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machines which I have made, am making, or intend to make, and some other stuff. If you find this site interesting, please leave a comment.

Tag: Stuart Tankard

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.

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Stuart, doing another CNC upgrade wiring.

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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.

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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.

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The rats nest is disappearing.

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.

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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.

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.

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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.

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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.

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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.

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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.

 

 

 

 

 

 

And the safety valve with its new spring…

 

 

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

 

 

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

 

 

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.

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.

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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.

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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.

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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….

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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.)

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.

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.

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

It is a 6” Duplex pump from Southworth Engines.

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.

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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.

 

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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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