Stuart Tankard | johnsmachines

June 30, 2021

G Codes for CNC Lathe. Ezilathe.

Most hobby modellers who use a CNC lathe, run the lathe with Mach3 software. Some have progressed to Mach4, but apparently 4 is not straight forward, and my expert advisor says that it is best to stick with Mach3 for the time being.

Mach3/4 requires instructions to control movements of the lathe carriage (X and Z movements), spindle on and off, spindle speed, coolant on and off etc, and those instructions are in the form of G codes.

G coding is not difficult to learn. There are excellent YouTube tutorial videos on the subject, Udemy courses, books, and so on.

The problem is that mistakes in G coding can be easily made, costly, and sometimes scary. The biggest problem is that G coding is time consuming.

Fortunately, software is available to make G coding automatic, fast, and reliable. This post is about the program which I use for G coding. It is called Ezilathe. It is available at no cost as a download from CNCZone. (see details of downloading later in this post).

Ezilathe was written by Stuart Tankard, who I met a decade or so ago at a meeting of GSMEE. Stuart gradually persuaded me to get into CNC, and frankly, the decision to do so has resulted in a quantum leap in the scope and standards of my model engineering efforts. Now I use a CNC lathe, CNC mill, CNC rotary table, CNC 3D printing.

But I digress. This post is about G coding for CNC lathe. Until Ezilathe came along, I was programming G codes manually, making mistakes, and consuming lots of time. And experiencing crashes. Exciting, damaging, and sometimes dangerous.

To CNC turn an object, the profile must first be drawn with a CAD program such as AutoCAD. There is a very basic CAD drawing facility in Ezilathe, but it is so basic that I prefer AutoCAD. In AutoCAD I then rotate and move the object as it would be held in the lathe chuck, and move the tailstock end of the profile to the X=0, Y=0 position. Only half of the original drawing is required, so I delete everything below the X 0 line. I delete or hide all lines which are not part of the profile. The profile can be saved as a polyline, or as separate lines, arcs, splines etc. It is named and saved as a dxf file.

Then Ezilathe is opened, and the dxf file is imported.

The stock diameter is entered. The z position of the tailstock end of the profile is entered (usually Z=0). Feeds and speeds are entered using the tables in Ezilathe or another source. I use an app named “FS Pro”. Also select which lathe tool is to be used (the lathe tools are all entered in advance) or select a “point tool” which has an infinitely sharp point, and no width. In the example shown in the pictures below the turning was achieved with one tool. If multiple tools are required on one job, each tool will have to been set in the tool editor. So far I have not used the tool editor, but I can vouch that it works well, having seen the superb results which have been achieved by Stuart.(see the photos below)

Then the polyline of the profile, OR, each line and arc etc is selected in the machining sequence. Important not to miss any small lines or arcs as unintended results can occur. That is why it is sensible to save the original drawing as a single polyline. (Stuart tells me that any gaps will be automatically filled by Ezilathe as straight lines.)

Then go to the simulator, and see how Ezilathe will manage the sequence of cuts. In the picture below, the cuts are the straight lines, and there are 2 finishing cuts along the profile.

If all looks well, generate the G code. I usually visually scan the G code, looking for obvious errors. Usually there are no errors. Save the G code. Then ready to use the G code to make the part.

AN air cut with no work stock or cutting tool is sensible for beginners.

This was a demonstration of Ezilathe to GSMEE members. Stuart Tankard watching carefully to correct any of my errors. The G code is on the right side of the drawing.

This is the CNC turned finial, which was demonstrated to GSMEE members. Fortunately the turning all worked out well.

I made this bookcase about 30 years ago. Can you see the finial? It was a very delayed addition.

Now some examples of items made by Stuart using Mach3 and Ezilathe. All of the components in this valve were made by Stuart.

And when he makes an item he finds it difficult to stop churning them out!

Stuart made this cutter to make the seats on the valves. Some turning on the lathe using Ezilathe, and some mill work. And heat treatment. Not bad hey!

There is a lot more to Ezilathe. This has been a very brief introductory summary. Creating a lathe tool library, and entering startup strings for different lathe setups for example.

To download Ezilathe, you need to register at CNCZone. It is quite a good, useful site. In CNCZone go to downloads, Postfiles, Page 2. Select Ezilathe, and Ezilathe.pdf. The pdf is a comprehensive manual. Save them to a directory named C:\Ezilathe and unzip them. The program has been fine tuned, and updated. The latest version is 1.7.3. Then, on page 1 of Postfiles there is a small bug fix, Version 1.7.3.3. 1.7.3.3 is an executable which should be run after 1.7.3 is installed. If there are problems or questions Stuart can be contacted via CNCZone.

I have no hesitation in recommending this excellent program. It is just amazing that it is free.

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June 14, 2021

Final Lasering on Armstrong RML model cannon

The lettering on the muzzle reads “Marshall’s Iron”. It refers to the steel bore of the barrel, which was supplied to the Royal Gun Factory by a specialist manufacturer, Marshall Iron. The rest of the barrel was made from wrought iron, as a coil, as described in a previous post.

Stuart operating the fibre laser, and Jamie who runs Stuart.

The barrel is 300mm long, too high for the laser machine to focus. So the setup used a low profile 3 jaw vice, hanging out from the edge of the machine, with the breech of the barrel down the front of the desk/bench.

Immediately after lasering, which took about 20 seconds, (and about 45 minutes to set up the machine/supports). The circle represents the junction between the steel bore and the outer iron coil. The vertical line was used for sighting.

The lines and lettering looked a lot sharper after a quick rub with emery paper. Those letters are less than 1mm high. A very magnified, not well focussed photo.

The cannon is now mounted on a shiny acrylic/wood base. It reflects the underneath details. And has handles.

Thanks once again to Stuart Tankard, for using his fibre laser machine to accomplish the engraving. Stuart told me that he has done more jobs for me than he has done for himself. I call it “getting experience”.

And, WordPress has now improved its program to the point that captions cannot be added to photographs, and a title cannot be added to the post. Well done WordPress. (p.s. 16 June… captions and headings have reappeared. Hooray!)

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March 13, 2020

Boxford TCL125 CNC Lathe, 3rd AXIS.

Below is a video which was recorded by my machining mentor friend, Stuart Tankard. Stuart made a milling attachment for his Boxford CNC lathe, and he demonstrates it in the following video by making some lovely small valve control handles.

I followed in Stuart’s footsteps by making a similar attachment for my identical Boxford 125 CNC lathe, but I have not yet video’d it in action. Not much point when Stuart’s video is so good. I really like the absence of irrelevant, irritating music. Just machining sounds. Enjoy. (if you want to see it full screen, copy the YouTube address from the settings icon).

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December 19, 2019

A modification to the Radius Master

The Radius Master is a quality 48″ x 2″ belt sander which is impressively versatile with its 7 work stations.

The work station which is vertical, and against a platten is the one which I expect to use most often.

Vertical belt, and using the backing platten.

But the supplied work – tool rest is a bit narrow for my taste, and I decided to make another one.

I really like the one which was supplied with the Acute Tool Sharpening System (ATSS).

The Acute Tool Sharpening System from Eccentric Engineering.

So I bought some 4mm steel plate and cut it to size (150 x 150mm), and CNC milled a support bracket to fit the Radius Master.

The Radius Master with larger work-tool rest.

The rest is adjustable for angle and distance from the belt. Copied from the original. The bracket is screwed to the plate. I did not want to risk heat distortion by welding the join.

Then the penny dropped.

Why not use all of the ATSS fittings and fixtures on the Radius Master? So that is what I have done.

The ATSS system looks quite at home, yes?

Hey Gary Sneezby, maybe you should do a deal with Radius Master.

I can quickly swap the ATSS fittings and fixtures between the CBN grinding wheel and the Radius Master. It will be interesting to see whether the cubic boron nitride wheel or the belt is preferred for different applications. I expect that the belt will be best for quick removal of material and the CBN wheel for tool sharpening, but we will see.

Oh, and by the way, the bigger work plate does not interfere with any of the other work stations.

And I will ask my friend Stuart to laser engrave some guide lines on the plate. I have a new design to try.

And finally, here is a link to the video of using the ATSS, by Eccentric Engineering. It is worth considering. If you have not done so, I suggest that you look at Eccentric Engineering’s other tools too. They are very interesting. The lathe parting tool is the best one which I have used. And the Diamond lathe tool gets more use on my lathe than any other.

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December 4, 2019

A Modification to the Acute Tool Sharpening System

I have several tool sharpening machines, including an industrial Macson 3 phase machine, a Harold Hall grinder rest, and a Quorn Tool and Cutter Grinder.

But, the one that I use most often is this Eccentric Engineering “Acute Sharpening System”. It was made from a kit and plans supplied by Eccentric Engineering.

Photo 1: The Acute Tool Sharpening System (Photo courtesy of Eccentric Engineering)

The system consists of a table which is adjustable for tilt and height, a work arm consisting of parallel links and a work head, a straight arm which is adjustable for position and angle and which the work head will slide along, and various fittings for holding lathe tools, ER collets, and others.

Photo 2: My ATSS. The ATSS with cubic boron nitride wheel on the LHS, and the elegant but less frequently used Harold Hall grinder rest with diamond cup wheel on the RHS.

I purchased the kit of laser cut and spotted parts and the excellent 32 page bound plans from Eccentric Engineering. The parts in the kit require final machining, including drilling, reaming, tapping, turning and milling. It would be quite possible to use bar stock for the parts, having purchased the plans, but the kit is good value ($AUD 250 + GST) and it made the job quick and straightforward. A completely machined, assembled system is also available. Details at https://eccentricengineering.com.au.

Photo 3 These are the fittings which I made from the kit, and some extra parts which I bought later.

From the left: hex keys for quick adjustments, angle and gauge templates – most bought from Eccentric, but some made by me, tool holder centre, and collets on the right. Some of the collets are blank to be machined as required. Top right is an ER collet chuck.

Photo 4 This collet holds a 6mm lathe tool.

This post was not really intended as free publicity for Eccentric, although I am very happy to give it a good rap. It is actually to show a modification which I made to the ATSS table. Shown in the next photos…

My colleague Stuart Tankard recently acquired a CNC laser engraver which will engrave steel and brass and cut thin metal. I thought that it would be useful to have some accurate lines on the table in a grid, and others at angles to assist with setups. The grids are at 10mm intervals, and the angles are 30/45/60 degrees. In the above photo the straight slide is easily set parallel with the wheel face.

Of course, the cubic boron nitride wheel must first be accurately set to the table, and the grid assists with that….

Photo 5 Straight edge lined up with the wheel edges and grid.

Photo 6 And here the tool holder base is set at 60º to the wheel.

The angle gauges supplied by Eccentric will serve the same function. Time will tell if the table marks are useful.

Also I am thinking that the work table on the RadiusMaster could use similar guide lines!

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November 3, 2019

CNC Lathe Toolpost Mill

Just a quickie to show you a progress photo of my current project.

It is a very small milling motor with a small ER collet, mounted onto the toolpost of my Boxford CNC lathe, which will convert the lathe from 2 to 3 axes.

At this early stage the toolpost holder and cylindrical motor have been mounted to the water jet cut bracket on the right side. Pulleys and drive belt yet to be fitted and I will trim the shaft at the left hand end of the motor. Then the motor wires are connected to a speed and direction and on-off controller.

The usefulness of this tool is apparent in the following video of a completed unit in use. The main spindle motor of the lathe is now a 750w AC servo motor, which can be controlled from Mach 3, to go to programmed positions and hold the position while a milling procedure takes place. Of course the milling procedure will be with small cutters or drills, perhaps up to 3-4mm diameter.

The idea, plans, and some of the parts are courtesy of Stuart Tankard, my very clever friend, whose completed machine is the subject of the following video.

Stuart’s video is republished here with permission. The original, with comments, is visible on YouTube. If you have technical questions about the setup, I suggest that you contact Stuart via his YouTube post.

October 1, 2019

Next Tool Project…A CNC Laser Cutter

The Southworth steam powered boiler feed pump has many gaskets. I have not counted them, but there must be 15-20. All with many 2mm and 4mm holes.

And in the process of making the machine, I have broken quite a few of them with the multiple assemblies and tear downs.

But, fortunately, 2 of the members of my model engineering club have laser CNC cutters, so extra sets of gaskets has not been an impossible ask. (Thank you Brendan and Stuart!)

So, some time ago I asked Stuart, if it would be possible to attach a laser cutter to the CNC mill. His initial answer was NO. But recently, he changed his tune. He attached a laser head to his 3D printed CNC mill and started producing gaskets on request! So, as is a recent pattern, I am walking in Stuart’s footsteps, and I have purchased a 15 watt laser head on Ebay. Chinese of course.

Laser kit 15w

This is the kit. Cost $AuD146.

Laser head

And this is the 15w laser head. Now I have to work out how to attach it to my mill. Shouldn’t be too difficult, as long as I don’t turn on the spindle while it is attached.

My CNC mill, during the electronics upgrade. Most recent photo. Soon to have a laser head.

Stuart assures me that Mach3 can be configured to operate the laser…. turn it on and off, move the axes at an appropriate speed, etc. I think that some trickery is involved.

And future gaskets will be as simple as ….

So watch this space .

8 Comments

July 25, 2019

CNC Mill Upgrade -5

I have been putting quite a few hours into the upgrade, but not much to show photographically.

Finally got the new servo motors installed. Replaced the X axis belt. The most difficult servo to access was the Y axis, and of course that was the only one where the alignment of the timing belt was out. Finally sorted by using a fibre optic camera to see why the belt was climbing onto the flange of the pulley. The pulley was 1.2mm too far onto its shaft. I know that, because I solved the problem by inserting washers under the motor mounts. 1mm washers did not work, nor did 1.5mm washers. But 1.2mm washes did work perfectly.

Today Stuart arrived and removed more of the old wiring.

Stuart, doing another CNC upgrade wiring.

The old 7k computer has been removed, leaving some buttons. I might be able to use those. The computer enclosure might disappear too. Not decided yet.

The old CNC mill has lost some weight. Those cartons are full of old parts. Note that the floor has been swept. Stuart was concerned that we might be infested with snakes, but it is winter here, so we should OK until the weather warms up.

The rats nest is disappearing.

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February 24, 2019

Model Trevithick Dredger Engine on Steam. Fail. Well, maybe a bare pass.

Well, I was really not expecting this.

After all, the engine was running well on compressed air at 30psi, and the burner appeared to have a good flame.

And Stuart was coming to be involved with the big event. So nothing could go wrong!

I set up the iphone on a tripod. Checked the light. Oiled the bearings and slides. Filled the boiler. It takes 2 litres of water. And hooked up the propane. when Stuart arrived I lit up the burner, and sat back to see how long it would take to raise steam.

Some steam leaks were expected, on this first steam run. Leaks don’t show on compressed air, unless they are severe. As the water heated up, some leaks appeared. The water feed clack valve and the sight glass were bad. The clack valve just needed some goo. Later I disassembled the sight glass, and cleaned the valve, with some improvement, but more work needed. Or a new sight glass valve. A couple of other trivial leaks were easily fixed.

So we watched the clock, and checked the temperatures. Ot took 20 minutes to start raising steam. That is a bit slow. Eventually it reached 20psi, but the pressure refused to go any higher, despite fiddling with the gas and air controls.

At 20psi, I opened the throttle and gave the flywheel a swing. You can see the result.

After that, we let it cool down and fixed the clack valve leak. The sight glass valve leak was looked at later, but could not be fixed simply.

The burner flame. A bit feeble. A bit yellow. And occasionally blown out by the cylinder exhaust gas puffing into the chimney. Stuart says that I need to angle the cylinder exhaust gas upwards in the chimney. Apparently Trevithick did not do that on the full size models, but perhaps he should have.

The burner was definitely not up to the job, so in this last video, it got some assistance.

It does go! Just needs a few tweaks. Lovely sound.

10 Comments

February 15, 2019

Making Springs and Other Stuff

Other stuff first.

MOVING STEPS

SWMBO has always considered that having a winch on a vehicle is a bit of a wank, but I have used it many times getting out of bogs, getting other people out of bogs more often, moving machinery, pulling down/moving trees, straining fences etc etc. SWMBO was intending to replace these concrete steps, because they were crooked with respect to the house which she is fixing up. I said that I could straighten them.

This is after straightening. I jackhammered the path slab, lifted the floor slab with the 4WD high lift jack, and pulled the steps with the Landcruiser winch. Easy as. Took 30 minutes. SWMBO was delighted!

MAKING SPRINGS

And I used my new spring tool. Brilliant! Recorded on videos. Again, apologies for my lousy video technique. I had forgotten to bring the spring making instructions, so it was all trial and error.

This was my first effort. Aluminium wire, just to try the tool. As you can see, there were multiple errors. Feed rate too slow for the RPM, forgot to enter a stop command at the end, feed rate much too slow at the beginning on the left.

So I started with aluminium, making many mistakes, sometimes repeatedly, but eventually learning. Progressed to soft iron wire, and eventually to stainless steel spring wire.

Following is a series of pics and videos.

The mandrel was 4mm diameter, and there was a bit of spring back, with the final ID of 4.4-5.0 mm.

Initially I secured the end of the wire by catching it in the collet, but quickly replaced that method, and drilled a 1.5mm hole in the mandrel. Again, I forgot to issue a stop command in time. The starting coils were hand wound by manually turning the spindle and jogging the feed. If I was making multiples of the same size spring that would be simple to program on the CNC.

Ah! Getting the hang of this! That one looks good!

In the next video, a good spring is made. The mandrel wobble is occurring because I had bent the mandrel, when the steady was not hard enough against it. Bend straightened afterwards.

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And the safety valve with its new spring…

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But screwing in the safety valve was a bit of a struggle…

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And re-installing the safety valve lever was almost comic..

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So, that’s it for this post.

How did you like the videos? I suppose that I should have stitched them together into one long video. Maybe I will do that later for YouTube. And to edit out all of the errors.

Later today I will post another video, this time a longer one, a tour of the Trevithick engine.

4 Comments

February 13, 2019

Well, what a nice day!

Wednesday is always a good day. That is when our model engineering group has its weekly meetings. Mostly a 2-3 hour informal gathering around a large table, chatting about current projects, new tools, the weather, rarely politics or religion. Coffee. And once each month a more formal evening meeting, involving discussion of club business, “models on the table” and usually a guest speaker. Today was the informal 2-3 hour chat variety.

I used the opportunity to ask about methods of making a rectangularish water tank for the Trevithick dredger engine, riveting, folding brass, caulking with solder, etc etc. And Stuart T, knowing that I had to make a stainless steel compression spring for the safety valve of the Trevithick, brought in his tools for making springs.

This is one of the tools. It was designed by Dwight Giles, and made by Stuart.

Published in Model Engine Builder 2007.

The tool is mounted in the lathe tool post. The V supports the chuck mounted mandrel, and the brass washers apply drag to the spring wire. The lathe threading gears supply the pitch to the spring. Looks excellent, and I was hoping that Stuart was intending to lend it to me. Otherwise I would make one of these tools. But why were there two of the tools? “Oh, one is for you! I was making one for myself, and it was just as easy to make two.”

Not the first time have I been the recipient of Stuart’s generosity. When I make the spring (soon) I will take some pics, and post them here.

Later in the meeting, Swen Pettig, recently returned from a fabulous trip to Scandinavia and UK, called for shoosh, and stood up to make a presentation. Some people knew what was coming. I didn’t. But in “recognition for writing about his model making” (now my ears pricked up), Swen had picked up an item in the UK which he thought I might find interesting. Knowing of my current interest, some might say obsession, with Richard Trevithick, he had looked for and found the following item.

A Two pound coin. I did not get the significance, until I looked more closely. Holy Shit! That is a Trevithick engine on the coin. The Pen-y-Darren railway engine if I am not mistaken. Made in 1804. And using many recognisable features which are in my slightly later dredger engine. The coin was minted in 2004, 200 years later. Wow!!

I did not even know about the coin until today. But I am honoured and very grateful for this lovely gift and thought, Swen.

One wag suggested that I should make another gas knob for the engine, and mount the coin in the knob. (thankyou for the suggestion, President Brendan. I will do no such thing). It will be a valued possession.

Incidentally, the reverse of the coin has an image of the Head of State of Australia.

5 Comments

February 3, 2019

Trevithick Dredger Engine Base.- 3

Just a quickie.

One of our GSMEE members, Stuart Tankard, solved the base issue on his most recent engine build like this….

Those bricks are CNC’d out of aluminium bar.

Reader Huib suggested that if I follow suit, I should program in some imperfections!

Maybe I will ask Stuart to make my base. (relax Stuart. I wouldn’t do it to you.)

4 Comments

January 6, 2019

Another axis for the Boxford 125TCL

Watch the video of Stuart Tankard making tiny valve handles on his CNC lathe. Changing the old Boxford spindle motor to a new generation servo motor allows him to use Mach3 to control the spindle to turn very slowly and to a set number of degrees, producing the very attractive handle cut-outs and rim dimples. i.e. he has added the functionality of an indexing head to his CNC lathe.

It required adding a small milling head and motor to the toolpost.

I can see one of these on my Boxford 125TCL in the near future.

August 1, 2018

Steam Driven Water Pump for Vertical Boiler

Unfortunately I did not make this pump. It was made by Stuart Tankard. I have the castings and plans, and intend to make one for my 6″ vertical boiler but I have too much on the go at present and will finish the vertical boiler and the Trevithick engine first.

Enjoy the pics. Stuart sets the machining standard for the rest of us to aspire to.

We did not see it running today, but it does work.

It is a 6” Duplex pump from Southworth Engines.

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January 12, 2016

Boxford CNC lathe (5)

The following pictures and video were supplied to me by Stuart Tankard.

They show the rarely used tailstock in use, supporting a relatively long thin workpiece.

The lathe is Stuart’s, and his control panel is fixed to the lathe cabinet. (Mine is an identical machine except that I use a wireless MPG).

The tailstock is the part coloured bright yellow, and it normally sits unused in a drawer, or hinged down and out of the way. As you can see however, it occasionally is useful.

Stuart’s lathe. Note that the G code for the part was generated by a program called EZILATHE. I also use this very handy program. Ezilathe is a free download.

The part is the first step in making a link for the beam engine which Stuart is completing. The headstock end is held in an ER collet. The tailstock contains a small roller bearing held in a shop made fitting. After turning, the tear drop ends will have flats milled onto the sides, then holes drilled and reamed for shafts.

Check out the following Youtube video to see Stuarts lathe in action.

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