5"g Simplex steam loco build (hopefully)

[bazmak]

Just the passageways and valve gear to do.Normal practice is to fit
studs and nuts approx 15 each side.More realistic but ugly so decided
my favourites the hex sock sets.In order to maintain location when the fixings and cover plate are removed i fitted 2 no recessed csk screws to secure the
steam chest. The 9 screws down the long sides co thru and fix to the cyl
while the 4 end ones are drilled and tapped to the chest only to avoid
clashing with the steam passages.The result is eaqually spaced fixings
as seen on top of the cover but when removed the chest stays put to
adjust the valves..Only one miss drilled hole which i plugged.Now to finis







h the valves and tidy up everything

 

[bazmak]

Slide valves finished and fitted.Now to finish the cylinders
Steam passages etc.Then its a full strip down to finalize the
wheel and axle quartering etc and to ease off all the tight spots

 

[bouch]

Just the passageways and valve gear to do.Normal practice is to fit
studs and nuts approx 15 each side.More realistic but ugly so decided
my favourites the hex sock sets.In order to maintain location when the fixings and cover plate are removed i fitted 2 no recessed csk screws to secure the
steam chest. The 9 screws down the long sides co thru and fix to the cyl
while the 4 end ones are drilled and tapped to the chest only to avoid
clashing with the steam passages.The result is eaqually spaced fixings
as seen on top of the cover but when removed the chest stays put to
adjust the valves..Only one miss drilled hole which i plugged.Now to finisView attachment 91518

View attachment 91519

View attachment 91520

View attachment 91521

View attachment 91522h the valves and tidy up everything

Interesting idea there. I've never seen anyone use significantly countersunk screws to hold the steam chest to the cylinders without the cover attached... That's an idea I might have to steal someday...

BTW - my father is about 95% done with his Simplex. He's working on the superheater now...

 

[bazmak]

Two csk screws give an accurate repeatable conn,not quite as good as dowels
but far easier.I use the principle often.The only reason the countersinks are so deep is that i did not have long enough screws,so dont read anything into that
I could have used cap heads with the heads undercut to suit the c,sink/bore
only benefit of that is that you use larger allan keys
Pistons finished ,fitted and connected/pinned. Still turns over by hand but a lot stiffer due to compression resistance by the pistons.I am waiting for delivery of some small endmills so i can finish the cylinders and cut the passageways which
should greatly improve the resistance.I have now started on the linkage between cylinders and valves.Lot of work with not a lot to show so may be a few days before further posts.I am fitting Viton O rings to the pistons and plan to fit O rings to valve and piston rods in leiu of the old fashion stuffing boxes
with graphite/asbbestos Any comments ?,i assume O rings under compression are suitable for the rods ? Also did the full strip down and fixed the loose drive pin.Checked the wheel quartering had not moved and decided to leave as is for now. May key the axles later

 

[bazmak]

Another half day to finish 2 anchor links,along with 1 day to finish 2
combination levers. How i wish i had cnc.Very difficult to get such small items
perfect,only needs a few thou to make them look like dogs +++++ nut
these are not too bad. Will polish up everthing later if i live that long

 

[bazmak]

Good days work,finished the pair of rad rods.Complicated little sods
How i ever attempted anything like this without a mill i will never know
Just to wind down i finishe with something simple.Made the weight shaft ,spacer collars and bushes.No 3/8" reamer but as i remembered in the past
drilled the bushes 9.5mm and a perfect running fit for 3/8" round bar

 

[bazmak]

Or expansion linkage,the name is not important but as Brian Rupnow on his
thread says its a very interesting mechanism.I had the materials on hand
and while waiting for some cutters to finish the cylinders i decided to make it in tandem with Brians thread. We both may learn something.After approx 3 days
of hard work i got to the stage shown
2 problems. the front and rear plates have pivot pins which are slightly askew
may cause problems down the line. Also the 8 no spacers 7x5x2.5mm are not
perfect and are terrible to fit during assembly,all have to be individually marked
So to overcome both problems i will probably remake the front and rear plates
but machine from solid to incorporate the spacer as part of the plate.Then redrill and ream for the 3/16 pivot pins to overcome the out of plumb problem
Depending what arrives in the post i may start now while setups are still fresh in my mind or later if i find something more interesting.That video you posted
of the reversing mechanism was great Brian but lacks a little more in depth look at the end of the main reversing principle.Its difficult to understand in your minds eye,cant wait to see it working:thumbup:

 

[Builder01]

I have just recently found this forum and your thread about building a Simplex locomotive. You have done a nice job on the expansion links and radius rods. This is not a simple job. I have built a set also, but, for a Super Simplex. They are almost exactly the same. Eventually, you may discover that you might have to do a bit of filing to make sure you get full valve travel. You should also make sure that the die block does not bottom out in the expansion link when in full forward and full reverse. The limit should be at the reversing wheel, not at the expansion link. I think the full valve travel is 9/16". Good work!

David

 

[bazmak]

Thank you David for your comments,just what i have been waiting for from
someone who has built the loco and willing to pass on advice.Please tell me
what is the difference between the simplex and the super simplex ? In simple terms.I am working to original drawings i have had in drawer for many,many years and have bought the build book ($150) and not much use.The book was written in the 1940s and assumes the builder has only a lathe and V slide
at most or hacksaw and file.All the main build descriptions concentrate on
setups on faceplates etc.I am currently remaking the front and back plates
to incorporate the 8 small spacers.If i had thought more initially instead of
blindly following the drawings i could have improved the design much better

 

[Builder01]

Hi Bazmak,

The simplex was designed by Martin Evans, who was at one time the editor of the Model Engineer magazine. If you are building the first version of the Simplex, it was first published in a series of articles in Model Engineer starting in April of 1967. It was a very popular locomotive and many have been built. It was decided by Martin to update the Simplex and republish it. The Super Simplex has a few improvements and was also published in ME starting in April of 1989. The building book for the Simplex is pretty much exact copies of the articles in the ME. I actually found the articles helpful, as I have never built a locomotive.

The main differences are very slight, but, important. The first and perhaps most different is the boiler. The boiler has been enlarged to 5" outside diameter, but, more important is the lay out and distribution of the fire tubes. Also, the Super features three super heater tubes instead of only one.

The entire valve motion has been changed a bit and is perhaps a bit easier to set on the Super. The cylinder bore was enlarged on the Super, but, should actually be reduced. I have bored my cylinders to 1-3/8" instead of the 1-9/16" on the drawing. Don't worry, at this diameter the engine still has plenty of power and can easily spin it's wheels! It was suggested by a very experienced person in England to reduce the cylinder bores. Also, by use of a locomotive design spreadsheet, it was shown that the original bores are much too large.

The forward and aft coupling rods are connected together in the more traditional manner on the Super.

The water tanks are build quite differently on the Super versus the Simplex. On the Super, the tanks are not part of the running boards. I have further modified mine such that the tanks are also not part of the cab either. This way, the cab can be removed without have to remove the tanks as well.

Also, as suggested to me by friend in England, I made a few other modifications to the boiler. I just had my boiler certified in May of this year. The locomotive is not yet finished, but, can run under it's own steam. I have had a fun time running it this year, it has been quite a learning curve having never driven a coal fired loco before.

This winter, I will hopefully finish the plate work. I have been running the loco with no tanks or cab. I have been using my riding car as a "tender" to supply water to the loco.

As for the expansion link, I made it exactly like the drawing. the little spacers did not seem to be a problem for me. I also did as you did, and tapped the inside plate to eliminate having to use nuts.



David

 

[bazmak]

Thank you for your input David and please keep the comments coming.The finish on the your conn rods looks excerlent i hope i can get somewhere near.At the moment i am leaving as machined with a blending in with a file
when things come together i will start polishing etc
Well i wasnt happy with the expansion links and remade the the outer plates
to incorporate those pesky little spacers. I wonder how many others have gone this way or just blindly followed the drawings
Pressing the pins into 2.5mm thk matl was asking for trouble so i made the plates a full 5mm and remade and pressed in the pins full depth.I then machined the centres down to 2.5mm so the spacers are integral with the plates. Boy did it make assembly so much easier and it looks better too
Made and fitted the link from silver steel but dont plan on doing any hardening or case hardening just yet. With careful use of a no of needle files i achieved
nice and full movement.to the dims on the drawings.Hopefully it will be sufficient when everything is turned over

 

[Builder01]

That is certainly another way to manufacture the outer plates of the expansion link, clever!

As for "full travel" of the valve gear, you will not really know this until you have the reversing wheel and reach rod fabricated and all connected up. You will be looking for about 9/16" movement of the slide valve when in full gear, forward, or reverse.

David

 

[bazmak]

Thank you David,i wonder if anybody else has done it this way or am i the first
The reach rod for F & R on my drawings is for a folded brky,which i have made
rather than flat brkt and spacer and for a screw adjusting slide.Question, i have seen a quadrant brkt and lever arm on U tube as an alternative.It looks more authentic and a speedier changeover.Before i go too far,is the quadrant better
and if so where can i get the drgs

 

[Builder01]

I don't know if anyone has built the expansion link as you have, but, I do not know many builders of steam locomotives!

The screw reverser is certainly a European style piece of equipment, and to be sure is British. Screw or quadrant, neither is better than the other, just different. I went with the screw reverser. It is a double lead, left handed, 1/4"-20 thread. Since it is double lead, it is actually two 10 per inch threads, one nested inside the other. Also, since it is really 10 threads per inch, going from full forward to reverse takes but a moment. With the screw, it is also infinitely adjustable for the cut off. The Super features a flat mount for the reverser versus the folded. I don't yet have the top plate for the reverser fabricated, but here is a photo of the double lead screw, it works quite well.

Both the nut and the screw were single point cut on the lathe. I made the screw first, using the pitch diameter for a 1/4"-20 thread. I made the nut second, to fit the screw.

I do not have drawings for a quadrant type reverser. Both the Simplex and Super have the screw type.

David

 

[bazmak]

Thank you David for the advice and the nice photo.I have made the folded brkt
and silver soldered the 2 brass blocks in posn.At least i hope i have they seem to have stuck.I was well versed in silver solder over the years but only have at the moment a small mapp gas torch so i am limited to small items that can be adequately heated or small items of silver steel than can be hardened and tempered. Will soon have to look at ways of getting more heat quicker
In the UK i had oxy/acet but at 70 yrs of age with only a small shed i dont know if its viable.I have a barbeque with a gas bottle so i dont know if i can hook up something better.I think the local hardware store supplies disposable oxygen bottles.Many,many years since i did any serious gas welding
Back to the screw reverser,i had in mind just to go the simple el cheapo way just for starter.That is some M6 s/s althread RH single to to see how it goes
As for double pitch i could manage to screw cut the male but the nut would be beyond me

 

[Builder01]

As for a torch, your mapp gas will work just fine for many small items. I use a small mapp gas torch to do all of my pipe fittings. The big torch only came out for the boiler fabrication.

For the reverser, I did not attach the blocks to the stand until I was sure the screw, bearing blocks and the nut block were all lined up well, just in case I needed to adjust anything. All those holes must be concentric or it will bind.

A single lead right hand screw will work just fine, except it will take a few more turns to get from forward to reverse. I'm sure you will get use to that. It will be obvious which way the nut block is moving. When you get the reach rod connected and the return crank and eccentric rod installed, the nut block should go forward for the forward direction, and aft for the reverse direction. It is possible to install the return cranks such that the opposite happens!

Since you are limited torch wise, what are your plans for the boiler?

David

 

[bazmak]

Havent even thought about the boiler,too scary at my age.Will how how far i get for starters,my main aim is to get it running on air before thinking of the boiler
With the right equipment,oxy/acet and pickling bath etc i have (had when i was younger) the capabilities to fabricate and silver solder the boiler to a good standard.However i am 70 yrs old with only a small shed.The boiler materials are priced at $1200 then the cost of the equipment ? May check out the cost of having a proffessional boiler made if i am happy with the air run chassis
Thank you for the info on the screw reverser.I did make a spacer
/jig/fixture to hold the brass blocks while i silver soldered in position but the small mapp
tourch really struggled.Took too long to heat up so increased oxidisation etc and the main rulle with slilver solder is quick heat for cleanliness (next to godliness)
Its 30oc today and my shed has a translucent roof so will be too hot for long hours,but i have started 2 lever arms for the weight shaft and i am hoping to finish them and spend more time polishing hoping to achieve somewhere near your high standards

 

[Builder01]

$1200 seems pretty high for boiler materials. I got my boiler materials kit from Blackgates. This included all copper and several bronze castings for some of the larger bushings. It also included a bronze cast "stick", to make the rest of the bushings from. With shipping to the U.S., it cost £450.32, which is about $600 U.S. dollars. I think this is about $800 Australian Dollars. I have not included the cost of the silver solder, but, I got some pretty good deals for it off of Ebay. My torch is a Sievert, it was about $80 U.S., I had to buy it specifically to construct this boiler.

It is also, for a little more money, you can get the kit with all of the plates flanged. I did not do this as my fire box is not made to the drawing. I flanged all of my plates myself. In the U.S., 1 inch scale locomotives run on 4-3/4" gauge track. So, part of my Super Simplex build was to re-gauge it for 4-3/4" track. This consisted mostly of "squeezing" the dimension between the frames by 1/4". As you can imagine, this effects everything that fits between the frames, this includes the fire box of the boiler.

As far as polishing rods goes, I actually did very little. My finish was mostly achieved by carefully de-burring, and that's about it. What helps is to get a good finish to begin with. A rigid setup, sharp tools, and make the last cut very light and feed the work very slowly. I have no automatic feeds or DRO on my milling machine. Also, when using small diameter cutters, make sure the RPMs are fast enough, but, not too fast or you will burn the cutter. If you can afford it, carbide is the best. I can only afford carbide for my smallest cutters.

You are 70? I guess your avatar is not a photo of you! HA! (Shh...I'm 56!)

David

 

[bazmak]

Thanks for your input,will ask many more questions as i go on. The boiler kit is from my nearest supplier in Melbourne and i too thought it was a bit high
Will look at a price for buying the basic materials from my adelaide non ferrous metal supplier and a suitable gas torch etc when i get nearer that position
Please send me some more closeup photos as i move forward so i can get a better feel for how good your finish is,camera lighting etc.I can see one of my problems is deburring,its excessive on small items. I have just finished 2
reversing links,one to my current standard and one taken to the next stage with 120g emerycloth.No deburring by filing the corners just the faces which
produces a crisper corner.Its true you younguns can teach old dogs new tricks
Have also posted a couple of shots of my 3/12" G Heilan Lassie which i sold part finished in 2004 prior to moving from UK to Oz permanently.

 

[Builder01]

Your lifting arms look great! I did notice that you machined the large hub by turning. I machined the sides the same way as I did the main connecting rods. On the weigh shaft, I saw a few back and forth scratches, there might be a burr on the inside of one of the bores.

Your 3-1/2" gauge locomotive is really nice! Too bad you did not get finish it. I would like to make a pacific in 1" scale, but, it's a pretty big project. Maybe a 2-6-2T instead.

Attached is photo of my weigh shaft and lifting arms assembly early in my build. As you can see, the eccentric rod is a temporary adjustable type. I actually ran the loco for several months with the temporary rods. They have since been replaced.

The second photo shows one of the final eccentric rods in place.

David