Vince's version of the Monitor Steam Engine

[sshire]

Vince
I was concerned that the set screws(grub screws) would dimple the shaft so I didn't really tighten down on them too hard. Bad idea. At Cabin Fever, after running for an hour, the eccentric slipped and the timing went down the tubes.
When I got home, I disassembled and filed flats. Highly recommended.
Also switched from the standard cup-point to flat point. Better on a filed flat.
Don't know about your suppliers but McMaster-Carr has them in metric and imperial. Alloy steel and stainless steel.
I did have a fleeting thought to use extended point set screws which are designed to lock into a mating hole on the shaft.

[bruedney]

I used the 3 at 45deg with no flats - no problems. I suppose it depends on the load. My valve rods were binding due to the tendency to tip with only one end supported hence my redesign of valves and rods to allow for support at both side of the steam chest.

I also drilled and tapped the 2 halves and added a 3mm screw just to make sure the loctite didn't let go. I cut the heads off and filed flat

Looking good though Vince

Cheers
Bruce

[vcutajar]

Thanks gents for the comments and suggestions.

I have to think about it.

Vince

[10KPete]

Where possible, I like to turn a shallow groove around the shaft in the way of the set screws. Not deep, but enough that any burr raised by the screw won't interfere with the bore of the (insert item name here). The item can be positioned at any rotation and the groove takes care of any burrs.

Pete

[sshire]

Good one, Pete.

[zeeprogrammer]

Where possible, I like to turn a shallow groove around the shaft in the way of the set screws. Not deep, but enough that any burr raised by the screw won't interfere with the bore of the (insert item name here). The item can be positioned at any rotation and the groove takes care of any burrs.

Nice idea! Thanks. 

[b.lindsey]

Looks like you are in the home stretch Vince. That last family shot looks terrific too!!  Looking forward to seeing it run.

Bill

[Flyboy Jim]

Where possible, I like to turn a shallow groove around the shaft in the way of the set screws. Not deep, but enough that any burr raised by the screw won't interfere with the bore of the (insert item name here). The item can be positioned at any rotation and the groove takes care of any burrs.

Pete

Well geeez...........file that in the "why didn't I think of that" category! Good one Pete. 

Jim

[vcutajar]

Good idea Pete.  Have to keep it in mind.

Vince

[vcutajar]

More work on the eccentric sheaves.

With the help of a 10 mm rod in the tailstock I put the sheave in the 4 jaw chuck and carefully tightened the jaws.



Made a quick check on runout.  Showing 0.1mm.  Good enough for me as the next operation does not require lots of accuracy.



Started machining the shoulder around the 10mm hole.



Both of them finished.





Next for the final operation which will be drilling and tapping the three 3mm holes for the grub screws.  Decided to make them as per plans; i.e. with 45 degree spacing.  Realised that doing this will not be as simple as I anticipated.  Will have to sleep on it.

Vince

[zeeprogrammer]

 

Almost there!

[sshire]

The suspense is killing us

[Don1966]

The eccentrics and sheaves turned out great Vince of coarse I expected no less buddy. Still with you and enjoying it.......

Don

[b.lindsey]

Beautiful looking assemblies Vince. Things should be getting close now !!

Bill

[vcutajar]

Thanks guys for keeping me company.

So today I took the dividing head out to drill the holes for the grub screws.  Drilled the first one and started tapping the holes.  The taps were not cutting too well.  I guess the material got work hardened when drilling and the taps are not sharp anymore because on the last hole I broke a tap.  Disaster, as I could not get the broken part out.

After a siesta I went back to have another look at the situation.  I could make a new part or use the one I had with two grub screws.

Eventually I found I had a small carbide burr with a taper shape.  Let's give it a try.  It actually worked as it started breaking up the broken tap in the hole.  With a little patience and a hardened 2mm pin punch I managed to chip it all out.

Phew.  Managed to save the part.

Vince