Forward:
Aristo-Craft's second Diesel the U25, will soon have been in production for almost ten years. It has benefited tremendously from lessons learned by Aristo-Craft on the FA/FB diesels. Together these two diesels have brought Large Scale Model Railroading into more modern times. They left behind all the other manufactures and their toylike lilyput European models. The also gave those of us who wanted more than a western theme or Narrow Gauge railroad a place to start.
When these first pioneers were manufactured the hobby industry had not progressed to state of the art machinery that permitted CNC wheels and ball bearing gear boxes and other parts to be produced at a price that could be afforded by most all Large Scalers. Aristo-Craft's new motor block has changed all that.
In my first article I described how to convert the aging first and follow on runs of the Aristo-Craft FA and FB into better running and performing models at a fraction of the cost of a new locomotive. At the time I had converted all eight of my FA and FB’s. I originally started out to convert one set of FA/FB’s, my oldest. The original motor blocks were built to last forever, you could swap out the wheels and run them forever, however the wheels were cast and chrome plated as was the practice at the time they were manufactured. After close to 1000 hours of outdoor running the plating was starting to wear through and on the oldest pair completely gone. After the first pair was converted and I saw the benefits I knew I would not be able to rest until all of my older diesels had the new wheel blocks. Not only do they start at a lower voltage, run smoother, and run for hours without the wheels getting a layer of crud. As an extra benefit the locomotives now seem to put out more smoke from the smoke units.
Repowering the Aristo-Craft U-boat
Many of you are going to ask is why is this any different than the Aristo-Craft FA/FB.
Well first of all these are two completely different body types. They share a common motor block and that is about where the similarity ends. The Aristo Craft U25B, U-boat is still the second largest selling Aristo-Craft Diesel to date. It was the second Aristo-Craft diesel offered to the public, and most have been running for a very long time. They also pioneered the way for several other brands to evolve in the 1/29 market. I have over a thousand hours on my three U25’s that range from the second and third runs. Well anyway I did until this spring, when I zero timed them. The Chesapeake, Allegheny and Blue Ridge Large Scale Model Railroad Society still has three U-Boats that have close to 4000 hours on them. When I was maintaining these they still had all the original motors, and for the most part original wheels, and gears. I did have to replace a few parts in the motor blocks as they don’t like to fall four feet from a module and land on there wheels. No repairs were made for wear and tear, as there was simply no need for them, other than a couple of bushings that wore through, and this was simply normal wear and tear.
The U25b like other Aristo-Craft products has been steadily upgraded over the years. These changes were brought about by Aristo-Craft steadily improving their product.
As I have stated before this is not a commercial, nor was this statement solicited by Aristo-Craft, it is my personal experience resulting from thousands of hours of operations on my railroad, and two modular railroads built by the modular club I help form. It also comes from repairing and doing maintenance on club owned rolling stock and members personal rolling stock. Most of the repairs I do are for damage not workmanship or quality of the parts. There is just so much punishment you can inflict on something before it breaks.
By shopping around you can get a pair of these new motor blocks. This includes a new A frame, side frames, and a wiring harness for each motor block. The new wheels on this unit are worth the effort, they have a better profile, and run for hours with out requiring cleaning.
Tools and supplies needed:
Here is what your going to need as a minimum.
1.
A pair of the new Aristo Craft Motor blocks, complete with Harnesses and
the new A frame and side frame assy.
2.
A small thin bladed flat tip screw driver
3.
A number O and OO Phillips screwdriver
4.
A pair of wire cutters and stripers
5.
A small set of metric sockets or ignition wrenches, or a very thin set of
pliers.
6.
A soldering iron with rosin core solder (or small wire nuts if you do not
solder.)
7.
A roll of electrical tape or heat shrink tubing if you chose to solder
the connections.
8.
A set of jumpers with alligator clips one each end (optional but worth
the trip to Radio Shack and they cost less than $5.00 for a dozen), you will
need at least four as minimum.
Here is How: I hate to break it to you, but like the FA/FB your
going to have to take it apart. Sounds
hard? Not really!
First of all I highly recommend that you go to the Aristo Craft web site
and download the exploded parts diagram. This
will give you a clue in case you get interrupted for a day or two.
If you don’t have internet connectivity or your not a computer type go
to your AC Dealer and purchase the book of exploded parts diagrams.
It is under $6.00 and a must have.
Step 1: Remove the hand rails. Exercise a little care here, these are pretty sturdy, but there is a point to which something can be bent to where it won’t bend anymore without breaking. A small flat tip screwdriver with a thin piece of masking or cellophane tape on it so that you don’t scratch the paint is handy for getting the rails lose from the sides. Then your going to have to gently pull up on the stanchions. Once you have all the side hand rails off lay them aside.
Step 2: Turn the locomotive over (upside down).
Tip: I have a cradle made of Styrofoam that I use to hold the locomotive in an operation like this, I also have one of the new hands free work stations. Both of these help keep the work steady and minimized damage to the finish, but if you don’t have something like this find an old white towel or two that you can place on each side and under the locomotive so that you do not damage the shell. It also will provide you with a more stable place to work, it will also make it easier to find the screws your going to drop.
The first thing you want to do is note the orientation of the old motor blocks. They should be installed with the little transmission end pointing towards the center (fuel tank). This sometimes varies for one reason or another and occasionally I find one that is different. These have usually been changed by someone to allow for some strange operational configuration. If they are pointing in any other direction, and the locomotive goes in the proper direction and the lights work correctly, then you want to install the new blocks in the same direction. Don’t go reinventing the wheel, The primary thing here is that the locomotive goes in the same direction as all the others and the headlight is on in the direction that the locomotive is going.
Step 3: Remove the fuel tank. This step requires you to remove the four screws that hold the fuel tank in place and set it aside. If you have a sound system installed in the tank you will have to disconnect the modular connector between the tank and the floor of the diesel.
Tip: If you run into a Phillips head screw that is tight, don’t force it. Put something behind it to make it stable, put the screw driver tip back in the screw and give the screw driver a tap or two with a small hammer. This will usually loosen the screw enough that it will screw out, without tearing the head up. If the head is chewed up try a straight tip screwdriver there may be enough surface to get a grip on the screw and back it out.
Step 4: Here your going to remove the front short hood of body of the locomotive. Just in front of the front motor block and side frame assembly there are two screws. These are just below the front of the side frames. Remove these. Now lift off the short hood and lay it aside.
Step 5: This is were the fun starts, Here you are going to remove the Long hood and the cab. Just behind the rear motor block there are two screws that have to be removed one on each side directly below the rear of the side frames on the motor block. There are four screws altogether that hold the rear (long body) on the frame. The other two are in a single file in front of the motor block, one in the middle of the weight, and one right behind the cab. The Cab is held in place by four screws in an L shaped metal bracket. You will have to turn the locomotive right side up to get at these. Just remove the two bottom screws in the short part of the L. Once you remove these two screws do not lift up on the cab. Turn the locomotive up side down again and very carefully remove the floor keeping the cab upside down. It is important to keep the floor of the cab pushed in or down against the roof as firm as possible. If you don’t the windows are going to drop out of the frames in the cab. While this is not fatal it takes a lot of juggling to get them back in correctly. I usually put a couple of very small dabs of hot glue on the bottom of the cab and the cab side walls to hold everything in place. There is also a modular connector on the bottom of the cab that provides the power for the forward headlight and a cab light. All that I have encountered had very short wires that were hard to reconnect without a hemostat or long pair of tweezers. Exercise care in disconnecting this connector.
Step 6: By now you should have all the side hand rails, and the entire body off the locomotive. This is a good time to check and make sure that everything in the cab is correct and re secure the engineer if he is loose. You might also want to make sure that the air tubing that goes from the fan to the smoke unit is in place. I use a dab of low temp hot glue to make sure that these are secure. Just be careful not to melt the tube or get carried away with the glue.
Step 7: Remove the two screws at each end of the floor that hold the “A” frame in place. These are in slots close to the end of the floor. I unscrewed mine from the top and let the old “A” frame fall loose from the floor. Disconnect the modular plugs from the motor blocks and remove the whole assembly.
Step 8: Install the new “A” Frame and side frame assembly using the screws that you left in place in the floor assembly. Make sure that the notch in the A frame lines up with the notch in the hole that the wiring harness uses.
At this point I install the motor blocks in the new side frames. You may have to loosen them later to connect the wires but it is easier to work without everything flopping around.
Tip: This is an excellent time to add a little light plastic compatible white grease to the swivel area of the new A frame. This will help it operate a little smoother.
Note: You may find some variation in the internal wiring other than what is described here. out of over two dozen I found one that the wiring varied from the other 23 or so locomotives. This may have been one of the later runs. Aristo Craft continually upgrades their product, this will sometimes result in some deviations from what is described here.
Step 9: Wiring. The U-Boat is going to be a lot easier to convert the wiring on. You will still have to remove the white female plug from one end of the new harness. Be sure that it is not the Red oblong plug that mates to the plugs on the motor. This version is only going to require one harness for each motor block. The original hookup for the motor stays the same.
The white plug on the other end of the new harness will not
fit anything on this locomotive. Cut
it off as close to the plug as you can, and strip about 3/8th to ½
inch of the insulation off of each wire. You
will have to do this to both of the new harnesses. On the floor assembly you will have to remove the small red
modular plug from the Black and Red wires that supply power to the locomotive
this has to be done so that you can splice the new harness to the old. You will
have to mate these two harnesses up
as below:
Red to Black
Black to Red
Step 10: At this point you can insert the modular plugs through the square hole in the floor assembly. I connect all of the plugs on my locomotives on the outside. I have never had a problem with the plugs getting in the way providing you have some slack in the wiring. I do this because it is a lot easier to swap motor blocks or remove them for service and repair if you don’t have to try and fish the connectors out from the inside of the locomotive.
Here is where the Radio Shack jumpers come into play. I use them to make temporary connections, set the cab back on top the frame with the modular connection on the long hood hooked up and make sure the locomotive is going in the right direction and that the lights are showing in the right direction.
If everything works out ok, you can make the connections permanent by soldering or using wire nuts etc. I use what is know as a western union splice. It is a strong mechanical splice that usually can not be pulled apart, but I still put a little solder on the connection. Heating and cooling can make any mechanical connection unwrap itself over time.
Note: Don’t get overly confident here, this is a fantastic time to make sure that everything is working right. Place the floor of the locomotive on your test track and connect the modular plug that goes to the long hood and apply power make sure it is going in the right direction and that the lights are working correctly. i.e. showing to the front in forward and off when in reverse. If everything is satisfactory, you can now replace the shell and reassemble the locomotive.
Last Step: Go out and enjoy your brand new U-Boat. You will notice that this unit now starts moving at about ½ amp less that it formerly took, that it will run smoother, and draw a lot less amperage than it did with the same load before conversion.
I hope that you enjoyed this article and that you gained some useful information from it. This article by its nature had to be a little longer than I like. As spring has started this is a rainy day project that you can start now and enjoy the end results this summer. If you have any questions or wish more information you can contact me, Ronald Wenger, at: wengerr@ix.netcom.net.
Acknowledgements:
Special thanks to Bill Frank, a friend, neighbor, and a long time model railroader who retired from Aristo-Craft as their Customer Service Manager several years ago and relocated to my area. Also to George Schreyer, George is another individual who has contributed to my knowledge greatly but indirectly since we have never met face to face. The rest I came into like many of you, by years of experience or trial and error. I do not profess to be an electronic whiz or a mechanical expert. If you have a better or an easier method for doing things than I have described here, Let us know, old dogs can learn new tricks.
George Schreyer, operates a free web site and data base with more tips on all brands of large scale than you can read in a day. He does this as a service to all Large Scalers. He spends a lot of time doing it, and it is used by many large-scaler’s for reference. George also does new product reviews that are frank, honest and without any bias. His tips go from those that are quite technical in nature to tips that are very simple. George’s site can be found at http://trainweb.org/girr it is well worth the time to visit.