Romford or Markits wheels not quartering correctly?

[John Isherwood]

1 hour ago, Captain Kernow said:

The theory has been confirmed.

 

New Markits wheels arrived today, thanks to the most efficient offices of Wizard Models and one set has replaced the problematic ones.

 

The wheels were a good, tight fit on the axle ends and didn't require any fettling, prior to being attached.

 

The wheelset appears to be quartered correctly and more importantly, is consistent with the quartering on the other wheels. Most important of all, the chassis rolls along nice and smoothly.

 

 

Did you use a new axle, or the original one?

 

If the latter - the problem was the wheel(s).

 

John Isherwood.

[Captain Kernow]

I used a new axle and new wheels, John.

 

I have put the problematic ones to one side, for later investigation and possible rectification.

 

[Rowsley17D]

I wish I had looked for this topic a few days ago. I have spent much of two days modelling trying to get a Markits-wheeled 2P kit to go without the wheels binding. I opened out the crankpin holes and re-bushed them again several times. It was only when I filed the holes of the driving wheels with a square file did I get it to run properly.

[gordon s]

Like you CK, I built my J50 chassis on an Avonside C2 jig, and know it is accurately spaced and level. DJH supplied the new style of crank pin with top hat nuts and I found I had to open the coupling rod holes so much, that it really slopped around. It looked dreadful and after a chat with Tony Wright and Co on Wright Writes, I changed the crank pins for the earlier design with solder nuts. I had to bush the coupling rod holes and effectively start again and whilst they are better, the holes still seem oversize, particularly when they fitted the Avonside pins perfectly.

 

I have ordered a new set of etches from DJH so I can start the process again with brand news rods and take it slowly to see if I can get a better result. Jonathan, having been down a similar route, you have my sympathy....

 

Having read of CK’s issues, I’ll make some additional checks.

 

Thanks for the info.

[Captain Kernow]

Like many folk, I always retain the coupling rods on the older type of crankpins temporarily, with little pieces of plastic wire insulation.

 

When I'm happy with the running, I remove the rods and the crankpins from all the wheels.

 

I then put each crankpin, in turn, in a vice (with the screw thread that goes into the wheel sandwiched beween two pieces of card, to avoid damaging the thread). I then place the coupling rod on the crankpin, then a small sliver of thin paper (in which I have already made a small hole and cut a slot from said hole almost - but not quite - to the edge of the paper).

 

The round crankpin 'nut' then goes on top of this and is pressed down onto the little piece of paper and the coupling rod, but leaving a small gap for 'working slop'.

 

The nut is then soldered in place, with the crankpin, coupling rod and 'nut' ensemble still in the vice.

 

I then snip the excess off with a pair of Xuron rail cutters and file the top of the round 'nut' smooth, everything still in the vice.

 

When the top of the round 'nut' is cleaned up and smooth, I then cut a very thin slot in it, right across the middle, with a fine piercing saw blade. The whole ensemble is then removed from the vice and the process repeated for the remaining crankpins.

 

The slot across the top of the round crankpin 'nut' allows you to then simply screw the rods in place, when you reassemble the chassis.

 

Once painted and weathered, I don't notice the thin slot when the loco is in use, but if it bothered me, I could always put some filler in it, on the premise that I could always scrape it out again, if I needed to remove the rods again for maintenance.