7mm Class 150/2 DMU in Northern rail colours with lights and sound

geoff_nicholls

Western Thunderer
construction of the body seems to be going okay, once I started using the plywood former. The kit is by Peter Clark, the castings and etching are very good, I'm going to use the motor bogie etches for the unpowered bogies.
When you buy the add on motor/gearbox bogie kit it comes with 3' dia wheels, I'm thinking of replacing these with something nearer the 840mm prototype.
Now the questions
I'd like to build it with
internal lighting,
directional lighting
sound.
It will run on our club layout which is purely analogue, is any of the above possible? perhaps with RC?
 

Steph Dale

Western Thunderer
Geoff,
You can use a DCC decoder to provide much of the functionality you require, and then just drive it on an analogue controller.
It seems the easiest way to get sound, although there are RC options.
Steph
 

The Penguin Of Doom

Western Thunderer
I'm led to believe that many DCC decoders can be run on analogue controllers so I don't think there would be an issue.

I use Bachmann decoders in my 4mm stock but only have an analogue test track at home but have never had a problem.

I like the build so far and recall these units being introduced with only the gangway door on the front painted Yellow. They looked completely different compared to everything else with full Yellow ends.

Cheers.

Sean.
 

geoff_nicholls

Western Thunderer
thanks, Sean, Matt and Steph, I'm sure there will be further questions.
In the meantime the smaller (2' 8") wheels arrived from Roxey, insulated one side only which should dispense with wiper pickup. If I've understood the drawings correctly the floor height should be 1144 or 26.3mm in O gauge, and that's what it is, with the new wheels. And they seem to look right with the bogie frames as well.
Off up to Sheffield in an hour's time, so hopefully I'll see the real thing. I need to check if Northern Rail has any 150/2's with 2+ 2 seating, as that is what I ordered with the kit.
 

geoff_nicholls

Western Thunderer
003.JPG 004.JPG A couple of photos showing the power bogie cardan shaft and motor. The motor will sit in a hole cut into the paxolin floor, but I don't think it will protrude above floor level. The brackets holding the worm axle have slotted holes for the screws, so the tightness of the gears can be adjusted.
I've never had to make this adjustment before so would appreciate any tips on how to get that right. 003.JPG
 

adrian

Flying Squad
The brackets holding the worm axle have slotted holes for the screws, so the tightness of the gears can be adjusted.
I've never had to make this adjustment before so would appreciate any tips on how to get that right.
An interesting design - until somebody comes along with a more scientific method : for adjusting the gears I'd just use the fag paper clearance technique! Get some thin paper, e.g. fag paper place this between the worm and spur gear, hold everything tight whilst tightening the screws. Turn the worm to remove the paper leaving the required clearance. If it's too tight then try thicker paper!
 

geoff_nicholls

Western Thunderer
I had heard about that method, I'll buy some Rizzla papers from my corner shop. This 7mm is quite fiddly now I've got used to gauge 3,my fingers feel like thick sausages. I've now idea how anyone copes with 4mm

The bogie wheelbase is 8' 6", Peter Clark was happy to sell me three more to replace the white metal unpowered bogies on my kit, I don't know if he's able to sell them as a separate item. the shaft of the cardan shaft is not fixed to the two ends, it has a spline, so it can lengthen or shorten going round curves.
 

Pugsley

Western Thunderer
the shaft of the cardan shaft is not fixed to the two ends, it has a spline, so it can lengthen or shorten going round curves.
I'm under the impression that the ability to lengthen and shorten like that is what actually defines a cardan shaft. If it's fixed length, it's just a drive shaft.

This is an interesting project - I'll be following with interest, as I fancy a 150 at some point in the future.
 

Mr Grumpy

Western Thunderer
Hi Geoff,
Enjoying your build.
I have built Pete's 205 Thumper, and I thought the etches were very good and fitted well. I did use some JLTRT lost wax castings and PHD's etched grille, but other wise a very nice kit.
In the future I fancy building his super voyager, so wondered how you found his resin cast cabs?
Love the motor/ bogie drive system :thumbs:
 

geoff_nicholls

Western Thunderer
The resin cast cabs do look very nice. They are fabricated, not 3D printed, and fit well into the etched body. The doors and corridor connections are also resin, everything else is white metal. I'll post some photos, but being cream, they might not show the detail. I hadn't realised that was what a cardan shaft is, I'm on a steep learning curve.
 

geoff_nicholls

Western Thunderer
As you can see I cut the hole for the motor then put everything together, just to check it all fits. I tried running it at a very low voltage, it does work, but is quite noisy. Now I need to screw it all together and adjust the gears to get it running smoothly. And sort out the pick ups. Our club's new test oval will be ready in a couple of week's time, to give it a good running in.
 

Steph Dale

Western Thunderer
Geoff,
Those gears should mesh okay, even some of the machining does look a little odd. The best approach to take is to work one axle at a time. Start with the mesh fractionally tight, so any tight spot can be readily found and then slacken the mesh slightly. You want just a smidge of barely-detectable backlash in the gears at that point. Then do the second axle.
Where yours gets a bit tricky is that the two worms are on a common shaft, so expect to have to go back round again to get the mesh perfect as adjusting the mesh for the second gearset will slightly alter the meshing centres of the first axle.
Use a decent lubricant to help them on their way; I use the Woodland Scenics Hob-E-Lube 'Gear lube' and you'll probably want some fine oil for the axle/shaft bearings.
It's not desperately tricky, but you do need a consistent method and a little time.
Steph
 

geoff_nicholls

Western Thunderer
thank you for the suggestion about the choice of oil, Steph, that would have been my next question.
Pete Harvey also used the word 'backlash', is that the amount of back-and-forth movement of the axle against the worm?
 

Steph Dale

Western Thunderer
Backlash is as you describe, might also be interpreted as 'slack' or, more accurately, 'clearance' between the gear teeth.
Steph
 

geoff_nicholls

Western Thunderer
the powered unit had its first test run yesterday on the club's test track. Rather disappointing. Everything appeared to work fine, it was just very slow, even the controller at full speed (14v). It wasn't that the enormous oval made it look slow, there was a new Dapol Terrier whizzing along, and a nice L1 loping around the track, but mine was running at little better than shunting speed.
The motor (mashima 1833) was not getting hot, though not stone cold, and no sign of problems with the gears.
I'm wondering if my choice of smaller(actually scale sized) wheels is the causing the problem...

Any thoughts or help would be appreciated.
 

Steph Dale

Western Thunderer
Geoff,

Gear ratio might be a bit high - looking at your earlier pictures they look like single start worm drives so must be around 25-30:1. Combine with a slow motor and yes, it'll be a bit slow. The Mashima 1833 is 8500rpm, so a Canon 1833 or Mashima 1830 at around 11000rpm might help - then again, so would lower gear ratios.

I use 13:1 gears with Mashima 1833 motors in similar applications:
Trade - Steph Dale Model Products - Class 22 + Hymek drive??? | Page 15 | Western Thunder

Steph
 
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