New project started, double acting "steam" engine!

[John Hill]

First step,  boring the cylinder using a boring bar I made.



Cylinder roughed out and a smaller diameter for the valve,  holes drilled for the steam ports..


Of course if I had been smart I would have drilled the holes for the ports prior to boring but I didnt so back in the lathe it goes for a light skim to get rid of any burrs from  the drilling.


Decisions, decisions!    I have to decide what type of valve to use, a simple spool type would be easy enough  but a rotary system would get me to use a couple of spur gears I have.

[sbwhart]

Good start John

Every project beings and ends on a lathe   

Thats looks a tidy part off tool you've got there.

Stew

[John Hill]

Good start John

Every project beings and ends on a lathe   

Thats looks a tidy part off tool you've got there.

Stew

Thanks Stew.

The part off tool was a 'set' on sale which was still quite expensive but I treated myself to it.  A month or two later I had broken both ends of the blade and I was shocked to find the blade now cost more than the 'set' had.  I gritted my teeth and bought another blade but I am blankety-blank careful about how I use it!

[bogstandard]

This brings back memories.

A month or two later I had broken both ends of the blade and I was shocked to find the blade now cost more than the 'set' had.  I gritted my teeth and bought another blade but I am blankety-blank careful about how I use it!

The trials and tribulations of getting to know the limitations of your machinery and tooling. I still go thru all that at times.

Can't wait to see how this one turns out John. Should be something special.


John

[NickG]

Nice 1 John,

Can't wait to watch this project unfold!

Nick

[John Hill]

OK, I got half the verandah painted so I have earned some 'shop time!


Turning a few bits for the piston.  This was a challenge until I figured that I could glue all the pieces together and use some trusty string to drive the work between centres, the string only broke once!



These are the bits of the piston, those rubber washers were a failure and with no suitable thin leather at hand I am making do with some vinyl, time will tell! This will be an air engine (no steam) so I expect the vinyl will be OK at least for a while.



All the bits so far, piston assembly on the left, spool valve, valve chamber and the cylinder with the cylinder head in place.

[bogstandard]

John,

If you can get your piston within 0.002" (0.05mm) clearance in the bore, no mechanical sealing would be needed. If you just cut a couple of very shallow oil rings around the piston, then the oil in the engine will form a perfectly good seal for what you are doing.
 
I am not trying to say what you are doing is wrong, it is your build, but it could have saved you a little work, and your wife's vinyl corset wouldn't be full of circular holes.

It might be something to consider for your next build.

Seeing as you want to do extraordinary engines, maybe a sleeve valve next.

Coming along great BTW. Finding and using your own little techniques to get the job done.


John

[John Hill]

Thanks John, I did consider the close fit piston route and could still go to that without any problem.  The little nutating engine works well but it leaks so much air that the compresser runs more often than seems acceptable sp this time I am trying for a low leak solution.


 Dont worry about the corset, I cut the circles out of the back of the new sofa and it will not be noticed until we clean behind there!

[John Hill]

No, this project has not been abandoned!

Todays project was to make the small throw crank to drive the valve system.  The throw is the same as the  diameter of the crankshaft.

Find some likeley bits of metal:-




Put a long bit and a short bit in the drill and make a couple of holes:-




Poke some thin stuff through to pin them togehter:-


After a bit of careful work with the hacksaw it was time to carefully grind the crank pin using the recently made tool post grinder.  (Looks like a couple of Bog's pidgeons came over and poopsied on it! )




It looks a bit rough, it should probably be thrown under the bench  but maybe I can put some lipstick on it.



Ah, thats better,  a bit of bondi and a puff of black paint hides most of the mess!

[bogstandard]

If it works John, then no problems.

No need to bling it up just because of us.

Did your toolpost grinder work as you thought it would?


John

[John Hill]

Thanks John but I would like to have something nice looking come out of my shop at least once in a while!

The tool post grinder did an excellent job of getting the weld splatter off and trued the 'journal' nicely without putting terrific strain on the assembly.

I have bought quite a few nice toys over the years and never had the time to really learn how to use them properly and the MIG welder is one of them.

[sbwhart]

Nice use of the grinder John 

Cheers

Stew

[gingerneer]

Looks a nice project, i like how the crank shaft has been put together. Are you buikding it to plans or are you designing it your self?

gingerneer

[John Hill]

Looks a nice project, i like how the crank shaft has been put together. Are you buikding it to plans or are you designing it your self?

gingerneer

No plans,  just making it as I go along!

[gingerneer]

I am redesiging the engine unit on my loco i am building, the original plans required the use of castings (no long available) and the slide valves were hidden in the middle of the cylinder block (a pain to try and set the timing of the valves). Are you designing it as you go along or have you worked it all out?

gingerneer

[kellswaterri]

Hi John, never seen that one with the ''String'' drive for between centres turning...could you enlarge on how it is done...this should be a very interesting engine build.
      John.

[John Hill]

Hi John, never seen that one with the ''String'' drive for between centres turning...could you enlarge on how it is done...this should be a very interesting engine build.
      John.

It is a bit hard to describe, just tie the string around the centre and wind on tight until it no longer slips then attach it to the work, I was lucky in my work in that as the pieces would be screwed together I could attach the string to a screw head.

[chuck foster]

looking good john  can't wait to see it run 

chuck 

[John Hill]

I cut the lawns yesterday and as the weather was not the best I got to spend a few hours in my shop today!

Turning a connecting rod,  I put a piece of 12mm square in the four jaw and began to slim it down a little.



Now I am going to solder a couple of short tubes to one end....



... the rod is being held in a small vice so that I can work on it with my 100Watt soldering 'iron' and my Big Boy's Hair Dryer!


A few minutes later and I have the two pieces soldered in place and I have drilled a hole that is just a tad undersize for that desired to fit the crank pin.




Then into the band saw it goes for a little trim...



Ready now for a clean up and I need to drill that hole to the final size too!



One crank assembly, the short rod is to the piston and has a long stroke, the long rod goes directly to the steam chest whereas the piston rod goes to a cross slide.



You might be wondering why I am using lead solder for this job,  the main reason is that I do not have a safe place to use a torch and neither do I have a good enough torch.  With lead solder I can do the job quickly and easily using just the big electric soldering iron and a hot air blower.

[John Hill]

I turned a couple of fly wheels out of cast exercise weights, getting the letters off the casting is a challenge and this was the first one I did using an angle grinder, not good as you can see.  The letters are actually quite easy to clean off neatly with a cold chisel showing that sometimes the old ways are the best ways.



I assembled all the bits on a piece of brown stuff to see what needed to be adjusted, sorry to say that there were a lot of things to fiddle and juggle and just about every bolt hole is now a slot and all clearances, including those which were once too tight, are now in the 'rattle' classifications.



So lets take a look around the assembly of ill-fitting parts!



Crank shaft end and showing the cross slide.


Other end of the cross slide showing the piston rod and the end of the valve chamber (aka 'steam chest'?). That pin will be getting a trim.



Patience please while I work out how to post the last bit..

[DeereGuy]

Hi John, very interesting build you have going here....

Mowing the lawns...holy crap I think I am moving to NZ for the winter.  Nothing but snow and freezing rain here this evening.

[chuck foster]

looking good john 

chuck 

[John Hill]

And here it is!   Seems to load really slow.




This is on about 10PSI or less although it is a bit hard to read that end of the gauge.

[Gerhard Olivier]

Very nice engine John -love the slow motion and the sound of it is great.

Gerhard

[sbwhart]

Wow that's a nice machine John love the sound a real nice runner 

Have fun

Stew

[Stilldrillin]

That`s great John! 

Love the sound, & slow pace..... 

David D

[NickG]

Well done John - will have a look at vid tonight!   

[Darren]

Well done John, you are getting the hang of this.

It might be slow but isn't that a long stroke, does it have power?

What is the size, it's hard to tell ... 

[John Hill]

Darren, it is quite big I suppose, 50mm bore, 50mm stroke, 105mm diameter flywheels and about 375mm overall length.

Thats about as slow as it will run at least until the tight spots get eased a bit  but of course it goes really fast too if the air is available to drive it.

It does have considerable power and I am wondering what shop device I could put it to work driving, maybe a paint can shaker or perhap a reversed Stirling to cool my beer supplies.

[NickG]

John, I had no idea it was that big!  That is HUGE!
Nice work!

Nick