Does anyone know if both the Stewart FT & F3/F7 chassis are the same, or are they different? I have a Highliner shell I want to fit to a Stewart F-unit chassis. I just tested the shell with a F3 chassis and it seems to fit well. I didn’t know if the FT chassis would be the same.
Thanks,
Tom
Mechanicly they often run a little different I have a little different gearing in my F3 and my FT set but the F3 is about 25 years old. The FT chassis would be incorrect for an F3 or any other F unit. The FT’s had a shorter wheelbase than all the other F units. (they were originally designed to fit on a steam turntable as AB’s- they were almost always connected by a drawbar in AB sets. (There were a very few exceptions to this and technically these were FS units) The Stewart FT’s have the short wheelbase which is correct only for them and were only sold as AB sets. The F3-F9s all have the same chassis that would be correct for the Highliners shell. I will also note that Bachman FT and F7’s have the same chassis making the FT have an incorrect wheelbase- plus it has a coupler on the rear which was wrong. Hope that helps. Jim
Hi,
I’ve had some of each type (ATSF of course) and to the best of my knowledge, the F unit chassis are all the same, the FT is different. Note that I’m basing this statement on Stewart locos bought 10 plus years ago.
My Stewart F3A, F3B, F7A, and F7B locomotives all have the same chassis, made by Kato, and the best locomoitves ever made in my oppinion.
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I sold by FT ABBA set a decade ago because the chassis were different, not made my Kato, it did not run as well, and there was not an easy way to power the B units.
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-Kevin
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That would be my assessment too; of course Stewart chassis did go through a change when Steve Stewart acquired the tooling from KATO and had it shipped over to the US. The basic chassis was the same but motor and some components were replaced with others. That said, they were reviewed to run as well as the KATO versions.
Stewart was later acquired by Bowser; I can’t speak to changes made by Bowser as I have never owned a Bowser Stewart, only the KATO versions and the post KATO versions.
I never owned any FT’s but I would exercise caution as the real FT’s had a different wheel base and coupler mounting so if the model chassis followed that, it would be different than the F3/7/9 chassis.
I know the coupler mounting is different- they are set up for a screw-in drawbar between the A and B.
All powered Stewart and Stewart / Kato F3, F7 and F9 take the same frame. The dummy has a similar, but cut-down frame. But, they all fit each other.
The Stewart FT frame is different. It only fits the FT.
I just compared the length of a Stewart F3A shell with a Stewart FTA. The FTA is noticeably shorter so the chassis must be shorter, as well. The Highliner shell will be for a less-common F2A so I will sacrifice/utilize that F3A chassis for that purpose.
Thanks again, folks!
Tom
Hi again,
May I add…those Stewart F chassis/locos were the best I’ve ever had, and I have had a lot over the years. I guess the older Atlas was very close to the Stewarts.
I bought a lot of the FTs, and ended up selling all but one ABBA consist. They were just not of the same running quality as the Fs. Don’t misunderstand, they were still pretty darn good though.
The Stewart FT chassis is shorter than the chassis for other F-units like the F3 or F7 because the prototype FT was shorter and was built differently than all later F units. As designed FT A and B units were meant to only have couplers at one end, and run in A-B sets (or A-A sets) with the two units connected to each other with a drawbar. The chassis is somewhat “offset” because of that, the trucks are closer to one end than the other, since one end has to stick out a little longer to make room for a coupler (on both the real and model chassis). If you look carefully at broadside photos of FT’s, you can clearly see the difference.
Beginning with the F2 in 1945, GM changed the design by adding more room on one end so the trucks were now spaced the same distance from the end and couplers could be used on both ends of the units.
Note that the Stewart FT A and B bodies both fit on their FT powered or dummy chassis, so if you buy an A-B that came with one powered and one dummy chassis, you can buy a separate powered chassis to power both units.
I believe all the other (i.e., non-FT) Stewart F units use the same chassis as the other non-FT F-units, so an F3 chassis and F7 body or vice-versa should work.
The Highliner shell was originally designed to fit an Athearn F-7 chassis. I do have an engine that has a Highliner F2 shell on a Stewart chassis. The body fits OK but I had to shim it a little bit in the back to get it to sit properly.
I guess I’ve been fortunate with my three FTA-B sets, Bill. They have been very smooth and strong runners and of the same quality as my Stewart F3s.
Tom
If you are going to use a Highliner shell, I would suggest a Proto-Power West chassis with a Mashima motor.
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-Kevin
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Yeah, the FT is unique, the others are all the same. I have some with Kato drive and some Stewart made ones with the Buhler motor. They all run great. The only post-Bowser ones I have are some power chassis that I swapped the old shells onto to get sound the easy way. The F7 seems identical to the Stewart F7, maybe it’s not a Buhler motor but it runs fine, and runs with the powered but no sound A unit. I have some AS16’s, not sure who made the motors in those, and then I have my bunch of Baldwin switchers which all have Canon motors and naturally run incredibly well. The sound chassis from Bowser seems to be in every way identical to the non-souind chassis it repalced, other than the weight being cut down to make room for the speaker. I always thought it was kind of quiet, but I was always running it at club shows in giant open rooms with tons of people around making noise. I recently fired it up on my workbench and it blew me out of the room, I need to reduce the volume a LOT for home use.
Someone asked about fitting a Stewart F shell to an AThearn drive - that will take a good bit of work. Way back when I bought my first F7 AB unit, the B unit came with a broken stirrup step, and since it was completely sealed in the palstic back and the broken off part was not also in the bag, I figured it had to be done before it left the factory. Only thing is, I got it off some random person on eBay. New and sealed, but not a Stewart dealer. I emailed them anyway, first they were going to send me an undec shell, then they wrote back and said they were sending me an identical decorated repalcement, which is indeed what they sent. So I had a spare B shell, with a missing step. And at some point I came across one of the Athearn Heavyweight F units with a shell done in some road name no oone wanted. The heavyweight ones had this extra big slug of metal that went over the motor space, it increased the pulling power AND that big block of metal made the motor quieter. So I set about trying to m
I usually just remove the big added weight that the Athearn F-units have, it’s a separate piece that just lifts off. If needed I add some weight in other places, but since I’m usually running a couple of engines together it seems to work fine.