buffalo's workbench

What a beautiful looking mechanism Nick! If it runs half as good as it looks it must run very well indeed. No doubt you'll get those minor issues ironed out.

 

You mention you have run the loco "for short periods". I know it's good to run in locos at different speeds, but is it also good to start with short running-in periods and then make them progressively longer?

I like the colour of those tyres.

What a beautiful looking mechanism Nick! If it runs half as good as it looks it must run very well indeed. No doubt you'll get those minor issues ironed out.

 

You mention you have run the loco "for short periods". I know it's good to run in locos at different speeds, but is it also good to start with short running-in periods and then make them progressively longer?

 

Thanks, Mikkel So far, the running has improved with each little tweak, so I'm keeping my fingers crossed...

 

When I started running it, everything was still quite stiff so the motor would get hot very quickly. I'm running it for increasingly longer periods as it improves, but just ensuring that the motor does not get too hot and giving it time to cool down in between. For each run I usually start it at a moderately high speed (60-70%), then slow it down to a speed at which it will keep running. I then let the motor cool and do the same in the other direction.

 

I like the colour of those tyres.

The wheels are painted with Railmatch Indian Red (maybe a little too purple-ish to my eye). The tyres were blackened with Birchwood Casey Super Blue before painting. Glad you like it, because I'm quite pleased with the result.

 

Nick

Thanks for the info on running in there, Nick, that's very useful.

 

I agree that the colour of the tyres has come out really well!

That does look nice.

 

There is a definite art to getting something running smoothly - I think it's called persistence but it's one I've yet to master!

 

Correct me if I'm wrong but it looks like you're driving on the rear axle. Sorry to say but IMHO this is one of the hardest set ups to get right because of the knuckle joint in drive chain before the second set of wheels. If you disconnect the rods from the rear set of wheels does it run smoother? Do the front coupled pair rotate smoothly?

 

Get this cracked and the rest will be easy!

Yes, it is rear axle drive with the knuckle joint before the next axle. I think you are right, persistence is the key... Hopefully, I can get this right, because the Dean goods has the same arrangement.

 

The separate sections run quite smoothly, though not yet perfectly. The latest tweak has been to adjust the inner flanges of the High Level hornguides to minimise the possibility of fore and aft movement of the axles. I noticed this was happening on the middle and front axles. The hornblocks on one side at the front and both sides in the middle were a little slack. This has made another improvement and it will now run fairly smoothly with the wheels turning at about one revolution per second in one direction, though not so slowly in the other.

Nick - were your horncheek flanges tight on the blocks when setting up the wheelbase during chassis construction?

Nick - were your horncheek flanges tight on the blocks when setting up the wheelbase during chassis construction?

 

Yes they were. I think they may have moved a little when scraping stray paint off them so, hopefully, the overall alignment won't have been affected too much.

A brief update: persistence is paying off

 

After running the chassis off and on for the last couple of days as I described in reply to Mikkel above, it is now much smoother and will run in one direction at about one revolution in eight seconds. It's not quite so good in the other direction -- maybe about 5 seconds at most. Still, that is quite slow and so I'm very pleased with the progress.

 

This evening, I fitted the body and have been doing more running-in with the extra weight on the chassis. Apart from needing to adjust one of the rear splashers where there was some contact with the wheel, it was running moderately well, but not as well as without the body. I removed the body again and took a careful look around and discovered that the front axle is rubbing against the front edge of the slots in the outer frames on both sides, and the central axle is also rubbing slightly on the rear edge on one side. So, tomorrow's task will be to file back the frames a little to provide some clearance at these points. Then more running with the body in place...

Very pleased to hear it's running smoothly, particularly that the binding has gone, which is probably the most annoying (and common) chassis fault. Did you drop your wheels out before squeezing the horncheeks or did you manage to do it in situ?

 

 

Cheek squeezing was done with everything in situ. The clearances are better but still maybe a little wide so I'll try to reduce them a bit when I strip it down.

 

Today I filed some extra clearance as needed on the outer frames so it is now running quite well with the body in place. This time I screwed the body on rather than just resting it in place to be sure that everything was in the correct positions.

 

The two unpainted cranks need to be loktited in place now that I'm happy with the quartering. I've marked the alignment with a couple of lightly scribed lines on the cranks and axle ends so, hopefully, should be able to get them back in the correct positions.

 

Next, I'll strip everything down and give it a thorough clean. For this I just need to remove the rods, unscrew the motor and pull out the CSB springs. I deliberately over-oiled it for the running in and adjusting phase and the oil is now black. Then a few more details such as lines of Archer's rivet transfers along the ashpan, touch up the paint and give it an overall wash of dirty grey and leather. I'm thinking about adding some very simple dummy inside motion as the space between the frames in front of the centre axle is quite visible under the boiler.

Fingers crossed for the crank loctiting, Nick.

 

CofG ok?

 

 

 

Thanks for the reminder! CofG currently about 5mm behind centre axle so very close to midway between outer axles. That's without backhead, safety valve, dome, crew or coal so it might change a bit but won't need much extra lead to keep it in the right place.