New Peppercorn A2 “Blue Peter” in 5” Gauge

[RGR 60130]

That's interesting Richard. It's good to know I wasn't imagining it.

Reg

[RGR 60130]

Progress has been very slow lately – my model engineering is something I only do when I’ve not got anything else better to do, it’s far from my reason for living!

The steel tyres have now been fully machined and came out well. The next step is to start sorting out the axles.

Reg

DSC00072 by reg.rossiter, on Flickr

[44767]

Those look great, Reg. Well done!

[RGR 60130]

Having been busy of late fitting steel tyres to my A1, I’m now back to the A2. I was going to make the axles but I need to check the clearances between the bogie wheels and the outside cylinders on my mock-up so I have therefore started on the bogie.

My M.L.Breeze design Peppercorn A1 has a fabricated bogie centre which involves quite a lot of work and isn’t particularly prototypical at the end of it so I decided to go for a casting. After looking at a couple of them, I eventually decided on the casting from the Clarkson A3 which is available from Blackgates Engineering.

Machining the stretcher is fairly straight forward though there isn’t a lot of meat on the sides so a bit of care and attention is needed. The side plates bolt on with 19 x 8BA bolts which should keep them in place. In full size they used rivets but I’m going to stick with hex-head bolts. A blind man on a galloping horse will never see the difference. There’s a bit more finishing work to do on the casting but you’ll get the idea. I’m including a photo of the bogie fitted to ‘Tornado’ to show the arrangement I’m aiming to replicate.

Reg

DSC00118 by reg.rossiter, on Flickr

DSC00119 by reg.rossiter, on Flickr

DSC00122 by reg.rossiter, on Flickr

DSC01508 by reg.rossiter, on Flickr

[Jim]

You have done some superb work there Reg.

Jim

[RGR 60130]

The next items were a pair of plain stretchers made of 3/4” x 3/16” section with a couple of 8BA holes tapped in each end. Once again I used my beloved vertical slide. It’s easy to set up and very rigid. Also, using this arrangement you aren’t restricted on the length of job unlike on a mill or drill where the job has to fit between the drill and table.

DSC00124 by reg.rossiter, on Flickr

The bogie horn castings come in the form of 2 pairs in one stick. I clamped them to the milling machine table and moved the clamps around as I machined my first datum face. Having got that, I finished squaring them up by holding them in the milling machine vice. They now need separating and the ends faced to length.

The axle boxes came in the form of a stick of cast iron as supplied by Blackgates for the Clarkson A3. The machining procedure was similar to the horns. I separated them with a 3” diameter x 1/32" slitting saw running at 80RPM. The top and bottom faces still need machining.

The collection of bits is growing!

DSC00130 by reg.rossiter, on Flickr

Reg

[suctionhose]

"Your beloved vertical slide"...We had two that were the antithesis of beloved! Man, that's hard work Reg.

A milling machine with gravity 90 degrees from your vertical slide AND adequate table travel is so much easier!

Still, I had a note this week from a model engineer here that still uses a treadle lathe and hand powered shaper... I can't imagine!

[RGR 60130]

Mar 17, 2022 8:48:11 GMT suctionhose said:

"Your beloved vertical slide"...We had two that were the antithesis of beloved! Man, that's hard work Reg.

A milling machine with gravity 90 degrees from your vertical slide AND adequate table travel is so much easier!

Still, I had a note this week from a model engineer here that still uses a treadle lathe and hand powered shaper... I can't imagine!

Ross,

I do have 3 milling machines for milling but on a job where I want a repeatable set-up to put some holes in the end of a a bit of bar I always use the vertical slide. They can't get you for it - well not yet any way!

Reg

[suctionhose]

Reg, You got me there! I can see the convenience for that use...
R

[RGR 60130]

Pushing on with the bogie, the bogie horns were separated with nothing more technical than a hacksaw and faced to length in the vertical slide. The tool makers clamp was employed as a stop to give a repeatable set-up.

DSC00134 by reg.rossiter, on Flickr

Before fitting the horns I made the four horn-stays and roughed out the centre block.

DSC00136 by reg.rossiter, on Flickr

I also made a wider horn-stay that I could use to position the horns prior to drilling the 3/32” holes for the rivets.

DSC00140 by reg.rossiter, on Flickr

The bulk of the excess rivet material was removed with an end mill, leaving the last thou or two to be dressed off with files and emery.

DSC00145 by reg.rossiter, on Flickr

Each rivet hole was drilled to suit the casting – Drilling the holes in the frames first then hoping they appear in the correct positions between the webs is a big ask.

DSC00147 by reg.rossiter, on Flickr

There was just enough space between a group of 3 holes in the centre casting to drill a 3/8” hole to position the side control springs.

DSC00144 by reg.rossiter, on Flickr

This is progress on the bogie so far though I have some other bits started which I’ll include in the next update.

DSC00148 by reg.rossiter, on Flickr

Reg

[terrier060]

Lovely work Reg - I often think that making and building up the chassis is the best bit. After I have got mine running on compressed air and if it runs OK I find the boiler and platework hard going!
Ed

[RGR 60130]

Before moving on with the suspension arrangement I thought I’d better get the axle boxes finished. Some of the photos I took came out decidedly blurry so I can only try to illustrate the operations with what I have.

Firstly the axle boxes needed machining to the correct height so yet again I used the vertical slide while it was set-up and clocked in. With the repeatable set-up shown I could take a cut, remove the job, measure from the axle bore to the faces and take a bit more off as required.

DSC00152 by reg.rossiter, on Flickr

The oil holes needed to be at 55 degrees so I used a Wixey gauge to get the angle correct. The axle box at the other side of the vice keeps the jaws parallel.

DSC00155 by reg.rossiter, on Flickr

I knew from the drawing that the oil holes also needed to be 3/16” from the side and front faces. By putting a bit of 3/8” silver steel with a squared off end in the drill chuck it was easy to find the hole position within a couple of thou – never under estimate the accuracy of a Mk 1 thumb nail.

DSC00159 by reg.rossiter, on Flickr

To start the hole on the inclined surface I used a 1/8” slot drill. That was followed with an 1/8” drill (shown). Using the drill after the slot drill gave a pointy bottomed hole to guide the final 1mm drill which was fed ever so gently as it broke through into the axle bore.

Fortunately I didn’t get any drill breakages but with these axle boxes being symmetrical top to bottom, you could always turn them over and start again providing you don’t have a broken bit of drill poking into the bore.

DSC00161 by reg.rossiter, on Flickr

It’s important to remember that you need to make 2 left hand and 2 right hand axle boxes.

A blind 1/8” flat bottom hole was required for the suspension bridge pins so these were formed with a 1/8” slot drill, taking care not to go too deep and break through into the bore.

DSC00164 by reg.rossiter, on Flickr

And one of the completed ones-

DSC00166 by reg.rossiter, on Flickr

Not one of my most interesting updates especially for the experienced though hopefully it may help someone.

Reg

[RGR 60130]

A dose of man-flu has kept me out of the workshop this last week. However I’ve now managed to complete the bogie drawing. Every time I thought I had it correct and printed it, I’d find another glaring error etc. etc. I’m hoping I’ve got it somewhere near now, though I won’t hold my breath.

Reg

A2 Bogie Construction Drawing by reg.rossiter, on Flickr

[RGR 60130]

For the bogie wheels I found a set of four which I’d obtained as part of a job lot in the dim and distant past. It transpires they are Reeves castings for Nigel Gresley. Despite the surface rust they were quite crisp and appeared ideal without too much to machine off.

Ask ten people how to machine wheels and you’ll get ten different answers. For what it’s worth, here’s how I start the job. For me the front of the wheel is the first datum face and therefore it helps if it’s flat. I used a catch plate to do an initial ‘See if it rocks’ test.

DSC00182 by reg.rossiter, on Flickr

To show where the high spots were I cut the centre out of an 80 Grit double action sander pad, placed it on the catch plate and gave the castings a scrub on that.

DSC00186 by reg.rossiter, on Flickr

The result shows two diametrically opposed high spots. This isn’t unusual and can be caused by the pattern being wobbled side to side when removing it from the sand.

DSC00189 by reg.rossiter, on Flickr

A bit of work with a file and a few more scrubs showed a reasonably flat surface.

DSC00191 by reg.rossiter, on Flickr

The fronts of the wheels were put against the jaws in the lathe chuck and the back surfaces cleaned up. They were then turned over and the fronts cleaned up thus.

DSC00194 by reg.rossiter, on Flickr

At this point it is wise to check that all the spokes are a similar distance from the front face of the wheels. Any run-out needs to be sorted before progressing the job.
From here it’s a basic machining job which I described when fitting the steel tyres to the driving wheels. Be certain to get the inner face of the rim running true before boring the axle hole or you won’t get an even tyre line and it will look terrible as it runs down the track.

I finished off the suspension arrangement temporarily and made up the two axles such that I now have something to push up and down the breakfast bar – sound effects optional!

DSC00197 by reg.rossiter, on Flickr

Reg

[tincanhero]

Hi Reg,
Interesting stuff! I'm just starting a A4 by M.Breeze and your posts have been valuable.
Are you still building her?

One quick question, What's the drawing number for the bogie? 5007?

Regards, Matt

[RGR 60130]

Hello Matt,

The A2 build has been on hold since I broke my collarbone last year. After it healed I did some work on a motorbike, threw a hot-rod together to get it sold then started on another bike restoration. I might get back to model engineering again in the winter though that will probably be my A1 rather than the A2.

The bogie drawing is indeed 5007.

Another useful site is this one: a1peppercorn.com/

Reg