Drawing 902

Smokebox

Tuesday 31st October 2011

A few holes at a time, finally finished drilling through the spacer ring into the boiler. Horrible job, it seemed like every time I drilled a hole the smokebox shifted and had to be realigned. It wasn't until around half the holes were filled with bolts that the damned thing stayed put whilst the remainder of the holes were drilled.

Tuesday 3rd October 2011

Now that I have the boiler, I turned up the spacer ring between the boiler and smokebox. 'Orrible job - the casting is so thin when nearly finished that it distorts, both in the chuck and when fitting to both boiler and smokebox. So a snug fit on each part individually results in no fit when all three parts are put together. It has to be a sliding fit on at least one of the parts.

If I were doing it again I would rotate the part by one sixth of a turn each time it gets taken off to check the fit (it's not practical to check the fit with the ring in the lathe). That way the distortion introduced by the three jaw chuck would be minimised. Initially my spacer ring varied in thickness by up to 50 thou...

Dodgy looking setup for aligning the smokebox & boiler

Once the fit is good with both parts comes the problem of aligning the boiler and smokebox so that the rivet holes can be transferred from the smokebox to the spacer and the boiler. After much thought I set it up on the milling machine table - it's the biggest flat surface I have. Bloody precarious setup though...

Please ignore the iffy usage of a Boxford ER32 chuck - I only have two machinist's jacks...

Friday 14th May 2010

Bent up the lamp brackets and finished them. Took ages to get rid of some marks made on the metal by the vice brakes bought from Warco. Filed a nice rad on the anvil to (hopefully) avoid this in future.

Assembled the smokebox to take to the MJ Engineering open day. Looks rather smart, if I say so myself!

Finished Smokebox!

Bent the butt strap to match (roughly!) the contour of the chimney and jig drilled the holes for the rivets from those already drilled in the chimney. Used 7BA bolts to hold the butt strap in place. It was an absolute bugger getting the nuts on the ones in the middle of the chimney - how on earth do the 2" boys manage it?!?!!

Thursday 13th May 2010

Back from holiday in Washington DC, nodding off on the sofa through jetlag (landed at 08:10 this morning) so went out and milled / filed the profile on the lamp brackets. Also cut a bit of stock to the right size for the chimney butt strap.

Friday 30th April 2010

Got the smokebox door ring fitted back into the smokebox, with some Boss White to seal the small gaps.

For some reason, the smokebox door hinge bracket and flush "rivet" nuts now clash quite badly on one side. Can't think why that's changed... Ground up a pair of "one size smaller" 4/5BA nuts which solved the problem. They're not terribly hexagonal - or at least *regularly* hexagonal, but they do the job.

My steel order arrived today so I had a quick go at bending up the lamp brackets. Made some scrap by getting one of the bend positions wrong and more importantly mis-reading 1-11/16" for 1-1/16" on a poorly copied drawing. Harumph.

Tuesday 27th April 2010

Made three more slotless countersunk bolts for the flush rivets under the chimney base. Not much progress, but I'm trying (and occasionally succeeding!) to keep up with the "do at least something every day" philosophy...

Monday 26th April 2010

Despite taking ages to set, the JB Weld seems to have done its thing. Drilled out the holes filled by the epoxy and filed the blob down so that the smokebox door ring fits again. The edge wasn't square so I applied a little bit more on the front edge.

Sunday 25th April 2010

Marking the mounting holes for the nameplate Finished smokebox door

Fitted the name plates to the smokebox door. Set up the smokebox on the angle plate using the same jig as for the marking of the hinge plate. Set up the hinge to be vertical, then rested the name plate on two very powerful small magnets. Measuring from the smokebox door edge, as well as from the centre and using a height gauge to establish the horizontal, moved things around until the plate was in the right place. Then I went and got a second opinion. This bit is hugely visible so I want to get it right... Turned the door upside down to do the second plate. Looks rather smart I think!

Applied some JB Weld to the bottom edge of the smokebox to fill the rather large gap where the rolled smokebox joint is. Unfortunately I think I've done something wrong... It's now about 5 hours later and it's only just going off. It dribbled through the holes requiring me to turn the smokebox over every 10 minutes or so... Have to wait and see whether it sets properly.

Saturday 24th April 2010

Finished off cleaning up the smokebox. To make the job interesting I interspersed it with filing, sanding and polishing the smokebox nameplates. Now there's a job which is disproportionate on the effort / reward scale...

I think the smokebox might have wanted those lines. The bloody thing attacked me towards the end of the job and drew blood. Bugger.

Friday 23rd April 2010

Soldered the arms onto the door hinge barrel. I soldered it in place so that the alignment would be guaranteed. Worked OK eventually, but I badly underestimated the amount of heat the smokebox would take away from the joints.

Decided to clean up the smokebox so that hopefully it doesn't have to be dismantled again. Learning point - scribe lines as gently as possible. It's taking me *ages* to get rid of the damned things - I've been at it 45 minutes and I've only done about 1/4 of it.

Thursday 22nd April 2010

Made the two arms to hold the smokebox door hinge barrel. Bolted them onto the smokebox in position, then clamped the whole thing to the milling machine table so that it wouldn't move around as I filed the arms to fit the hinge barrel. After a long session of filing and trial fitting the barrel locates well in the arms - so much so that holding it on while silver soldering should be quite easy.

Tuesday 20th April 2010

Once again, some excellent answers on Traction Talk. Countersink the rivets which clash is the answer. So I went out and marked things out - still very very tight, so I brought the centrelines of the hinge brackets in 1/32" each. Shouldn't notice... I've also had to make my own countersunk threaded rivets, with the threaded section 4BA instead of 2BA so that the smokebox door ring bolt / rivet will fit next to the bolt / rivet for the smokebox door hinge bracket. Actually they look rather smart - better than the screws I've used under the chimney base. I think I might have to make some more for there as well.

What still isn't clear to me is how to hold the two bracket arms onto the hinge barrel in the correct place for silver soldering. Have to think about that...

Monday 19th April 2010

Silver soldered the upper and lower hinge barrels to the smokebox door hinge bracket. Filed the ends of the bracket carefully to match the barrel, made a thin "centre section" of the hinge barrel to space the end pieces apart without the risk of soldering the whole thing into one(!), clamped it up with the hinge pin fitted and soldered it together. Now, I hate silver soldering - just don't seem to get on with it - but it seemed to work OK! Until I tried to pull the hinge pin out. Bugger - I seem to have soldered the hinge pin in. Fortunatley that wasn't the case - it was just flux holding it together. Phew!

However, I seem to have got the hinge centreline ~1/32" too far forward. Won't notice, I'm sure. Well - I sure as hell aren't making it again...

But there is another problem: the other half of the hinge bracket - the two bits which rivet onto the smokebox door - if made to the drawing will clash with two of the smokebox door ring rivets. I think the solution is to mount the two bits closer to each other than the drawing shows. I've asked another question on Traction Talk to see if anyone else has had the issue, and asked how they got around it.

Sunday 18th April 2010

Filed the other nameplate. Marked and drilled the holes for the smokebox door hinge bracket, by holding the door on an angle plate and then marking with a height gauge on the surface plate.

Setup to mark the smokebox door Smokebox door on its jig

Friday 16th April 2010

Following some very good advice in response to a question on Traction Talk Forum, filed the back of the upper name plate to fit the smokebox door.

Also finished the third locking pin.

Time passes...

It's now April 2010. In this passing time, I wasn't totally idle... So what have I done?

  • Drilled the holes in the smokebox for the smokebox door ring and the boiler spacer ring.
  • Chain drilled and filed the hole for the chimney base.
  • Machined the chimney base and bored the hole for the steam pipe.
  • Made and bent the smokebox door hinge bracket, and the hinge pin and "barrel".
  • Filed and sanded the chimney, marked and drilled the holes for the butt strap rivets.
  • Machined the base of the chimney (what is the proper name of this bit?).
  • Made the hinge pin for the chimney.
  • Made and welded together the smokebox door locking bar brackets (only welded 'cause I couldn't work out how to hold them to silver solder them...).
  • Made the smokebox door locking dart.
  • Decided to use rivet headed bolts to secure the smokebox door ring to the smokebox.

    I have absolutely no clue whatsoever how much time I spent on the above tasks. I didn't keep a record. Or take many pictures. Sorry...

    But what pictures I took are here:

    Progress to date! Marking the horionzontal centreline on the smokebox Machining the front axle Machining the smokebox door dart
    Boring the steam pipe hole in the chimney base

    An observation...

    It took me 3 goes to mark the lines for the butt strap rivets. Whatever I tried, the lines weren't equispaced about the chimney join line. Then the penny dropped - the join line isn't straight. It's not far out, but enough to look really crappy when two parallel lines are scribed either side of it. In the end I marked the correct distance left and right of the join line in as many places as I could and joined the dots. So the lines of rivets won't be straight, but they'll look it compared to the joint line. If anyone ever spots it I'll be stunned...

    Saturday 25th February 2006 - 3 hours (total 75.5)

    Setting up to cross drill the axle Cross-drilled the axle for the pin through the collars which hold the wheels on.

    Clamped a vee block in the machine vice and clocked the spindle to the flat end, then clamped a bit of silver steel bar in the vee block and clocked off its diameter. Clamped the axle to the vee block, using a 0.1" gauge block so that the edge of the rad on the axle wouldn't screw up the measurement. Set square against the huge bottle square I got off ebay, then centre drilled before finishing to size.

    Then found I needed to file the holes quite a bit before the pins could be put through the collar and the axle...

    Put the whole assembly so far together. And here it is!

    Assembly so far...

     

    Sunday 12th February 2006 - 5 hours (total 72.5)

    Push bracket and push pin Made the pushing bracket. Clamped the upper and lower plate blanks together to drill the 4 rivet holes, then used 6BA bolts to hole the whole lot together while it was sawed and filed to shape. Not the most pleasant of jobs!

    Once to shape it was off to the mill to bore the 1.5" hole, and the 4 mounting bolt holes. The holes in the spacer were jig drilled from the bottom plate and the three pieces rivetted together. Getting better at this rivetting lark - not nearly as many bruises to the surrounging metal from wayward blows...

    Then drilled the hole for the drag pin, and filed the whole lot to fit into the forecarriage.

    Saturday 11th February 2006 - 7 hours (total 67.5)

    Made the heatshield for behind the smokebox door. Cut roughly to size then bolted it to an arbour in the lathe and turned to size. A horrendous interrupted cut which rang like a bell. Apologies to the neighbours...

    Learned to rivet! (More apologies to the neighbours!) Took a while to gain enough confidence to attack the forecarriage... But when I did, it only required one rivet to be drilled out and re-done. Not bad, although some of the off-target hammer blows might take some getting out...

    Using the boring head, bored the 1.5" and 1" holes in the forecarriage.

    Friday 10th February 2006 - 1.5 hours (total 60.5)

    Using radiussed milling cutters, put the rads on the axle spacer (using a file for the inside bits) and cleaned it up.  Filed the axle to be a snug fit in the spacer.  Assembly finished! (Well, almost!)
     
    Front Axle Assembly! Front Axle Assembly - other side!

    Thursday 9th February 2006 - 1 hour (total 59)

    Milled the slot down the middle of the spacer.
     

    Sunday 22nd January 2006 - 6 hours (total 58)

    Using drills then the new boring head (first time out of the packet!), bored the pivot hole in the front axle, then did the same for the spacer.

    Using a radiussed tool and an arbor turned in place on the Colchester, turned the "bosses" on the axle fork spacer.

    Axle fork spacer having bosses turned.
    "Turned" up an arbor in the rotary table on the mill using a milling cutter so that the spacer would turn true, then milled the large radius on the end of the spacer.  During this operation it became abundantly clear that mounting chucks on 2MT arbors poking out of the central hole of a rotary table is not a very rigid setup.  Need something better...

     

    Saturday 21st January 2006 - 3 hours (total 52)

    Made the drag pin - haven't finished the ball turning attachmend yet, so used files.  Not too bad...

    Filed and then sanded the smokebox door.  Long nasty job... Looks good now though!

    Thursday 19th January - 1 hour (total 49)

    Filed the blend between the baseball bar and the boss.  Polished up both bits - don't look bad at all!

    Smokebox Door Handles

    Sunday 15th January 2006 - 3 hours (total 48)

    Smokebox door smaller handle.  Again - machined from solid.  Started with a piece of square bar, turned the baseball bat portion then milled the boss flats at 10 degrees.  Drilled the hole and tapped it, then used the rotary table to machine the round bit of the boss.  Not very happy with this bit - the hole isn't central to the boss - should have machined the round threaded part of the fixture in place on the milling machine.  I'll put up with it for now, but might remake it if people notice!

    Sunday 8th January 2006 - 3 hours (total 45)

    Made the spacer between the push brackets.  Marked out - found an error in the drawings again - the radii specified don't actually meet...  Adjusted the drawing, then machined out most of the material on the mill, finishing off with a file and plenty of sanding.  Looks OK...  but when all said and done it's not the most visible part in the world, so it'll do.

    Saturday 31st December 2005 - 5 hours (total 42)

    Smokebox door larger handle.  Machined from solid - still have no confidence in my silver soldering...  Made the 'baseball bat' end and drilled the hole through the centre.  Then made the pivot pin for the machining of the boss.  Needed three bloody goes at it - first two galled on the pin I was going to use as a pivot to manually feed the boss on the milling machine, the third snatched on the mill and bent the pin.  Not a job to be manually fed, methinks.  Oh well - file the hole square like it needs to be, then make a square pin on the rotary table, with a threaded portion for a retaining bolt.  Done first time.  Then used files to blend the baseball bat into the boss.

    Friday 30th December 2005 - 6 hours (total 37)

    Made the front wheel retaining collars.  Nice turning job, using a file to produce the radii.  Cross-drilled and milled the hole and recess for the retaining pins.  Discovered an error in the drawing - if the centre for the retaining pin hole is drilled as per drawing, there would be very little material remianing - not very strong...

    Made the retaining pins for the front wheel retaining collars.  Cross drilled for the wee split pins.  Cute!

    Front wheel retaining collars

    Monday 21st November 2005 - 3.5 hours (total 31)

    Finished off the plain turned portions of the axle.  Although it's been done between centres, there appears to be ~0.1mm run-out of the collers...  Don't really understand why...

    Made another pivot pin, including slot.  Right this time...

    Made the cotter for the axle fork.

    Made the dustcap.  Very satisfying job, that!

    Dust Cap

    Tuesday 15th November 2005 - 0.5 hours (total 27.5)

    1/8" Slot drill arrived.  Milled the slot into the pivot pin.  Bum - wrong.  Forgot to account for the diameter of the cutter, so the slot is too long.  Also milled it undersize by 10 thou, then finished it - this caused the (rather slender) cutter to bend at the bottom of the slot...

    Tuesday 8th November 2005 - 3 hours (total 27)

    Did another surface of the stock for the axle fork spacer.

    Made the axle pivot pin so that the axle fork spacer can be made to fit it.  It then occurred to me that the axle should be done before the spacer so that it too can be used to ensure a good fit.  Still need to machine the slot in it for the cotter.  Need a long 1/8" slot drill though.

    Marked and drilled centres in the ends of the axle and set it between centres on the lathe.  Machined the O/D of the collars - came in ~72 thou under size because the casting appears to be slightly bent!  Shouldn't either show or matter much fortunately...  Started machining the plain portion of the axle stub.

    Monday 7th November 2005 - 1 hour (total 24)

    Started machining up a piece of stock for the axle fork spacer thingie using a fly cutter.

    Tuesday 1st November 2005 - 1 hour (total 23) Setting the axle fork ready for machining the slot

    Set up the axle fork in the mill again to make the slot for the cotter.  Set it level using a DTI, then ran the edge finder off the fixed vice jaw and the upper bearing surface of the axle fork.  Marvellous things - DRO's...  Drilled two holes the right diameter, then filed the hole out to a slot.  Much easier than expected!  A bit of filing all over and this bit is done!  One down, a few to go...
     

    Monday 31st October 2005 - 1 hour (total 22)

    Having finished off the refurbishment of a boring head kindly given to me I bored the axle pivot hole to size.

    Monday 24th October 2005 - 2 hours (total 21)

    Set up the axle fork for drilling the hole for the axle pivot.  Mounted a stout piece of bar in the machine vice horizontally and set the fork over it, clamped with toolmakers clamps.  Having marked out the hole centre on the upper side using a centre square from several angles and centre popped the "average" position, the initial hole was drilled.  Note that the "bottom" fork was unsupported and flexed rather on drilling - just as the book of words said it would!  OK - I'll have to bore the hole to final size.  Got it drilled though...

    Thursday 20th October 2005 - 2 hours (total 19)

    Finished off the axle fork milling - the inside is now done.  Not quite to the bottom - leave room to file a nice rad for strength.  Filed the rad - quicker than I imagined...

    Tuesday 18th October 2005 - 1 hour (total 17)

    Machined the outer faces of the bosses on the axle fork.

    Monday 17th October 2005 - 1 hour (total 16) Milling the axle fork

    Set up the axle fork on the milling machine ready for machining the outside and inside of the fork itself.  Rather difficult to do actually - which face of the casting do you take as datum?  If I were to do it again, I think I'd do it by finding the centre of the bosses on the outside and setting them to be equdistant from an angle plate set at right angles to the table.
     

     

    Sunday 16th October 2005 - 5 hours (total 15)

    Drilled and countersunk the four mounting holes on the axle fork bearing using the rotary table on the mill.  This is the first complete part!  Big celebration!  (A pint of Hogsback Brewery Hop Garden Gold beer!)

    Locking Ring.  Machined the ID, ID and length.  Slots remain to be done.

    Locking Bar Brackets.  Made 1/3 of the locking bar brackets (bent then to match the ID of the smokebox) before discovering that I don’t have any 3/16 Smokebox door spacer “ steel to make the other two bits…

    Smokebox Door Spacer.  Turned the spacer between the smokebox door and the heat shield.   Drilled the holes (6 on one side and 4 on the other) using a little arbour on the rotary table and, which was still set up and centred from doing the axle fork bearing.


    Saturday 15th October 2005 - 8 hours (total 10)

    Lamp Brackets.  Tried bending the lamp brackets, heating the blanks using propane.  Marked out the bend line and tried to get that into position in the vice for bending.  Resulted in the bend in the wrong place, and more heating sessions than were necessary ‘cause of the cooling whilst positioning.  Rigged up a stop for the blank so that the bend line is automatically in the right place – this try went better, but still resulted in slightly wonky brackets – blank not absolutely upright.  Maybe need to think of either (a) a rig to keep the blank at right angles or (b) a tool to do the whole bend… Faceplate mounting of the axle fork - hairy!

    Axle Fork.  Started to machine this as per the instructions in the handbook.  Bolted the fork to the angle plate on the faceplate.  Unfortunately the required angle plate resulted in an assembly which wouldn’t swing without removing the gap piece (the inside face of the angle plate isn’t machined).  Never happy removing gap pieces – they never seem to go back with quite as good alignment as when they came out.  This time was no exception…

    Quite a hairy looking setup – only dared revolve it at 72rpm…  Worked OK though, except that the large bearing surface diameter came in undersize once the cut was continuous.


    Axle Fork Bearing.  Machined from the gunmetal casting.  Straightforward turning job.  Dimensions changed to match the slightly altered axle fork.

    Machining the axle fork bearing

    Saturday 1st October 2005 - 2 hours

    Drilling for lamp brackets

    Forecarriage.  Drillled the holes in the forecarriage to rivet the bits together, as well as the 4 holes for the lamp brackets.

    Mistake #1... used the wrong offset for the holes on one side.  Filed oval to correct (they'll be hidden by the bolts and therefore won't show) and gave myself two gigantic blisters doing it...  :-(