Northumbrian Build Thread

[peteh]

It's got a bit too hot to be in the shed now so a quick update on this mornings work - finishing the Pump eccentric arm. I have also modified the linkage by changing the pivot pin from one threaded both sides to a single side thread and a head - one less nut to work lose (although I will be using thread locker) and, in my mind a neater looking fit
Next job, when it's cooled down is to start on the vavle eccentrics.

Attachments:

[peteh]

Here are the valve eccentric straps as per noon today. You can see the size of the 'adaptor collars' I had to make to change from the smallest small bore I could make in the castings to the correctly sized valve eccentrics.One is almost 2mm thick

Once it has cooled off a bit I will see about the eccentric arms and also drilling the holes for the pins for the slip eccentric gear.

Attachments:

[peteh]

Just another quick update - Eccentric arms are now rivited in and they are set up together to drill the linkage hole, ensuring they have the same throw.

Will have to slow down for the next couple of days as forecast is 38/39 Celcius!

Attachments:

[peteh]

I have not been able to get into the shed for a couple of days, and probably won't for a couple more. I have had a progressivly worsening ric'd neck and ended up at emergency last night just making sure as none of the painkillers were touching it.

Long story short - as far as the Dr. can tell it IS a ric'd neck but I am now on such a mixture of opiates/anti inflammatries that I am not allowed near the workshop for a few more days - at least until the neck has settled down and I can come off the pills.

Sorry for the delay guys

[Smifffy]

Bummer!

Get well soon Pete.

Smifffy

[steam4ian]

G'day Pete

I am enjoying your thread. It is great to be taken through a build step by step.
Are there any 3.5" G tracks in Perth? If you are ready by the AALS convention this coming April you can bring the loco to SASMEE.

Sounds like your neck needs more lubrication; keep pouring in the appropriate fluids. Better not, could be interesting effects with the pills.

One point of satisfaction, it will be hot in Perth over the next few days. If your workshop is anything like my excuse for the same it becomes unbearable for most of the day. just noticed Stratco have evap coolers for $79 so I will go off and buy one. Still need a sweat bandana to keep the drips out of my glasses!

Regards
Ian

[peteh]

Hi Steam4ian,
my club, Northern Districts Model Engineering Society (NDMES) in Balcatta have 1", 2.5" 3.5" 5" and 7.25". South Australia is a fair distance from Perth mate - especially with a locomotive and family in tow

Thanks for the kind regards Smiffy

[Smifffy]

...but what a great drive it would be Pete :-)

[peteh]

Been there, Done that - twice

My brothers live in Queensland so I have driven over a couple of times. We may do it again once my daughter finishes school if I can get the time.

[Smifffy]

Cool, I did Cairns to Darwin back in 1988 and then in 2010 managed Perth to Darwin.

Both fantastic experiences :-)

[peteh]

Finally! I have managed to get a little more done! Finished the stop collars and added valve eccentrics and stop collars to the driving axle. Let the build re-commence ;D

Attachments:

[peteh]

Well a very mixed bag today.

It started out so well (with thanks to Queen) with the silver soldering of the handrails. Very happy with the result.

I also cleaned up the hand pump while I had some fresh citric acid which is looking marvelous. Made the handle for the pump and it pumps well - even before I put in the O-ring on the ram

Attachments:

[peteh]

The next job was the silver soldering of the inlet and outlet fittings to the axle pump, one goes on the body of the pump and the other on a bolt in fitting. I obviously used too much heat - both fittings have melted and sagged. Not sure if I can rescue the casting or have to fabricate a new pump from materials in hand.

Attachments:

[Deleted]

Don't worry Pete, you aren't the first....

I've found that brass fittings, especially those with small bits attached, react badly to too much heat. However, I've never had a problem with good quality bronze. Were you soldering brass to bronze?
JB

[brozier]

Hi Pete,

Did you heat this from the top (as seen in the pic)? What you have is the classic attaching a big thing to a small thing. The trick is to get the big bit (bronze casting) up to heat first and keep the torch flame away from the brass bits.

If you can balance it across a gap between two fire bricks you'd be able to direct the torch underneath so the flame only touches the bronze part.

Heating from the "far-side" of the joint is generally the best way as the Silver solder will flow towards the heat.

I'd say you can drill out the melted bits of brass and try again.

When I'm making up stuff like this that only needs a tiny bit of solder I use the smallest diameter wire I have and rest it on the joint before I start heating. That way it will flash round as soon as it gets to the right temp. Takes a lot of the guess work out.

It's all a learning experience ;D

Cheers
Bryan

[peteh]

Gunmetal casting and thin brass threaded parts. The flame was aimed at the junction of the casting and threaded part.

The right hand part was two small brass parts, independant of the casting - I just put them together on the pump body to make the photo easier

Thanks both for the reassurance, and telling me I am not a ground breaker Unfortunately the silver solder and brass have flowed into the pump body holes and also ruined the ball seat, so I think a new body is in order.

[brozier]

Hi Pete,

I don't know how expensive this casting is but I'd have a go at rescuing it - you tend to learn more from correcting mistakes than when things go right

Can you not re-machine the holes and re-make the ball seat slightly further into the casting? As long as you keep the ball lift the same a slight change in position won't hurt.

If you've already made the part which controls ball lift you could always soft solder (or Comsol) a bit extra on!

Cheers
Bryan

[peteh]

Brozier - It's not so much the cost of the casting, but the delay in getting stuff shipped to Australia from England. It's also not unusual for the cost of the postage to be similar to the item brought, thus doubling the cost.

Not much done yesterday due to having to prune trees and fill a skip we've had on order since November - Council provides up to three skips or tip passes a year.

However I have already turned up a new pump body and valve body so just have the passages to drill and I can have another go. This time I have left a fair bit of metal beyond the Tee so that I can grip the piece after silver soldering to finish the ram bore last, which should avoid any distortion issues from the heat affecting the bore.

[peteh]

Well I can finally report a little progress. Valve and pump eccentrics all done and fitted. New axle pump made and fitted with packing. I'll need to give the axle a turn over with a cordless, very slowly, to help remove a little stiffness.

Attachments:

[peteh]

Okay - onto the rocker assembly. I had two problems here with the laser cut pieces.
1/ The holes are not square to the material, I think this is due to the angle of the cutting head as you can see the angle on the outside of the pieces.
2/ The previously mentioned hardened holes which are not quite round ;D

Solution was to cut new ones. Drilled holes in a spare piece of 3mm plate and cut out. Used laser cut arm as filing button for the whole piece ;D

Photo shows laser cut and 'home brew' side by side, laser cu on left. Still have one more to cut and file.

Attachments: