5"g Simplex steam loco build (hopefully)

[JCSteam]

I was meaning with the missing paint on the frame.

 

[bazmak]

The missing paint areas are where i filed down the rivits i fitted
to hold the horns.Every time i have a strip down i clean the worn areas and
reapply the u coat

 

[bazmak]

Almost finished these 2 little assys.Lot of work involved but interesting
Not sure of the exact location.The Ga gives a dim from the driving wheel
but the frames are not predrilled which indicates to me that the exact location is important and determined by the cylinders and piston stroke so may just fit to dim with a couple of smaller screws so i can adjust slightly if necessary
Still waiting for my wheels

 

[bazmak]

Made these 2 tricky little fellows.Lot of work involved more than the frames
The drg shows the back plate silver soldered and the front fixed with 4 no 8ba
Just enough meat to go up to M3 so drilled and tapped thro and screw fixed both plates front and back wit machined csk hex sock. Final fish to be done at a later stage.All silver steel pins will be hardened also later.They look good
Still waiting for the wheels

 

[bazmak]

Made the last 2 conn rods,half polished and bushed one end before
fitting to the cross heads.Rest of the bushes will be made when some 7/16'
silver streel arrives with my wheels,then i can make a D bit as i dont have a reamer that size

 

[JCSteam]

I bet by when the wheels arrive they'll be in the chuck quicker than I can blink.

Enjoying watching this loco come to life, and the steps your taking to achieve a good fit on all parts.

Keep posting I'm sat with my cuppa enjoying it

 

[bazmak]

I bushed,made and fitted the brass angles and finished/fitted the motion brackets.Made the guide bars.Then i made a couple of support brkts from the scrap bin to act as substitute for the cylinders and to enable to fit all the motion and adjust/check out everything.Near enough for now.Cant be taken any further until i have the wheels and cylinders

 

[bazmak]

The wheels arrived this morning,straight out of the box and onto the lathe
I will document the process as it is not by the book and may seem a long and drawn out process with lots of unneccessary operations but i will explain so
nobody is thinking what a long winded way of going about thing
Two main requirements to my mind are to get the front of the wheels looking correct with the insie edge of the wheel rim concentric and the axle central to the centre boss.If we go by the book and mount the wheel with the rear side out,remove approx half of the excess material,turn the OD to just over size and drill and ream the bore we can encounter 2 problems.
1- the bore may not exit the front face dead centre with the boss
2- when the outside face is finished you may get too close to the front of the spokes or even touch them,bad
To overcome this i will take the long way round so it becomes apparent

The castings were of good quality,machined well with few hard spots and most importantly had plenty of excess material
First i mounted in the 5" 4jaw self centering chuck and skimmed the face and OD just enough to remove the skin and clean up.I then reversed and did the same to the outside faces and the wheel dia.Now the wheels are still well oversize but can be replaced in the 4 jaw SC within a couple of thou of concentic and can be treated as fresh out of the box with regards to the
following operations. Cant wait to start tommorrow

 

[bazmak]

Got a good 5hrs in today and almost finished the wheels.One with the spokes shaped at the back and a coat of paint.When i get them all to this stage
i will make a dedicated turning fixture to finish the OD and tyre to size and hopefully dead concentric to the bore.Only bad moment was taking a cut to the rear face and got a loud bang.My heart stopped i thought i had broken a spoke
but it was only skin/seepage between the spokes coming loose and jolting the tool. When the paint is drying i will make the silver steel crank pins

 

[JCSteam]

Looking good can you explain to the lesser learned (ie me) what is seepage? Is that a chilled piece of casting coming loose or build up on the tool bteaking free, or something else entirely.

 

[bazmak]

If you look at the first photo of the second batch of the back of a wheel in the lathe you can see a couple of spokes are infilled with metal about 20 thou thick
where the molten metal has seeped under the mold and formed a web between spokes.Dont know the correct term but when i faced off the rear side thes thin
skins break loose and jolted the cutter or fly off,no big deal but it made me jump

 

[JCSteam]

Ah right I see what you mean now, the gap between the spokes is missing on the second photo, as it's infilled with metal. Gotcha!

 

[Charles Lamont]

Dont know the correct term

That would be 'flash'.

 

[bazmak]

Thanks Charles i remember now.Flash is correct.I actually spent 2 weeks
in the foundry during my apprenticeship.Too hot and dirty for me

 

[JCSteam]

That would be 'flash'.

FLASH AH AH!! No flash gorden fan???? Fair enough

 

[bazmak]

Flash is alive? he l save everyone of us
Someone mentioned putting castings in the oven to help paint dry
Just put my wheels in the sun for 4 hrs and a lovely baked enamel finish
Its only about 20oc but the castings got up to about 40oc,no complaints from the wife

 

[bazmak]

Wheels all turned to size and drilled/reamed for crankpins
No problems all went according to plan

 

[bazmak]

Just spent a pleasant/productive few hours in the shed. I made and fitted
the crankpins from 7/16"silver steel and started a D bit from an offcut
I finished the axles and pressed on a wheel to each Starting to look like a train
I now need to make the bushes and fit the conn rods to the nearside only
No matter how far out the rod centres are they will always fit but the the wheels may not turn so i have to be confident i dont have any tight spots
before even looking at the far side.These wheels need to be quartered that is the crank pins need to be 90o apart.The 90o is not critical, what is critical is that all 3 are exactly the same.What i have in mind is to press on the centre
wheel at 90o as naer as i can and then set the others with the conn rods as i press them on.Press fits can be a problem if the wheels twist slightly you lose the centres and then you have to start again.One side pressed on and the other locktite is easier.I have made quartering fixtures before but always got a tight spot.Time will tell.It has taken 6 wks to get this far,not that i am rushing
A lot more work is now required with not as much to show for it.

 

[bazmak]

I made and fitted the rest of the bushes to the conn rods.The D bit worked great,it actually cut about 2 thou oversize but when they were pressed in
they squeezed down to an ideal running fit.I fitted the front conn rod and you guessed it tight spots.Also pressed on the farside wheels and everything locked up solid.Miles out as they say in Yorkshire.Had to make a bodge up puller to get the wheels and then spent 2 days trying to put everything right.The horn centres on the frame i knew were = 5 to 12 and i had made the conn rods to suit or so i thought.For whatever reason the conn rods were spot on. So i set up
in the mill and skimmed the horns to much nearer size.Also checked the wheel Quartering and again miles away.the wheels had twisted out of position as they were pressed on.So attacked it from another direction.Calculated the height and made 2 spacers to fit under the crankpins to give 45o each side from vertical.Had to keep checking and adjusting as they were pressed on,boy did they move.Could see where my problems originated.Then i crossed my fingers and said a prayer before reassembling
BINGO just like a bought one. Now i will take a well earned rest while i ponder the next step

 

[Herbiev]

Just wondering where you got the silver steel Baz.