BR Standard Class 4 Loco Build

Discussion in 'Locomotives' started by Is Line Clear, Mar 6, 2018.

  1. jakesdad13

    jakesdad13 Staff Member Moderator

    Messages:
    2,285
    Likes Received:
    115
    Joined:
    Dec 14, 2015
    When I build up the con rods on my locos I use the drill bit method, if you use the blackened type solder won't stick to them.
    I use 2mm drills for O gauge locos, not sure what 4mm crank pin sizes are.

    Pete.
     
    Is Line Clear likes this.
  2. Is Line Clear

    Is Line Clear Full Member

    Messages:
    759
    Likes Received:
    289
    Joined:
    Aug 20, 2017
    Thanks Pete... I'll use 2mm drill bits... I'll get round to finishing those 4mm kits soonish tho
     
    jakesdad13 likes this.
  3. Is Line Clear

    Is Line Clear Full Member

    Messages:
    759
    Likes Received:
    289
    Joined:
    Aug 20, 2017
    Here is a brief update on this build, not waiting any longer I purchased some axle alignment springs from Midland Railway Co of Kettering and these duly arrived a couple of days later so I was able to start assembly of the frames and wheelsets proper. The 5'8" driving wheels from Slaters have had their crank pins fitted with the conversion set fitted to the middle drivers. The frames are true and square and both side rod sets have an equal length between openings for the crank pins.



    So I decided to have a dry assembly run first to check beforehand that wheels and side rods fitted properly and the loco frames would sit evenly on some track.


    I couldn't resist a photo of the wheeled frames and tender together.:avatar:


    Next job now is dismantle and remove the wheelsets then fit side rods to the axle alignment bars and solder the axle bushes into place... wish me luck please. I think it will go alright.
     
    Rob Pulham, paul_l and Steve Fay like this.
  4. Is Line Clear

    Is Line Clear Full Member

    Messages:
    759
    Likes Received:
    289
    Joined:
    Aug 20, 2017
    Just playing now, here the BR Standard 4 frames sit alongside the F5 and the Jinty... I think I may have overloaded that Mineral wagon a bit to much.:oops:



     
  5. Rob Pulham

    Rob Pulham Staff Member Moderator Feature Contributor

    Messages:
    732
    Likes Received:
    215
    Joined:
    Sep 15, 2017
    Hi Paul,

    Now you have me intrigued what are the 'conversion sets'? I haven't heard the term in conjunction with standard locomotive frames/wheels - As opposed to extended axles on early locos that is.
     
    Is Line Clear likes this.
  6. Is Line Clear

    Is Line Clear Full Member

    Messages:
    759
    Likes Received:
    289
    Joined:
    Aug 20, 2017
    Apparently the Slaters wheelsets come with a standard length crankpin which is 20.5 mm in length and not sufficiently long to accept the second brass bush for the con rod, so a conversion set is offered for loco's with outside motion. This consists of two longer crank pins and a couple more brass bushes, to secure the assembly one uses the 12BA nut and washer as supplied with the original wheelset pack. I'll post a picture for you to see what I mean.
     
  7. Is Line Clear

    Is Line Clear Full Member

    Messages:
    759
    Likes Received:
    289
    Joined:
    Aug 20, 2017
    Hi Rob,
    Here is a picture of what Slaters say you need to do regarding the extended length crank pins on centre driving wheels carrying the con rod on outside motion. I suspect excess thread on the crankpins after nuts have been spun on will have to be filed down so that the con rods have unhindered movement... just my suspicions.:scratchchin:

     
  8. Rob Pulham

    Rob Pulham Staff Member Moderator Feature Contributor

    Messages:
    732
    Likes Received:
    215
    Joined:
    Sep 15, 2017
    Ahh, got you, I usually replace the 12ba screw supplied with a 10 ba countersunk screw and then tap both the wheel and both bushes which then allows you to solder the return crank to the outer one and tighten it up into the correct position. I am almost there with the Coronation so I will make sure that I take explanatory photos
     
    Is Line Clear likes this.
  9. Is Line Clear

    Is Line Clear Full Member

    Messages:
    759
    Likes Received:
    289
    Joined:
    Aug 20, 2017
    Thanks Rob, that is great advice and I'm looking forward to your next installments of the Coronation build.:thumbs:
     
  10. Rob Pulham

    Rob Pulham Staff Member Moderator Feature Contributor

    Messages:
    732
    Likes Received:
    215
    Joined:
    Sep 15, 2017
    Thanks Paul,

    I have been beavering away but without a great deal to show just yet, principally working out how to get the cylinders etc to be removable. Fingers crossed I have cracked it and will take photos once it's soldered together.
     
    Is Line Clear likes this.
  11. Is Line Clear

    Is Line Clear Full Member

    Messages:
    759
    Likes Received:
    289
    Joined:
    Aug 20, 2017
    I think a little bit of jiggery pokery is required here as the distance between the outside faces of the parallel angle slots on the main frame holding the cylinder block together measures 21.5 mm across width, however when the front and rear cylinder profile pieces (which act as a kind of saddle) are soldered to the nickel silver etch side wrapper piece the measurement across the width becomes 24 mm. :scratchchin: So do I carefully open the slots out by 1.25 mm on each face or seeing as its Friday should I go down to the pub instead for two or three pints of Timothy Taylors?

     
    Last edited: May 19, 2018 at 5:23 PM
    Rob Pulham, jakesdad13 and Steve Fay like this.
  12. paul_l

    paul_l Staff Member Administrator

    Messages:
    5,007
    Likes Received:
    262
    Joined:
    Dec 5, 2015
    enjoy .... but I'd wait until tomorrow before making any further progress
     
    Is Line Clear likes this.
  13. Is Line Clear

    Is Line Clear Full Member

    Messages:
    759
    Likes Received:
    289
    Joined:
    Aug 20, 2017
    Good advice as always Paul... I'm going to have a think about the best way forward over this one, if I enlarge the frame slots to take the block I need to make sure the angle of each of the cylinders is true and that a centre line down the slide bars meets with the mid point of the centre driving wheel.
     
  14. paul_l

    paul_l Staff Member Administrator

    Messages:
    5,007
    Likes Received:
    262
    Joined:
    Dec 5, 2015
    You could try making a jig - piece of straight round piano wire the same diameter as the cylinder shaft, feed it through the cylinder holes and use that to align with the axle.

    Paul
     
    Is Line Clear likes this.
  15. Is Line Clear

    Is Line Clear Full Member

    Messages:
    759
    Likes Received:
    289
    Joined:
    Aug 20, 2017
    Yes I think I'll make an piston alignment jig, something simple as you say which feeds through the cylinder in a straight line onto the middle wheel centre, another thing would be to measure the distance of the front and back top edge of the cylinder block with the top edge of the main frame, that way the cylinder can be soldered in nice and square when the time comes. Also I think I have fathomed a way forward with these slots on the main frame, it will require some packing straps to put the block in the correct position and angle on the frames when I cut new slots with my piercing saw. I'll discuss this when I eventually put some pictures up. But thanks Paul for your advice.:thumbs:
     
  16. Rob Pulham

    Rob Pulham Staff Member Moderator Feature Contributor

    Messages:
    732
    Likes Received:
    215
    Joined:
    Sep 15, 2017
    Paul,
    Don't do anything until I speak to you, please PM me your phone number
     
  17. Is Line Clear

    Is Line Clear Full Member

    Messages:
    759
    Likes Received:
    289
    Joined:
    Aug 20, 2017
    You have my number Rob via PM, now all I have done is to make up the cylinder block, I've done some very careful studying of reference material photos etc and think it prudent to post these pics up first so a good idea can be had and further advice taken. As the instructions state "add this sub assembly (cylinder block) to the chassis, the position is determined by lining up the cylinder axis with the centre of the middle driving axle bush". I am not at all ready to do this yet of course.
     
    Rob Pulham likes this.
  18. Is Line Clear

    Is Line Clear Full Member

    Messages:
    759
    Likes Received:
    289
    Joined:
    Aug 20, 2017
    So I've fabricated the four elements together that make up the basic cylinder block, checked everything for square and all is well.



    Now when the block is lined up with the slots in the main frame as we can see there is an issue, I very much doubt the nickel silver side etches are too wide so deduce that the slots are the problem in being incorrectly spaced. As measured earlier the outer face distance of the slots was 21.5mm apart.


    And here is the proof the outer faces of the block measures 24.3mm.

     
    Rob Pulham and Steve Fay like this.
  19. Is Line Clear

    Is Line Clear Full Member

    Messages:
    759
    Likes Received:
    289
    Joined:
    Aug 20, 2017
    The discrepancy is a 1.4mm shortfall on each slot so I marked the main frame accordingly and proceeded to very carefully cut out the excess using my piercing saw and needle file.


    The result is a goodly fit of equal proportions all round.




     
    Rob Pulham and Steve Fay like this.
  20. Is Line Clear

    Is Line Clear Full Member

    Messages:
    759
    Likes Received:
    289
    Joined:
    Aug 20, 2017
    Now that's as far as this goes as a dry fit, I need to put the alignment springs back on so I can solder the axle bearings on the compensation beam, I'd set this up last week and soldered in the front wheel bearings but decided to fit Type B thin brass washers behind the bearings on the beam for better strength. At the moment I'm waiting for these to be delivered, once soldered in with wheels and side rods refitted I'll test rotation for smoothness again. The wheels can then come off once more and the middle bearing will be the datum point for aligning the cylinder block and fitting the slide bars.

     
    Last edited: May 19, 2018 at 9:14 PM
    Rob Pulham and Steve Fay like this.

Share This Page