Skip to content

Making Dice in Brass (or other metal)

Here are some notes on making dice (or just one die) in brass (etc) in the metalwork shop, suitable for a total beginner. I did it with my 10-year old. I used some half-inch square brass stock.

  1. Set the stock in the lathe using a 4 jaw chuck. Get it close to centred by sighting the edges against the cutting tool. I tend to face off with a TCMT (carbide tipped) tool where the tip points away from the tool post (i.e. a 60 degree angle to the work). I used my top speed of 1800RPM but you could go faster.
  2. Face it off.
  3. Mark out and cut off slightly over 1/2″ from the stock, file it down a bit to remove the unevenness.
  4. Fly-cut (1″ or slightly larger fly cutter) the sawn face to get to a cube.  Use a speed of about 1100 RPM and work in stages of measure-then-cut. This is quite easy even in a small mill/drill. Lock the table in position and the head in place while cutting. A digital scale on the vertical axis is really useful for this (the vertical fine-feed on my machine is hopeless) . An alternative is just to face-off this end in the lathe but I find it easier to finish off at the correct length flycutting and it demonstrated the technique.
  5. Gently remove rough or sharp edges with a fine file or emery paper.
  6. Set up an arrangement like the photo. The tool clamp provides a positive location so that the die can be turned over and around and returned to the same position.
  7. Turn the cube over so that the previously-turned face is upper-most. Fit a centre-drill into the chuck with a point of the size you want the die dots to be. Traverse the milling table so that the centre of the face is lined up. The marks from the facing-off operation should be sufficient and give a nice appearance. (this is why you need to get it “close to centred” in step 1). Make sure  you remember to take account of backlash in the leadscrews. I made sure I approached the centre by turning the handwheels in a clockwise direction. Zero the collars or mark off the handwheel positions carefully.
  8. Drill to depth. Set the depth-stop and drill again to meet the stop.
  9. Remove the die, rotate to another face, snug-it up against the tool clamp and secure the die. Drill another centre hole (say for the “3” side) then a final hole (say for the “5” side). Remember opposite sides of dice add up to seven.
  10. Decide where the corner dots will be and traverse both axes of the milling table to position the cube appropriately. Traverse the same distance for each axis. I opted for a whole number of revolutions of the handwheels for simplicity. Remember to turn them the same way as in step 7 to mitigate for backlash.
  11. Reclamp the table and drill a dot. Loosen the milling vice and rotate the die by quarter of a turn. Repeat until you’ve made the “5”. Use the same process to make the “3”.
  12. It should now be obvious how to make the “2” and “4”. The “6” is made by making a “4” then return one of the milling tables to its “zero” position (step 7). Reverse back past “zero” by about half a turn of the handwheel them advance back to “zero”. Clamp the table and drill. Rotate half a turn and complete the last hole.
  13. Polish it up, slightly round off the edges and corners and you are done.

My daughter was well pleased with the result and rather impressed by the simple little tricks that make it quite easy to get a neat and regular result with minimal fuss and fiddle: the trick with the tool clamp, rotating the die, the depth stop. If I were to make another, I think I would place the “spots” slightly further from the edges.

Wallace & Gromit Inspired Arms in Brass/Steel

Here is the product of a fancy, something less demanding than making something that really works. It was made relatively quickly from a page of sketches I made over a cup of coffee so it isn’t perfect. I’d probably change some details if I made another.

I’ve written some construction notes and transcribed my pencil sketches to a CAD drawing in case anyone finds that useful. I’d be pleased to hear of any improvements anyone makes.

Download: Zip of plans, construction notes and larger pictures (770kB total).The CAD plans were made using Draft-IT (by CADLogic) but a lower res GIF is included in the zip)

Cheers!

Easy Chili Sauce Recipe

There are lots of chili sauce recipes on the web but here is my variation. I grew some relatively mild chilies from nursery plants named “chenzo”, “cayenne” and “cheyenne” and this recipe worked for me, creating sauces that can be smeared thinly on bread with cheese or dolloped onto a plateful of food. The balsamic vinegar and “vecon” help to give a rounded taste.

Ingredients:

  • 65g chilies
  • 2 cloves garlic
  • 20ml balsamic + 100ml white wine vinegar
  • 1/2 teaspoon sugar
  • 3/4 teaspoon salt
  • 1/4 teaspoon “vecon” vegetable stock

Method:

  1. remove stalk from chilies but do not remove seeds etc and chop or mince finely
  2. chop the garlic
  3. boil up chopped ingredients with the vinegar until tender and to reduce the volume slightly and a thicker consistency is achieved. Use a non-metallic pan. I kept the lid on initially until the chilies were part-cooked and then removed it reduce the mix.
  4. puree the chili+vinegar mix in a blender along with the remainder of the ingredients. a small hand-held blender is perfect
  5. Decant into bottles (preferably sterlised with e.g. boiling water), allow to cool and refrigerate

For the “cheyenne” chilies, which were sweeter but milder, I used 90g rather than 65g.

Enjoy…

A Template for “Top Trumps” using MS Powerpoint

I had a fancy to create a template for my kids to make their own Top Trumps cards and thought I could do better – from the point of view of usability – than what I could (relatively easily) find on the web.

Here is my first attempt Top Trumps Template, NB only uploaded for MS Powerpoint 2007 as there are a couple of niggles to resolve for backwards compatibility. Let me know what you think. The same “Creative Commons” licence applies to reuse just as for everything else on this site. Please feel free to comment…

Some notes on using and adapting the template:

There are 3 layouts set for the “slide master”, one for the card (with lots of placeholder boxes for text and a picture), one for a title card and one for a rear side.

I’ve used a combination of placeholder boxes (i.e. the boxes you normally add your content to) and some boxes that are only editable in the slide master (for content that will be the same for all cards). I’ve also set the background colour in the slide master.

The table at the bottom of the card is achieved by a bit of a dodge. There is an empty table with an alternating row style which I have “sent to back”. In front on the left side is a text box with the category names that can only be changed in the slide master. In front (of the table) on the right side is a placeholder for per-slide text. Font size and line-spacing has been chosen carefully to match the table. Basically: if you want to change the number of categories you need to know what you are doing

Model Watt Governor – CAD Plans and Construction Notes

Having had a hankering to make a Watt-style governor but having failed to find any plans to my taste, I decided to design my own. Here it is, with 2D CAD plans produced with Draft-IT (and GIF images of the same) and my construction notes for download. The design is hand-cranked and lacking a valve lever because it was made as a retirement/60th birthday gift and I ran out of time to complete the valve lever (I wanted to assemble the governor before dimensioning the lever).

Inspiration for the design, and especially the proportions, came from Muncaster’s book and photographs I took of real governors.

All of the downloads are covered by the same Creative Commons licence as everything else on this blog. Feel free to adapt but I’d like to hear about modifications, ideas etc…

Downloads:

GPS/GPX Waypoints for PDMHS Newsletters 122-133

The download below is a GPX file suitable for GPS and digitak mapping software. The locations are of sites mentioned in the Peak District Mines and Historical Society newsletter editions 122-133. These are not sites I have GPS-located but have been transcribed from grid references in the newsletter. These are sometimes 6 figure OS Grid refs and sometimes 10 figure. They may be wrong! The comments are generally very brief and the intent is that reference is made to the appropriate newsletter, using these “waypoints” as a spatial index. The waypoint names are of the form “PD-N122-03” which means the reference is in Newsletter 122 and is the third one (generally in the “Observations and Discoveries” section).

(At present Newsletters are not on the PDMHS website but many of the old journals are. Join PDMHS!)

GPX download: pdmhs-newsletters-122-133-for-web

Using the British Geological Survey WMS Service with Mapyx Quo

Major kudos to BGS for making their 1:50,000 geological maps available online including via a WMS Service.

I’ve been struggling with scanning BGS maps and importing them into Mapyx Quo for a while. Its an arduous process and the scanned maps contain the roads, placenames etc as well as the OS topographic map I have in Quo so its not as pleasing to use as it could be.

I was thus motivated to write a little Windows .Net programme to access the BGS WMS and automate the import into Quo. The process is not completely automated (partially because Quo uses a non-XML file for storing the user-loaded maps) but is still quite simple.

The programme is not as polished as it could be – its good enough for me – and has only been written with the BGS service in mind (although it could well work with other services).

I am making the Windows installer (I use XP still) available (no warranty blah blah) but please do not distribute it (refer people to this web address instead): download installer (about 350k)

Usage is simple:

  • In Quo set the coordinates to WGS 84 decimal degrees
  • Right-click and copy the location of interest to the clipboard
  • Paste it into WMS2Quo (my programme)
  • Choose which layers you want. e.g Bedrock and Superficial (bedrock is the default)
  • Click “Fetch”. This uses the geonames service to find the name of a nearby location. This will be used in the name of saved files. You can edit/change this in a text-box.
  • (the segment of the geological map should appear)
  • Save the map and a Quo calibration file
  • In Quo “Explorer”, select the “Loaded Maps” tab and use the document-with-green arrow icon to import the map image. This will cause the image AND saved calibration file to be read. I usually now change the transparency to 80%. You should see the geological map in Quo.
  • You can “query” the map one layer at a time to find the kind of rock (etc) at a given point by clicking the mouse on the image. This information is remembered and can be saved out as a GPX file containing “waypoints” for each location. Import this into Quo and set it to show the waypoint “note” and you will get geological labels showing.

There is a “settings” button which can be used to alter the save location, image size etc. Take care and NB that the BGS WMS server will sometimes return a blank image if your image size/map size combination are out of its range. A known bug also means you need to restart the programme if you change the save location. I recommend you change the save location as the first thing you do. Also, watch out for your firewall blocking web access; if you get an error on “Fetch” this is the first place to investigate.

I would like to acknowledge Paul Dixon (paul@elphin.com) as I adapted code of his (GPL Open Source) for the coordinate transformations that are used. This is JavaScript whereas I used C#.Net. I’ve uploaded this for use, adaption or what you will under the same licence: DLL, Source code.

If you would like the C# source code for the “WMS2Quo” app please contact me. Similarly, I’d like to hear of any bugs (you know what I mean by “like”).

Orrery and Gear Spreadsheets from Mike Shuter

Thanks to Mike Shuter, who commented on the previous entry, for sending me his two spreadsheets with Orrery gear ratios and the “continuous fractions” method of determining wheel/pinion pairs. He has permitted me to post them here but please contact “m [dot] shuter [at] ntlworld [dot] com” if you find them useful. Please do not repost without contacting Mike as he is the creator.

Mike Shuter’s Spreadsheets

Windows Program for Compound Gear and Orrery Calculations

This is a first public release of a Windows program for calculating compound gears (2 pair of gears) in “normal” or epicyclic arrangement. It also fully or partially automates Orrery calculations and has presets for various solar system periods, which can be modified and added to by editing the PeriodData.xml file. It allows the tolerance and min/max gear sizes to be specified as well as having various customisable presets, e.g. to only use Meccano or Lego gear sizes.

It is not fully tested and must not be distributed in its present form; it may only be downloaded from here. When it is a little more improved I will post source code and intend to permit distribution eventually. i.e. I’m only granting you a licence to use it yourself at present; a liberal Open Source licence will happen eventually.

It is written in C# and anyone interested in working on the code should contact me.

Download: Compound Gear Calculator Installer (Windows MSI, 380Kb)

If you use it, please provide feedback.

Building an Orrery #1: Looking for Plans

I don’t remember what made me think of it but I took a fancy to build an Orrery a little while ago. Naturally, my first recourse was to scour the web via Google for plans. I would have liked to find some dimensioned drawings in the style of engineering. What I did find was lots of other people looking for plans, designs, cad drawings etc. Noone seemed to have drawn together the following links, although a few were referenced here and there.

So, for any one else on the same quest, here is what I found…

James Ferguson: Mechanical Paradox and Sun-Earth-Moon Orrery

The so-called mechanical paradox is the basis for an orrery that differs from general practice in the way the moon is treated.

Scanned/OCR of the original account including both paradox and Orrery.

Construction notes for the paradox but not the orrery from Amateur Work Magazine Vol4.

Notes on the paradox and construction of a the orrery by Ian Coote and James Donnelly (which also appeared in the Horological Journal):

Using Meccano

This wasn’t what I was looking for but these articles contain some ideas on approaches to construction that could be useful in designing an Orrery as well as some possible gear trains.

From the Scientific Instrument Society, two articles by Michael Whiting:

Less important (IMO) is an article from Meccano Magazine.

Using Lego

Again, not what I was looking for… and Lego is not what I intend to use but possibly useful.

Best is the NASA Kepler mission has quite a few pages of information, with several models. These inspired Robert Munafo to make some modifications and to document his work.

I also found a couple of other sites that might be of interest if you do plan to use Lego:

Other Useful Sites

An anonymous blogger briefly describes making an Orrery with a minimum of tools and purchased gears. This is a bit inaccurate for my taste but the design is nice and unfussy.

The SAO/NASA Astrophysics Data System (ADS) has scanned articles from 1938 detailing gear trains (using standard gears), an initial one by Roy Marshall and a subsequent one proposing improvements by Charles Balleisen.

There is also usually a book, “Making a Tellurian/Orrery” (ISBN 1905013027) for sale on ebay.

Calculating Gear Trains

If you plan to design from scratch then the question of what gear ratios to use comes into play. If you don’t mind an inaccurate Orrery then a simple pair of gears is easy to work out but compound gears don’t have quick calculator-based solutions.

The old way of doing this, based on some 19th century maths (it still works though and is elegant to those with a mathematical bent) and going under the name of the “Stern-Brocot Tree” is mainly of historical interest. The less elegant but more practical modern approach is a fairly simply computer algorithm with a bit of brute force computer power to do lots of calculations quite fast. One such algorithm appears in Robert Norton’s Book, “The Design of Machinery”, which is freely available on Scrib as an old edition or for purchase (which includes a CD/DVD).

I have almost finished writing a program in C# for Windows using the above-mentioned algorithm which I will make available via this blog in due course (including source code).