JasonD
Western Thunderer
Just in case:
Jason
Jason
Red Caboose GP9 kits - ALL builders/Models/Info/References welcome
- Thread starter mickoo
- Start date
richard carr
Western Thunderer
Jim
Mick has beaten me to it and I have to agree with his measurements, my set is the 48-7 one that Mick mentions
Richard
Mick has beaten me to it and I have to agree with his measurements, my set is the 48-7 one that Mick mentions
Richard
Big Train James
Western Thunderer
Thanks for the replies on the lettering. Microscale 48-7 was the set that I was looking at.
Reference photos I've download would seem to agree with Mick's numbers, or at least that the hood and cab side lettering appear to be the same height. And the hood lettering fits across 7 engine doors. I'm going to go ahead and run with this set, adjusting the vertical spacing on the hood if necessary.
From RRpicturearchives.net, with copyright to Chuck Zeiler as noted below the photo
Reference photos I've download would seem to agree with Mick's numbers, or at least that the hood and cab side lettering appear to be the same height. And the hood lettering fits across 7 engine doors. I'm going to go ahead and run with this set, adjusting the vertical spacing on the hood if necessary.
From RRpicturearchives.net, with copyright to Chuck Zeiler as noted below the photo
richard carr
Western Thunderer
I have been making some progress on the chassis
The decoder is Loksound L V5, I got a blank one and have uploaded the ESU sound project for an EMD 567C prime mover.
At the moment it has a sugar cube speaker , which is OK, but I will add a small tangbang speaker where the sugar cube is and move that to sit on top of the rear gear housing.
Once I had made a few tweaks to the motor settings it runs well. I will post a couple of videos later.
The main changes were to set the PWR frequency to 20,000. Increase the acceleration time and braking time and set the slow speed adjustment (slow K cv52) to 34. There is none set in the default settings and setting it to 61 was terrible, 34 works nicely and overcame a tight spot in the gears.
The decoder is Loksound L V5, I got a blank one and have uploaded the ESU sound project for an EMD 567C prime mover.
At the moment it has a sugar cube speaker , which is OK, but I will add a small tangbang speaker where the sugar cube is and move that to sit on top of the rear gear housing.
Once I had made a few tweaks to the motor settings it runs well. I will post a couple of videos later.
The main changes were to set the PWR frequency to 20,000. Increase the acceleration time and braking time and set the slow speed adjustment (slow K cv52) to 34. There is none set in the default settings and setting it to 61 was terrible, 34 works nicely and overcame a tight spot in the gears.
richard carr
Western Thunderer
Here are the video but both are a bit c R a p really.
The first one is after adjusting the slow speed controls
the second one is before but at a mid speed.
Hopefully the videos will work
Richard
The first one is after adjusting the slow speed controls
the second one is before but at a mid speed.
Hopefully the videos will work
Richard
mickoo
Western Thunderer
I've been bouncing around the Roco/Atlas chassis drive train for some years, it's not the best in the world but it works reasonably well, side frames look okay to me and they're cheap as chips.
The only problem is the rather high input drive line and transfer tower which inflict their ugliness into the cab. I did manage to flip the tower around and reduce the impact but it was still there and if driven the shaft still ran through the cab. To that end I decided to only power the rear truck and somehow cut down the front truck to clear the floor.
In a parallel universe I wasn't happy with the RC GP9 chassis being plastic so set about developing a new nickel silver etched version that fits the GP-9 and uses all the bits from said model and Roco/Atlas F9. I kn ow there are milled plates out there and many other options but I went for etched for several reasons, I'm in control, I own it and can tweak as I see fit, there are no import charges or 4-8 week delivery times. More importantly it'll be cheaper and have extras that milled frames et al do not have, aka full fishbelly under frame beams, webs, flanges, fabricated coupler pocket and pilot rear reinforcing plate work.
With that in mind the two universes crossed and as the moons aligned it was possible to make the new chassis fit a new style of un powered front truck. The new chassis should hopefully come late next week and I'll do a test build to see if it all fits.
Whilst that was all going on the new cut down front truck was tackled, several options were explored (mentally) and discarded, the problem here is hanging onto what Roco/Atlas and RC already have, the reality is that you've an open field and it takes a while for that penny to drop, well it did for me. The upshot is that rather than mess with the existing trucks I could just print new ones.
The Mk I truck is pretty much a clone of the Roco/Atlas truck with out most of the tower, it's shape and form follow pretty much the same shape, monkey see monkey do. To fit you simply cut the old tower bracket off, plate over the gap and using the centre screw secure the new truck.
On the new chassis that option is just a flat plate across the hole but that'll have to be a supplement (or on the Mk II if any revisions are required) as I only just thought of making the truck top level with the chassis top. The initial plan was to have the raised section a little higher but still below floor level. I still need to adjust the height of the fixing but it's close as it stands.
The raised section runs full length and matches the Roco truck, the disc is inserted after printing as it removes an overhang and distorted printing with supports that need cutting out. It occurred to me as I took the photos that I really didn't need the length of the the raised bit as there are no gears in there now, Mk II will have the whole raised block removed and the round disc extended down to the main larger block, that will daylight the view across the truck at low levels, possibly pointless as the rear will still be blocked. I may also add some detail to the block on the top to represent the transverse bolster where it joins the side frames above the main springs.
Removing the raised section and just leaving the round tower then means you can close off pretty much all of the bog bone opening in the chassis, you can either leave one big hole for the tower to rotate in, or slab the whole lot and just have a small hole for the fixing screw, that'll all fall under MK III experimentation if the below doesn't work out, I'm may still do it anyway as I'm still happy with one driven truck.
Moving onward and accepting you can pretty well make what you want it naturally came to the point of wondering if I could hack the design to get a below cab floor drive, well you can.....just.
The tower is reduced to the bare minimum and the top plate just fits below the floor, I say just as the 6BA fixing nut that holds the center peg will just impinge on the floor plate. At the moment the powered truck is very much work in progress so only the base core is done and being tweaked as I go along.
The trick here is to shuffle the gears around and find a decent orientation that holds as much of the shape square as possible, near impossible in SLA printers so it's just printed flat as it would be sat in the engine, that means there are ripples, artifacts and pooling to contend with. However, being as virtually none of this is visible it doesn't really matter (epiphany No 2) and can be printed at minimum to speed up the print times. Any imperfections can just be sanded or filed smooth as there are no surface details to worry about.
The problem here is that the three (32T) gear wheels from Roco won't fit the new arrangement so some math and trig resulted in the need for a new 25T gear, they came out well and work just fine, meshing with both the wheel and primary gear (black). I have a couple of split gears on axles so will work up a new gear there as well, the plan is to add a beefier shoulder each side of the actual gear to prevent them splitting again.
If they don't work then I'll just import some NWSL brass wheels and sets, i'd rather not and try to get better profiled wheels in the UK and modify them to fit with a bespoke gear.
To be honest the resin I'm using probably will not suffice long term or long running but as a proof of concept it's fine now and maybe for light use in a model. The alternative is a stronger more durable resin of which they are available from Form, so long as you buy a new tank (£144) and new resin cartridge (£144).
The upshot of the low line drive truck is moving the input shaft down by about 15 mm, more importantly, below the cab floor. Currently I'm tuning the fixings for the worm and bronze bearings so hopefully that all be done on the next print and I power up the whole drive train.
One down side to printing with no angle is that the truck exhibits a bit of a sag in the middle, the curse of large parts in SLA printers, in this instance no angles actually works better than angling the part as other areas then tend to sag or ward which cannot be overcome (easily).
Once I'm happy all the bits fit and work and the cover plate is signed off then the base unit will be redesigned with a inverse sag (hog) in the master, thus when printed it should come out pretty flat. To be honest, the warping makes no odds or has an effect on the running, it's just a visual thing and being as virtually none of it is visible when fully assembled it's more a niggle than a must resolve point.
The only problem is the rather high input drive line and transfer tower which inflict their ugliness into the cab. I did manage to flip the tower around and reduce the impact but it was still there and if driven the shaft still ran through the cab. To that end I decided to only power the rear truck and somehow cut down the front truck to clear the floor.
In a parallel universe I wasn't happy with the RC GP9 chassis being plastic so set about developing a new nickel silver etched version that fits the GP-9 and uses all the bits from said model and Roco/Atlas F9. I kn ow there are milled plates out there and many other options but I went for etched for several reasons, I'm in control, I own it and can tweak as I see fit, there are no import charges or 4-8 week delivery times. More importantly it'll be cheaper and have extras that milled frames et al do not have, aka full fishbelly under frame beams, webs, flanges, fabricated coupler pocket and pilot rear reinforcing plate work.
With that in mind the two universes crossed and as the moons aligned it was possible to make the new chassis fit a new style of un powered front truck. The new chassis should hopefully come late next week and I'll do a test build to see if it all fits.
Whilst that was all going on the new cut down front truck was tackled, several options were explored (mentally) and discarded, the problem here is hanging onto what Roco/Atlas and RC already have, the reality is that you've an open field and it takes a while for that penny to drop, well it did for me. The upshot is that rather than mess with the existing trucks I could just print new ones.
The Mk I truck is pretty much a clone of the Roco/Atlas truck with out most of the tower, it's shape and form follow pretty much the same shape, monkey see monkey do. To fit you simply cut the old tower bracket off, plate over the gap and using the centre screw secure the new truck.
On the new chassis that option is just a flat plate across the hole but that'll have to be a supplement (or on the Mk II if any revisions are required) as I only just thought of making the truck top level with the chassis top. The initial plan was to have the raised section a little higher but still below floor level. I still need to adjust the height of the fixing but it's close as it stands.
The raised section runs full length and matches the Roco truck, the disc is inserted after printing as it removes an overhang and distorted printing with supports that need cutting out. It occurred to me as I took the photos that I really didn't need the length of the the raised bit as there are no gears in there now, Mk II will have the whole raised block removed and the round disc extended down to the main larger block, that will daylight the view across the truck at low levels, possibly pointless as the rear will still be blocked. I may also add some detail to the block on the top to represent the transverse bolster where it joins the side frames above the main springs.
Removing the raised section and just leaving the round tower then means you can close off pretty much all of the bog bone opening in the chassis, you can either leave one big hole for the tower to rotate in, or slab the whole lot and just have a small hole for the fixing screw, that'll all fall under MK III experimentation if the below doesn't work out, I'm may still do it anyway as I'm still happy with one driven truck.
Moving onward and accepting you can pretty well make what you want it naturally came to the point of wondering if I could hack the design to get a below cab floor drive, well you can.....just.
The tower is reduced to the bare minimum and the top plate just fits below the floor, I say just as the 6BA fixing nut that holds the center peg will just impinge on the floor plate. At the moment the powered truck is very much work in progress so only the base core is done and being tweaked as I go along.
The trick here is to shuffle the gears around and find a decent orientation that holds as much of the shape square as possible, near impossible in SLA printers so it's just printed flat as it would be sat in the engine, that means there are ripples, artifacts and pooling to contend with. However, being as virtually none of this is visible it doesn't really matter (epiphany No 2) and can be printed at minimum to speed up the print times. Any imperfections can just be sanded or filed smooth as there are no surface details to worry about.
The problem here is that the three (32T) gear wheels from Roco won't fit the new arrangement so some math and trig resulted in the need for a new 25T gear, they came out well and work just fine, meshing with both the wheel and primary gear (black). I have a couple of split gears on axles so will work up a new gear there as well, the plan is to add a beefier shoulder each side of the actual gear to prevent them splitting again.
If they don't work then I'll just import some NWSL brass wheels and sets, i'd rather not and try to get better profiled wheels in the UK and modify them to fit with a bespoke gear.
To be honest the resin I'm using probably will not suffice long term or long running but as a proof of concept it's fine now and maybe for light use in a model. The alternative is a stronger more durable resin of which they are available from Form, so long as you buy a new tank (£144) and new resin cartridge (£144).
The upshot of the low line drive truck is moving the input shaft down by about 15 mm, more importantly, below the cab floor. Currently I'm tuning the fixings for the worm and bronze bearings so hopefully that all be done on the next print and I power up the whole drive train.
One down side to printing with no angle is that the truck exhibits a bit of a sag in the middle, the curse of large parts in SLA printers, in this instance no angles actually works better than angling the part as other areas then tend to sag or ward which cannot be overcome (easily).
Once I'm happy all the bits fit and work and the cover plate is signed off then the base unit will be redesigned with a inverse sag (hog) in the master, thus when printed it should come out pretty flat. To be honest, the warping makes no odds or has an effect on the running, it's just a visual thing and being as virtually none of it is visible when fully assembled it's more a niggle than a must resolve point.
Rob R
Western Thunderer
Scale7JB
Western Thunderer
garethashenden
Western Thunderer
Well, I have taken the plunge and bought a GP9 kit. I got an undecorated kit from Des Plains Hobbies. I will build it in P48 as a late Boston & Maine unit. Probably one of the ones they rebuilt and renumbered into the 1800 series. Something for the early '80s, more modern than most of my modelling. Something like this:
I do have a couple of questions. First, no fuel tank was included in the kit. Is that normal or was it forgotten? It was advertised as without air tanks, but I think I'll contact them about the fuel tank. Second, what should I do for trucks? The P&D brass ones look very nice, but are they $200 nice? I'm thinking of using a NWSL Stanton drive. It will only ever need to move two or three cars at once, if I build a layout, so that should be sufficient power, although I'm happy to consider other more affordable drive methods.
I do have a couple of questions. First, no fuel tank was included in the kit. Is that normal or was it forgotten? It was advertised as without air tanks, but I think I'll contact them about the fuel tank. Second, what should I do for trucks? The P&D brass ones look very nice, but are they $200 nice? I'm thinking of using a NWSL Stanton drive. It will only ever need to move two or three cars at once, if I build a layout, so that should be sufficient power, although I'm happy to consider other more affordable drive methods.
JasonD
Western Thunderer
Des Plaines is obviously worth a try, but AFAIK they haven't had any for years - someone's got a box of the sprues - optimist me, as usual. One of our list members beefed up an MTH fuel tank by wrapping a thin brass sheet around the factory 3-rail compromise. Gareth, O-scale can often be the supremely satisfying journey from"... how am I going to fix that ..." to "... no, I did it myself, it's come out pretty well hasn't it ...". Jordan, did you anneal the brass sheet, I can't remember? OK, OK, softwood former, if necessary.
I picked up some aluminium(?) bolsters for Atlas/Roco F9 drives at a Chicago Meet. Never tried them, D&H didn't have F-units, they fit in the notches in the F9 chassis and pass thru' the truck, eliminating the high drive, maybe usable in the chassis you build for the GP9. I have spare original drive gears if needed.
You can sometimes pick up a whole original (single centrally-mounted motor, not China drive)) Weaver GP38-2 for less than those brass trucks. Different chassis design, but if anything, easier to work on. Hardest part will be trying to decide what to do with the bodyshell when you've taken the guts out (6 x 2-56 screws for a start).
I started modelling Nth American railroads over 50 years ago with an Athearn GP, then picked up a scratch-built Canadian Pacific O-scale box car a few weeks later (£2.50 in W&H, if anyone's still with me). Nth American 2-rail, O-scale, best black hole in the universe, I believe.
Jason
I picked up some aluminium(?) bolsters for Atlas/Roco F9 drives at a Chicago Meet. Never tried them, D&H didn't have F-units, they fit in the notches in the F9 chassis and pass thru' the truck, eliminating the high drive, maybe usable in the chassis you build for the GP9. I have spare original drive gears if needed.
You can sometimes pick up a whole original (single centrally-mounted motor, not China drive)) Weaver GP38-2 for less than those brass trucks. Different chassis design, but if anything, easier to work on. Hardest part will be trying to decide what to do with the bodyshell when you've taken the guts out (6 x 2-56 screws for a start).
I started modelling Nth American railroads over 50 years ago with an Athearn GP, then picked up a scratch-built Canadian Pacific O-scale box car a few weeks later (£2.50 in W&H, if anyone's still with me). Nth American 2-rail, O-scale, best black hole in the universe, I believe.
Jason
mickoo
Western Thunderer
As far as I can recall, there are five different types of fuel tank, all Railroad/period/duty specific. The kit should come with the full width triple scallop base type.
I will probably be printing new ones for mine anyway, same for the air tanks that sit behind the fuel tank, so I should have a spare set here if your interested. There's two types of air tank, the normal location mounted transversely behind the fuel tank that the kit should come with, then there's the high level ones mounted on the roof.
SP use the roof mounted ones (hence the nick name torpedo's) on their commuter GP-9s in the San Francisco bay area, these were steam heat boiler fitted (high short nose boiler vent) and the water tank was grafted onto the rear/or front of the fuel tank filling up all the space between the trucks, thus taking up the space where the normal tank location would be.
I will probably be printing new ones for mine anyway, same for the air tanks that sit behind the fuel tank, so I should have a spare set here if your interested. There's two types of air tank, the normal location mounted transversely behind the fuel tank that the kit should come with, then there's the high level ones mounted on the roof.
SP use the roof mounted ones (hence the nick name torpedo's) on their commuter GP-9s in the San Francisco bay area, these were steam heat boiler fitted (high short nose boiler vent) and the water tank was grafted onto the rear/or front of the fuel tank filling up all the space between the trucks, thus taking up the space where the normal tank location would be.
garethashenden
Western Thunderer
Des Planes came through with the fuel tank parts. Two pieces on one sprue arrived in the mail today. I also have some wheels from Right-O-Way meandering their way through the postal service. I have an idea for the drive. N20 gearmotors are too big, but I have some N10s on order. Should be able to hang them off the axles…
mickoo
Western Thunderer
I'd be interested to see how you gear the wheel to the unit, the RoW wheels have the gear in the middle of the axle, it may shift to one end but then the axle box might need to come in board.
I like the idea of the N10's, I'm going to grab a couple and see if I can draw up a 3D motor block to hold them and the axles to make up a below floor motor brick. That would solve a lot of niggles I have elsewhere for other models I'd like to do.
Looking at some N20 data sheets, there's a lot of free space between the gears in the gearbox, you could probably turn down the spacer tubes and reduce the length of the gearbox by 4-5 mm, that'd just give you enough space to fit between the wheels and have space for the final drive gear on the output shaft. The advantage of the N20 is a 12v motor option, I've not seen that with N10 units yet.
There's an abundance of final shaft speeds to choose from, just need to work out which one would be best for a switcher.
Looks like another rabbit hole to run down
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garethashenden
Western Thunderer
I didn't buy wheels with gears. I bought 8 40" wheels with plain 1/8" axles. Actually I'm not sure if they have axles, but they take 1/8" axles. My idea is to 3D print a housing for the N10 that slips over the axle and then find gears to fit at the other end. I'll probably fit some top hat bearings left over from my P4 models onto the axle so that it doesn't wear the resin. There is a risk that it will end up being geared really low, but I won't know until I try. I'm not sure about cosmetics yet, but functionally this will be close to the prototype.
mickoo
Western Thunderer
It does depend on what ratio you opt for and the motor shaft speed, I'm thinking something around 500 rpm will be mid range, you can always change the final ration with the gears on the output shaft and wheel axle. I've yet to work out what wheel rpm you'd need for GP-9 wheels at say 50 mph.
I've 3D printed gears before in the GP-9 low input shaft power brick I did, they work fine but life cycles are unknown, probably fine for the limited shunting I might do; there are stronger nylon types resin around which could be explored.