Total frustration

[Bandit Mick]

A bit of help please with this mystery. Both of my 0-4-0 Pecketts (oo gauge) ride up then lurch to the side as they exit the heel of a short radius point and join the next piece of track. They only do this when running one way. When running the other way from track to point they don’t do this and they don’t do it when running through the point backwards in either direction. The points and track are laid absolutely flat and the horizontal surfaces of the points and track are bang on in line. The fishplates are correctly installed and the point blade is tight up against the rail. It only happens when the point is set one way I.e. on the curve.I’ve taken off a section of granite setts in this area and still the same happens. There is no debris in the track or points. Both locos run superbly through all other points in either direction forwards or backwards. No other locos do this but these locos are 0-6-0s etc. Can anyone enlighten me as to what is wrong as I am completely stumped. Thank you for any help you can give me.
P.S. I hope this post is in the correct section.

[brian1951]

Difficult with not seeing them in the flesh, i would just change the point.

[Steve M]

Could the trailing wheel be dropping off the frog into the gap before it reaches the rail? The wheels on those things are very small so won’t bridge much of a gap.
Are you able to watch from track level with the loco running slowly across the point? Maybe at a slow crawl?
If your phone is capable maybe film it as a slow motion film clip - it may give you some clues.

[Bandit Mick]

Thank you. Yes I have watched both locos travel very slowly. It seems that they both ride up where the point joins the rail - the gap is the standard credit card. Strange that they don’t ride up when travelling from the other direction or ride up when travelling backwards in either direction.

[dtb]

is the set of points perfectly flat, pinned down and level?

[Steve M]

Thank you. Yes I have watched both locos travel very slowly. It seems that they both ride up where the point joins the rail - the gap is the standard credit card. Strange that they don’t ride up when travelling from the other direction or ride up when travelling backwards in either direction.

I think Brian's suggestion has some merit - change the point and see if the problem goes away.

[Ultima Thule]

What make is the point?

[Bandit Mick]

It’s a peco streamline short point bought new. I have 15 other points all the same and they are fine. Perhaps it is a duff point. I’ll try adding a shim of plasticard at the frog before I replace the point as I will have to take up a large area of granite setts to get to it.

[Stese]

Would also be worth checking the back-to-back measurements of the wheels are within spec.

[Bandit Mick]

Thank you Stese. I’ve heard of back to back measurements - could you please explain the term.