Connoisseur Models? N7 Rebuild/Upgrade

This one is a little different for me, the gent that I am building the J6 for is building a layout based on Hitchen in the late 1950's/early 1960's and N7's were there a plenty. He has several N7/5's but needed at least one N7/3 so he bought one already built from Ellis via eBAY. Edit, to add that although it came in one of Ellis's boxes I was incorrect and it wasn't bought from Ellis.

It's lacking some detail and has some that needs to be removed.

The photos below are as it came to me and are copyright of my customer and used here with his permission.





It's new identity is to be 69618 and I am working to a supplied photo of the engine as at 23rd May 1959
So far this is what I have observed needs to be done:

• Window guards to rear cab - half height of windows
• Condensing pipes - remove
• Safety valves, remove base and refit/replace
• Vacuum ejector pipe – boiler to cab
• Remove valve from dome
• Hinge on smoke box door
• Move lamp iron from top of boiler to smokebox door
• Step on Piano front
• Knobs on Piano front
• Oilers under smoke box door – either side
• Steps on tank fronts
• Plate in coal rails
• Glaze cab
• Reversing lever and fittings under boiler to help disguise worm gear from motor
• Move steps from outside of valance to where they should be.

Before going on holiday 3 weeks ago I bought 10 bottles of nail varnish remover from Wilkinsons (Wilcos) and left the body to soak in it while I was away.

Quite a few bits dropped off and others were coaxed to release their grip followed a scrub with Bar Keepers Friend got it to a point where I was able to use the microflame to remove other parts

 

Thanks Ian,

I had best not disappoint then.

The application of a bit of heat removed a few more bits and pieces







First thing this morning I placed a biggish order for parts with Laurie Griffin and one with Walsall Model Industries for the Buffers.

The jury is out at the minute as to whether I replace the Westinghouse Pump with one from Ragstone.

Next job is strip the chassis down for it's dunk in the paint stripper.

 

I forgot to add photos of the roof which has cleaned up nicely too.

 

Despite cleaning up the N7 and ordering the bits for it the mojo has been a bit lacking since I returned from my jollies so I decided to have a play with my lathe to see if I could kick start the mojo.

My first effort turned to dismay when I found that the tail stock didn't centre on the work piece and then when attempting to turn a short length of brass rod, it was turning off centre - great for turning crank shafts perhaps but useless for what it's designed for.

All sorts of fears went through my mind from worn bearings to faulty chuck. So I started a bit of trouble shooting and having swapped the 3 jaw chuck for a Jacobs drill chuck I found that the running with that was concentric and I turned the thicker end of the example below. This left the fault being with the 3 jaw chuck. I very quickly deduced that when I have taken the jaws out to clean them I hadn't got them back right. I tried each combination in turn trying to get them to go back evenly by screwing them on but didn't have any luck. In the end I had to strip down the chuck by removing the mounting plate and then removing the circlip from the back to get the front plate far enough away from the back plate to allow the three jaws to slip over the spiral and into the centre equally spaced. Then I pushed the font and back plates together and reinserted the circlip. All looked well so I added the mounting plate and tried again.

Thankfully this seems to have resolved the problem and the other end it the result from using the 3 jaw chuck.



Now by now you may be wondering what this has to do with the N7 and the answer is absolutely nothing but it did restore my mojo so being in a machine tool mood I set to drilling out the buffer stocks for the fake mounting bolts.

A while ago I mentioned that I had a Proxxon Dividing head. Up to now I haven't actually used it but it was bought with this very thing in mind and it very quickly turned these



Into these



I then proceeded to make some fake nuts by filing hexagonal flats on some microbore tube
Using a pin vice as a guide - A technique that I picked up from Nick Dunhill.



Once filed up short lengths were cut off using a scalpel and a piece of 0.8mm rod inserted into the tube. This rod was subsequently cut to length and soldered onto the buffer shanks to give these



I took the photo when I had done two but all four were done before I packed in for the evening.

 

Thanks Paul,

I must admit that it's the little details that float my boat...

 

One of the more difficult aspects of the refurbishment of the N7 in my mind was the half height coal bars on the rear windows of the cab and I had been wracking my brains as to the best method of drilling the rear of the cab in situ to get the holes both in a line and equally spaced while not being able to get the drill bit at 90 degree to the workpiece.

At the same time I was also struggling from the photos that I had to work out just how many bars there are as luck would have it a bit of web surfing turned up a partial shot of the back of the cab back of the preserved engine and this a is a further snip of that showing my get out of jail free card



This meant that I could make them off the loco and fit them as a single unit. Some time later making best use of the Proxxon mini drill and coordinate table, had me with two pairs of strips each with 9 x 0.5mm holes 1.2mm apart. The eagle eyed will also note that I have put additional holes in each end for the retaining bolts.

Before packing it in for the night I had the first one soldered up ready for fitting.





I just need to do the other and then I think that I have broken the back of the difficult bits so I will return to the J6 until the rest of the parts orders arrive.

 

And then there were two, I successfully made the second grill last night so that's a bit of a relief.

I am still awaiting some of the replacement bits for the chassis - they were ordered later after my customer decided that he would like the chassis improved too.

 

The replacement castings for the brake gear arrived this morning from Ragstone. Sadly this plnker quickly realised that I didn't order brake shoes and hangers so a further order is required...

All are cast brass apart from the brake cylinder and westinghouse pump

 

It's the folding flap that covers the cylinder covers between the front frames under the smokebox door.