild a MP RSD15; ended up way too fragile, way too light, and pulled about 1/3 what the original chassis did.

[thomasjmdavis]

I have 4 NSN (edit- see my post below) frames for Kato Fs that I picked up inexpensively when visiting Model Railroad Supply near Salt Lake City while on vacation out there 5 years ago.  Figured it would be the easy way to get DCC into my eldest Kato units.  Haven't found the "round tuit" to facilitate the conversion, but the plan is to use the original frames with spare shells and trucks to create B unit dummies that I can cram with sound gear.

[peteski]

I have 4 NSN frames for Kato Fs that I picked up inexpensively when visiting Model Railroad Supply near Salt Lake City while on vacation out there 5 years ago.  Figured it would be the easy way to get DCC into my eldest Kato units.  Haven't found the "round tuit" to facilitate the conversion, but the plan is to use the original frames with spare shells and trucks to create B unit dummies that I can cram with sound gear.

Randy mentioned that NSN only made frames for GP7s.  But you have NSN frames for kato F units?  Are those cast from lead or pewter?

[thomasjmdavis]

Randy mentioned that NSN only made frames for GP7s.  But you have NSN frames for kato F units?  Are those cast from lead or pewter?

My bad. Not NSN.   What I have are "Digi-frames"- that is, Kato frames marketed by Digitrax that were machined to remove a big chunk of metal from the back end.

[Mark5]

FWIW, NSN made retro frames for many locos.

https://www.ebay.com/itm/N-Scale-Of-Nevada-retro-frame-RETRO-01-Con-Cor-SD40-2-SD50-Frame-Replacement-/293060095305

[peteski]

FWIW, NSN made retro frames for many locos.

https://www.ebay.com/itm/N-Scale-Of-Nevada-retro-frame-RETRO-01-Con-Cor-SD40-2-SD50-Frame-Replacement-/293060095305

Thanks Mark.  That was what I remembered, but with Randy's comments I was beginning to doubt my memory.

[randgust]

Randy mentioned that NSN only made frames for GP7s.  But you have NSN frames for kato F units?  Are those cast from lead or pewter?

Hey, I just said I only had one myself, and it was the GP7.  When I was at John's house in Reno - a couple years before he passed - he had closet FULL of stuff that he was 'stuck with' (to teach me a lesson, I think) and I remember seeing a lot of frame kits in there.   They had to end up somewhere.   He was making a point of how bad he'd misjudged the market on Ntrak 3-track signal bridges, but obviously the frames had a short spurt of interest as well.

[ns737]

i copy'ed a atlas gp40-2 frame to lead. and the engine pulls like my kato gp38-2 and gp50

[jdcolombo]

I won the battle.

Photo of now-completed sound install:

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I'll post more details in a thread in the DCC section later.

I won't do another.  But I have lots of extra H16-44 frames if anyone needs some!

John C.