Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Can anyone help make this make sense since I have no idea what's going on here?   I attached a photo below.  Both arrows point to the confusion.  The screw on this plate that touches one of the eccentrics.  What does this screw, screw down to?   Does it go through both eccentrics through a hole, and into that pulley which is screwed down to the shaft?    The plate itself... what is the purpose of the plates.   How does this eccentric rotate?   Under the plate, is there a disc that is hard soldered to the shaft, and the eccentric strap wraps around the disc?   I am confused. 

How do you adjust timing?   Clearly it is done by loosening that small pulley next to the eccentric.   I just need a basic understanding about this.   Also, are these "plates" needing to be tight or loose?

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Timing is easy.

Just place the crank arm vertically. (straight up or straight down)

Then set set the eccentric so the high point is extended horizontally all the way forward or all the way back.

It is just a matter of having the eccentric 90 degrees to the crank shaft.


Regarding that screw on the side, it should be tight and it serves only to hold the outside disc in place which is just there to keep the eccentric straps from falling off.

Gil

How is the eccentric sheave attached?   If it has straps around the sheave, is the sheave welded to the axle/shaft?      If it was, it would always be fixed. That’s where my confusion is. How does adjusting that pulley change the timing (movement of the eccentric in relation to the crank).

Quote from: rails4ever on February 06, 2024, 05:21:29 pm

Quote from: RedRyder on February 06, 2024, 05:09:10 pm

Timing is easy.

Just place the crank arm vertically. (straight up or straight down)

Then set set the eccentric so the high point is extended horizontally all the way forward or all the way back.

It is just a matter of having the eccentric 90 degrees to the crank shaft.


Regarding that screw on the side, it should be tight and it serves only to hold the outside disc in place which is just there to keep the eccentric straps from falling off.

Gil

How is the eccentric sheave attached?  If it has straps around the sheave, is the sheave welded to the axle/shaft?      If it was, it would always be fixed. That’s where my confusion is. How does adjusting that pulley change the timing (movement of the eccentric in relation to the crank).

The eccentrics are part of the pulley or attached to it.

If you take it apart and then remove the screw holding the sheet metal disc, the eccentric straps will come right off. There is no need to do this. Just make sure your timing is good as per my instruction and it will run in both directions.  (it doesn't even matter how it is attached)

There is a set screw in the little pulley. IF your timing is off, loosen it and turn the pulley until it is right.

The engine is quite loud under load. Even if the faux governor is attached there is considerable knocking.   Nothing is loose.  If I remove the faux governor belt it runs very quiet and nice.   The timing is spot on for what you stated.  Is the knocking coming from not enough steam cushion in the cylinder?

That faux governor robs a noticeable amount of power from the engine.

I’d like to remove it entirely.  I know the shaft goes under the engine and there is some sort of retainer clip you have to remove… but I’m not messing up the rivets to do it.  I’d have to remove the engine off the base, to get to it.

Quote from: rails4ever on February 06, 2024, 09:32:18 pm

Quote from: St Paul Steam on February 06, 2024, 07:17:44 pm

That faux governor robs a noticeable amount of power from the engine.

I’d like to remove it entirely.  I know the shaft goes under the engine and there is some sort of retainer clip you have to remove… but I’m not messing up the rivets to do it.  I’d have to remove the engine off the base, to get to it.

Better to just leave the belt off the governor and leave it in place.

It's honestly an eye sore.

It can be quite nice with the addition of brass governor balls.

Sadly I have no machining tools or abilities to do metal work.      I'd have to fully rely on someone like you or someone else on the board to do this kinda stuff.   I can only do minor tweaking.   I wish I could remove the entire model from the metal base and put it on stained & sealed wood like your 75EL BB,    and have the skills to put the variac onto the back, put the immersion rod into the boiler,  and put that beautiful copper paint on it,  install roller ball bearings,   and wilesco transmission.     I really want that 75ELBB.   you sold it around thanksgiving and when I saw this post today already sold I lost my mind! 

Keep your eyes open here. Bruce does fine work and his creativity knows no bounds.
I am certain more of his work will surface.

Ditto all of that ....... in Spades!!!

Timing is easy.

Just place the crank arm vertically. (straight up or straight down)

Then set set the eccentric so the high point is extended horizontally all the way forward or all the way back.

It is just a matter of having the eccentric 90 degrees to the crank shaft.


Regarding that screw on the side, it should be tight and it serves only to hold the outside disc in place which is just there to keep the eccentric straps from falling off.

Gil

I tried to mess with timing and the noise never improved it only got worse.  I might have caused damage to the cylinder wall, I ran it purposely out of time to see how it ran and it ran very rough.  Then, I set it back to how it was. It’s only louder now.  lol.  I guess I learn with a cheap one instead of an expensive one.