Live steam Bagnall loco and other railway stuff

[michael mott]

Thank you for all the kind comments. I have now finished putting all the pieces together for the cylinder "casting" I can now re-polish the cylinder bores and make the pistons, and D valves. in order to spot the bold holes for the cylinders I had to take the frames apart and lay the bolting flange next to the opening and spot through from the backside to make sure that the holes lined up. After that was done the flanges were soldered to the block. The first picture show the raw cylinder "casting" set into the raw frames. The coppery color come from the pickle bath and since the cylinders are going to be painted Black I am not going to be concerned about it.

 

The next picture is showing the replacement of the keeper studs with the final ones machined with the unthreaded part in the centre,

 

Next picture shows all of the studs have been replaced with the proper ones. Also while the hornblocks have been taken out and the drawings from NRM  (National Railway Museum), have arrived I can finish them off now before replacing them into the frames.

 

 

Once I finish the pistons and D valves I will be able to test the seals for the assembly.

There are still lots of screws and bolts to make. and the whole valve gear is now beginning to loom it's "hydra head"

 

Michael 

 

 

 

[realworkingsailor]

Very nice machine work! What manner of valve gear did the locomotive use? Given your valve location between the frames, I’m guessing Stephenson’s?

 

Andy

[michael mott]

Good evening Andy.

The loco uses the Allan straight link valve gear this diagram shows the configuration The link from the valve rod is shown in plan view in the top elevation as the long lifting link lifts the straight link the opposite side drops the link to the valve rod.

 

If this is not clear enough I can post more information. I did manage to make a couple of pistons today I will be using o rings.

 

Michael

[realworkingsailor]

The diagram makes sense.

It’s basically a derivative Stephenson’s valve gear, but by moving the radius rod at the same time (and opposite direction) as the link, the same valve action is effected in something like half the space.

 

Andy

[amateur]

Ah, this is were you are hiding

Nice work on the loco's!

 

Jan

[michael mott]

Andy, Yes your analysis is correct and the way that this little loco was working in the Horwich works was slow and a lot of forwards and backwards basically the "fork lift" of the day (1887)There was not a great deal of need for speed but a lot of stopping and starting. This was a very small locomotive only 7 foot 4 inches long.

 

Jan Thanks for stopping by, I'm in model engineering mode at the moment this will of course wane and then I will be back at the cutter.

 

Michael

[michael mott]

I have been working on the D valves and the small keeper that fits into the cross slot so that the valve gets pulled and pushed back and forth in the valve steam chamber.

First the keeper had to be drilled and reamed for a taper pin these pins are used in clockwork and are really handy. This box of pins I must have been using for the last 30 years, I don't use a lot but they work really well in some applications. There is a set of taper pin reamers that are specially made for these pins and The reamers are also good for opening up holes a little when needed.

 

The next picture shows the keeper glued to the valve shaft with some loctite then clamped for drilling the hole for the pin.

 

 

The next shot shows the taper pin reamer being worked through the assembly.

 

 

After the pin is seated with a light tap of the clock-makers hammer

 

 

Then the long ends are snipped off leaving enough proud so that the pin can be remove if needed for repairs down the road. The valve shaft and the D valve are now ready to be set into the steam chamber.

 

The first valve fitted

 

 

The next picture shows both valves set into the chamber,before closing it up.

 

 

and finally the slide bars are now cut to length and width ready for the cross slide. The space between the frames feels small enough the I am guessing that I will need to make some special tools for getting to some of the parts. Sort of like the articulated right angled whatsit wrenches that the auto supply folk charge an arm and a leg for in order to change a spark plug that is buried next to the firewall.

 

 

Michael 

 

 

 

 

 

[Kevin]

So very very clever

[michael mott]

Progress on the springs which need to be in place before the axles and therefore the eccentrics. New spring hanger screws were fabricated and the holes in the hornblocks drilled for the spring rod and the keeper plate on the bottom. the top portion of the springs was more difficult to make than I had originally considered. I tried bending the loops at the ends first and this was not going to work, so the only other ways are to machine from a solid piece or assemble three parts. I chose to assemble the three parts. first part is the plate with the angles at each end for the machined tubes with the correct hole size and outside diameter. the plates were cut to length and the .055" hole drilled

Next a jig was developed that could be used to ensure that both ends were the same length from the hole and that the bevel angle could be machined.

Next using my accurate adjustable third hand which allows me to set up parts for gluing or soldering very precisely was used to set the tube guides to the correct distances to ensure that all the parts would fit as planned.

Then using a second small toolmakers clamp I silver soldered one end using the medium paste silver solder that comes in a syringe.

Once all 4 had the tube set on the one end I set up the tube pins to the exact dimension that they needed to be apart 1.2" which equals 12 inches at 1/10 scale. because the pin diameters are .075" the extra distance was added .0375" to each pin so the vernier needed to read 1.275"

Using the small toolmakers clamp as a counterweight which caused the end that next needed to be soldered to contact the other tube accurately it was fluxed with the paste silver solder and soldered.

Next I  added the slots and spring hangers. These were set up in the mill and a 1/16th end mill was used to make the sluts at each end.

Next the hangers were cut from some .075" brass sheet

after the holes were drilled and the individual hangers were cut out they were assembled in pairs to shape. A couple of filing buttons were fabricated with the 2 different diameters on set .150" and one set .125" the filing buttons were made from drill rod or silver steel as it is sometimes called.

The next step was to turn up a couple of .075" pins to connect the hangers to the springs.

Now that the sequence is sorted there are only 3 more sets of hangers to file. after that I will be making the rest of the spring leaves which are .025' thick thinner than the top one which is .031 They will of course need to be slightly curved as will the top one.

Because I am not going to actually make these springs fully functional I will be adding a tiny micro compression spring which will not be seen to give the axles a small bit of spring suspension.

 

Michael

[michael mott]

I Have been whittling away at bit and pieces finished the springs.

 

 

Then a sketch of the axle and the eccentric sets

 

 

The saddles for the springs was cut from a solid piece that was first milled to create the opening for the leaves of the springs then it was cut into 4 with the jewelers saw.

 

The saddles were then finished off on the mill.

 

I had to make a few 0x80 stainless bolts along the way. to bolt the cylinder assembly to the frames.

 

Then started on the keepers for the axles.

Then the eccentrics which are turned out of some 3/4" mild steel.

 

The bottom ends of the 4 eccentric rods were made from some bronze discs that were then cut in half with the jewelers saw.

 

Then cleaned up and soldered back together to be shaped and drilled for the 0x80 stainless bolts to hold the 2 halves together later after all the shaping. they will then be un-soldered

The steel eccentric discs were bored out in the waste chuck to the final size of 5/16 which was offset .087 to give a throw on the eccentrics of .175

A little bit of dry fitting to check that the clearances will work The discs will be keyed to the axle so I will need to make some jigs to quarter both the sets of eccentrics and then the wheels.

I must say it seems to be getting rather full in-between the bearings, which are actually sprung with some small springs wound up from some .023" music wire. That brings things up to date. Just in case you were wondering, the Bristol cutter is waiting patiently within easy reach, I have not forgotten about it.

 

Michael

 

[popeye the sailor]

amazing work Michael.........you never cease to amaze   

[michael mott]

A quick update I have almost finished the eccentric rods. I cut up some brass stair nosing that I acquired some time ago, in retrospect I would have been better off machining these arms from some hard brass bar stock. This material although cast was not easy to machine. 

 

 

After squaring the material up I drilled reference holes and then milled the slot which will become an open fork. but the enclosed slot is easier to machine.

 

 

After a lot of fiddly milling the arms are ready for some final shaping.

 

 

First a test fit to see that I am on the right track.

 

 

And a test fitting on the eccentric discs, the white styrene is a test guide for the straight Allen Gear.

 

That's all for now.

 

Michael

 

 

 

 

 

 

[druxey]

Lovely work, Michael.

[mtaylor]

Impeccable work, Michael.   

[FriedClams]

Just came across your log Michael and I wanted to state, as others have, how fantastic I find your work.  You are a true craftsman and artist - from the sculpted figures to your precise engineering and machine work.  Wonderful work (like all your work).  Thanks for showing us the process.  Oh - and a great garden railway also.

 

Gary

 

  

[michael mott]

Gary , Mark and Druxey, thanks for you very kind words. I spent all morning finishing and polishing up the first set. I also made a proper link out of some steel plate that was left over from the frames.

I can tell already that this is going to be a challenge to get all this stuff put together in the frames, and get it to actually run smoothly.

 

And with a little rotation of the axle you can see the change in the angle of the straight link.

 

Now that my fingers have had a rest, and I had a nap I can tackle the second set.

 

Michael

 

 

 

[michael mott]

Second set is done. The ends were cut off with the jewelers saw,

 

 

now on the the radius rods and the weight shaft and lifting arms. the pins are proxy keepers waiting for the final ones that will need tiny taper pins somewhere between "60 and #70 Drill before using the taper reamer.

 

 

With the new straight links cut from some .075 inch thick steel I have increased the width of the new  links by .010" and narrowed the slot from .125" to .098 to give it a bit more meat so to speak. the new link is in the forward set, I just have to finish filing up the second one to replace the rear one.

 

 

Michael

 

 

 

 

[druxey]

Lovely work as ever, Michael. Your bench pin has an interesting additional hold-down. Your own custom design?

[michael mott]

Hi Druxey, thanks for the kind words. The bench pin has two 6x32 Allen head cap screws threaded up from the bottom and a couple of the thumb nuts from Home depot to act as hold downs, I did design it for myself to relieve the ache in my fingers while holding tiny parts. and it really works nicely, I also put a groove along the long axis in order to hold round tube or solid and the thumb nuts keep that snug for cutting onto the ends. The variations on this Idea are quite broad and eliminate the need to fiddle with clamps.

 

Michael   

[druxey]

Nicely thought out, Michael.

[RichardG]

Michael,

 

So now I get two benefits from reading your log. 

 

First and foremost, a visual treat just seeing your amazing work. Second, an excellent bench pin that I can actually make and use (I'm sure it'll work on wood). Unfortunately my lack of skills (and temperament probably), preclude me being able to reproduce the former.

 

Thank you so much for sharing,

Richard.

[michael mott]

Druxey and Richard, thanks for the Kind remarks, and thanks to all who are following along and pushing the like button. I do appreciate them. I did drill and fit the taper pins into the slightly wider side of the forks the taper-pins just graze the retaining pin for the straight links. I used a .023 thou drill bit for the work. The first three shots cover the drilling and reaming of the holes.

 

 

 

Then a few shots of the axle assembled back into the frames it is getting crowded in there!

 

 

 

 

Time to put up my feet now for the night.

 

Michael

 

 

 

[amateur]

It’s a shame that all that fantastic stuff is hidden inside that frame.....

 

Jan

[vaddoc]

Just went through the log Michael. I was left speechless. Wonderful work!

 

I am clueless in this area but could I ask, how are all this moving parts kept lubricated? There are no sealed ball bearings, just metal on metal. I presume there were no ball bearings in the real thing either.

[michael mott]

Jan I have thought about that a great deal, and then what comes to mind is the immense amount of work that goes into the building of a ship model like the Young America and how much incredible joinery and elements that will be very difficult to see, and some not at all.

Good afternoon Vaddoc the lubrication was done with oilers in hand in some areas, others used cups within castings that were topped up again by hand held oil cans. The other thing was to use bronze bearings on steel. Oil is added to the steam to lubricate the pistons and slide valves. There are a couple of holes in the frames for reaching difficult locations. The space between the frames was also open so many spots could be reached easily with a long spout oil can.

 

Michael

Edited December 3, 2019 by michael mott
grammar

[amateur]

True, but actually, I was thinking of this loco compared to the ones that have their driving shafts on the outside of the frame. Do you know why some machines have the whole mechanics on the inside, I would think that maintenance would be far easier when you can easily reach all the moving parts....

 

Jan

[michael mott]

hello Jan I cannot answer your question with any real knowledge as to why the designers choose one method over another other than that space restriction or aesthetics. here is a picture of the actual locomotive that is in the narrow gauge museum in Wales.

 

Michael

 

Edited December 4, 2019 by michael mott

[realworkingsailor]

16 hours ago, amateur said:

True, but actually, I was thinking of this loco compared to the ones that have their driving shafts on the outside of the frame. Do you know why some machines have the whole mechanics on the inside, I would think that maintenance would be far easier when you can easily reach all the moving parts....

 

Jan

It has a lot to do with the history and development of the various types of valve motions (valve gear). Early forms of Stephenson’s valve gear (the predecessor of Allan’s straight link) were directly connected in line with the valve stem (no articulated linkage). This required the valves to be placed horizontally in line with the pistons.  If the steam chests (the mechanical structure that contains the valve and piston) were to be turned outwards, the locomotive would be made considerably wider than necessary. Even later versions of Stephenson’s gear (on locomotives with vertical oriented steam chests) still kept the rigid valve stem, although the action was transferred laterally through a series of cranks and cams. The real limitation of inside valve gear is the size of the locomotive. Smaller locomotives generally had lighter, more open frames (with more space between). The advent of external type valve gear such as Walschearts, allowed for increases in size of locomotives by permitting heavier frames.

Andy

[amateur]

Thanks for the explanation!

 

Jan

[michael mott]

Thank you for your explanation Andy I did not know that background, can you recommend any particular reading on the subject?

 

Michael