P48 for Cotton Belt: Roster addition SW1200

[Yorkshire Dave]

Valhalla

Well...... I spent ages trying to get these to run smoothly but not to my satisfaction .



So after ripping out the consumable items: truck frames, motors, gears etc both of the internal truck frames were given a viking funeral with the aid of a blowtorch .

Ashes

Not the disaster of the series down under - instead the truck chassis remains of after cleaning up...



Phoenix

Not even Arizona as it been snowing again this morning...... to continue I decided to remake the truck chassis using parts rummaged from the 'that'll come in useful one day' crate. Aye, there's nowt like a good old rummage....

These were parts left over from my 4mm and HO modelling days way back when. Alan Gibson hornblocks, one flexible coupling and a pair of Exactoscale 2:1 reduction gearboxes (one shown below of which the bottom gear is mounted on a sleeve to accommodate a 2mm shaft


I also purchased four of these...


As the Alan Gibson hornblocks and Slaters gearboxes utilise 1/8'' axles so I cut four new axles from steel rod (two have already been used). Protocraft 36'' Grabowski insulated wheels were used this time as they fit onto a 1/8'' shaft.


After cutting the frames to take the hornguides the first job was to install these and add the 3mm brass angle to the top for mounting to the top plate.


The Protocraft wheels have a pronounced boss on the inside the top of the truck chassis was narrowed to 23mm to allow for this and insulated spacing washers.

After Much Faffing in the Marsh and building the Slaters gearboxes, mounting the hornblocks, insulating washers and wheels to the axles - this is the end result.



Not elegant from the underside but it does work.... I've lost some of the mounting holes but no worries. - my prime objective here is to get the entire drive train working first and consider the rest later .



And testing..... Eventually the motor will sit in the fuel tank and the propshafts will be shortened to fit and horizontal.

Just another one to make now..... and source a short flexible coupling followed by fine tuning.

It might not be the most efficient drive and as it's for a switcher kicking a few boxcars - am I bovvered ..... nah.

 

[Heather Kay]

Loving the ammonite fossil test ballast weight!

 

[P A D]

Loving the ammonite fossil test ballast weight!

Fossil? I thought that was the loco body!

Just shows, I know even less about US locos than I do about BR.

 

[Yorkshire Dave]

Loving the ammonite fossil test ballast weight!

Even a lump of iron pyrites (fool's gold), makes a good weight.... [iron sulphide FeS2]

Fossil? I thought that was the loco body!

Or an allegory to railway modelling......

 

[Yorkshire Dave]

Some more photos of the Slaters and Exactoscale gearboxes mounted onto the axles.

The 2mm drive shafts will be shortened once I've received the silicon tube and 2mm steel ball bearings to make up CV (Constant Velocity) couplings.

 

[Yorkshire Dave]

Well...... constant velocity full of double entendres.

The silicon tube and stainless steel ball bearings arrived today all for the princely sum of £4.89. I have sufficient materials to make loads if they fail I can just make up another set. The idea was taken from the CLAG guys Construction, assembly and application notes for constant velocity couplings

I made up a pair CV joints from 1.5mm I/D silicon tube, 3mm ball bearings and a length of steel rod between the balls . Ohhhhh I say!

And this is the result - the top joint is yet to be fitted to the second truck. It runs well and now not sure whether to use a larger O/D but same I/D tube to increase the rigidity.... Ohhh hello nurse . On the other hand if it ain't broke don't fix it.

 

[Big Train James]

Curious, what is the benefit of this type of coupling, when the axles are fixed in a frame. What flexibility is needed? Normally I would expect a universal style joint between trucks, or between a truck and the motor, but not within the truck itself. Is there a reason to not just use the tubing by itself, other than therefor missing the opportunity to discuss tubes, shafts, rods, balls, sheaths, stiffness, rigidity, and the relevance of larger diameters?

.

 

[simond]

Well, having gone to the trouble, he can now have independent suspenders, no, sorry, suspension.

 

[Yorkshire Dave]

Normally I would expect a universal style joint between trucks, or between a truck and the motor, but not within the truck itself.

I only went down this route as I could not find a pair of flexible joints small and short enough to join the two gearboxes within the truck. To be truthful I also couldn't be bothered wasting too much time trying to source then on the internet and trust my own ability to use a fixed shaft between the gearboxes without seizing them with retaining compound.

Having said all that the resulting drive is silent and the only noise comes from the wheels on the track. The true test will come when the whole lot is under load, however, I remain quietly confident.

 

[mickoo]

Dave, you could probably get away with just one ball in the middle, though if out of true might generate wobble

I need to get some of these gearboxes as I've a use for them on a project, I want to try full suspension and visuals are no issue as the bogie is a deep plank side affair and the chassis has deep skirts so there's no gap visible between the bogie top and chassis base. I now need to find some suitable 1/8" axles and wheels and will probably just sleeve standard 5/32" Slaters bearings.

MD

 

[Steph Dale]

Mick,

Deffo need two joints in the shaft in case of misalignment, one joint only puts a 'bend' in the shaft; you need two to cope with an offset.

Depending on what motors and other gubbins you have in stock, don't forget that we have stand-alone 13:1 gearboxes in our range. They use normal 3/16" axles.

Steph

 

[mickoo]

Steph,

Yup I can see the logic in that and I'd forgotten we had stand alone boxes on stock The 3/16" axle will be a benefit for one of the applications, may be both.

MD

 

[Steve]

Hi Dave,

I just joined this Forum because I searched the Internet about Gilmaur U-Boat parts and found your website post that mentions your 2016 purchase of a O-Scale GE U-Boat with a Gilmaur Shell, wrong Cab type, and mismatched Truck parts...

Your msg post with above pic said, "Trucks - however these are incorrect as they for a switcher. They should be AAR type B road trucks for the U23B..." and "My intention is to build a Santa Fe low nose version but I will have to source the correct trucks which will become evident below. The alternative is to build a Western Pacific version as they ran on Blomberg trucks and into California. A few C&O U25Bs also ran on Blomberg trucks."

Are you still looking for these O-Scale 2-Rail parts for your U-23B? I ask because I probably have them and may be interested in a parts trade... I own 2 complete Central Locomotive Works Brass U-25B Kits, a matched pair of unpowered CLW Brass AAR Type B Trucks with 40"wheels, and have the original CLW U-25B Low-Nose Cab complete set of parts you may need. I am interested in the Brass AAR Type A Trucks for Switchers...

Please email me in private with your email address about your O-Scale U-23B parts needs and I can send you detailed pics of some of the U-25B parts I have available for trade and I could send you a scanned copy of the complete set of CLW U-25B assembly instructions + parts diagrams...

Regards, Steve Neago
Cincinnati, Ohio USA

 

[Yorkshire Dave]

We finally have a drive.

The 1833 motor was a purchase from Bristol show last weekend. A motor cradle was made up from brass to the same length as the fuel tank and soldered into place between the frames.

Excuse the blu-tac as this is holding the motor in place whilst testing - once complete the motor will be held in with double sided car rear view mirror tape. The drive shafts were cut down from the branchlines universal joints.


Underside

Normal viewing angle and the drive shafts disappear. The whole drive system is within the sill and fuel tank- nothing protruding into the body.

Side view - the drive shaft is just visible however most will be hidden by the air tanks which are situated either side of the fuel tank.

 

[Jordan]

Curious, what is the benefit of this type of coupling, when the axles are fixed in a frame. What flexibility is needed? Normally I would expect a universal style joint between trucks, or between a truck and the motor, but not within the truck itself. Is there a reason to not just use the tubing by itself, other than therefor missing the opportunity to discuss tubes, shafts, rods, balls, sheaths, stiffness, rigidity, and the relevance of larger diameters?

.

I hope I'm right, but if you look carefully, the axles are not rigidly fixed in the frame. they're in hornblock(?) guides. They're like what I could do with on my Atlas SD40 so it could tackle my kind of track.

 

[Yorkshire Dave]

I hope I'm right, but if you look carefully, the axles are not rigidly fixed in the frame. they're in hornblock(?) guides.

Correctomundo. They're 4mm Alan Gibson hornblocks and guides. Something from my old 4mm days I found in the 'this may come in useful' or the descriptively more accurate 'I don't know what I'll do with this' crate .

 

[Yorkshire Dave]

A couple of weeks worth of evenings has seen some dawdling.

Making up the radiator screen surround from scrap etch and adding the strengthening strips (again scrap etch) and visible on later photos to the radiator shutter.


Adding scrap etch to the underside of the hood roof engine hatch.


Then rounding the corners and top edges to make it look 3D.


With the motor now in the fuel tank the latter had a channel sliced out of it and the two panniers boxed in, filled with lead shot and a lid soldered on.


Fuel tank in situ.

Then making 29 of these from 0.45mm brass wire - door handles ......


The other detail added - door hinges, bonnet engine hatch, exhaust stack, cab steps, doors, opening windscreen.


Rear cab door and steps


Also glimpsed here are the air tanks which were supplied with concave ends. Here I added chemical metal and domed the ends using wet'n'dry emery cloth.

Fireman's side cab door and steps.


Engineer sides cab front window

 

[Yorkshire Dave]

Nothing to do with modelling whatsoever but it looks rather like a Breugel painting today, and the snow is beginning to drift in the strengthening wind.

 

[oldravendale]

That is rather bleakly beautiful, Dave.

B

 

[Yorkshire Dave]

Or to paraphrase Kate Bush ...

Ou t'on wiley, windy moo-ers.....