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Research

Here you will find articles on things you may have wondered about but never got around to researching. I hope that they give inspiration and explanation.

Locomotives


The Lathe and The Mill...

The following articles are on the Seig C-1 Lathe and the Seig X-1 Milling Machine. I bought both of them in about 2003 and apart from replacing the primary drive gear on the X-1 Mill, which is "sacrificial" and initially more than a few 1A fuses, they have both served me well making all my parts and wheels, (up to 105mm). Although I now have the larger and more powerful Seig C2A to make steam locomotives with, as a "First Lathe" the C-1 series is pretty much unbeatable. On the net you will find CAM systems for the X-1 including belt drive conversions which enable quieter running and higher speeds. Unlike a fixed large machine both can be classed as "luggable" and sit on the kitchen table or worktop whilst in use.


3D Printing.

This has become quite common and in fact is something that I researched before coming to the conclusion -that with the high price and low number of things I would print with it I didn't need one! Most modern commercial kits are based on "Iteration 3 of the J.PRUSA design" or "i3PRUSA". A group of four of use once seriously contemplated buying one between us that would I feel have given the RepRap a suitable market for its use...

These are ideal for the production of several parts for models and can use either ABS plastic or PLA. The main use for them could be the production of casting masters.

The paragraph above was true when I wrote it some months ago. However the market has "crashed" and it is now possible to buy £350 machines for a little over £100...

The three articles below (updated June 2019) detail the construction and use of an i3Prusa RepRap kit, OpenSCAD which is the "Design Software", and CURA which is the "Production Software".

The production cycle for a RepRap system is:

A RepRap compatible machine, there are SEVERAL designs available. A design program that can produce STL files from the raw design, again there are several programs. There are several sources of both STL and GCODE files on the WWW. Chief amoungst these is the site "Thingiverse". A production program that takes the raw STL file and generates the GCODE file for the RepRap to use dependant on the choice of machine, material and user options...

I have documented the ones that have appealed to me and I have found very easy to build and use.

Now that you have some idea of what is possible -the next problem is what do I do first? The basic text files for OpenSCAD will have given you some primitives to work from. You should be able to assemble a station from them -just as I have. The station as printed is 1.8metres long and 50cm wide. The primitives are taken from LMS stations but given the time period... A short survey of the Art Deco style as mostly used by Southern and the Futurist style as adopted by the LNER will give you the working basics.


The Laser Etcher.

I bought my laser etcher at the end of 2018. It came as a Chinese made kit and with "Chinglish" instructions. Fortunately along with it on a "thumb drive" came the software and a short video on how to put it all together. The machine is rated 450nm at 2.5W -which may not sound a lot but is more than enough to cut through 160g/m2 card or 1mm thick ply at one pass.

The bed of the device is A4 -however the cutting area of the device is A5. This means that there is a lot of waste if only using A4 sheets. My normal use of this device is to make templates. Although it does sterling service cutting gaskets... At the moment I am using it to build a 2-NOL from the Locomotive Designs plans.

The standard software for this device is called Laserweb, (current release is 4), The software will take scans in the format of PNG or you can produce drawing in SVG or DXF format for it to use. The software is easy -but I would caution that it does require some practice before you undertake major operations with it. The system can be programmed to accept scans from scanners -but the default setting for the DPI may not be the correct one required for perfect scaling. In the case of my device the scaling is 577 DPI for a 600DPI PNG image.

The main problem using the software relates to the cutting speeds and the laser intensity. 100% laser power can easily cut and set fire to your work at the same time... 10% to 20% and using multiple passes is probably a better bet. The speed of the cut really defines how much time the laser will be in the same place. It is "about right" for cardboard at 200cm and 300cm for wood.

Focussing the laser is a manual operation and has to be done with the laser glasses removed -however the glare can be quite painful. If you wear the glasses then these should block the laser frequency -but this leaves you with the problem of trying to focus something that is now invisible! I have found that a laser focus of 0.1mm is achievable with a few attempts.

The best results are produced with the laser in RASTER mode. This is similar to the old 625line B+W tv as it produces a point with either an on/off state. The laser is driven via a PWM driver and you can set it to produce 256 shades of grey if required. Mostly you will set it to Black only.

I have tried it with "laser plastic" in the hopes of producing my own builders plate and shed code plates. The main problem is the fact that the plastic cannot really cool down fast enough between passes as you are dealing with fonts in the 5pt to 8pt region. Large "poster" scale size fonts in the range 16pt to 24pt will cut with little difficulty.

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Page last modified on August 08, 2019, at 01:54 PM