Author: Adam

GPS/GPX Waypoints for PDMHS Newsletters 122-133

Posted on by Adam

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

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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

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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

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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

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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).

Good Results with Cheap TCMT Tools

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From the outset of setting up my metalwork shop I decided to use tungsten carbide tipped tools for the lathe. I just don’t want to be bothered with the fiddle of sharpening and having to keep changing the shims under the tools. This is at variance with the received wisdom that the low power and low spindle speeds of small lathes like my Warco 918 indicate that HSS tooling is appropriate.

The first set was from Warco and I never really got good results with the CCMT left and right hand tools, especially on aluminium but the DCMT tool with the point symmetrically arranged seemed much better. This encouraged me to try a cheap TCMT set from Chronos and must say they seem like the business. I think the small radius points and lower point angle is what allows me to get really quite good finishes on even small parts with small depths of cut in Aluminium with a max of 1800 RPM. Brass and steel are also fine.

So, my recommendation: if you are starting out get a set of 5 TCMT tools.

BTW, tip codes are generally of the form TCMT 110204, where “04” designates a 0.4mm radius on the cutting tip.

DIY Milling Machine Rev Counter for Under £5

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As I have a variable speed millling machine without a digital readout (its an Axminster SIEG X2) and wanted a bit more control at the hundreds-of-RPM level than I could get by listening to the pitch of the machine or watching the chuck, some technology was required…

Cycle Computer Rev Counter on an X2 Milling Machine
Cycle Computer Rev Counter on an X2 Milling Machine

The answer was simple and cheap: use a cheap cycle computer that can read RPM (I got a new one for under a fiver off ebay). I carefully dismantled the sensor to expose the reed switch inside, which I taped to the outside of the cover for the top end of the spindle on the X2. I attached the magnet that normally fixes to the cycle wheel to the top of the spindle with a blob of blue-tack so that it ran close to the cover. Thats it! I suppose a better attachment could be achieved than blue-tack but it works fine at the relatively low spindle speeds I am interested in and I just remove the magnet afterwards.

How to Make and Use a Split Bush (Chucking Piece) for Concentric Turning

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I’ve recently been making a Stuart 10V with the help of the Andrew Smith/Pengwern building guide. At one point they recommend the use of a split bush to afford a greater degree of concentricity in turning the piston rod (and both the piston and cross-head attached to this). A sketch of the split bush is provided with the throw away comment that its use requires no description. OK, that much I agree with but the making of the device led me astray.

The basic idea of the split bush is to get around the fact that the lathe chuck is likely to be a wee bit off truely concentric to its rotation axis. i.e. even perfectly cylindical rod in an unworn chuck will not rotate about its centre. The split bush is bored in situ, which does guarantee the hole is centred on the axis of rotation and the work is held in the hole. In the 10V, there is a 5/32″ piston rod and 1/8″ valve rod that need to be treated in this way. By the way, I use a Warco 918, a relatively cheap Chinese lathe and I have demonstrated that the chuck is about 0.001″ out.


(click to enlarge)

A split bush for 1/8″ diameter rod. The shoulder should sit againt the outer nose of the chuck, which is tightened to cause the bush to grip the work piece

 The problem with being a self-taught novice is that you don’t know some simple stuff and don’t know which of various factors actually matter. Paranoia about defeating the whole point of the operation by removing the bush from the lathe between boring the hole and using it – would the hole now be true – led me to make the bush the wrong way. Part of the reason for this is that I had previously made a larger (1 1/4″) chucking ring where a boring bar had been used. The error I made was to drill and ream (actually I use home made D-bits) the hole after cutting the slot in the side. This doesn’t matter when using a boring bar but it does when drilling, especially as the slot size gets close to the hole size. I didn’t notice this problem with the 5/32″ piece bit it became obvious with the 1/8″ piece (see below):

I didn’t spot this until using the bush as (remember the paranoia) the bush wasn’t removed after boring and before using it. Its not like I didn’t know about drill wander but I was surprised it made so much difference and I was still paranoid. It seemed like there was no way ahead. Some Googling was done and eventually I found more than an assumption that everyone knew how to make/use these devices; I found enough to get me to have another go, the proper way. Actually I had tried to find out how to make split bushes before but not found anything so had a go… the wrong way. I decided to write this post in case anyone else needs a bit of help to do it the right way the first time.

How to Make a Split Bush Properly…

(this one did indeed seem to be right – I checked quite carefully)

  1. Face the end of some brass and turn down the 1/4″ section.
  2. Part off or remove and saw off
  3. Re-chuck, ensuring the shoulder seats on the chuck nose “nicely”
  4. Face off, centre drill, drill 3mm and ream/D-bit 1/8″ (I love mixing units)
  5. Identify one of the chuck jaws (I centre punched the chuck backplate) and mark the nascent bush to it may be precisely aligned with this jaw. A light centre-punch is nice and permanent.
  6. Remove the piece, insert a piece of rod into the centre and cut the slot in the opposite side to the marked point. The rod avoids hard-to-remove swarf buildup in the inside which will interfere with the workpiece. I’ve started using a Dremel tool for little jobs like this.
  7. Return to the lathe chuck, reseat carefully and lightly tighten the chuck, insert the work piece, tighten the chuck fully and there you are…

GPS Waypoints for Bradwell Area Caves and Mines

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The following GPX file uses data from HNH/PeakDistrictCaving, specifically their index to the Bradwell Catchment (PDF).

I created this after a trip around Bradwell Dale, mostly looking at the geology, and compared with a set of GPS waypoints and the tracklog. Based on this, I am sceptical of the accuracy of the Grid Ref for Bradwell Parish Cave. I would place this at SK17255 80605.

Bradwell Catchment GPX file.