How many modellers have purchased Romford/Markits screw couplings, only to find them so rigid that they are unsuitable for anything other than cosmetic use ?
This article discusses a simple modification which can be made to these couplings to make them completely flexible and workable for the purpose they are designed.
The main problem with Romford/Markits couplings is that the 'bearings' on the joints are too tight. Lubrication makes no difference. What needs to be done is for the 'brearings' themselves to be modified. To do this, the two loops need removing from the 'screw' and the 'lips' filed down (removed) as shown in the following diagram:
Once this modification is made, the two loops can be re-assembled carefully and the result is a fully flexible coupling. Provided the loops are not too tight, the coupling should flex under its own weight.
The finished modifications:
Graham Plowman (07/12/2010)