Louvre Doors
Modelling British Railways diesel shunters will usually require louvre panels to be made for the engine bonnet access doors. The louvres on the full size locomotive are to allow ventilation of the engine compartment and also to provide air for the engine intake filters, whilst the doors provide access to the engine bay for maintenance. Any openings in the bonnet also become a potential entry point for airborne dust and water ingress.
On a model shunter, which will generally the a storage battery locomotive, there is no need to allow cooling air into the battery compartment, and no need for combustion air intake. But perhaps more importantly the ingress of water through the louvre openings is not desirable due to it encouraging corrosion and the need to provide a drainage method.
Full size louvres are produced using press tooling which on initial contact sheers a line perhaps 12” long in the sheet steel and then continues on its downward stroke to form the profile of the louvre opening. The tooling may form one louvre per stroke with the material then being fed forward by one pitch for a second louvre to be formed, and then progressing until the required number are formed. Alternatively a multiple tool may form a number of louvres per stroke dependant on the capacity of the power press.
A previous shunter model was built with plain doors to the engine room, and despite an intent to return later and fit the correct profile louvres time has passed by without going back. Various ideas of making miniature press tooling and producing doors in soft material such as a copper sheet were considered but never adopted. The lack of correct pattern louvre doors did not affect the running of the loco, but it never quite looked right.
The need for louvre doors on a current model met with a resolve 'must try harder', and having considered and dismissed many methods in the mind over the 6 years since the earlier model a completely fresh idea came to mind.
This method uses a triangular plastic section marketed by Raboesch as the louvre. This can be cut to any length and glued in place to any spacing required. Several sizes of triangle are available, 3mm is used in the photographs.
The accompanying photographs probably explain the method almost without text but non the less:-
Simplicity itself, and six years of thought to get there!
Modelling British Railways diesel shunters will usually require louvre panels to be made for the engine bonnet access doors. The louvres on the full size locomotive are to allow ventilation of the engine compartment and also to provide air for the engine intake filters, whilst the doors provide access to the engine bay for maintenance. Any openings in the bonnet also become a potential entry point for airborne dust and water ingress.
On a model shunter, which will generally the a storage battery locomotive, there is no need to allow cooling air into the battery compartment, and no need for combustion air intake. But perhaps more importantly the ingress of water through the louvre openings is not desirable due to it encouraging corrosion and the need to provide a drainage method.
Full size louvres are produced using press tooling which on initial contact sheers a line perhaps 12” long in the sheet steel and then continues on its downward stroke to form the profile of the louvre opening. The tooling may form one louvre per stroke with the material then being fed forward by one pitch for a second louvre to be formed, and then progressing until the required number are formed. Alternatively a multiple tool may form a number of louvres per stroke dependant on the capacity of the power press.
A previous shunter model was built with plain doors to the engine room, and despite an intent to return later and fit the correct profile louvres time has passed by without going back. Various ideas of making miniature press tooling and producing doors in soft material such as a copper sheet were considered but never adopted. The lack of correct pattern louvre doors did not affect the running of the loco, but it never quite looked right.
The need for louvre doors on a current model met with a resolve 'must try harder', and having considered and dismissed many methods in the mind over the 6 years since the earlier model a completely fresh idea came to mind.
This method uses a triangular plastic section marketed by Raboesch as the louvre. This can be cut to any length and glued in place to any spacing required. Several sizes of triangle are available, 3mm is used in the photographs.
The accompanying photographs probably explain the method almost without text but non the less:-
- Cut out the door as a sheet of 1mm steel.
- Mark the position of the louvres on the door.
- Glue plastic triangle to the door allowing a few millimetres for trimming to length.
- After glueing the required number of louvres allow to bond for a few hours.
- With a sharp craft knife trim the ends of the plastic to length and then chamfer at 45 degrees, being careful not to mark the steel with the blade.
- Paint the door with primer, and progress to top coat colour.
Simplicity itself, and six years of thought to get there!