Member postings for Martin Johnson 1

At one time Hemingway did a kit for a Dore Westbury look alike head. Construction (and drawings) was written up in earlyish MEW. I am away from home so cant look up the issue numbers. Perhaps some other kind soul will.

Martin

That might be why you haven't done it yet. Tools are there to be used, not preserved.

Martin

Do you already have some babbitt or whitemetal? If not expect eye watering prices. I purchased some a few years ago to make a steering nut.

Martin

Getting the new seal needs care with larger diameter, thin sectio seals - they can buckle at the vital moment. Don't ask......

Cut a disk of at least 3mm plate, or a hog end of bar if you have one slightly smaller thaan seal OD. Preferably press in, or pull in with scre and stongback.

Martin

My guess is that it would not have a capacitor. You can achieve the same result with windings of different inductance, so one winding will be lots of turns of thin wire, the other fewer turns of thick wire. It is probably the thin one that has failed.

Martin

Start with 6mm square bar. Mill the end slot & tab. Grip in 4 jaw and turn 5 dia. Reverse & grip in collet to turn 3 dia.

Martin

Hi Nigel,

I don't know of a full size wagon with turbo generator, I was hoping to do something a bit off piste. Itake your point about effy in relatively small sizes, 70% is probably optimistic. I shall be using LED lamps, but the main current demand is a winch and motor mover for shifting the thing when out of steam. It would be useful to spend idle time at a rally generating to recharge ready for loading to go home. Iam thinking more along reciprocating engine lines now as turbines can drone like an angry wasp.

Martin

One full size loco I worked on had the dome made in 2 pieces - a hemisphere top silver soldered or brazed to a cylinder. The joints were caxtellated and easily seen close up. The bottom of the cylinder was flared to sit on the boilrt.

Martin

Hello Andre,

Miracles do happen as I found your post, and it is not even Christmas.

I am intrigued by what you might mean as semi turbines?

Martin

A blast pipe (or jet pump) has a maximum effy. Of arond 30 to 33%. Typical locomotive configuration will be well bolow 25%. Cant help with natural draught chimney.

Martin

The book is available at https://b-ok.cc/s/Exactly? As an epub free of charge. Also lots of other model engineering stuff.

Martin

Have you had a look at Traction talk forum? There's several detailed build threads on ther to give a good idea of challenges and solutions.

Martin

I am nearing the end of a 7" scale steam lorry build. Machine tools used:

Kerry 11 x 23 lathe

Tom Senior M1 mill.

Try looking at lorries, the big bits are smaller in a given scale. Alternatively contract out the really big bits, most suppliers also do a machining service for flywheels, final gears, crankshafts etc.

Dont forget you will also need to manhandle, tansport and house a sizeable lump.

Martin

I had two look alike sanders to the Sheppach from another supplier, both ended in smoke with failed capacitors within days. Third one from another different supplier is Ok but very poor build quality - the disk has stupid amounts of swash due to rubbish machining on the hub. The belt drive drum is also very loose on the drive shaft, same Chinese tolerances!

On the upside it has run for over 10 years on metal of all sorts. I use it mounted on the wall to save space, with home brewed dust extract and work rest. Very noisy though. I never use the disk sander.

I think i will build the next one from scratch.........

Martin

I also have the second type from AIM tools. Very good and I am building a 7" scale steam lorry with it, so it is not cossetted!

Martin

My first lathe was an ML4 and the cross slide screw is indeed 12 tpi, which whith dials calibrated to 80 divisions is a recipe for making parts consistently undersize. Go do the maths, but don't ask me how I know! Anyway, I still have the tap I made to cut a bronze nut whichh was loctited and grub screwed into the saddle.

Having said that, if I was doing it all again I would use 20 tpi which I think could be 3/8 BSF (or isit 5/16?), then remake some decent size dials.

If you want the 12 tpi tap, PM me.

Martin

Can I state the flaming obvius here? The smaller your workshop, the cheaper it is to heat.

Therefore, choose your equipment carefully, place it efficiently in a small footprint. Then worry about insulation & heating. I also have an unheated area for welding, grinding etc. Woodwork gets done mostly in twhe unheated garage (car booted out).

For reference I live in the Scottish Highlands near Cairngorm 800 feet above sea level, we know a bit about winter up here.

Martin

My short answer for metalwork is to not do it that way. Surface plate, rule stand and scribing block or vernier height gauge are the right tools for precision marking out.

Martin

An associated problem is where to buy decent terminals of whayever type. Ebay is awash with tin foil rubbish, but decent gauge stuff is rare. Any suggested sources gratefully received......

Thanks in advance,

Martin