Workshop Part 2

First off – a warning. Myford lathe chucks screw onto the mandrel, therefore DO NOT USE IN REVERSE, as I said I did last time.


2015-11-13 10.10.17Now, here is the first photo. Why a boring bar in a vice? Well, the finish on the outside of the wheel was not the best (somewhere near the worst) so I brought along my biggest bar. Easy, put into a tool holder and carry on. Not so lucky. Had to take quite a few file strokes to get it down to a size to fit. At least I took it off the two sides adjacent to the holding slit!

2015-11-13 10.59.38Outside finished to size and an insert tool being used to bring the web clean and to then bring the rim to finished thickness. The depth of the web to the edge can then be determined and taken down to the required size.

2015-11-13 11.29.49That’s it. One side of one wheel done. Will update again when all the other sides/wheels are finished and I can make a tool to take out the middle of the web.

Don’t forget that the workshop is open to all our members. You can use it for any of your larger requirements. A Bridgeport mill has been acquired and will be installed shortly to fit alongside our larger lathe, for those of you who already have a Myford. Please note, I have cleaned up, good workshop practice to leave it ready for the next operator.

Just ask.

Alan Hooper

Using the Workshop

Evening all

I thought it might be of interest to show how the Workshop is operating. Today, on a particularly wet morning during the maintenance Friday morning, I have brought to the site the rear wheel castings for the 1″ Minnie traction engine. Some of you will remember that I spent most of the last exhibition machining some of the castings. Well I thought that I should perhaps get the large rear wheels to the same ‘roughed out’ standard. Now I know most of you will have the necessary machinery to do this at home, but I don’t, having only a 2.1/2″ lathe.

2015-11-06 10.05.21This is our machine, a ML7, refitted back in the workshop. If you come up to the site, please be aware that there must be two people in the workshop. Just basic safety as it is not like being at home. You must also remember to bring any tooling required although for this machine there is a fairly extensive selection available. Measuring tools are also needed.

2015-11-06 10.06.27This photo shows what I brought up with me.

2015-11-06 10.10.41Now, not wanting to teach all you engineers how to suck eggs, I’ll just run through what the procedure was I used. Tool inserted into post. Casting mounted via the inside jaws. The hammer is there to knock the casting into a reasonably circular orbit and the chuck tightened.

2015-11-06 10.33.24Now, I only intend to rough machine these castings rather than do all the cutting in a single stage. Time consuming maybe, but a lot safer for those of self taught machinist! Unfortunately the topslide would not let me reduce the diameter across the complete face so another set was required.

2015-11-06 11.23.53This picture shows a boring bar mounted upside down and with the lathe running in reverse. Much to small a boring bar but nothing else was found on site and you guessed it, I didn’t bring one with me. It did it, though there is a lot of chatter marks.

I did have two more photos, but the site seems not to let me add them to this post. No doubt I’m doing something wrong – again. They where to show that the front face was cleaned back and lastly, because I had to leave early to return the car to ‘her indoors’, I did clean up the lathe. I do not want to be on the wrong side of the Workshop Manager!

I will continue this should anyone be interested.

Alan Hooper. Secretary



Touch DRO Project info

Hi all.

Just a quick post regarding the inexpensive Touch DRO that many people around the world have been building including myself. The project itself was designed by a skilled software developer and model engineer by the name of  Yuriy Krushelnytskiy of Portland, Oregon,who has released the design and firmware under open source licence to enable others to share and collaborate in the project. The DRO consists of some cheap Chinese scales marketed in this country by ArcEurotrade among others, an Android tablet, an Arduino micro controller or MSP430 Touchpad micro controller and a few other electronic bits and pieces. I have used the Arduino and managed to build the scale interface electronics for around £15. The cost of three scales amounted to about £113 and the 10.1 inch Android tablet was a christmas present, but can be bought for around £80. So for about £220 a mill can be fitted with a DRO with a touch screen and three axis readout plus rev counter. The DRO has the following features :-

  • USB and Bluetooth connectivity support
  • Display for up to three* axes
  • Support for metric an imperial units (mm and inch)
  • Support for standard DRO functions:
    • Tool Offset
    • Preset Dimension
    • “1/2” Function
    • Hole Circle (Arch)
    • Hole Grid
  • Unlimited** point memory
  • Multiple workspaces
  • Worskpace preview

For full details go to :-

Polly Progress

Progess has been slow due to other commitments but now I’m hitting the workshop in ernest.

The base, firebox and baseweight are assembled.



The engine standard has been curved to fit the firebox, axle bushes turned and soft soldered to the bottom of the standard and the portface has been drilled/milled and riveted and soft soldered to the top of the standard.

Last night I turned the crank and crank pin, I just need to tap it 5BA now (guess what the one tap I’m missing is? Grrrrrr)

Polly Boiler – can it take the pressure?

Pickle saved the day! Following my misshap with the steel washer in the old pickle (see comment on previous post) a further week in fresh pickle reversed the copper deposition.

Also the silver solder finally flowed. The improvement was down to using more flux and using a bigger burner to get the temperature up quicker.

The finished job may look a little messy to the more experienced practitioners out there, but to me it looks lovely as it’s my first sucessful boiler build 🙂


Now I like to say it held pressure on its first test, but that would be a fib. Two of the bushes leaked when I tested it initially at 10 psi immersed in a bucket of water. The answer? MORE SOLDER.

It has now been tested to 30 psi and not so much as a nano bubble escaped – phew

Polly Brazing

What did I say about luck and a fair wind?

The solder around the base ran as expected. Dead easy this soldering! I don’t know what people go on about.

So on with the base of the chimney. Heat up, watch the flux melt and go clear touch the solder on……. nothing. More heat then…. nothing MORE HEAT……. still nothing HEAT HEAT HEAT HEAT and yes – still nothing. Out of luck. Dang it!

It all went into the pickle to try again the next day (well today). This time the base went on fine.

Dead easy this soldering, I dont know what people go on about.

So turn it over and lets do the top. I just about managed to get the top of the chimney done and one of the bushes. The other two bushes and the rim of the top, Nope. Nothing doing. Rien de rien.

The /^&/$@#/ thing is back in the pickle now ready to try again tomorrow.

Sean Griffiths

Tubal Cain’s Polly

I am taking part in the SMEE course for beginner Model Engineers, the course covers the building of a small boiler and oscillating engine to the design ‘Polly’ by Tubal Cain.

The boiler is designed around a tube of copper with formed endplates and a central chimney that doubles as a stay. Brass bushes are placed in the top plate to hold a safety valve, steam pipe and filling point.

Here is my progress so far.


Cutting the end plates from sheet


Discs held on an mdf base for drilling the central hole


I had heard lots of horror stories about drilling sheet but using these drills it was no problem. Not a triangular hole in sight.


Here you can see a part formed disc and the next one to be formed fitted to the former. The ball pien hammer was an old abused one that I cleaned up with emery and then polished up on a buffing wheel bought at one of our auctions.


And then it a case of beat, anneal, clean…… until formed.


All the copper parts complete. The holes for the bushes were drilled using the drills shown previously and the holes for the chimney were opened out with a boring bar on the lathe.


And here are the bushes turned from brass.

My next step is to silver braze everything together. I got a few sticks from Ron at the last meeting and the only thing holding me back now is a little trepidation but with luck and a fair wind it will be done tomorrow.

Sean Griffiths