Refurbishing an Old Model Steam Engine.

[Tony Bird]

Hi,

I am at the point where the engine frame should be bolted to the new base plate, so to that end I had a look through my 'come in useful' box for something to lift the base plate up a bit. I came across some bits that might or might not become a permanent part of the model: two pairs of candle sconce's, the candle columns having already been used for other jobs and as a bit of a bonus an aluminium flywheel which is too light but is something to play with was found.

The bits.



The sconce's the same but different.



It was decided to turn the heavier pair to the same size as the smaller pair. To this end the first sconce was mounted on a wooden mandrel in the lathe.



The sconce was first roughed out using a fixed tool.



This done the compound slide was removed from the lathe and a home made tool support was fitted to allow the hand turning required to finish the sconce.



After a bit of hand turning.



A lot of swarf later.




So with 'feet fitted to the base the engine now looks like this.





Whether the 'feet' will be come part of the engine remains to be seen. Certainly the flywheel won't unless I can find a heavy ring to go around it.

Regards Tony.

 

[Tony Bird]

Hi,

Not a lot of progress yesterday, other things to do as I am playing trains over this weekend at the CMES. The four screws to secure the engine support to the base have been made and holes drilled and threaded in the base. It took sometime to find the best line up but the cross head goes up and down in its guides and I think at right angles to where the crank axle will be. It fits where it touches would be a good description. A couple of photographs that were taken.

A bush was used to centre a centre punch in the support.



Two of the four screws made.



A provisional line up for the crank axle and bearings.



Not likely to do much more for the next couple of days.

Regards Tony.

 

[gus]

Hi Tony,
Interesting project. Rebuilding the ancient model steam engine. Will be following your project. I am back on the Howell V-2 Gas Engine after a three month break.

 

[Tony Bird]

Hi Gus,

Good to hear that you are back at the bench.

Some progress has been made on restoring the model; just in case some material turns up that can be used to increase the weight of the flywheel the flywheel rim has been cleaned up.



A start has been made on making the big and small end of the connecting rod by using the remaining piece of brass from the clock case base that the bearing was made from.







The small end roughed out.



A test fitting of the small end to the cross head.





When the big end has been finished it should be possible to fit the crank shaft and main bearing to the base plate.

Regards Tony.

 

[bazmak]

oely work,very interesting.Congrats

 

[bazmak]

Lovely work,very interesting.Congrats

 

[Tony Bird]

Hi,

Not a very good day, I took SWMBO to the bus for London. While walking along the pavement I tripped and now have an impressive bruise on my forearm and some painful ribs! Lucky I short and roundish if I was taller there could have been some real damage. So I didn't get quite as much done today as I hoped. The intention had been to finish the connecting rod and mount the bearings on the base plate. well the connecting rod got done.

The crank pin has a hole drilled in it and even before I turned the rust off it didn't have a large diameter. My best guess was that it had held a retaining collar to hold the big end in place using a taper pin or screw. But given the pins small diameter I wonder if it had been a shouldered bearing that had held in place? This was the way I decided to go.

The shouldered bush held in place using shellac to line up the holes drilled for tapping.



The finished bush and pin.



Assembled bush and pin fitted to the crank.



The big end was shellac to a stub mandrel to turn shoulders on it.



The big and small end have been cleaned up a bit and fitted to a temporary connecting rod to get a centre length.



Might get the bearings fitted to the base plate tomorrow.

Regards Tony.

 

[Twizseven]

Tony,

I'm staggered at what you have achieved so far with this, from a complete and utter basket case to what looks as though it will be quite an eye catching model especially at the size it is.

Colin

 

[Charles Lamont]

The unusually light columns give it an amusingly anthropomorphic air.

 

[Tony Bird]

Hi Charles,

The unusually light columns give it an amusingly anthropomorphic air.

Yes it is a bit cartoonist. In practical terms the columns could do with being a bit heavier with larger feet.

Still suffering with a couple of bruised ribs and another job so didn't get a lot done today. A couple of brass spacers (washers) were made to go either side of the big end when fitted on the crank pin.

The drill is there to catch the spacer which is being parted off, saves crawling on the floor looking for it.



The bed plate has been drilled for the bearings. With the engine to date assembled it was turned over in the lathe for a bit



Video: I wonder how many years it has been since the cross head went up and down in its guides?


https://youtu.be/q1hBiW-C6tg

Next job is to make 4 screws for the bearings and as yet I don't have a flywheel or a lump of metal to make the aluminium flywheel I have heavier the following job will be the eccentric, its strap and the valve rod . Some drawing will have to be done to work out the valve travel needed.

Regards Tony

 

[Barnbikes]

https://youtu.be/q1hBiW-C6tg

I see a slight wobble - is the crank bent?

Beautiful work done so far.

 

[bazmak]

When the model is packed up on bits of wood,not fixed down and not dead centre to the lathe axis then you get movement or wobble.Not the fault of the engine but the setup.Good job and well done congrats will keep up with this post

 

[Tony Bird]

Hi,

Some of the wobble can be attributed to the rusty shaft. One of the first jobs done was to put centres on the shaft so its bearings and crank could be cleaned up. As the shaft is in poor condition it is not quite concentric with its bearings. This hopefully will be corrected when it is trued to fit a new eccentric and flywheel. Also some of the wobble is due to its set up on the lathe.

Yesterday the screws were finished.



I drew out the position of the ports and the valve. This engine never ran using this valve! As can be seen by the drawing below as soon as the valve moves steam will go to both passageways and exhaust.



The slot in the valve needs to be a lot shorter for it to work.



It would be easy enough to make a new valve but I think I will try filling the original valve and machining a new slot. Maybe later today.

Regards Tony.

 

[Tony Bird]

Hi,

The valve recess has been filled with brass and silver solder and a new recess machined.







A start has been made on making the eccentric strap. A piece of bronze tube was used and another set of filling buttons made.









The bottom half of the eccentric strap needs to be finished, some screws made, an oil hole needs to drilled and an oil cup made and a spigot made and fitted to the eccentric strap for the valve rod. Then the eccentric itself can be made and fitted.

Regards Tony.

 

[Cymro77]

Tony,
You stated -
"recess has been filled with brass and silver solder" I am not sure how you achieved this - brass filings? Solid piece of brass soldered in place?
Another technique I would like to understand.

 

[Tony Bird]

Hi David,

You stated - "recess has been filled with brass and silver solder" I am not sure how you achieved this - brass filings? Solid piece of brass soldered in place?

It is just a roughly shaped piece of brass hard soldered in the hole and machined flat. I haven't tried it but brass fillings mixed with solder it could work?

I have finished the eccentric strap.



But it was a bit late in the day to make a start on the eccentric so I made up some unions which will allow the engine to be tested on compressed air. It is unlike that I will be able to steam test it as my test boilers aren't large enough. If I get really enthusiastic I suppose I could connect the engine to one of my 5" gauge model locomotives. As can be seen in the photograph the holes for the unions aren't perpendicular to the casting, there isn't much square in any of the engine.



Eccentric next and if I can find a flywheel it shouldn't be long before we can find out how well it will work.

Regards Tony.

 

[kiwi2]

Hi Tony,
As far as the flywheel goes, can you get a bit of schedule 80 steam pipe of the right diameter, turn it to suit the flywheel and loctite it on? I've just made a flywheel from an offcut of 5" nominal bore pipe and the finished dimensions are 125mm ID with a wall thickness of 8mm.
Regards,
Alan C.

 

[Tony Bird]

Hi Alan,

As far as the flywheel goes, can you get a bit of schedule 80 steam pipe of the right diameter, turn it to suit the flywheel and loctite it on? I've just made a flywheel from an offcut of 5" nominal bore pipe and the finished dimensions are 125mm ID with a wall thickness of 8mm.

What a good idea I will have to see what I can find.

A short day today as we have friends visiting later. So I decided to put off making the eccentric and fit the flywheel to the shaft instead. The hole in the flywheel was bored out and the shaft turned to fit it. The flywheel was then trued on the shaft. I have several smaller fly wheels in stock and decided to fit one as a pulley along with the flywheel. This flywheel/pulley was bought a few years ago for £1 as it had a blow hole in its centre, there is a thread on machining it somewhere.

Turning a shoulder on the shaft.



Truing the flywheel.



As the engine looks with flywheel &'pulley' fitted.






The flywheel pulley might just have enough mass to allow the engine to be checked on air.

Regards Tony.

 

[Tony Bird]

Hi,

The eccentric was made and fitted today.







At the end of the day the engine looked like this.




I did time the engine up and try it on air. But with no packing or gaskets the air came out everywhere, it did want to go and might have with a heavier flywheel. I will strip the engine make and fit gaskets and I will also paint what is to be painted so it will be a couple of days before I can try an air test. Both the piston and valve rods are very poor fits and I hope some packing will remove most of the leaks and I don't have to fit new rods, time will tell!

Regards Tony.

 

[10K Pete]

Looking good Tony! That sure is a leggy lookin' critter, isn't it?

Pete