Stuart No 9 - A simple Horizontal Steam Engine

[Jo]

I have a need for some simple castings to try out a potential new milling machine with, so having looked round my casting collection I happened upon this little one which seems to have all the necessary features to put the machine through its paces.  I will have to study the drawings and fondle the castings to check that it is a suitable test piece 

I know that there are a few bits missing from the casting set: The crosshead bronze, the Main bearings, the big end bearing and the flywheel 

Jo

P.S. If anyone has a spare 5" Flywheel I would willingly find a new home for it 

[Jasonb]

I have two but you would have to put up with curved spokes but at least it would be a bit different from every other Stuart that is churned out

I was shown a picture of some flywheels that came from RC-Machines that looked nice and reasonably priced and being metric they would appeal to you though unfortunately they don't have 127mm, 124mm would be closest

J

PS I hope you will be giving that machine a decent test by using a slab mill to do the base in one pass and not mucking about with small cutters

[Jo]

I checked out RC-Machines their 124mm flying wheels seem to have flown the coup  .

Jo

[Jasonb]

I wondered if that was what the red bar meant, expect they will be back in stock, my source must have cleaned them out though most he had looked larger.

I suppose you could always let loose with the Moths and get one from Stuarts.

Were they the extruded bearings on that engine? separate bearings and caps will look nicer if they were.

[scalemodel]

Hi there jo, what model of stuart is that?  If it's the no9 then I maybe able to help out as I've got some castings for a 9 intact I've got a big box of stuart turner castings left over castings etc

Jonathan

[Jo]

They are separate bottom bearing and top caps/bearing castings. And the bearing castings are not as wide as the sole plate casting is where the bearings fit 

Hi Jonathan a PM is coming your way 

Jo

[Jo]

  This cylinder casting looks good, there is about 1.6mm on all faces for machining, not far out of square. The ports are full of  , as they won't blow through, so I will have to give them a poke with a bit of wire when I get time.

But the valve ports are too big: They need to be 3.2mm wide and one of them is already 3.8mm  They are also not central they are offset away from the crank by 1mm But I'm going to ignore it and centralise the valve slightly further up the cylinder to use the existing ports

For some reason there are bosses for the drain cocks on the opposite side to the valve face and the bottom of the cylinder.  Maybe the other set are so they can use this casting for another engine And there is a sticky out boss where the exhaust is due to go that is not on the drawing  and it is too small for the exhaust gland so it will have to go.

Jo

[Nick_G]

.
Good morning Jo.

Over 20 years ago I had a very brief dabble at model engineering and bought a set of No.9 castings. I then proceeded to make a right 'dogs-danglers' of them.  Shortly followed by having to vacate where I was and thus having to get rid of the machines.

Recently these butchered castings came back to me. I mulled them for a while and considered them to be 'FUBAR' 

Anyway here are some little touched or raw ones I have. - They are no use to me. But maybe they are to you.?



If so PM me your addy and I will pop them into a jiffy bag and post them to you.

Nick

[Jasonb]

Jo not only are the extra drain bosses there so the casting can be used on other engines they also allow you to build the No 9 in left or right hand versions, if I remember rightly the bed casting has a pad cast on both sides so the valve rod guild can be placed on either side too. Could always do them as a "Double 9) with the amount of extra castings you are being offered

[Jo]

Thanks Nick, PM on route 

Yes it can be built in either handing, the other pad being for the pump.

Jo

[Jo]

We need to mount the cylinder with the crank end sticking out. This will make sure that the cylinder bore and the face that will be mounted on the sole plate are at exactly 90 degrees to each other.
Having had a good measure up earlier I would like to offset the bore of the cylinder towards the opposite side to the valve face as there is only 3mm of spare metal overall in that dimension and there is 4mm the other way.  By doing this it gives me the full 2mm on the valve face for making sure that has a nice finishing cut.

To help mounting the cylinder in the four jaw a drill chuck was poked in the end of the bore. Then the sides and face were checked to be square to the chuck. At this point the casting could be lined up with the offset on the bore I had decided up. You will note that I have marked the casting with the crank end. With a safety bar in place 2mm was taken off the end of the cylinder.

There is a danger when boring that you could catch the chuck jaws with the boring bar if you are not watching the count down on the DRO but Mr Silky also has a bed stop. So first having poked the boring bar in to touch a jaw and zeroed the DRO the bed was dropped back 1mm and the stop put in place. Boring has commenced, the clutch is working nicely to stop the power feed within 0.002mm every time. As you bore through the cylinder you can hear when you are nearing the end as the ports cause an intermittent cut. The bore is currently sitting at 37mm  .

Jo

[Jasonb]

I have a need for some simple castings to try out a potential new milling machine with,

That does not look like trying out a milling machine, more an excuse to start on another set of castings

I notice that the bed wipers come very close to the carrage stop. On a job that may produce more swarf is there not a risk of this swarf getting pushed up against the stop and possibly moving it along the bed before the clutch is activated? I suppose that is one of the downsides to this type of bed where there is no hole for swarf to drop through.

J

[Jo]

That does not look like trying out a milling machine, more an excuse to start on another set of castings

Its preparing them for Sunday.

No it would trip the clutch before moving that stop. There is nothing wrong with cleaning the swarf off as you go  .

Jo

[Jo]

A bit of panic set in when I turned the cylinder round having finished the boring. I was lazy and didn't line the cylinder up  so I turned the lathe on and  my bore was wobbling all over the place. Its not very nice when your bore wobbles all over the place  But it wasn't the bore it was the cylinder so I realigned a bit to stop me worrying  .

I checked the depth of the casting by using a drill to measure the gap behind the casting while mounted in the four jaw and added that to the length that I wanted for the cylinder. But it is still 0.05mm too long 

The final bit of preparation needed was to mount it on a mandrel ready to have a play on Sunday 

Jo

[zeeprogrammer]

P.S. If anyone has a spare 5" Flywheel I would willingly find a new home for it 

Drat, drat and drat.

So many opportunities...so little to offer.