Reverse for my mill engine

[Herbiev]

Could someone please tell me if it is feasible to add reverse to my little mill engine as shown in my avatar. If so what would be involved.
Thanx in advance
Herbie

 

[Tin Falcon]

In general oscillating engines are easy to reverse as are rotary valve make a reversing valve to redirect the air. Other engines the direction is related to the timing change the timing change the direction.
Tin

 

[kvom]

I believe it will depend on what type of valve it has (can't tell from the picture).

A piston valve can be reversed by swapping the input and output ports via an external valve. However, A slide valve cannot, as the timing is controlled by the eccentric alone.

Someone more experienced may correct me on this.

 

[Mosey]

I assume that this has to do with the direction of rotation of the output shaft, so how about a little reversing gearbox?

 

[Hilmar]

Herbie, temporary or permanently ?
If permanent then You could offset the vale ex center to the Crank by 180°?
Hilmar

 

[cfellows]

The direction of rotation is determined by the relative position of the eccentric. There is a type of reversing mechanism where the eccentric is free to turn on the shaft, I think by 1/2 turn. By rotating the eccentric 1/2 turn on the crankshaft, the engine will reverse. You need to be careful, however, which way you allow the eccentric to turn. It needs to be in the opposite direction from which the engine will rotate in the new position.

Chuck

 

[Blogwitch]

What Chuck is describing is called a slip eccentric.

This site explains it fairly easily

http://roundhouse-eng.com/ss04.htm

Basically, when made, you rotate the flywheel whichever direction you want the engine to run, this puts the timing eccentric into the correct position for when you turn the air/steam on.

One of Elmer's engines ( #43 Horizontal ) had a reverse lever in conjunction with the eccentric that did the same sort of thing, but as far as I can remember, could actually be made to reverse on the run.

I made Elmer's mine engine and fitted a slip eccentric, and it was fairly easy to do, just a bit fiddly.

The picture on this post actually shows the slot that need to be cut into the flywheel.

http://www.homemodelenginemachinist.com/index.php?topic=389.msg2792#msg2792

If you read the above post from the beginning, it is a bit of a dead loss, as this was the time I lost a lot of pictures from my photobucket account, but by this far, they are still there.

Hope this explains things OK

Bogs

 

[Dan Rowe]

Slip eccentric gear is also one of the Dockstader valve gear programs. There is a setting for rocker or no rocker on the top menu bar.

http://www.jf2.com/bcwrr/Dockstader-Valve-Gear.html

Dan

 

[Maryak]

Herbie,

Slip eccentric is the way to go.

Best Regards
Bob

 

[Dan Rowe]

Herbie,
If you do not want to download the whole set of Dockstader programs the slip eccentric module was one of the last gears added so it is most likely in the 10M file or the 10L file.

If you ger stuck with Dockstader just ask, I have made several paper drawings work with the programs.

Dan

 

[Herbiev]

Thanks very much for all the replies. Very much appreciated. Will let you all know how things turn out.
Hilmar, temporary is what I am looking for. Now to do some reading and then into the workshop :bow:

 

[speedhound]

The wilesco toy models use a Slip eccentric.