Author Topic: CONWAY 0-4-0 3 1/2" GAUGE LOCO  (Read 51041 times)

Offline Firebird

  • Full Member
  • ****
  • Posts: 854
  • East Midlands UK
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #360 on: March 03, 2018, 10:26:18 PM »
Hi

I will need to fit drain cocks to the cylinders. I came across this design for automatic drain cocks by Stewart Hart



A question please.

Would they be about the right size for cylinders this size?

Cheers

Rich


Offline Firebird

  • Full Member
  • ****
  • Posts: 854
  • East Midlands UK
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #361 on: March 08, 2018, 08:43:25 PM »
Hi

Re the drain cocks. GLR Kennions only list 2 types 3/16  x  40  and 1/4  x  40 so I think 1/4  x 40 it is

Time to machine the ports. First I marked out the port faces by using a black marker pen and scratching with digital calipres. Then some careful setting up and using the DRO's. Can't afford to get this wrong. :ShakeHead:

The exhaust port is 5/16" wide so I started with 6mm end mill



Then joined the holes up and to depth



Then machine to width by taking equal amounts from each side a few thou at a time



Followed by the inlet ports. These are 1/8" wide so I used a 3/32" end mill to chain drill and machined to width similar to the exhaust port





I broke a couple of the 3/32" end mills but luckily they came out ok. Its a very slow job a few thou at a time



Believe it or not this took the best part the day.

Next I have to drill the passages which are a little on the long side. The passages are 1/8" x 3/16".  Reading the text in the article he says to drill the first 1/8" hole then insert a 1/8" rod into the hole and drill the second hole which overlaps the first to give a 1/8" x 3/16" passage.

Hmmmmmmmmmmmmmm not keen on that idea  :thinking:

If you remember a few pages back when I was machining the regulator body a similar overlapping hole had to be drilled. The first hole drilled ok but the second hole drifted off until the drill snapped and I had to spend quite some time overcoming that problem :Mad: :cussing:

So I think I will drill 2 holes of 1/8" side by side.

I have to figure out a way to accurately angle the cylinder to drill the passages. I have drawn a couple of lines on the plan of the cylinder. The angle is 41 so that might help.



Cheers

Rich

Offline Florian Eberhard

  • Full Member
  • ****
  • Posts: 380
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #362 on: March 08, 2018, 09:04:38 PM »
Hi Rich

For setting up such workpieces at an angle, I use several different methods:

1. use an angle protractor if i can hold it against something straight

2. machine a "vee" block with the required angle out of some aluminium to use it like parallels

3. use another vice: I clamp the part in a not too big vice and then clamp the vice together with the workpiece into the "big vice".

Cheers Florian

Offline crueby

  • Full Member
  • *****
  • Posts: 6585
  • Rochester NY
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #363 on: March 08, 2018, 09:31:01 PM »
Nice job on the valve ports, thats always a nerve wracking step.   :ThumbsUp:


For the angled holes, I like to draw the widths and depths of the ports on the outside of the steam chest, move the table in so the drill can be lowered outside the chest to double check the angle visually. Also lets you count turns when raising the drill so you know how deep you can safely drill.


 :popcorn:

Offline zeeprogrammer

  • Full Member
  • *****
  • Posts: 6191
  • West Chester, PA, USA
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #364 on: March 08, 2018, 10:55:15 PM »
Still  :popcorn:

I enjoyed the videos. It's always good to see what's happening and to hear the sound. Gives me an idea if what I'm doing is 'normal' or not.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Online b.lindsey

  • Global Moderator
  • Full Member
  • *****
  • Posts: 12019
  • Dallas, NC, USA
    • Workbench-Miniatures
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #365 on: March 09, 2018, 01:00:57 AM »
Nice set-ups and a very nice result on those cylinders. Those are some big hunks of Cast iron!!

Bill

Offline Firebird

  • Full Member
  • ****
  • Posts: 854
  • East Midlands UK
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #366 on: March 10, 2018, 06:17:24 PM »
Hi

Thanks Florian, Crueby, Carl and bill  :ThumbsUp:

I used some of the ideas you have suggested, Hopefully I will get the progress posted soon.

My grand daughters birthday today and Mothers day tomorrow.

A quick question though, I might be having one of my thick and stupid moments  :headscratch:  :old:

Take a look at this



I have drawn in the 2 passages I have just drilled on the top drawing

The cylinder covers have the bolt holes oddly spaced but surely one of them is directly over the passage??

Cheers

Rich

Offline Florian Eberhard

  • Full Member
  • ****
  • Posts: 380
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #367 on: March 10, 2018, 07:20:46 PM »

The cylinder covers have the bolt holes oddly spaced but surely one of them is directly over the passage??

Yes that looks the same to me! Could it be that the hole over the passages should be a threaded hole for a dummy screw screwed into the cover instead?

Florian

Offline NickG

  • Global Moderator
  • Full Member
  • *****
  • Posts: 1420
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #368 on: March 10, 2018, 09:04:23 PM »
Florian, thats the only explanation I can think of too. Dummy screw and it actually looks like the hole is different like it is depicting a thread  but it just says 10x No.34 so not sure. Think Id do the dummy trick in any case.


Sent from my iPhone using Tapatalk

Offline Firebird

  • Full Member
  • ****
  • Posts: 854
  • East Midlands UK
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #369 on: March 10, 2018, 09:56:19 PM »
Hi

Thanks Florian and Nick  :ThumbsUp:

Its not me going daft then, just another error on the plans  ::)

I do like the idea of the dummy bolt, I wouldn't have thought of that  :praise2:

I have found the text from the original article and there is no mention of leaving out the hole over the passages




Cheers

Rich

Offline Firebird

  • Full Member
  • ****
  • Posts: 854
  • East Midlands UK
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #370 on: March 10, 2018, 10:32:21 PM »
Hi

With ideas from Crueby and Florian

Print out the side view of the cylinder and glue on




Mount in a tilting vise using the image as a guide





Start with a 1/8" end mill



Then follow  with a 1/8" drill







All went well until the last hole and the end mill snapped off in the hole :help: :facepalm: :facepalm2:

With absolutely now way that I could see of getting it out I opted to drill another hole to one side. I don't think it will affect the performance of the engine and can't be seen so it will be our little secret ;)




Drill from the side into the exhaust port



Machine away some of the side down to the level of the port which is where the thickness of the cylinder should be



I just need to make up a little lug now, possibly flanged to turn through 90

Cheers

Rich
« Last Edit: March 10, 2018, 10:36:41 PM by Firebird »

Online Kim

  • Full Member
  • *****
  • Posts: 2998
  • Portland, Oregon, USA
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #371 on: March 10, 2018, 10:55:04 PM »
Rich, sorry to hear about that end mill mishap!  :o
Looks like you've got it figured though.

There is so much work and so many steps to those cylinders!
Looking good!
Kim
« Last Edit: March 10, 2018, 10:59:10 PM by Kim »

Offline crueby

  • Full Member
  • *****
  • Posts: 6585
  • Rochester NY
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #372 on: March 10, 2018, 10:56:44 PM »
Nicely done (that end mill aside) - At least your fix will work just as well!   :cheers:

Offline MJM460

  • Full Member
  • ****
  • Posts: 605
  • Melbourne, Australia
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #373 on: March 11, 2018, 06:40:23 AM »
Hi Rich, following along and loving every post.

With those cylinder covers, I notice that your drawing shows the bolt holes on the vertical and horizontal centrelines (and in between of course).  I don't know if that is normal for locomotives or not, but in the industry I come from bolt holes are always put "off centres", so symmetrical about the principal centre lines.  This would normally put the steam ports between two holes, even if a little licence was taken on the spacing to make sure the ones each side of the port are far enough apart.

I am a bit late, I know, but I keep thinking about those drain valves.  I always understood drain valves were to remove condensate from the cylinders when they initially warm up.  The drawing you posted look like the flow to lift the ball is into the cylinder, as in snifter valves, which admit air to the cylinders if the engine is coasting.  Did you want drain valves to drain condensate?  Or snifter valves to admit air instead of drawing a vacuum when coasting?  Or am I misunderstanding the drawing?

Even with that broken mill,my our steam ports seem to have turned out pretty well.

MJM460
The more I learn, the more I find that I still have to learn!

Offline Firebird

  • Full Member
  • ****
  • Posts: 854
  • East Midlands UK
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #374 on: March 11, 2018, 08:16:49 AM »
Hi

Thanks Kim, Crueby and MJM  :ThumbsUp:

MJM the automatic drain valves are to drain condensate. I'm not 100% sure how they work but a lot of the steam loco guys use them and they are much easier to fit, not requiring any links to operate them

Cheers

Rich