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Kit 16 - Hornplates

Hornplate kit contents - missing RH Crank Housing

Tuesday 11th March: Kit 16 Finally arrived today.  The packing of this kit was not as good as I have come to expect and many of the parts were loose amongst shredded waste paper.  Fortunately I found the small packet of washers provided to shim up the back axle.  As I did not want to throw anything away  in the packaging I carefully checked the packing list.  All the small parts were accounted but I was missing the RH Crank Bearing Housing (F41805).

Trial Assembly of left hand hornplate

There are a number of issues with this kit  and ModelWorks are working to resolve them.  Firstly there are errors and omissions in the fastener list.   There should be 4 csk M6 bolts to secure the hornplates to the top boiler bracket (b in photo).  Three of the lower bolts securing the RH hornplate to the boiler need to be M8 csk.  ModelWorks have these on order and plan to send them out when available.  The bag containing M5 x 10 csk bolts has mistakenly been packed with M6  x 10.

I noticed that the three fixing holes for the pump eccentric (a in photo) are not tapped M6 as intended.  This appears to affect all kits - I understand ModelWorks will be asking customers to tap the holes with assistance for those without the capability.

The step between the shoulders of the top and bottom housings

Paul R has alerted me to a problem with the LH bearing cap.  There is a step between the shoulder on the top and bottom halves of the bearing housing.  While this was not intended it can be ignored as it will not affect the ultimate alignment of the crank.  I understand ModelWorks will be machining the crank to suit the resultant bearing position.  The gap will be covered from view once the flywheel is fitted. 14/3/08 I have now fitted and aligned the bearing and I experienced no difficulty with alignment using the top half as a guide.  Once the bearing cap screws were tightened the bearings were firmly held and are unlikely to move.  While at first worrying this is has proved to be a non problem.

The rear guard suport filled to clear bearing housing

I started with the left hand hornplate as this is not affected by my shortage.   As the edges are "non functional"  I generously rounded the edges to help the paint stick.  There are several angles supplied to fix the boiler mounting brackets and guard supports.  I plan to permanently fix these before painting the hornplate.  I had to file about a 1/16" off the rear guard support angle as it fouled the bearing housing.
  

The dummy extension of the 2nd shaft had to be filled to enable the hornplate to lie flat

Thursday: The missing RH bearing housing arrived today together with Kit 15, the boiler accessories.  I found that there were a number of "things" mounted on the inside of the hornplate hornplates pressing on the boiler preventing the hornplate lying flat.  The worst offender was the dummy stub extension of the second shaft which required about 1/6" filling off.  I also had to trim the bottom of the rear guard support angles.  I found the best way to test for unwanted contact was to fit and slightly tighten the bottom two mounting bolts and check that the hornplate aligned itself the upper mounting bracket.

The instructions describe an onerous alignment technique for the hornplates in which the hornplates are gently tapped into alignment.  I ignored this!  I loosely fitted all bolts and then tighten all the csk bolts as this action centres the hornplate.  I then progressively tighten the other bolts.  I then mounted both bearing on the alignment aid and dropped the bearings still on the alignment aid into the housings.  I then fitted the bearing caps and loosely fitted the caps bolts.  I then jiggled the bearings to align them up against the housing's shoulder before progressively tightening the cap bolts.  The alignment was excellent and I could even side the alignment aid side to side through the bearings (Any twist and the bearings would jam on the shaft).

I made close fitting bushes for the boiler mounting bolts to help prevent the hornplates moving

In the early days of running my Burrell I found that the hornplates moved upsetting the alignment.  I have heard of constructors whose plates moved sufficiently to smash the gauge glass.  To put an end to this problem I fitted brass bushes to the hornplate bolts.  Fitting the bushes was made more complicate as the engine was finished.

There probably won't be the same problem with the Foden as there are twice the mounting bolts and the hornplates don't take the bulk of the engine weight.  However as it will be much more difficult latter I decided to fit sleeves onto the mounting bolts.  These are tapped M8 with an outside diameter of 9mm.  At 9mm The sleeves on the bolts are a sliding fit through the hornplate mounting holes thus allowing the hornplate no room to wriggle.  The fact that my technique works is a testament to the accuracy that ModelWorks have machined the mounting holes on the boiler and hornplates.  By carefully fitting the bearings after the hornplates I found it easy to get good alignment.  I wonder whether ModelWorks difficulties were because their hornplates were not mounted flat against the boiler as a result of clearance issues with the dummy second shaft?

Profiled washers were made to match the curve in the bracket angle

Friday: The bolts securing the boiler need to be done up tight but it is surprisingly easy to overdo it  and either weaken or break the bolt.  Addition care is needed with one of the top boiler bracket fixings as the face onto which the nut is tightened is not flat having a distinct curve on one side.  As the nut is tightened it will make contact with one side first and then as the nut is tightened further the shaft of the bolt will be bent until both sides of the nut into contact with the bracket.  This bending is undesirable as it weekends the bolt.  If the bolts is undone, for example for painting, when it is returned it is likely to need to be bent differently bring failure one point closer.  One solution would be to use fresh bolts on each assembly but I decided to make specially profiled washers to allow the nut to seat properly.

Trial assembly of the hornplates with all mounting brackets fitted


Fitting the stubs through the saddle into the boiler


The saddle fitted to the boiler

I have prepared and temporally fitted the boiler mounting brackets to the hornplates.  Before I paint the brackets I want to trial assemble the boiler into my chassis as I suspect I may have to file a few holes.

For the trial assembly I need the front saddle fitted and as I have this ready and painted I see no reason not to fit it permanently.

The saddle is secured to the boiler by studs which are screwed into threaded holes in the boiler shell.  As these holes connect with the steam space of the boiler  the stud needs to make a steam tight seal.  When I first encountered this on the Burrell it was a worry but todate I have had no leaking studs and as a result I decided to adopt the same procedure as I used on the Burrell.

I first ensure that the tapped hole is clean either by inserting a bolt or carefully running a tap through. In this case these was quite a lot of paint to shift so I used a tap.

Rather that use the double nut technique to grip the thread I use special adapters which screw onto the end of the stud.  I claim no originality for this idea as it was described in the Burrell's instructions.  A short length of hex bar is drilled and tapped with a blind hole.  This will screw on the end of the stud.  The clever bit is that a ball bearing is put at the bottom of the hole which stops the stud binding.  This ball bearing can be held in place with any gunge for example Folaic.  The advantage is that once the stud has been fitted the adapter is simply removed by sharply turning the other way.

With the stud already screwed into the inserter I wrap about 5 turns of plumbers PTFE tape around the threaded end that is going into the boiler.  I then carefully screw the stud into the boiler making sure that it is not cross threaded.  For this reason I always start the stud by hand before changing to a socket for final tightening.  The stud should be screwed home such that its unthreaded portion just jams when it arrives at the surface of the boiler.  This has to be done by feel since the saddle blocks the view and is made difficult since the PTFE tape increases friction.  The saddle studs are only M6 and it would be very easy, even with a short wrench, to strip the threads in the boiler - take care.

Monday: I have spent the day worrying whether my cylinder will fit on the boiler. The short answer is probably but here is the long answer.  Paul alerted me that the cylinder fixing studs may be too short so I decided to check.  I fitted two studs and dropped on the cylinder immediately I could see the studs were way too short but I was more concerned that the cylinder did not sit nicely on the boiler.   It was as if the saddle was made for a boiler of slightly larger diameter.  With it touching the gasket in the centre of the saddle there appeared to be about 1mm gaps at either edge.  ModelWorks have longer studs on order and these will be sent out to all constructors when available.

The cylinder temporarily fitted to the boiler
The problem corner is on the left

After a lot of measuring, head scratching and mathematics  I concluded that the boiler was not perfectly round; the effective radius varying around the circumference.  The nominal radius should be 5.375" but the portion under the saddle was 5.22"  

Before getting too upset I decided to try and bolt the cylinder down.  I fitted the gasket dry as everything was going to come off and used some long M8 bolts as temporary studs.  Something must have had some give as the cylinder settled down on the boiler except in one problem corner.  Even here the gap was relatively small and I suspect I might have been able to close it if had I fully tightened the fixings.

ModelWorks are sending me some additional gaskets and I hope that with two gaskets fitted it will be enough to enable the saddle to make all round contact.  

Thursday:  I received an addition gasket from ModelWorks today together with a collection of studs.  With two gasket under the cylinder the fit between cylinder and boiler looked very good.  I covered everything with Folaic and began inserting studs.  It soon became apparent that the holes towards the outer edge would not line up.  The extra thickness of the additional gasket has the effect of moving the fixing holes out of line with the boiler.  A bit of maths reveled that the effect of raising the cylinder buy 1/16" would change the alignment of the holes at the end of the arc by 40 thou (1mm).  I struggled on hoping than by compressing the gasket using the centre fixings I could make the outer hole line up but I only managed to get the four centre studs in place at the front and back of the block.  I had two choices either remove the addition gasket or use a file to elongate the cylinder mounting holes.  I opted to remove the additional gasket as previously I had noted I had almost been able to close the gap.  With all the fixing tight I was able to bring the cylinder down onto the boiler and I am hopeful that I have made a good seal.

With the cylinder fitted to the boiler I was able to get on and fit the cylinder accessories. I have described this in the kit 13 account here.

With the boiler fixed the chassis was manoeuvred into position


The central support bracket was 1/2 a hole out


The boiler fitted between the chasis rails

Saturday: Today I tried the boiler in my chassis.  The boiler is way too heavy to lift without special equipment.   Richard sent me this picture of the setup he used to lift his boiler into the chassis.  He says even with the host he found it difficult.

I removed the support bracket from the hornplates on the right hand side and then simply dropped the chassis rails over the boiler.  Note: I had previously attached the front chassis saddle to the boiler.  I supported the rear of the chassis at roughly the right height and put in one fixing screw on each side thought the chassis rail into the saddle.  I then fine tuned the rear support to the correct height and inserted all the saddle fixing screws.

Both of the rear support bracket F41402& F41404 fitted easily with all fitting holes lining up.  The alignment of the central support brackets F41401 &F41403 was not good and I estimate that the vertical alignment of the fixing holes were out by half a hole.  I elongated the top and bottom fixing holes so that I could bolt the brackets into their correct positions an I plan to sort out the other holes when I remove the hornplates for painting.

Having confirmed the fit of the boiler between the chassis rails I returned them to storage propped up against the back wall of my garage.  

I found my technique of fitting the chassis to the boiler very easy and stress free and I recommend this method to anyone who can make the chassis light enough to lift.

Hornplates hung up to dry

I like to give paint several weeks to go hard before handling as I find paint remains soft for a surprisingly long time.  I shall leave them hung up to dry until kit 18 arrives at which time I will permanently fit them to the boiler. 

Scene in the back of my garage this morning before construction restarted


Final assembly of the hornplates

I started by fitting the manhole cover and firehole door which I had previously painted.  The instructions call for the manhole with gasket to be fitted dry without any sealing compounds and for the nut on the fixing clamp to be only slightly tightened.  I hope this provide a good seal.

A few weeks ago I was contacted by Richard to say that his hornplates when fitted to the boiler were too far apart and not parallel.  The inside faces of the hornplates should be 10 15/16" apart.  Richard problem turned out to be distortion caused to the RH hornplate by the fitting of the dummy boss.

I am now ready for the crankshaft which I hope Steam Traction World will shortly be able to deliver.  Once this arrives I place to get the engine running on air.  This will be described in the kit 18 account.

Lifting the Burrell's transport to the ceiling of the garage to make room to assemble the Foden.

Tuesday 19 August:  Today I moved the Burrell into it's winter quarters and lifted it's transport trailer to the ceiling of my garage.  Now the garage floor is available I will be able to assemble my Foden but it will have to be out by March 2009 so I can prepare the Burrell for the 2009 season.  Since starting the Foden it has become clear that I do not have room for the Burrell and Foden and I plan to sell  my Foden to the higest bidder received by the end of March.