long probe repeatability issues

[[Ma...]]

Howdy, I have a 425mm long probe mounted horizontally. Ive been getting some weird repeatability issues on this bore and im looking for some advice on how to make this program more repeatable. 

The length of the measured bore is around 337mm long and we have to use a line scan for the given geometry. You can see the crest at the end of the bore indicated by a 20X mag of points and the cylindricity plot.
Every time i run the program the crest is either in a different location radially or not there at all. Any ideas of what could be causing this and how to avoid it.

Scanning direction is pulling (is it more stable to scan in a push direction?) at 7mm/s 
DK10 L425 
Contura 
Vast XTR. 

[[Ma...]]

I would say pull will be better.

Due torque of probe tip weight will tip go down, so pulling would help instead of a push. But counter weight could help more.

Is it needed to be measured by scan? Couldn't it be measured from both sides so you could have shorter probe?

[[Ri...]]

Turn down your probing dynamics, if the setup isn't very rigid, it will be vibrating on the initial hit. 

 

Also pay attention that you have no filter applied - since you are performing linear scans, you will need to use wavelength instead of UPR.