Kit 11 - Cylinder

ModelWorks 4 inch Scale Burrell Agricultural Traction Engine
I collected kit 11 from City link 27 August 2004  
 


The contents of kit 11 laid out for checking

Friday: Unlike last month the packing was excellent and everything arrived in pristine condition.   

I was disappointed to read that the boiler will not be delivered next month.  It seems that it has taken longer to get the Pressure System Safety Regulation paperwork sorted out resulting in delivery being postponed to the year end.  Modelworks plan to keep on schedule by jumping  ahead to kit 15. The longer I have to delay bolting things together the greater the chance that I will lose something. Virtually all available storage in and near my workshop has bits of Burrell in it.

Below is an enlarged view of the cylinder and side valve.  I was pleasantly surprised to see that ModelWorks have incorporated a spring to push the side valve against the valve face.  This will prevent the valve coming away from the face at startup ensuring that the engine can be started smoothly.  When this happens with my POP I have to crack the regulator wide open to push the valves back against the valve faces.


 
 Saturday:  Made a start on cleaning up the cylinder block.  As usual I used the wire brush in the drill plus a bit of grinding from the mini drill.  The next job was to clean up the valve faces which, as per ModelWorks suggestion I glued some emery paper to the valve block. 

 Valve block with emery paper attached

The picture above right is before and the picture right after.  I found I hand to replace the paper several times, finishing with 400 grade.

Don't over do it it is more import to keep the ports flat than to get them polished. See

A small triangular shaped notch has to be filled on the regulator valve face to provide a controllable slow speed.

Regulator Valve Face

This is something I must do to my POP.

My final activity of the day was to give the cylinder a through washout with paraffin.  Once the plugs are fitted it will be difficult to remove the machining debris. 

16/1/06:  I have "moved" the notch to the other side so that I can setup the regulator such that pushing it forward makes the engine go.  
 

 The valve face before clean up
The valve face after clean up
CLose of on notch on requlator valve face
Sunday: It was a struggle to fit the 3/8 BSP plug in the side of the cylinder block.  The plug needed to be fully inserted to allow the side valve cover to fit.  With four turns to go it ground to a halt.  I was sourly tempted to omit the plug and rely on the valve chest cover but I persevered.  With the block on the floor and 15in of pipe to extend the allen key I was able to use my feet to both hold the block and turn the allen key.  Sorry no picture!

Fitting the saddle to the block was straight forward (I recommend fitting the BSP plugs first as once the saddle is fitted the block will not lie flat).  I cleaned up all the mating faces on the block with wet and dry paper supported by a flat backing (a long thin angle plate).  It took a while but I achieved a near mirror finish. 
 
Monday:  Today I painted the cylinder block with high heat black gloss. 

The paint is "Halfords High Temperature Engine Enamel Paint – Gloss Black". It says on the can that it is formulated to withstand temperatures up to 450 deg C

Since I am not in a hurry I will be giving the paint plenty of time to harden before final assembly.
 
Wednesday 8 Sept: 

Prompted by an e-mail from Mike I assembled the valve chest to discover two snags.  The valve buckle fouls the ledge at the bottom of the valve chest (red arrow) and the studs are too short for the valve chest cover.  Steve is aware of these issues and we will be asked to return the valve buckle for modification in the next kit's instructions.  Apparently 1mm needs to be shaved off the bottom of the buckle to match the 1mm that has already be shaved off the top. My inclination is to use my mill to correct the problem.

On the stud front I shall only loosely fit them and wait for longer replacements from Modelworks.  Steve also indicated that the studs are too short for the whistle and that these will be replaced at the appropriate time.
 
Thursday: Today I tackled assembly of the cylinder block in earnest.  It took some time to fit the studs but I soon got into a routine.  

Modelworks supply the piston as an assembly with the ring fitted because the cluput piston rings are easily broken.  At first sight I thought fitting the piston was going to be tricky.  I had to remove one of the studs to allow the buckle on the supplied jubilee clip room. This done the piston went in at the first attempt.  Because I though this step was going to be tricky I made the foolish decision to paint everything before performing a trial assembly - silly me.
Piston 3 inches in diameter Assembled piston (piston dia is 3inch)
 
17/2/06: ModelWorks have supplied a new piston with a single Cluput ring mounted in the centre.  This is to avoid a problem experienced by some constructor where the ring was trapped in the steam ports and was shattered.

On assembly of the rear cover I found some slight misalignment of the mounting and gland holes.  The most notable effect was on the piston rod gland whose holes had to be moved sideways before it would fit.  Note: The error was on the rear cover on which the stud positions were on radii that varied by 20 thou. 

Not wanting to be held up I decided to remove the 1mm (39thou) from the bottom of the valve buckle.  I used my mill but I am sure there are other ways of doing this.  The finish does not have to be perfect since the buckle will be hidden and the machined face is not in contact with anything. (The net effect is to make the wall at the top and bottom of the buckle the same thickness)  Constructors not able to do this themselves should not worry since ModelWorks will be offering to perform this task.  While it would almost fit before the valve now moves sweetly.
 
Constructors wothout facilities will be asked to return to MW
 
My last task this evening was to fit the spring inside the valve block.  See picture above.  I expected this to be a 5 second job but I found the the spring was a little too large for the hole in the valve block.  It took considerable longer as I had to wind up the spring to slightly reduce its diameter.

Saturday 11 Sept: I put the last few components on the cylinder block today.  This kit has been satisfying since I have been able to assemble all the parts supplied into one assembly any not be left with a bag of bits for later use.


 

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