A simple Vertical Steam Engine.

[Jo]

Thanks Kerrin 

Things never are simple with Orphans 

A few pages ago I roughed out a couple of pieces of steel for the cross heads and yesterday I got around to silver soldering them onto the end of the piston rods. Measuring the tops of each of the stands the crosshead was turned to the correct diameter for their respective stands and as you can see only one of the stands has been bored parallel, on the other two there is a taper of 0.1mm from top to bottom with the bottoms tight   so I have a bit of work to do there...

The easy way to fix this is using a stoned hone on Smelly, but I don't think I have a honing mandrel that size, and my supplier is off sunning himself at some posh garden party up North so I can't borrow one from him  So I will have to find another way to true up the bore.

Jo

[Jasonb]

Probably best to take a skim off the flange at the same time as if they were tapered there is no gaurantee that they will have been bored true or concentric to the flange or feet for that matter.

If you can hold by the flange and get it running dead true, maybe in soft jaws then you could get away with taking anything off the flange. Then bore out teh guide and skim the feet at that one setting then hone/lap.

[Jo]

Skimming any of the correct dimensions will throw the length of the connecting rod out 

I've opted for letting Tgs square up the bore for me. It looks like most of the offending undersize on this bore was in the last 20mm. It is now to within 0.02mm of parallel all the way down

While it is sitting there I must remember to drill some holes in the legs 

Jo

[Jo]

  How to decide on the correct length for each of the rods. I tried measuring things, and calculating things, and assembling bits and pieces 

In the end I rested the end of the piston rod on the top of the connecting rod with all the covers in place and measured the gap between the bottom of the piston and the bottom of the cylinder (top of the lower cover where the cylinder mounts), took the height of the cylinder and calculated the length of the rod required to get an even gap on each end of the piston to the covers. The result was two of the rods required 1mm taking off the lower face and the other the lightest of skims. The lower face is now the datum and the height of the crosshead was turned to be 28.6mm away from it. All of the bearing holes are now 16mm from this datum.

I never like the design of the crossheads it looks like you have to turn a round shoulder around the bearing and leave that proud. Well mine is going to be different  The sides of my cross head are going to be flat and I will be pressing in two bushes one from each side with a flange that will form that raised up shoulder. I seem to have a nice piece of 19.05mm bronze kicking round from an old boat prop shaft... it is a shame he who must not be named stole the propeller off the end  that would have gone very nicely on the Swan 

Jo

[Jasonb]

I expect on the originally supplied casting the bosses were cast in so all you needed to do was face them off to width and bore the hole which would have been quite easy unlike trying to cut from solid though not too hard a job on teh rotary table.

Pressed in bushes, whatever next

[Jo]

First rod off to H mount in the dividing head for support and mill the two sides to width. then mill down to open up the slot. Drill, open up then ream for the bearings.

One rod to the next stage, two to go 

Jo

[Jo]

6 bearings have been turned up. The central hole will not be reamed until final fitting in the rods  .

I still can't try the fit of the piston rods in the connecting rods as the ends still need their profile added  .

Jo

[Bluechip]

Jo

I've lost the plot again ...  reply #167, 3^RD Pic. down.

Did you just do a quick waft to remove the tight bit and let the cut wash out, 'cos I wonder why there's no packing under the trunk guide ??

Cannot believe you would risk the machine bed ... 

Dave

[Jo]

Evening Dave  ,

Did you just do a quick waft to remove the tight bit and let the cut wash out, 'cos I wonder why there's no packing under the trunk guide ??

The waft  went to the top of the legs where the nuttie bit dangles - the slidie bit does not go all the way to the top of the legs it would crush the nut 


Back to the piston rods...From the outside cutting full depth wind the cutter in to machine the curved bottom of the rod. The drawing looks like the curve should be at 25.4mm diameter but the rod still won't go down into the connecting rod  So I ended up rounding the edges of the curve I had just machined by hand - it has to be done by hand otherwise you will catch the sliding faces 

And the first piston I tried seemed to have the right gap underneath it  best stop before things go wrong..

  Oil holes, I knew I forgot something  .

Jo

[Bluechip]

Well, putting one's crushed nuts and dangly bits neatly on one side for the moment, we can attend to those later if required, I'm still baffled. 

The trunk guides were tapered. Smaller at the bottom end, engine orientation. So the rest of the bore was correctly sized ??

As you inverted the guides the small diameter is now upwards, ie. in the general direction of Polaris. I therefore asked if you bored down just far enough to clear the taper .... ?   .... otherwise if any material was removed lower down that part would be oversized ?  and unless there is a register the boring tool would hit the table ?

Sorry to be awkward bugger but I've got a test drive for a new car tomorrow and I thought I'd get a bit of practice in ... 

Dave

[Jo]

New car  Mine is 14 years old and its replacement will have to wait for my retirement 

Whoever bored these did them with feet on the face plate and a long boring bar. So on the outside they bored correctly but it went smaller on the way through. Then at the far end there was much more metal to take off so the bore had a marked reduction. The No 5 only required about 25mm the bit at the far bottom (the end I was boring from). The Second of the Swan cylinders was not so tapered (except the first 25mm again) but I wafted the full length of the guide to get the running area within acceptable limits.

Tgs has stops on his power feeds in all 3 axis and all in both directions 

Jo

[Bluechip]

New car  Mine is 14 years old and its replacement will have to wait for my retirement 

Whoever bored these did them with feet on the face plate and a long boring bar. So on the outside they bored correctly but it went smaller on the way through. Then at the far end there was much more metal to take off so the bore had a marked reduction. The No 5 only required about 25mm the bit at the far bottom (the end I was boring from). The Second of the Swan cylinders was not so tapered (except the first 25mm again) but I wafted the full length of the guide to get the running area within acceptable limits.

Tgs has stops on his power feeds in all 3 axis and all in both directions 

Jo

Last Friday ( to the day ) was the 15th anniversary of my retirement so I should be on my 15th new car then ??

Do you think it's me ? See what it's like anyway, can't be worse than the last Beemer I had.  Gotta be good to beat the Subaru , still might go for the XT or Outback.   

http://www.carbuyer.co.uk/reviews/bmw/x1/suv/149030/bmw-x1-sports-utility-vehicle-xdrive20i-sport-5dr-2017

My Warco WM16 has stops on the axes too. Hideous bang followed by the breakers tripping 

Dave

[Jo]

  Something looks wrong. Many years ago John Bertinat did a series on the Stuart 5A and modified the stud pattern to this. The advantage is that the studs do not break into the port but the drilled pattern is not like that  its worse: If you look where the web is on the standard the problem all becomes clear 

I feel a bit of plugging is in order 

Jo

[Jasonb]

Third picture, don't you have the cylinder rotated 90deg out of place?

Turn it so the valve face is across the crank and you won't get studs where the webs are.

Think you have been out in teh sun too long

[Jo]

Yes the cylinder is about 80 degrees round. The problem is that the two M6 side holes are too close to the web to allow for the nuts   

Holes bunged start again. This time I will be using 2BA studs 

Jo