Stock for Brent 1947 GWR

Do you mean you've cut the crosshead piston too short, or the slidebars?

 

I've been there, done that with both, but don't throw away the crosshead as it might be useful for another locomotive, if you can't get it to work with this one. I always nibble away a tiny bit at a time until there's just enough to function, and I try not to trim back the slidebars until I'm happy that all is working.

 

One possible cause of the anomaly might be that the crankpin throw on the drivers is a bit more than was allowed for by the kit designer, so that the crosshead travel is greater. Good luck anyway as I'm sure it will be a cracking model when finished.

I think the problem is both, I certainly cut the cross head shaft too short ( I cut it based on the crosshead at full length of slide bar.)

 

On the slide bar I thought you were supposed to cut on the Half etched line. The extra mm on the end would make it ok length wise.

 

To be honest I’m not overly happy with the quality of the cast crosshead relative to the etched ones I am used to with Mitchell kits or the machined Markits product (with which I am thinking of replacing these). The main problem being the amount of fettling needed to get a good fit on the slide bars, coupled with the fact it needs painting. I really didn’t like the bends in the rod. as an improvement I am thinking of cutting the rod off completely and replacing with brass soldered on (maybe with a 1mm diameter pin in the joint)

 

I’m also considering trying the Saint wheels to see if the crank pin is in a more suitable position (I suspect worse)

 

I’ve added a clearer photo from today after I redid the con rods with recessed nuts to clear the cross head

I don't think the Comet instructions are all that brilliant when it comes to the slidebar etches, so I know what you mean about cutting on the wrong line. Some of the rod castings I've had have been shockingly bent, too, although I've got them straight in the end. The fettling is a pain, but I've got a narrow-sided file which just about does the job. I was advised not to fettle the slidebars (other than cleaning up a bit and polishing) but concentrate on the crosshead only.

Cylinders look too short. They were substantial things on "Counties" - see also Rich's Part 3 of this project for further details.