Stuart beam: govenor belt fouls flywheel

[James Hall 3Participant @jameshall3]

Well, I’m stumped:

Recently completed Stuart beam with which I am delighted – looks good (to me anyway) and steams well at all speeds.

Thought a govenor would finish it off nicely (and, as a relative beginner, the machining would be interesting). Now finished apart from the valve and link to it and does all that is required of it when spun, but when I fitted the spring belt it badly fouls the flywheel and consequently just slips on the crankshaft pully.

I’ve checked all dimensions which seem correct – but I can’t believe that the design allows this to happen. Am I missing something too obvious to spot?

While I’m here, any advice on spring belt – how much tension, etc. – never used one before and have no intuitive feel for it.

[MikeKParticipant @mikek40713]

Can anything be gleaned from this short video?

https://www.youtube.com/watch?v=GrBypFjFlJE

Mike

 

[JasonBModerator @jasonb]

You need to move the crankshaft pulley and flywheel over so the pully can line up approx with ctr line of the governor and then th eflywheel enough to clear the belt. Outrigger bearing support will also have to move. The crankshaft will have enough length for this.

You might get away with the pulley up against the eccentric but check the belt clears the eccentric rod particularly near the governor. This does risk the belt slipping as it is at more of an angle. Flywheel will have to come over so it’s hub will have to touch the outrigger bearing and if lucky you may be able to turn some material off that side of the hub, just make sure it clears the bearing support. Otherwise you are going to muck up your paving to move the bearing support

My belt is 235mm end to end

Excuse the dust, Flywheel could be a bit closer than I have it

[ChrisLHParticipant @chrislh]

I have no explanation for the original design mess but a suggestion for making do. Pillar with vertical rod on which two free pulleys rotate and which is set close to the governor spindle. This could be set to push the belt over to lie parallel with the flywheel. Space looks to be very tight so could work better if the new pillar were set in place of the governor and the governor itself moved further away from the flywheel. Of course the result may end up looking nothing like the prototype.

[JasonBModerator @jasonb]

The reason for the “original design mess” is that the drawings for the basic beam engine give a distance for the outrigger bearing from engine ctr line. This gives minimal overhangs.

Adding the governor as an extra needs the outrigger and flywheel moving. It is too long ago for me to remember if a distance is given on the governor drawings or not, But if added after all the base has been made then you are a bit stuck.

It is the same for several Stuarts if you add governors, pumps, reversing sets then existing parts need to be altered adjusted or replaced

[James Hall 3Participant @jameshall3]

Thanks all for the helpful replies.

Feel rather foolish for not spotting the obvious solution of moving the flywheel over – can only plead that while Stuart’s drawings for the governor show the required mod. to the eccentric they don’t mention the flywheel position (though still a case of overlooking the bl**dy obvious on my part).

Fortunately the flywheel in its new position will pretty much hide the redundant pillar fixing holes though drilling the new ones to maintain exact alignment of the main bearings may be a little fiddly.

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