How to lock the film back tight on a Linhof Technika?

[w4m0330]

I am a newbie to LF, and recently got a Linhof Super Technika IV outfit.

When I attach the 4x5 film holder (a Riteway) onto the camera, it just cannot lock tight, when I flip it, the back can easily fall off!!
However, when I attach the Horseman 6x7 back, it fits well and tight.
It seems to me that the 4x5 film back is too thick to be locked in by the two slider.

Is it normal to Technika?? How to lock the back tight? or, I did somewhere wrong?

[vinny]

are you removing the ground glass frame before you insert the holder? THIS IS WRONG.
standard 4x5 sheet film holders fit underneath the ground glass.

[w4m0330]

Here is the slider
110418

It worked good for the thin 6x7 back
110420

but cannot tightly lock the 4x5 back, It is pressed in and hold in place by friction, not locked in, so very easy fall off.
110422

Anybody know what is the problem?

[w4m0330]

are you removing the ground glass frame before you insert the holder? THIS IS WRONG.
standard 4x5 sheet film holders fit underneath the ground glass.

Got it! SO IT IS!!!
Thank you!
:)