Model Engine Maker

Help! => Specific Engine Help => Topic started by: gbritnell on February 25, 2018, 01:50:55 PM

Title: 'Tiny' Domestic hit and miss engine question
Post by: gbritnell on February 25, 2018, 01:50:55 PM

I'm drawing up a version of the 'Tiny' hit and miss engine. It will be modeled after the Domestic side shaft engine with the cam drive shaft running along the side of the crankcase. I have everything drawn and the helical gears cut but I don't know what the flywheel governor mechanism looks like. I have watched numerous Youtube videos but can't quite make out the governor.
If anyone could explain it I would appreciate it.
gbritnell

Title: Re: 'Tiny' Domestic hit and miss engine question
Post by: Jasonb on February 25, 2018, 04:35:21 PM

If it is anything like the Stovepipe then there is a a bush that slips onto the crankshaft with a slotted hole in it, attached to this bush is an arm with the governor weight on it. The governor rod is bent into a circle to fit around the bush and the amount of movement of this rod alters as the bush is pulled by the weight a bit like a variable throw eccentric.

Far end of rod is threaded for nuts to adjust it's position on the "L" shaped latch

(http://img.photobucket.com/albums/v156/jasonballamy/Hit%20n%20Miss/Half%20scale%20Domestic%20Stovepipe/PICT0351.jpg)

(http://img.photobucket.com/albums/v156/jasonballamy/Hit%20n%20Miss/Half%20scale%20Domestic%20Stovepipe/PICT03532.jpg)

(http://img.photobucket.com/albums/v156/jasonballamy/Hit%20n%20Miss/Half%20scale%20Domestic%20Stovepipe/DSC05401.jpg)

You can see the two lock nuts on the rod at the top of this photo, as the weight moves the eccentric bush out further the rod will move further towards the head end of teh engine and that moves the long arm of the "L" shaped latch to the left and engages on the keep to hold the exhaust rocker open.

(http://img.photobucket.com/albums/v156/jasonballamy/Hit%20n%20Miss/Half%20scale%20Domestic%20Stovepipe/DSC05408.jpg)

Title: Re: 'Tiny' Domestic hit and miss engine question
Post by: gbritnell on February 27, 2018, 02:34:17 PM

Thanks Jason,
That helps a lot. I didn't realize that the eccentric rod slips into the lock out lever. I couldn't understand if it was threaded then it would osscilate the lock out lever back and forth.
gbritnell