US Hobbies GP-7

[sarge]

Woody:

It might be sacrilege, but if it was me I'd pull the drive in a heartbeat and replace with Weaver chaindrive components and old plastic (He's a heretic!) Weaver RS3 trucks, changing the bottom sprocket at the same time to gear 'em down. You get roller journals, eight wheel pickup, better starting performance, all for what amounts to being a screwdriver job.

You can carry it a bit further with NWSL wheelsets, again drop-in but with brass bearings and a choice of wheel thicknesses. I've never broken a NWSL axle gear, any of the components sold by P&D who also uses the drive, or Sterling/Stock Drive who sell different count sprockets and chain.

I did a set of Nick & Jack FA1s, painted them up and ran them for years; two units could take 35 brass cars up 2.5% with ease and no perceivable wear to the journals of the Weaver sideframe.

Once they were painted, no-one ever caught me and they ran beautifully.

[R.K. Maroon]

I am not sure what that thin orange colored line is on the backside of the wheel.
it may be insulation, if so then your wipers look to be very close to bridging the gap.

Hmm…Interesting question. As it is, I left on travel yesterday and cannot inspect the unit to see if there is something there or if it is an artifact of the photo. If there is some insulation there then we can be sure that all the wheels can't have it, as the original model did not have wheel pickups and there would be no way to get power off the rail to the motor. And I do know that all the wheels have the brass-steel combination. So the question is whether half of the wheels have insulation at that interface or, again, whether this is an illusion of the photograph. Unfortunately, it will be a week until I am back home and have an answer.

Well, it took me several weeks to get an answer, but I am glad I did not forget the question that MP57 raised, and to him I will award this month's "Eagle Eye" award (though as usual, I must note that we are banned by federal law from distributing actual eagle eyeballs to the winners). As a reminder, recall that the subject was a GP7 of either Max Gray or US Hobbies lineage:



It came fitted for OTR operation, and as part of the conversion I installed wheel wipers. MP57 questioned if the brass-steel separation constituted the insulation point. Indeed it does, and to answer my own question, I can say that indeed half of the wheels are insulated:



and half aren't:



And there you have it.

One other thing: I ran this chassis on the club layout today (without checking for shorts) and it ran great (which I think is something of a miracle, given the overhang of the wipers on the brass part of the insulated wheel). I will say I purposely bent up the tips of the wipers (just because it seemed like a good idea) but it sure looks like I was cutting it close. May bend them a bit more.

And though this has nothing to do with the wipers, I will report that, as suspected given the 16:1 gear ratio, this unit runs slow at full throttle and pulls like a mule -- perfect for one of those long drag freights that the Milwaukee Road was infamous for. I am looking forward to putting this guy (and its twin) into revenue service.

Again, thanks to MP57 for raising the question of that insulation point on those wheels. I have satisfied the "learn something new everyday" requirement and can quaff an ale in the satisfaction thereof.

Jim

[E7]

Another importer for geeps was Challenger. I think Oriental was the original importer and the project was picked up by Challenger along the way. I have seen Challenger GPs listed on Ebay. The bulk of stuff from both these importers was HO, but this particular project was "O".

Not sure how much bearing this has on this discussion, but FWIW.

[DeBruin]

Good looking GP there James, those triangular gear housings on the axle were stock?

[R.K. Maroon]

Pete, there was some speculation on that when this was first posted. Here is some evidence that Max Gray indeed used this style drive, at least with some of their models:









I found these photos in my file, taken no doubt from some eBay ad at some time. There is no guarantee that the drive is original but given that the locomotive is unpainted and still in the original box, my guess is that it has little run time and thus has the original drive. Further, the drive shafts, shaft couplers, and wheelsets don't look like All Nation to me. What I really need to do is to take a few measurements and compare to the All Nation. I recall that the only direct comparison I have made was a simple count of the gear ratios, and they were not the same (8:1 and 8.5:1). I will eventually get around to a more careful comparison, but given all the evidence so far, including those funky steel-on-brass wheels, and my guess is that the drives on both the GP and the FM are original and not All Nation.

Jim

[R.K. Maroon]

OK, I'll stop here with the bumping for now. I am embarrassed to say I still don't have my pair of USH Milwaukee Road GPs on active duty yet. They are in the short queue but even the short queue is pretty long. Dang-a-dang-dang.

Jim

[prrjim]

My understanding as to a main difference between the GP7 and the GP9 as-built was the louvres on the long hood doors. The GP-7 had the louvres as shown above, under the radiator and near the cab. The GP9 had louvres on 4-5 doors right in the middle of the long hood right where we see the lettering on most locos.

I have 2 MG GP35s which run great. They ran so slow with the original motors that I replaced the motors with Pittman's. That frame in the original post looks like an MG frame. And the open gear boxes in my experience imply Max Grey import rather than USH. All the USH stuff I have seen have the diecast closed gear boxes and the diecast gear tower. My GP35s have closed gear boxes, but they are fabricated brass, not diecast.

I always look for a decent MG or USH GP7 at the O scale shows, but still have not found one.

[R.K. Maroon]

I was looking to see if this is the thread where I showed that jig I made to remove wheels from KTM threaded axles (it isn't). I decided to bump the thread anyway to remind myself that I still have those Milwaukee GP-7s to finish. I even bought a caboose to go with them:


It's a stock Weaver. I haven't compared it to the Overland version, which generally sells for more than I am willing to pay when you see them on eBay. While I prefer older US-made models, there were not a lot of caboose offerings in the old days and it is important to me that the caboose be a decent match to the prototype, so imported brass it is.

Jim

[prrjim]

I have a number of MG and USH steamers and a few diesels. I have NEVER seen one with uninsulated wheels. I have an early MG PRR 4-4-0 and it was insulated for 2 rail.

So I think that converting from outside 3rd rail to 2 rail should merely require rewiring the pickups. If the previous owner merely connected one side to the outside third, very simple. It the previous owner put contacts on the insulated wheels to pickup from both rails, then a little more work, but not that much. One thought, the previous owner may have flipped some axles around so the insulated wheels are not on the same side on each truck.

As these came, they had 4 wheel pickup, one side from one truck and the other side from the other truck.

I just want to say it is very very unlikely that any wheel replacement will be required.

I have a pair of MG GP35s (or early USH). Mine have fabricated brass gear boxes, but I think cast towers. the mechanical layout and construction is the same as shown in the photos for you GP7.

[R.K. Maroon]

The USH GP7 made it back onto my work bench finally. Like many models of this generation, this locomotive had big round flashlight bulbs for both the front and rear headlights. I really like constant-brightness directional headlights, and I often will install a fancy LED system to do this. However, the one-bulb-per-end in this case lit two headlights, two number boards, and two markers. I didn't want to spend the time it would take to put LEDs on all of these so I decided to keep the setup but switch to low-voltage penlight bulbs. These have a built-in lense, and I set up the bulb so it would focus on the dual headlights. This puts most of the light out the headlights but provides enough scattered light to illuminate the number boards and markers:

USH GP7 Lighting 01.jpg (429.93 KiB) Viewed 7469 times

I am very pleased with the result. However, I have a question about the marker lights, which can be seen better in this night shot:

USH GP7 Lighting 02.jpg (188.85 KiB) Viewed 7469 times

As I understand it, the marker lights should be red and shouldn't be lit unless the engine is running light, and then only the rear markers should be lit. Is this correct? If so I will simply block off the back of the markers so they don't light up. I am not such a perfectionist that I need prototypically operating marker lights.

Jim

[bob turner]

For steam, it was either clear or green or off. Had to do with extra sections. Woody can tell you more.

[ScaleCraft]

Depends on railroad for markers/class lights, but running light, yes, and even in some cases last engine on pushers.
Little slide switch hidden somewhere through the floor....

[R.K. Maroon]

Thanks for the input -- I did a search and found this:

Classification Lights -- U.S. railroads used a single light and outer lens, with colored lenses in between that could be changed as needed. Canadian roads used three separate lights; on diesels these were often located near the numberboards on the front of locomotives. The purpose of classification lights was to help identify the train on which they were displayed. The three colors and their meanings were as follows:

White. Indicated an "extra" train not shown in the timetable. For much of railroad history, train-movement authority was granted by timetables. If a train was listed in the timetable, it had the authority to operate according to its printed schedule. Deviations from the timetable, such as a train running late, were handled with train orders from the dispatcher. Under this "timetable-and-train-order" system, it was important that trains kept as close to schedule as possible, and that any special trains not shown in the timetable be clearly identified as such with a white light. Many freight trains operated as extras, and thus carried a white classification signal.

Green. Indicated that, while the train displaying the lights was a regularly scheduled one, a second section was following behind it. This was done, for example, when ridership demand exceeded the capacity of a single passenger train. If there were too many passengers for a single section of, say, New York Central's 20th Century Limited, a second section was operated, and, if needed, a third, fourth, fifth, and even sixth. The engine of each section except the last would display green lights. While each section was a separate entity, the timetable's "train 25" would not be considered to have passed a given point until the last section of the train had gone by. For operational convenience, special trains that otherwise might have carried white "extra" signals were sometimes operated as advance or second sections of regular, but unrelated, trains.

Red. Indicated the end of a train. A train, be it a single engine, a group of engines, or an engine(s) with cars, must have a marker on the rear end. In the (relatively rare) situations when the last element in a train would be a locomotive, the red lights would be lit.

That makes it all clear. I think for general purposes I would want the lights off. Having said that, white is certainly acceptable, as one can simply state that the train running is an extra.

Dave, I already have installed two slides switches under the loco as it is -- one for each headlight. This allows me to MU this guy and have the headlights on or off as needed. Note that the classification lights do not have their own bulbs -- they are lit by the stray light from the penlight bulbs, so there is no way to switch the classification lights on and off individually (unless I add more bulbs, which I am not going to do).

Jim

[Wolf]

If your classification lights are "lit" by bypass scatter from the headlights, it would be prototypical
if all the trailing units of your engine consist would have their headlights switched off (and thereby
not illuminating the class lights). The only legal requirements are for the display of classification lights
or flags indicating any required classification of the train (extra train, additional sections of scheduled trains, etc.)
on the leading end, and markers (red lights or red flags) on the rear of the train. All other classification
and/or markers should be extinguished under normal circumstances. It should also be noted that regular
trains with a schedule will not display signals--only the added sections of a regular schedule will display
the green classification lights, indicating that there is another section of that train following.

[ScaleCraft]

Thanks for the input -- I did a search and found this:



Red. Indicated the end of a train. A train, be it a single engine, a group of engines, or an engine(s) with cars, must have a marker on the rear end. In the (relatively rare) situations when the last element in a train would be a locomotive, the red lights would be lit. [/i]


Jim

Yup. One of those odd ace-breaker questions on the exam.