Engine indicators

[Maurice Cox 1Participant @mauricecox1]

[Maurice Cox 1Participant @mauricecox1]

Can anyone please tell me the diameter and pitch of the threads in the bushes on full size engines, into which an indicator is fitted? I wish to add this feature to a model I am making, even though it will not be used, and would rather not guess the size. Thanks.

Maurice

[Gordon WParticipant @gordonw]

Can't help I'm afraid, 'Ive only fitted 2 indicators to two engines and the threads were compltley different. and can't remember either of them.

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

**LINK**

Hi Maurice – above link is to a huge and fascinating site covering many topics about steam engines . May take some finding but in there somewhere there are technical drawings of indicators .

MikeW

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

There are also scaleable illustrations and catalogue pages .

Some indicators that I've looked at in the past had universal fittings – a loose union nut on the indicator which joined onto a double male ended fitting in the engine cylinder . The double male ended fitting could be a supplied part or I suspect in some cases a rapidly made DIY job to mate indicator with any available hole .

MikeW

[JasonBModerator @jasonb]

This book may throw up some sizes, not had a chance to look all the way through it.

Prestons always have a few for sale but don't give sizes.

J

[Trevor Drabble 1Participant @trevordrabble1]

My Dobbie McInnes indicator has a 1.064" dia x 16TPI male thread on the bottom of the body, which I believe may be a Pg 21 conduit thread. Included in the set is a separate threaded removable collar for fitting the body to the engine. This collar has a matching internal thread to the body for half its length, whilst the other half is threaded to accept a 1.171" dia x 10 TPI whitworth form thread.

Hope this helps.

Trevor.

[Maurice Cox 1Participant @mauricecox1]

Thanks for the feedback gents. I thought they would be about one inch diameter, so I think I will go with the size described by Trevor.

Thanks again, Maurice

[Author]

Posts