Engineering in Chaos

Coolant Guard for Bridgeport Clone CNC Milling Machine

2010-12-31T14:50:00.000-08:00

Once I had the machine home, I really wanted to be able to use flood coolant rather than a mist or spraying from a bottle.

This was my first mod to the machine, and meant that I could really push the coolant in there. I find the flood coolant is as useful for blasting the chips clear of the cutting area as for keeping the cutter cool.

The coolant enclosure underhangs the front of the table by about 225mm and the underhang slopes down by just over 25mm from right to left so that the coolant naturally drains to one side. The original table drains are retained and the new one on the enclosure all run back to an external coolant tank.

The front centre panel lifts out for access to the work area.

Construction is Aluminium with 5mm polycarbonate for all the vision panels. The upper frame is all extruded channel material and very quick and handy to use.

The rubber curtain at the back is really handy as it contains most of the coolant heading that way. For setups with longer tooling or higher work pieces, I have a second piece of the rubber available to be put in place as required.

At this stage, I did away with the interlock switch from the old guard system and I could in theory run the machine with the front panel out of place, but why would I, It just winds up with swarf and coolant everywhere.

I guess with thinking it out and then putting it together, it was probably a couple of days of work but spread out over maybe 6 weeks or so.

My Milling machine

2010-12-31T14:33:00.000-08:00

Late in 2008, I had a nice little Boxford Milling machine, all manual controls and in very good condition. It did the job but I decided what I really wanted was to get better parts without spending endless hours winding the handles.

I concluded that the way forward was a CNC milling machine of some sort. As I work in the IT industry for a living, I was pretty confident I could get the computer stuff on the run without too much trouble.

After looking at the various options, I concluded that a good fit for me would be a second hand industrial machine. Eventually a suitable machine came along and I became the proud owner of a Bridgeport Clone machine made by Chen Ho in Taiwan, the machine had an Anilam control and was servo driven to all 3 axes.

The machine had some issues but the price was pretty good so I was happy for it to be a project in it's own right.

CNC Milled stretchers

2010-12-31T14:17:00.000-08:00

These are the first real loco parts that I cut on my CNC milling machine.

It was a huge learning curve for me to get this all working but the parts were very satisfying once cut.

The cycle time for the first one was about 3 hours, the second was done in just over an hour.

This was all cut from a 25mm slab of mild steel and created a bucket load of swarf.

The tabs were hand hacksawed out to release the parts and a touch of the file to complete.

Whilst this was an interesting exercise, ultimately it was not necessary, the parts very closely match the castings and I like the look of them but I now realise they could easily have been done as simple profiles in solid plate or the relevant thickness.

Ho Hum.

New to blogging

2009-10-24T01:18:00.000-07:00

Paul's Model Engineering Blog

I have been interested in model engineering on and off for many years. Time and circumstances led to doing something about this interest a couple of years ago when my Son Nick was very interested in the trains at the local model engineering club and wanted to get more involved.

For Nick aged 10 to get involved, that meant that Mum and Dad had to get involved as well. The club activities are very interesting involving running both 5 inch and 7 1/4 inch railway layouts and Nick really enjoys it. However, a good part of the fun is from owning and running your own Model locomotives, there are two choices, you can build or you can buy. We decided to build.

I served an engineering apprenticeship many years ago so the whole engineering part of the process whilst not completely new to me was pretty rusty.

As for anybody setting out to build a model locomotive, the question was what to build and how big to build it. Having looked at the various options, we settled for a 7 1/4 gauge GW 1500 steam locomotive.

This is a pretty ambitious first project but my thinking is that whilst the bits are bigger, the actual work involved for a 7 1/4 gauge locomotive shouldnt be a great deal more than for a 5 inch or even a 3 1/2 inch gauge.

I liked the design of the loco in that almost all the moving parts are located outside of the frames making access for lubrication and minor maintenance a straightforward matter. I also liked that it has a good reputation as a powerful locomotive capable of pulling a good load.

The picture at the top of this post is the full sized example of the locomotive in the Steam museum at the Severn Valley Railway.

I have spent a lot if not most of my first year in the hobby, re aquainting myself with basic engineering practice and setting up a workshop in the garage.

Building the Locomotive started just over a year ago with drawing up and ordering laser cut and marked frames, buffer beams and rear buffer uniting plates. as well as ordering some castings from Reeves.

Progress so far is to acquire and make some loco parts and to turn a quantity of perfectly good materials and tools into scrap. Happily, the parts bin is slightly fuller than the scrap bin but to be honest, at this stage there aint much in it. Things are improving with practice.

Given the startling costs of some of the castings for this locomotive, I am also looking at alternative ways to produce the parts I need. At the moment, I am using a CNC milling machine to make many of the parts that would traditionally have been castings.