a question for MTH service techs...

Also, would the 2/3 rail trucks fit in a MTH Premier SD80MAC or a SD9043MAC?

I should have mentioned that, I don't plan on doing any 2-railing... just 3-rail.

I know the MTH MAC's don't come with the 2-rail/3-rail switch. Could that connection on the 2-rail/3-rail trucks just be closed off...?


Rick

BTW, the M, in MAC, indicates the wide North American safety cab and the letters AC indicate... AC traction equipment/motors. Locomotives with AC traction equipment are superior performers, when it comes to heavy trains... like coal consists.

It is my understanding that EMD outfitted their MAC lines with their steerable HTCR(HT for High Traction, C for three axle and R for Radial) radial trucks.

MTH's Premier HTCR 2-rail/3-rail trucks are closer to the prototype re: looks... why not install the superior looking truck in the appropriate EMD models(the MAC's), they produce?


Rick

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looks better than -



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don't you think?



Rick

Not giving up on this one, yet. Made some calls today and will try again tomorrow. Surprising... so many so-called experts here, yet nobody seems to be able to answer some fairly simple questions.


BTW, the equals signs above represent the stairs and the bracket and dashes represent the truck and wheels. I made the space considerably bigger on the lower diagram, but it got closed up to just one space. That is the area that sticks out like a sore thumb to me... the space between the equals sign and the bracket, in the lower illustration.

Rick

"If" it's possible... changing the trucks. My choices for a doing the conversion would be SD70MAC's or SD9043MAC's. Throwing some of those silver colored trucks into an executive painted SD70MAC, might look pretty good.


Rick

One of my favorite North American locomotive styles, is models sporting the first generation North American Safety cabs. All of EMD's MAC models had variations of that particular cab style... including the isolated cabs.

I've posted numerous times about making these models as accurate as possible... especially, when it comes to the trucks. I'd like to have a least one of these models shod correctly.


Rick

How's this for an idea; since you're the only person expressing an interest in this possible conversion, and since you possess both models, take them apart and give it a go.

Let us(the forum) know the outcome.

Good luck.

Mike,

That is exactly what I'm considering doing, but not with the MAC's I currently own. I currently have a BNSF SD70MAC, a CP SD9043MAC and a NS SD80MAC and I would prefer to buy a new MTH MAC and have the truck swaps done, by my dealer; and then have the model shipped to me.

I've already made some preliminary inquires, just before Christmas, with my dealer. They didn't have time, during the busy Christmas season, to look into the matter, so we put it off until after Christmas.

I took some measurements, and the truck should fit the space available, in one of MTH`s Premier MAC`s. There should be enough room for the trucks to turn freely.

The electrical connections issues have not been looked into, yet. I thought I might be able to get some useful information here, but I guess I`ll have to find other sources...

Hopefully, I`ll get some answers tomorrow.


Rick

Kane,

The information that you are seeking is best obtained from MTH and I suggest that you call them.

I may fall into the category of "so called experts" having worked on numerous MTH and other makes of trains, but I must take exception to your use of the term because you don't get an immediate reply to your question. There are many variations of each locomotive produced and without having those particular models on the bench to make the proper judgement as to whether the parts can be swapped is asking too much.

Eric Hofberg
TCA, LCCA
MTH ASC Tech

chug,

I have been in touch with a number of people today, including MTH. It doesn't appear the wiring will be an issue. There are three wires for the 2-rail/3-rail truck and just two for the straight 3-rail model, but the connection is supposed to be fairly simple. Because the 2-rail option will not be needed.

So far, the concern seems to be re: the gearing compatibility.

I have an experienced MTH tech checking with MTH re: these issues...

My other concern is would the steps etc. line up correctly, with the replacement trucks?

I'm really liking the idea of installing silver 2-rail/3-rail trucks on a MAC, especially those with the BNSF executive livery. I think the silver, which shows maximum detail, would compliment the green and cream colors of the executive paint scheme.

This could turn into a really nice project... Jump in if you have any suggestions.


Rick

Nothing concrete to report. Today was more best guesses and nothing more...

So far, the guys in-the-know don't know for sure. It seems nobody's ever tried doing this before.

I've still got another route to try... maybe tomorrow?


Rick

Rick,

I think the real problem is not the trucks themselves on the 70M/70MAC and 80 and 90MAC models, but where they are placed on the frame. I also think a swap from the SD70ACe and M-2s either won't work and certainly won't solve what I agree is definitely an appearance problem.

This question came up a while back about the Dash 9s, i.e., could they be retrofitted with the MTH's newer and much better GE "Hi-ad" truck from the AC440s and ES44s. The consensus was no, because of where the trucks/motor assemblies mounted on the frames on the two different models. Nonetheless, I think some doubter (or optimist) contacted MTH and was told it likely wouldn't work. At any rate, I suspect it won't work for the 70 series models for these reasons:

1: Even if you can install the newer steerable truck, the problem remains where the motor mounts to the trucks through the frame. Whether a truck change fixes that is a hit or miss proposition, with high odds for "miss." Each frame is custom designed for that particular model and places the motor accordingly. I glanced at both an SD70M and an ACe and it didn't look to me like the trucks would come out any better given where the motors mount. In short I think the problem is the frame, not the trucks.

2. The ACes and M-2s have a shorter wheel base than the 70Ms, 70MACs and 80 and 90 MACs. Compare two models and you will see this. Thus you will end up with a shorter truck on the older models, which probably will only increase the awkwardness of the look. (I believe the shorter wheel base actually is prototypical; I seem to recall a design change to the trucks introduced for the prototype 70ACe and M-2 series, that included a shorter wheelbase).

3. Related to the truck redesign, I don't think the swap would be prototypical in appearance either. The trucks just look different. The MTH casting for the older steerable trucks, was pretty credible and represented what the prototype 70, 75, 70MAC and 80 and 90MAC series came with. I think the trucks from the ACe or M-2 would be wrong. And the side frames can't be changed because of the wheel base difference.

Around 2006, I think the first MTH diesels released with the 3/2 trucks actually were SD70Ms. These had been delayed for quite some time and included the new trucks. I had assumed that all subsequent models, including the 70, 80 and 90 MACs had the 3/2 trucks. The ACes and M-2s came soon after, but use different trucks and sideframes.

I agree you've identified a real eyesore with these models. The only solution I can think of (short of persuading MTH to re-tool -- we did that with the Dash 9) would be to cut out the motor mount "key hole" in the frame, tool a new sheet of metal to hold the motor and then mount that to the original frame.

I upgraded this SD70M to a fixed pilot and changed it to an SD75. This came with 3/2 trucks. It's a good model, but I too don't like the truck mounting. I just haven't screwed up my courage yet to try to change it....



RM

I spent a considerable amount of time, yesterday, measuring and trying to figure out if there is at least one truck, already in production, that could be used as a replacement in a Premier SD60M and a SD70MAC.

I have most of the three axle C trucks MTH makes, to try; and it isn't looking very good... I even tried GE Hi-Ads, with no luck.

Yesterday, I had a friends dad, who has unbelievable milling equipment, professional grade, who spent most of his working career making commercial tooling etc.; and he said we could mill a new chassis, but the hours and work involved would be significant. He said, if that was to be done commercially, from scratch, it would cost thousands of dollars.

I said, there is no way I am going to ask you to take on that big of a task, for me... it's just not worth it.

Both, my friend and his dad, felt the HTCR truck, that we looked at on my MRL SD70ACe, just might fit into the Conrail SD60M, we were using as our test model.

The SD60's fuel tank might be an issue though, the truck might hit it partway through a turn. We'd have to try it... to know for sure. We might be able to modify(grind) the tank, if we only encounter minimal contact...

MTH makes a Premier SD50 with a HT-C 2-rail/3-rail truck. I don't have that model, but it might fit; and SD60's used that type of truck.

I've got to take a break for a sec... there's one truck I haven't measured yet, the trucks on my new H24-66 Train Master.

Nope, not even close!

I just talked to my train guy/dealer and we're going to just try swapping out the trucks... for the ACe trucks... if it works it works!


Rick

I just ordered a brand new BN SD60M, in cascade green, black and, with some areas, on the front end, painted white. Burlington Northern's second 50 unit order of SD60M's were the first SD60M's, to sport the new two-piece windshield; and the tapered nose.

A perfect choice for my truck refit.


Rick

Rich M.,


I was just looking at the picture you posted of your SD70M, and I think that model is one of the best, produced by MTH, of the earlier North American Safety cab. I, at one time, had the CN version. That batch were the first to have the new all axles powered C truck. It was listed in one of the 2005 catalogs.

I returned mine, because it didn't fit the track curves that I had at the time, well. I would have loved to have tried the truck refit on that model. I haven't seen that model, the Premier SD70M, offered since the run I bought mine from.

At the time, little did I know I would be running on O-72 curves with DCS, and TMCC. That's one model I wish I still had...

BTW, besides my NS SD80MAC, that model was the only one with an opening front door. That feature alone, improved the dimensional quality of the model. The molded-in front doors on the other models, i.e. SD60M's and SD9043MAC's, don't appear as realistic looking.

If they would clear up the truck space issue... you'd have a great looking model.


Rick