2" Minnie Traction Engine

[packmule]

Following on from my introduction my efforts continue and as part of my build the chimney saddle is the latest part, still not quite finished but almost there. The first attempt was ruined by operator error  . With that still fresh in my mind I decided to machine the arc on the bottom first. This was followed by milling a shallow slot for the blower which I have silver soldered in place.All that remains is to fit the bottom plate,bore out for the exhaust and the centre hole.
This was a bit of a experiment as I was going to buy a casting but inspired by Mal's efforts I decided to have a go, more experience if nothing else and I'm pleased with the result .

[Steamer5]

Hi Packmule,
 Looks like you are making good progress, got the  at the ready

Cheers Kerrin

[Kim]

Nice work on the Chimney Saddle, Bob.  In the picture, I see what looks like a regular end mill. How'd you get the curve so accurate with that?  I'd have thought you used a boring head or something to get the shape.  It looks great, however you did it!
Kim

[Don1966]

Nice results Bob and good progress.......

Don

[scc]

Looking good Bob, I love watching these Minnie builds.          Terry

[mal webber]

Hi Bob, the chimney base looks really good I like the way you went about it ,keep the pics coming

[packmule]

Thanks for the replys,hoping to get it finished this week.
Kim
it is a 16mm end mill I fitted a set of dro's earlier this year other than turning the handles it does it all for you.The results as hou can see are v.good.Anything i can do to make life easier is always welcome.I did try with a flycutter but I didn't get on to well with that,more practice needed there.

Bob

[packmule]

Hi guys, following on the saddle is now finished albeit a bit of filling when it comes to painting. I hadn't a clue how to mark out the shape for the saddle plate for fixing to the smokebox when inspiration struck. I suddenly thought ,I have Visio on the pc so why not draw a ellipse and enlarge it to take account of the radius of the smokebox this was then printed onto a piece of paper which I glued to the rolled plate and simply cut and filed to the shape. Worked a treat and was so easy. Will probrobly line saddle and perch bracket up drill out the holes and bolt together. Then its back to making the throat plate former for more copper bashing.

I love it when simple ideas work.

[b.lindsey]

That is looking very nice Bob. Sometimes the simple  ideas are the best and your are right, it is rewarding when they work out just as you wish!!

Bill

[mal webber]

Hi Bob, the chimney base has turned out really nice with you 

[Kim]

Thanks for the replys,hoping to get it finished this week.
Kim
it is a 16mm end mill I fitted a set of dro's earlier this year other than turning the handles it does it all for you.The results as hou can see are v.good.Anything i can do to make life easier is always welcome.I did try with a flycutter but I didn't get on to well with that,more practice needed there.

Bob

Thanks for the reply Bob.  It was a very successful method, that's for sure!  Looks great!
Kim

[packmule]

Wow couldn't believe how long its been since last post.

Been busy working on the boiler just a couple of pinholes then pressure test.
Made a start on the front wheels and have turned the rims . I've left them oversize so if there's any distortion I should be able to machine them back true. While waiting for some steel plate for the tee's I bored out the chimney and ready to start tapering .Absolutely loads of swarf as its from 57mm solid

[packmule]

Following on from the last post. I've managed to bore out the chimney which took forever. Tapered both inside and out. I levelled it on the mill and machined a piece out as suggested in the book to give a rolled appearance and drilled for the rivets. For the chimney top I had some copper plate left from building the boiler so I decided to make two formers, one for the top and one for the bottom. I annealed the plate and began copper bashing the two pieces ,didn't take very long and I was happy with the result. These have now been soldered together and need boring to fit on top of the chimney and cleaning up and polishing. I'll post picture a.s.a.p

[packmule]

Disaster

The dreaded sticky copper gremlin grabbed the top while cleaning it up and threw it on the floor. Needless to say the air was a very thick shade of blue
Rather than start again I decided to see if it could be salvaged. I didn't have anything to lose so I cut the former so I could fit it inside and started bashing back to as good as shape as I could get. The result is far from perfect but I don't think its a complete disaster.

Put it together with most of what's completed so far and it at least looks as it should.

[zeeprogrammer]

Wow! Looks like a great save. 

That should clear up the air a bit.

[crueby]

Wow - amazing you were able to reshape that part that well. Very well done!

And I thought I heard some new words floating by the window...

[Kim]

Yeah, I've had that happen all too frequently!  Not always copper either, so I don't have the 'sticky copper' excuse.  The 'clumsy oaf' excuse is about all I can convincingly muster!

But your salvage job looks good to me!  I'd be pleased with that 

Kim

[packmule]

Hi guys,

Thanks for your kind comments. I'm sure you may well have heard my comments as they came thick and fast.
I've now started to cut the discs to weld into the front rims to form the tee's  will post more as progress continues.

Bob

[packmule]

Can't believe its Been so long since I last posted  apologies everyone.
 Well work is still continuing although I haven't taken many photos as it was pretty staightforward stuff. Anyway as you will see the front wheels are finished along with some of the gears and the crankshaft. The wheels were a copy of Mal Webbers in the they are welded rings inside the ring and ground back. The crankshaft was done almost to the book except I machined the webs together before  pinning and soldering.

Hope to make more progress now I've retired 

[Kim]

Nice to see an update on your project!  Looking forward to more

Your last picture looks a bit like a steampunk Tie Fighter! 

Kim

[mal webber]

Hi Bob
Still watching this build and it's looking good Bob,  my minne build has come to a stop for now until I finish Howitzer project I have started but when I do start back on the minne will be asking a few questions on the boiler side of things .

Mal

[packmule]

 Hi mal ,
Glad to see your still building. I've taken a short break from gear cutting to give my ears and arm a rest.
Started a small build if a stirling engine from Anthony Mount's book. Its a bit fiddley as quite a few parts are only 0.5 thick but getting there 

[packmule]

At last.........

After a lot of gas and silver solder i've finally managed to seal the boiler and its passed its first test at 200psi.
Now finishing the mounting blocks for the crank, gear and rear axle. These have been cut from steel bar and I'm press fitting bronze bushes rather than steel running on steel. Once these are finished I will fit to the hornplates and it will be onto the rear wheels which I was going to fabricate but in view of the time already passed opted for a pair of Ali castings.

will post pics later.

[Admiral_dk]

Concratulations for Passing the Major Milestone a Pressure Test - that Must have fellt Good     

Per

[cwelkie]

Congratulations on the boiler milestone!
Glad to hear that you are still fitting the Minnie into your life.
Charlie

[packmule]

Thanks for comments,

after spending what seemed a lifetime of soldering and chasing leaks if felt fantastic watching the pressure needle rise and not getting wet. There was a small amount of movement in the firebox crown nothing to bother about. The amount of solder that I've used i think it needs hallmarking as well although a fair bit of that is down to inexperience, but I don't  care now as the first hurdle has been passed.

[crueby]

Been there - the first boiler I did took forever, redoing seams multiple times, finally got it. Several boilers in actually had one pass test first try. I stood there and couldn't believe it!

[Kim]

Great to hear the progress on the Minnie!   
Looking forward to seeing the pictures too.

Kim

[packmule]

Pictures as promised of some of the other parts made whilst batting with the boiler.

First up is the boiler showing bronze stays which I threaded and screwed in 3mm stainless rod for the hornplates.
Second is hornplate fitted showing  shaft bearings, (third and rear axle waiting for bronze to make bushes )
Third  is winding drum and brake drum. Had big fun turning these as the steel was EN8 and would only cut using insert tips and light cuts.
Fourth one shows the 80t final drive gear and winding drum ratchet wheel.

Hope I've not bored you to death as no special techniques just plain turning.

[Kim]

Those are some great-looking parts, Bob! 

Kim

[packmule]

Few more pictures for you.
 After fitting the hornplates I set about the bearing blocks for the various shafts. These were all cut from solid steel milled down to size  and shaped on rotary table. Rather than have steel on steel I fitted bronze bushes to all. Just for inspiration I fitted the various gears, winding drum, brake drum and the front end. Quite pleased with the look so far.
Now its the rear wheels. Bit of a disaster in a way in that the castings are 10mm too big for the lathe so its off to the mill.
I glued 2 pieces of 12mm ply and cut a disk larger than req'd to take the rim, bolted to the rotary table and fly cut the top to make it flat. That done it was a case of bolting down the rim and centering. Lots and lots of light cuts and we are getting there but its slow going.

[Kim]

Great to see an update on your Minnie!   

The gears look great!  And your solution of using the RT on the mill for the rear wheels seems like a good solution to me.

Keep the progress coming!
Kim

[Admiral_dk]

Nice progress and parts 

I like that you found a solution that allows you to do it with what you got   

Per

[packmule]

Thanks Kim, Per for your kind comments,

One of my aims when I started to build was to try and not use any castings (or as  few as possible)  and to complete all the work myself using solid.
The thought being how much I could learn from my successes and failures. Thankfully any failures have only been small parts easy to remake. The only metalwork I had done was at school over 50 yrs ago so the amount I have learnt from forums such as this and the books i've  read has really paid off and I'm pleased with the results, not perfect but acceptable to me.

So big thanks to all contributors and the work continues.   

[packmule]

After a lot of machining first rim is done.
Had a break from all the turning on the rotary table and stated the hubs. Again done on the mill using DRO to round the ends. I originally tried to do the hubs in one piece which ended in disaster so I  decided to fabricate them as you can see in the pictures.
It was too cold yesterday to go in the workshop do spent a bit of time with the printer and made a jig for drilling the spokes which turned out perfect, nice when things go to plan.

[packmule]

Missed picture of hub soldered together

[Kim]

Hubs are looking good!  As is the spoke jig!  That's a great use of 3D printing! 

Kim

[packmule]

Finally,

After more turning of the rotary table than I would like to count the rear wheels are complete ( minus tyres ). This has taken forever and 1 mill motor which overheated and melted the insulation inside.

Rather than a lot of bashing with a hammer and snap I decided to make a squeezer for all the rivets on the spokes and the rim. It worked brilliantly and rivets were squeezed up in seconds and not a hammer in sight. I decided it was pointless making strakes and riveting them as the intension was always to fit tyres so saved a bit of time and metal there.
Once done I couldn't resist putting bits together just for pure satisfaction.

[crueby]

Wheels came out fantastic!   

[Kim]

Very nice!  And a lovely little rivet squeezer too! 

Kim

[cnr6400]

  It's lookin good. 

[packmule]

Thanks for all your kind comments.

Some of the rivets aren't perfect but I can live with that. Now I can start another part which wont take as long and it should start to come together

[packmule]

Starting to machine the cylinder block. The plans state to use gunmetal for the cylinder liner is this the best way to go or would you suggest something else ?

[crueby]

If the piston head is steel or cast iron I'd use bearing bronze (not silicon bronze, the bearing bronze is a lot easier to work). 'Gunmetal' is kind of a catchall term, depends what year and what country you are in what it really means, from what I've seen.

[Jasonb]

Rather depends on what you are doing for the cylinder and rings as the book/plans are based on using GM castings for both cylinder and liner and the use of a silicon ring.

If GM cylinder then a piece of hollow 660 leaded bronze bar would be my choice and that will work well with Viton or silicon rings.

Liner cut from grade 250 cast iron bar would be a good option particularly if it is an iron cylinder and you want to use iron rings. Fit with high temp 648 Loctite.

[Jo]

On model Locomotives they tend to use the relatively cheap Cast Iron cylinders and liners because of the amount of use the engines get doing public running, accepting that the slight rusting between uses will be quickly rubbed off in use. Most small model traction engines are not going to be steaming/ running 8 hours a month pulling heavy loads.

Gunmetal or bronze is preferred for less used models, it is much more expensive but does not have the same level of TLC required long term.

Jo

[Jasonb]

I just had a look at Blackgate sand the 2" Minnie is a CI cylinder so I would go with a CI liner loctited in. this is the same arrangement a smy 2" Fowler has.

Most locos don't tend to use liners unless someone is cutting from solid as they do not need the annulus around the liner so that steam can travel up from the boiler to the regulator ontop of the cylinder. Most small traction engines of 1" and 1.5" tend to have GM castings, most above that are iron.

[Jo]

Both of my Loco's cylinders have liners. The use of Liners are good practise on passenger hauling Locos because they are easily replaced 

Jo

[packmule]

Thanks everyone for your replies.
Yes Jason its a blackgates block so ci it is then.

[packmule]

Its certainly been a while but work is still progressing.

OK. The casting turned out to be a complete disaster, bull at a gate time.
I first machined the top flat straight out of the box without  actually checking the casting  When I checked the thickness of the saddle it was already below what I needed as a finished size. 

Consigned to the bin.

Not even comtemplating another casting I bought some thick walled steel tube and set about machining, boring out the centre to req'd size then the outside for the thickness. That done I bought a 100 x 100 steel block for the cylinder ,this was  cut on the mill to fit the saddle. As the block was undersize on the width I milled it flat and silver soldered extra steel to give me the width I needed. This was then set up in the mill and both ends milled so I could place on one end and bore out for the cylinder.  Following this I turned a wooden plug to fit in the cylinder so I could place in the vice and roll the block taking light cuts to shape to the radius req'd. The cylinder proper was machined from cast iron to a shrink fit and placed in the freezer over night, then heating the steel block the cylinder was quickly fitted

The ports were milled into the port face as usual practice and the cylinder was then placed in a tilting vice to drill the ways from the cylinder ends. This was setup using a simple jig with 2 equal length adjustable arms  so the end of one touched the inside of the cylinder edge and the other inside the top of the milled port. Perfect on 3 ,on the last managed to move slightly and just caught the edge of the milled port but I think should be ok.

will post some images tomorrow

[packmule]

Files from yesterdays post
3came as video instead of photo

[packmule]

Hi Guys,

 in need of assistance/ recommendations.
I've finished the cylinder and I'm looking to bolt to down to the barrel but i'm not too sure how many or what size to drill for allowing the steam in.
The book only says a cluster of small holes. I was thinking maybe 7 x 3mm . Would this be too many or not enough ?
Thoughts greatly appreciated,
Bob

[Admiral_dk]

I must admit that I haven't got a clue 
But I'm a bit surprised that no one has responded .... then again I don't know how many Mini Traction Engine builders are still left here 

Just to be clear - are you talking about fixing the Cylinder to the rest of the Engine or Steam passage in the Cylinder ?

Per       

[Jasonb]

I can't remember what I drilled my 1" minnie but for my similar size 2" Fowler the build notes say "five or six 3/16" holes"  so your 3mm sound a bit small.

If the Allchin were scaled upto 2" the the single hole would be 0.667"

[packmule]

Hi Per/ Jason,
 thanks for your thoughts. I will increase the size slightly and see what happens .

Per, its the holes from the barrel to allow steam into the cylinder.

Bob

[packmule]

Hi guys,

in need of thoughts with the port on the cylinder. While drilling tthe last hole from the bore to the port the angle of the vice moved as you can see from the photo.
Would you alter the valve slide or tap and plug the hole and redrill ?

On the plus side while cylinder was on the barrel it passed 2nd hydraulic test so very happy with that.

[Jasonb]

I think I would be inclined to mill a pocket 2-3mm deep that is a bit wider than the valve and a longer than it's extents of travel and then JBWeld & CSK screw in a thin Cast Iron plate that has had the ports cut into it into the pocket.

[packmule]

Hi Jason ,
         
Thanks for your reply, That is something I wouldn't have thought of.
However it wouldn't help in this case as it was the drill the broke though the port face not a slip with the mill, so although it would tidy up the face it would also block the hole and if I drilled it would follow the same path and I'm back to square one.
So I did tap and thread a new piece of steel in and silver solder either end. Once it was cold I flatted off  both faces repositioned in tilting vice (securely locked this time ) and re-drilled then just cleaned out the ports.
Your suggestion is locked away if ever the need arises. Nice one