Author Topic: 3.5" Northumbrian Loco  (Read 2178 times)

Offline Baner

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3.5" Northumbrian Loco
« on: July 03, 2018, 03:36:21 PM »
Hi

It has been so long since I started this loco that I can't remember when I did. The original was serialised in Model Engineer beginning in 2009 so I'm guessing I begun maybe 2010. In that time there's been brief flashes of activity followed by years of idleness. I'd recently got money enough to buy some more of the castings and so set to work again.
Here's the progress so far:
Northumbrian by DAVID BANER, on Flickr

Northumbrian by DAVID BANER, on Flickr

Couple more:

Northumbrian by DAVID BANER, on Flickr

Northumbrian by DAVID BANER, on Flickr

Dave.

« Last Edit: July 05, 2018, 01:10:23 PM by Baner »

Offline Baner

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Re: 3.5" Northumbrian Loco
« Reply #1 on: July 03, 2018, 04:04:03 PM »
First little job was to finish off the front wheels. The crank pins were all that was left:

Northumbrian by DAVID BANER, on Flickr

Pretty simple parts.One end of piece of 5mm Silver steel was turned down to 4mm, the other end was turned down to 3.2mm and threaded 5BA.

Then the wheels were clamped to the mill table, orientated so that the drill would break through safely in the table slots. A piece of 8mm HSS was chucked and used to line up the axle hole with the spindle.

Northumbrian by DAVID BANER, on Flickr

The DRO was zeroed then the chuck moved 14.2mm across and the crank pin hole drilled and reamed 4mm. 

Northumbrian by DAVID BANER, on Flickr

Finally the Crank Pins were Loctited home. (The stop pins on the eccentrics were loctited at the same time.)

Northumbrian by DAVID BANER, on Flickr

The couplings will be next and after that hopefully start to tackle some castings.

Dave.
« Last Edit: July 05, 2018, 01:17:18 PM by Baner »

Offline scc

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Re: 3.5" Northumbrian Loco
« Reply #2 on: July 03, 2018, 07:40:54 PM »
 :ThumbsUp:Nice

Offline zeeprogrammer

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Re: 3.5" Northumbrian Loco
« Reply #3 on: July 03, 2018, 08:12:05 PM »
Looking great thus far and I'm looking forward to more.  :ThumbsUp:
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Offline Baner

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Re: 3.5" Northumbrian Loco
« Reply #4 on: July 05, 2018, 01:40:30 PM »
Thanks Terry and Zee for looking in.

The couplings are next. Enough 3/8" square stock is cut to length to make 2 couplings. It is faced off, centred and spot drilled on both sides:

Northumbrian by DAVID BANER, on Flickr

The piece is moved to the lathe and centered in the four jaw:

Northumbrian by DAVID BANER, on Flickr

It's then turned down to 4.7mm for 12.7mm and threaded 2Ba:

Northumbrian by DAVID BANER, on Flickr

The process is repeated on the other side to give this:

Northumbrian by DAVID BANER, on Flickr

Dave.

Offline b.lindsey

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Re: 3.5" Northumbrian Loco
« Reply #5 on: July 05, 2018, 01:47:15 PM »
Nice looking loco David. Looking forward to more of your progress on it.

Bill

Offline Baner

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Re: 3.5" Northumbrian Loco
« Reply #6 on: July 05, 2018, 02:18:05 PM »
Thanks for looking in Bill

Continuing with the couplings. The material is then cut in half and clamped in the mill. The threaded section is standing on parallels whilst the square is butted up against the stop which is flush to the side of the vice. The square section is indicated to idiot check the set up:

Northumbrian by DAVID BANER, on Flickr

Part is then milled to finished height and a 3mm slot drill is run through, 4 passes to depth and  2 to finish sides. Light cuts are needed to stop the part being kicked out of the vice:

Grinding vice by DAVID BANER, on Flickr

Next is to drill a hole through the forks but a drawing review showed a minor problem:

Northumbrian by DAVID BANER, on Flickr

These 2 couplings are supposed to be joined together with a pin, but as drawn, (guessing at all the missing dimensions) the hole is in the wrong place, or the slot not deep enough or the radius is wrong or a bit of everything. I decided instead to reduce the width to 1/4":

Northumbrian by DAVID BANER, on Flickr

Then drill through 1/8" at 1/8" in from the edge. I then radius the part on the disc sander. Set up here is simple: a bit of scrap sheet steel is drilled through near the edge, a bit of round stock is inserted to use as a pivot and the part is turned back and forth by hand:

Northumbrian by DAVID BANER, on Flickr

Not the most accurate solution but very quick and good enough for this part:

Northumbrian by DAVID BANER, on Flickr

Dave.
 

Offline Baner

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Re: 3.5" Northumbrian Loco
« Reply #7 on: July 10, 2018, 01:39:31 PM »
Started work on the axle pump. I thought the casting would be a bit better than it was -  getting two cylinders perpendicular doesn't seem very difficult...
Anyway, bit of eye balling got it clamped in the vice near enough, and flats were very lightly cut on the port face and chucking piece:

Northumbrian by DAVID BANER, on Flickr   

The part was flipped onto parallels and the process repeated giving two parallel references:

Northumbrian by DAVID BANER, on Flickr

Flipped on it's side and clamped on the references a third larger flat is machined perpendicular to the last, then flip again and repeat:

Northumbrian by DAVID BANER, on Flickr

This gives a place for the vice to grip well enough to machine the ports.

Offline Baner

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Re: 3.5" Northumbrian Loco
« Reply #8 on: July 10, 2018, 02:17:56 PM »
Now that I can grab the casting properly the ports are fairly simple. The port face is milled to finished height, and drilled through 3.8mm. Following that the port is drilled 5.5mm to about 8mm deep, and the top 4mm tapped 1/4" x 40:

Northumbrian by DAVID BANER, on Flickr

A stainless ball needs to seal on the lower face so a cutter is needed to form a convex surface. A simple D-bit is made for the task:

Northumbrian by DAVID BANER, on Flickr

 The through hole is then reamed. Common practice to seat the ball is to hit it with a hammer, though I've heard pressing it in is better or maybe lapping. Does anyone have any experience or suggestions?

Moving on, the part is flipped and the other port receives similar treatment.
A side port is also required for the water outlet. The part clamped on its side and a piece of 4mm silver steel is inserted through the port. An edge finder is then touched off on the side of the rod to find the port centreline.

Northumbrian by DAVID BANER, on Flickr

 The 4mm rod is then removed and the port face edge is found. The table is moved in 5mm and drilled through breaking into the port. Final operation is spot facing to provide a seat for a future bushing:

Northumbrian by DAVID BANER, on Flickr

Dave.

Offline Baner

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Re: 3.5" Northumbrian Loco
« Reply #9 on: July 10, 2018, 02:53:49 PM »
I hope I'm not posting to much detail about simple operations; I enjoy reading about set ups, so I'm tending to post about them too. That said I'd welcome any suggestions as to how I might have done things better.
Next job was the pump barrel . A center point was eye balled then a little dimple was made with a spotting drill. Then into the four jaw holding on the previous milled flats, the dimple is centered and the barrel  lightly faced and center drilled. The tailstock center was brought up for support and the outside of the barrel trued up:

Northumbrian by DAVID BANER, on Flickr

The center was swapped for the fixed steady and the barrel faced to length:

Northumbrian by DAVID BANER, on Flickr

About the time of that photo I realized I didn't have a boring bar or measuring tools small enough to finish the bore. :facepalm: So I'll have to order a reamer to finish the job. Luckily everything is only rough  turned so the part can be removed and something else done on the lathe while I wait.

Dave.

Offline zeeprogrammer

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Re: 3.5" Northumbrian Loco
« Reply #10 on: July 10, 2018, 05:25:00 PM »
I hope I'm not posting to much detail about simple operations;

Not from my standpoint. I have a lot to learn.

I did some googling about the Northumbrian but I'm not sure I'm looking at the right thing.
Do you have a photo of what you're building?
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Offline crueby

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Re: 3.5" Northumbrian Loco
« Reply #11 on: July 10, 2018, 06:24:48 PM »
I agree - detail on operations is great, there are so many ways to do things, I pick up new techniques all the time from builds like this!
 :popcorn:

Offline Baner

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Re: 3.5" Northumbrian Loco
« Reply #12 on: July 11, 2018, 02:26:05 PM »
Thanks Zee and Chris, I'll carry on then.

The engine is designed by Tony Weale and is supposed to be an updated version of 'Rainhill', a freelance design by LBSC based on the first successful locomotives. It's basically a boiler on wheels, Zee.
Here's a photo of Tony's engine:
Northumbrian by DAVID BANER, on Flickr

And this is one completed by Doubletop whose build log you might have seen a long time ago:

https://www.homemodelenginemachinist.com/threads/small-locomotive-boiler-me-northumbrian.14718/

Doubletop Northumbrian by DAVID BANER, on Flickr

There are a few old drawings of the actual engine floating around but the best one I've found is this:

Northumbrian3 by DAVID BANER, on Flickr

I'm hoping to add a few bits and pieces to my model based on the drawings, and tidy up a few things that aren't great like the steam plumbing and backhead, and I'm not happy with the tender at the moment either.
It's not likely to get much if any track time so it'll need to look good on a shelf.

Dave.




Offline zeeprogrammer

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Re: 3.5" Northumbrian Loco
« Reply #13 on: July 11, 2018, 02:37:20 PM »
Thanks Dave! I'm looking forward to seeing more.
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Offline Baner

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Re: 3.5" Northumbrian Loco
« Reply #14 on: July 17, 2018, 02:50:17 PM »
Some work on Pump parts:
Here's a quick drawing to help make sense of these parts:

Axle Pump by DAVID BANER, on Flickr

Part 1 is the top cap which seals the outlet and limits ball travel, an easy little job:

Northumbrian by DAVID BANER, on Flickr

Part 2 is one half of a fabricated elbow. A bit of 3/8 round stock is chucked and drilled 3.8mm at 12mm deep. Being a ball seat this is also reamed 4mm:

Northumbrian by DAVID BANER, on Flickr

It's then of to the mill and cross drilled 4mm breaking into the previous hole. Then an 8mm slot drill cuts a counter bore:

Northumbrian by DAVID BANER, on Flickr

back to the lathe and parted off:

Northumbrian by DAVID BANER, on Flickr

There are two of Part 3 which are soldered onto the inlet and outlet as per the drawing. The end 4mm is turned down to 6.35mm and tapped 1/4x40. About 3mm behind is turned to 8mm to fit in the counter bore made in the elbow. A 3mm hole is drilled through, then a parting tool is used to turn a small boss to register in the 4mm hole in the elbow. This little boss is probably not neccesary but it seemed like it would help seal if the solder didn't flow properly. Then the lot is parted off:

Northumbrian by DAVID BANER, on Flickr

Dave.
 
« Last Edit: July 17, 2018, 03:07:44 PM by Baner »

Offline Baner

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Re: 3.5" Northumbrian Loco
« Reply #15 on: July 17, 2018, 03:07:02 PM »
The pump body needed prepping for the outlet soldering. A bit of scrap was chucked in the lathe, a section turned to 6.35mm and threaded 1/4x40. One of the port ends was screwed on and the live center brought up to support the other side. The outside of the port was cleaned up, the pump body flipped and the process repeated for the other side:

Northumbrian by DAVID BANER, on Flickr

The pump body is then taken to the mill and outlet port counter bored with the 8mm slot drill same as the inlet elbow. Missed a photo of that.
The parts to be soldered are fluxed and installed:

Northumbrian by DAVID BANER, on Flickr

Northumbrian by DAVID BANER, on Flickr

Parts are then soldered a dropped in the pickle:

Northumbrian by DAVID BANER, on Flickr

Dave.
« Last Edit: July 28, 2018, 10:13:30 AM by Baner »

Online Ye-Ole Steam Dude

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Re: 3.5" Northumbrian Loco
« Reply #16 on: July 17, 2018, 03:14:21 PM »
Hi Dave,

Love the looks of your Loco and will follow along.

Have a great day,
Thomas

Offline Baner

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Re: 3.5" Northumbrian Loco
« Reply #17 on: July 17, 2018, 05:04:00 PM »
Thanks for looking in Thomas.


I've done a little research into ball valves so I thought I do a post on what I found.

For those who don't know ball type valves are found all over model locomotives. They're variously called 'check valves' or 'clack valves' and elsewhere 'one way valves' or 'non-return valves'. Here's a picture:

Ball and seat by DAVID BANER, on Flickr
 
Basically liquid comes in from the bottom,the ball lifts, liquid flows. If it tries to come back down the ball is pushed onto the seat and flow stops. This only works if the ball seats properly.

The traditional method for creating the ball seat is to drill the port, ream, drop the ball on top the hole and smack the ball with a hammer, the ball is thrown away and a new ball is used in service. The ball is typically made of Stainless Steel.

My own experience is fairly limited, but I vaguely knew that some people had problems with sealing. So looking about I found, (in typical internet fashion) that the traditional method works for about the same amount of people that it doesn't work for...Some problems are as follows:

-Not hitting the ball hard enough.
-Hitting the ball to hard.
-Not reaming the hole.
-Not hitting the ball square on.
-Not replacing the ball after hitting.
-Cheap, out of round balls.

And solutions:

-Press, rather than hit the balls.
-Ream the hole. The hole needs to be perfectly cylindrical to fully contact the ball. Also, the reamer helps debur the seat area.
-Use a close fitting drift. Machine something up that's a tight fit in the bore to make proper straight contact with the ball.
-There's a few options for balls to use. Good quality stainless will generally work but is a bit wasteful and there can be minor differences between hit ball and service ball. Some people use rubber balls,(O-ring material) but they can get stuck on the seat or sucked into the pipe. There is also ceramic balls, (silicon nitride being the most common) which have the advantage of being super hard. These can form the seat without having to be replaced. They are a little more expensive than stainless steel, however.

So what I took from all that, and what I plan to do myself, is use the vice to press in silicon nitride balls with a suitable drift.

Two other things to consider. One is ball/seat size. Fortunately this resource is available:

http://ibls.org/mediawiki/index.php?title=Design,_Care_and_Feeding_of_Check_Valves

Here is a table from the link:

Everett Clem Ball Seat Table1 by DAVID BANER, on Flickr

I'm unsure how the data was compiled but plenty of people claim it sound. So in the case of my axle pump, the seat is 4mm or 5/32 so I've got 7/32 balls on order.

The other consideration is the finishing of the seat area. A concave finish such as left by a drill is considered unsuitable. Flat is better, and some say convex is best, though I found nothing definitive other than don't drill finish. I made a D-bit style cutter for a convex finish.

That's about it for balls. There is also another type of 'T' valve sometimes used instead of balls, (think tap washers) but I think I've gone on enough. If you got this far well done. I'm not anywhere near an expert on this, I've just collected other peoples experiences into this post. If there is anything I've missed (or got wrong) please chime in.

Dave.
« Last Edit: July 22, 2018, 02:32:14 PM by Baner »

Online Ye-Ole Steam Dude

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Re: 3.5" Northumbrian Loco
« Reply #18 on: July 17, 2018, 05:16:38 PM »
Hello again Baner,

A light compression spring centered over the top (outlet side) of the ball also aides in getting a good seal and it prevent swirling of the fluid causing the ball to chatter.

Have a great day,
Thomas

Offline crueby

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Re: 3.5" Northumbrian Loco
« Reply #19 on: July 17, 2018, 05:22:20 PM »
Great tips. I have always had trouble with them, one thing I had not done was ream the smaller hole, that could well be the issue I had.




Thanks!

Offline Baner

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Re: 3.5" Northumbrian Loco
« Reply #20 on: July 22, 2018, 02:24:48 PM »
Not a lot done on the loco this weekend, just one easy part, the axle pump ram:
Just a piece of 5/16" Stainless steel round cut and cleaned up to 26.2mm - whoops - drawing misread; make that 30.95mm:

Northumbrian by DAVID BANER, on Flickr

Then clamped in the collet block to mill a flat and cut a 2mm slot about 5mm deep:

Northumbrian by DAVID BANER, on Flickr

Then just drill through 3/32":

Northumbrian by DAVID BANER, on Flickr

Quick and easy:

Northumbrian by DAVID BANER, on Flickr

Shop time wasn't quite that dismal however, I also managed some lubricator pump bodies, half finished:

Lubricator by DAVID BANER, on Flickr

and put a new shelf up above the small lathe and mill for tooling:

Workshop by DAVID BANER, on Flickr

The old storage spot was the tool box under the lathe, but my two year old son has claimed it as his own and 're-organized' it all over the workshop.

Dave.



« Last Edit: July 22, 2018, 02:28:22 PM by Baner »

Offline Baner

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Re: 3.5" Northumbrian Loco
« Reply #21 on: July 28, 2018, 02:48:45 PM »
The pump continues:
I'd planned to ream the pump barrel to size, but for a similar price I decided to get something that would be used more than once:

Northumbrian by DAVID BANER, on Flickr

Small bore gauges are not super accurate but will get me close enough. Now I needed a small boring bar. I make these by cutting off a piece of HSS, then mill a flat on a length of silver steel (in this case 5mm). I cut a little piece of silver solder sheet, then stack all the bits up on and flux. Heat from underneath until the solder flashes, then grind to shape:

Northumbrian by DAVID BANER, on Flickr

So the pump body was chucked up again, and I'm back where I was 2 1/2 weeks ago. The bore is drilled, then slowly bored to size. Little boring bars like this are tricky due to deflection, but I got there in the end (and forgot a final photo):

Northumbrian by DAVID BANER, on Flickr

There's still more to go, this pump seems to be taking forever to finish...

Dave.



 


 

Offline Baner

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Re: 3.5" Northumbrian Loco
« Reply #22 on: July 30, 2018, 03:22:23 PM »
Next job is to turn down the barrel and thread it 1/2 x 32. I've got a Die to do the threading as the lathe is metric. I also managed to forget my lathe Die Holder is metric too. :wallbang:
More tooling! On the plus side the bigger lathe got some use for a change. An adaptor was turned up:

Northumbrian by DAVID BANER, on Flickr

And the barrel threaded:

Northumbrian by DAVID BANER, on Flickr

The pump ram is sealed by a gland that threads onto the end of the barrel. This part had been previous rough turned and threaded; it is now screwed onto the barrel and the bore finished to size, concentric with the barrel bore. Then off to the mill for some spanner flats:

Northumbrian by DAVID BANER, on Flickr

Dave.

Offline Baner

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Re: 3.5" Northumbrian Loco
« Reply #23 on: July 30, 2018, 03:46:07 PM »
Almost done!
I don't need the chucking piece on the pump anymore so that gets parted off and cleaned up:

Northumbrian by DAVID BANER, on Flickr

I need a lock nut to clamp the pump to the stay. I didn't have the right sized Hex bar so a stub of 3/4 round goes to the rotary table and get milled into shape. Then to the lathe and finished off:

Northumbrian by DAVID BANER, on Flickr

All that's left is to form the ball seats, (the balls have yet to arrive) clean up a bit and I'll probably paint the leftover raw cast areas. Here it is installed in the chassis:

Northumbrian by DAVID BANER, on Flickr

Dave. 

 
« Last Edit: August 04, 2018, 03:22:56 PM by Baner »

Online Admiral_dk

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Re: 3.5" Northumbrian Loco
« Reply #24 on: July 30, 2018, 08:48:57 PM »
Nice result on the pump  :ThumbsUp:

It looks to me like there is more than one eccentric on the axel next to it - are there more "service items" that will be driven from it ?

Best wishes

Per

Offline Baner

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Re: 3.5" Northumbrian Loco
« Reply #25 on: July 31, 2018, 03:39:16 PM »
Thanks Per -
The other two eccentrics operate the valves. Here's a drawing of the layout from the magazine:

Northumbrian by DAVID BANER, on Flickr

You can see the other eccentrics connected to a rocker shaft which transfers the motion outside the frame to the cylinders. The other 'service item', the lubricator, is connected to the same eccentric as the pump by ways of the pump ram; in post#20 I milled a flat on the ram - that is where the lubricator drive connects.

Dave.

Online Admiral_dk

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Re: 3.5" Northumbrian Loco
« Reply #26 on: July 31, 2018, 08:39:21 PM »
Thank you David  :cheers:

I hadn't realized that it was the main driving wheel axel I was looking at in the picture, but seeing the sketch certainly made it clear to me and explains it all  :ThumbsUp:

Per

Offline Baner

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Re: 3.5" Northumbrian Loco
« Reply #27 on: August 04, 2018, 03:03:47 PM »
Up next are the eccentric straps.
I'm not overly impressed with the castings I'd received, but they can be made to work. They're not going to match the drawing but the critical dimensions should be achievable. First a clean face:

Northumbrian by DAVID BANER, on Flickr

Now that there's something flat to clamp against I started to chase flat surfaces around the straps:

Northumbrian by DAVID BANER, on Flickr

 Eventually they all came in at matching, usable dimensions. Then the straps are marked for the next operations:

Northumbrian by DAVID BANER, on Flickr

Dave.
« Last Edit: August 06, 2018, 11:03:13 AM by Baner »

Offline Baner

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Re: 3.5" Northumbrian Loco
« Reply #28 on: August 04, 2018, 04:35:56 PM »
Now I drill through at 2.3mm and then drill 3mm clearance to 6mm deep, which is about half the depth of the side boss. Then the bottom half is tapped 6BA:

Northumbrian by DAVID BANER, on Flickr

Then it's over to the mill to split the piece in two. I'm using a 0.5mm saw here so I take it easy and make several passes to get through:

Northumbrian by DAVID BANER, on Flickr

Then 6BA studding is screwed in with a bit of loctite 243 for good measure:

Northumbrian by DAVID BANER, on Flickr

Dave.
« Last Edit: August 06, 2018, 11:06:42 AM by Baner »

Offline Baner

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Re: 3.5" Northumbrian Loco
« Reply #29 on: August 12, 2018, 03:29:53 PM »
I haven't had a lot of time for the loco lately so just a little bit more on the straps:
The rough cored hole leaves no reference for centering in the four jaw so a piece of flat bar is clamped in the tool post and the top edge brought to center height. Then we can eyeball the split line and the vertical center marked out on the surface plate back at post#27:

Northumbrian by DAVID BANER, on Flickr

Unfortunately the boring bar is going to hit the outside jaws, so the set up is changed and the straps are bored to size:

Northumbrian by DAVID BANER, on Flickr

The easiest way to machine the straps to width is to make a mandrel to clamp them to. The diameter is turned to just slightly larger the the strap's bore so they will clamp on without spinning. This also ensures the sides of the strap will be machined parallel to the bore:

Northumbrian by DAVID BANER, on Flickr

All three are done in the same way:

Northumbrian by DAVID BANER, on Flickr

Though these castings will be functional, as can be seen in the photo, they are not the nicest looking things. They'll be hidden from view inside the chassis, but I might need to do something about their appearance.
If I can figure out what to do.

Dave. 

Offline Baner

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Re: 3.5" Northumbrian Loco
« Reply #30 on: August 26, 2018, 01:28:13 PM »
There's not much to add I'm afraid. I've been busy, just not with loco parts. :( There's been a bit of shop re-organizing, work on another project, house and garden work, and preparing for a new baby due on Sept 4th...
All that's been done is slotting the eccentric straps for the rods:

Northumbrian by DAVID BANER, on Flickr

And cutting out some blanks for the rods themselves:

Northumbrian by DAVID BANER, on Flickr

I need to print out a drawing of the rod profile to glue onto the blanks to use as a shaping guide. Trouble is I don't have a printer at the moment, so I need to get to the local library and print there.
When I find the time...

Dave.

Offline zeeprogrammer

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Re: 3.5" Northumbrian Loco
« Reply #31 on: August 26, 2018, 03:15:00 PM »
Progress is progress.  :ThumbsUp:

And congrats on the upcoming event!
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

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Re: 3.5" Northumbrian Loco
« Reply #32 on: August 27, 2018, 12:16:04 AM »
Thanks Zee :)

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Re: 3.5" Northumbrian Loco
« Reply #33 on: September 01, 2018, 02:02:29 PM »
Alright, some progress!
I'd needed to profile the eccentric rods and my normal practice would be to print out a drawing to scale, glue it to a blank and have at with a file. Unfortunately my printer had long since died and I'd not been motivated to replace it. Turns out eccentric rods are the right sort of motivation:

Northumbrian by DAVID BANER, on Flickr

And after some drilling and filing:

Northumbrian by DAVID BANER, on Flickr

These fit in the slot previously machined in the eccentric strap. Whilst the cutter used was 2mm, and material used was 2mm, the fit was quite loose. This is an easy fix with shim stock. I keep a selection of sizes on hand for just this occasion. A small piece was cut and super glued to the rod (for convenience of handling):

Northumbrian by DAVID BANER, on Flickr

The pump eccentric strap was drilled:

Northumbrian by DAVID BANER, on Flickr

And finished by riveting the rod to the strap. The other eccentric straps will stay loose for now until more of the valve gear is made, in case any adjustments need to be made for fitting. I also managed to put some dings in the strap with the rivet snaps. I'll need to come up with some new snaps that give a little more clearance.

Northumbrian by DAVID BANER, on Flickr

Dave.