Author Topic: CONWAY 0-4-0 3 1/2" GAUGE LOCO  (Read 174529 times)

Offline NickG

  • Global Moderator
  • Full Member
  • *****
  • Posts: 1430
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #585 on: September 21, 2018, 10:14:19 AM »
Looks great Rich, think they should have lagging behind the covers as insulation.


Sent from my iPhone using Tapatalk

Offline Jasonb

  • Full Member
  • *****
  • Posts: 9466
  • Surrey, UK
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #586 on: September 21, 2018, 11:18:06 AM »
Yes the covers are theer to retain the insulation but you will need to do some more milling to create the space for it arounf your solid blocks, this is why cast cylinders have the flanges at the end full width but are waisted down for the majority of their length. Looks good though.

Reducing the mass also means the cylinder will warm up faster so less condensate for the drain cocks to deal with

Online Kim

  • Global Moderator
  • Full Member
  • *****
  • Posts: 7863
  • Portland, Oregon, USA
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #587 on: September 22, 2018, 05:31:01 AM »
Thanks Rich,
Yes, I do remember your discussion on springs, now that you mention it  :embarassed:

As for the cylinder covers, they look great!  And the discussion does help.

Thanks for the additional info Jason and Nick.  Always appreciate learning something!
Kim

Offline Firebird

  • Full Member
  • ****
  • Posts: 1328
  • East Midlands UK
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #588 on: September 22, 2018, 02:48:37 PM »
Hi

Thanks Nick, jason and Kim  :ThumbsUp:

I think there will be enough room to get a layer of insulation in  :thinking:

A quick update

The wheels have been painted



The two wheels that go on the front axle have been glued on with loctite. They have been quartered as regards the balance weights which needs no great accuracy, a square being good enough. The accuracy must come when the cranks are fitted. Slight pressure applied in the lathe to push the wheels upto their shoulders.




The left hand cylinder fitted and a trial assembly of the slide bars, cross head and support bracket



Cheers

Rich

Offline Firebird

  • Full Member
  • ****
  • Posts: 1328
  • East Midlands UK
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #589 on: October 13, 2018, 05:24:33 PM »
Hi

Well it seems ages since I posted anything, I have been away on holiday  :wine1: but now I'm back and fully refreshed.

There is quite a bit to catch up on so I will split it up a bit

Cheers

Rich

Offline Firebird

  • Full Member
  • ****
  • Posts: 1328
  • East Midlands UK
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #590 on: October 13, 2018, 05:32:08 PM »
Hi

A little crank which fits onto the right hand driving crank pin. This is the drive for the mechanical lubricator. Its optional and not needed if a displacement lubricator is used.

Straight forward job as per the plans







Cheers

Rich

Offline Firebird

  • Full Member
  • ****
  • Posts: 1328
  • East Midlands UK
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #591 on: October 13, 2018, 05:42:38 PM »
Hi

The cranks are cross drilled to take 3/32" taper pins. Initially they will be glued on with Loctite then pinned.



The crank pins are pressed in







Cheers

Rich

Offline Ye-Ole Steam Dude

  • Full Member
  • ****
  • Posts: 1571
  • Deep East Texas on Sam Rayburn Lake
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #592 on: October 13, 2018, 06:54:23 PM »
Hello Rich,

Coming along very nicely and enjoying this build.

Have a great day,
Thomas
Thomas

Offline Firebird

  • Full Member
  • ****
  • Posts: 1328
  • East Midlands UK
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #593 on: October 13, 2018, 08:26:56 PM »
Hi

Thanks Thomas  :ThumbsUp:

The cranks must be quartered accurately. Never having done this before I did as much research as I could. There are many methods, some involving some quite elaborate jigs. I settled on a version of this idea which suits my lathe and tooling but would be easily adaptable to other lathes.

I think it is worthy of a more detailed explanation but I'll try not to bore you too much.

Firstly I needed to make an extended centre, one that is long enough to extend past the face of the 4 jaw chuck by about
1 3/4".

Chuck a piece of round bar, 3/4" mild steel will do but I have used some 20mm silver steel. Centre drill.



With a centre in the tail stock mount another centre between. Mount a dial gauge on the top slide and set it over so that it moves exactly parallel to the taper of the centre. Lock the top slide in this position. Remove the floating taper and move the tail stock up to support the steel bar. Using the top slide only turn the taper.






Drill and tap the end 10mm



Fit the newly turned taper into the spindle and secure with a draw bar. Cut off to the required length and turn a 60° point on the end



Cheers

Rich

« Last Edit: October 13, 2018, 08:31:09 PM by Firebird »

Offline Firebird

  • Full Member
  • ****
  • Posts: 1328
  • East Midlands UK
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #594 on: October 14, 2018, 09:58:35 AM »
Hi

I have just thought of a simpler way to make this centre  :thinking:

Myford collets are held in with a threaded nose ring which can't be used as well as the screw on chuck. But I also have some MT2 collets for my milling machine which are tapped for a draw bar. Using a 1/2" collet held in with a draw bar and fitted with some 1/2" round bar all you would have to do is turn the 60° point  :facepalm2:

Cheers

Rich

Offline Firebird

  • Full Member
  • ****
  • Posts: 1328
  • East Midlands UK
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #595 on: October 15, 2018, 08:21:15 PM »
Hi

Fit the 4 jaw chuck and make a bracket from some ally angle which clamps across the lathe ways. Line the chuck up as vertical as possible and secure with a clamp to the bracket.



Cheers

Rich

Offline g0rph

  • Full Member
  • ****
  • Posts: 19
  • Location: Lincoln UK
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #596 on: October 17, 2018, 11:14:21 AM »
Hi Rich,   

I’ve not been on here for a while, but I note you are still making good progress on Conway.   She’s looking good.

I see (page 36) that you had the problem with the blowdown valve fouling the frames that I had mentioned a while back.   Your solution is a little neater than that on my engine.  The original builder of my loco seems to have just attacked the frames with a big file to solve that detail! 

I’m still working on refurbishment and here is another “gotcha” which may save you some time/effort/money.   Martins saddle tank drawing calls for a tube over the inner dome of 1.5” inside diameter.   That size however will not allow the tank to fit over the inner dome flange and the tank does not sit low enough as a result!   Leastways that is the case on my engine.    The tube needs to be about 2” ID to fit correctly.   

Take care though, that your outer dome casting is large enough to fit over the 2” hole at the top end.   Mine is just OK.   I suppose a stepped (or tapered) tube with just the bottom at 2” ID and the top at 1.5” would be best, but that’s too much work for me!

While looking at the pics on page 36 it appears that you have arranged the snifting valve bush on the right side of the wet header bush (viewed from the drivers viewpoint).    On my loco, the snifting valve pipe would either foul the blower bush, or the inside of the boiler barrel in that position (depending on the precise final angle of the wet header/superheater assembly).   

Maybe yours is yours is OK though?   I mentioned it as I’m busy re-making my inner dome, regulator and wet header assembly at this moment.    My loco did not originally have a snifting valve and I am trying to add one.

Oddly my wet header was assembled with 2 x M3 screws and 1 x 4BA!   For my new assembly I too have opted for metric.   BA screws are too expensive now unless essential.

Why is your axle pump upside down (page 39)?    ;)

I look forward to your next instalments.

Regards,   Richard.


Offline Firebird

  • Full Member
  • ****
  • Posts: 1328
  • East Midlands UK
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #597 on: October 17, 2018, 08:58:42 PM »
Hi

Thanks Richard  :ThumbsUp:

You were quite right the blow down valves were nowhere near where they are shown on the plans. There was a bit of fettling here and there to do on the frames so it was easier to strip them down and machine the openings.

Regarding the dome. I might be changing the design and going for side tanks so we can cross that bridge later.

Why is the axle pump upside down  :embarassed: :facepalm: :facepalm2: :shrug: :wallbang: :ShakeHead:

The snifting valve is on the left on the plans



Assuming I have followed the plans correctly thats where it will go.

I'll post more on the quartering shortly

Cheers

Rich

Offline Firebird

  • Full Member
  • ****
  • Posts: 1328
  • East Midlands UK
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #598 on: October 17, 2018, 09:39:34 PM »
Hi

Back to the quartering.

Make up a bracket that that bolts to the cross slide. I have used a bit of ally angle onto which is bolted an arm and a spacer



Move the saddle and cross slide until the spacer touches the rear face of the top jaw and lock the cross slide





Cheers

Rich

Offline Firebird

  • Full Member
  • ****
  • Posts: 1328
  • East Midlands UK
Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #599 on: October 18, 2018, 08:30:55 PM »
Hi

Move the saddle towards the tail stock

Fit the extended centre into the spindle and another centre into the tail stock.

Clamp a piece of steel onto the top of the front jaw

Fit one of the cranks to the axle with loctite

Mount the axle between centres with the already fixed crank towards the chuck, leave the other crank loose for now

Turn the axle until the crankpin of the fixed crank touches the underside of the steel plate clamped to the top of the front jaw

Apply loctite to the other crank and as quickly as possible (Loctite will start to hold after a few seconds) push it onto the axle turning it until the crank pin is in contact with the bracket and hold it there for a minute or so

The cranks are now quartered.

It is not essential that the cranks are at exactly 90° to each other. It can be 89° or 91° or what ever. The important thing is that both axles are the same



Cheers

Rich


 

SimplePortal 2.3.5 © 2008-2012, SimplePortal