Replacement Whistle on Polly V Steam Engine

Spluttering Banished to be replaced by a Banshee

It had become a standing family joke on steaming outings that my Polly V whistle left a lot to be desired.   Quite often it would do nothing more than a feeble splutter.   The Polly V kit supplied whistle is fitted under the running board on the left hand side of the cab.   The pipe run is long and somewhat tortuous.   I had insulated the pipe to reduce feed loss but this made little difference.   The whistle valve also had a gentle leak and was very stiff to activate.   All in all not a good setup.

A recent article in Engineering In Miniature (EIM) by Richard Wightman (September 2022) went into detail about a whistle and valve combination he had created.   The whistle was fairly conventional but very compact.   The steam control valve was unusual in that he used a standard tyre Schrader valve.   This tweaked my interest and I set about upgrading my Polly V locomotive using this technique. Here are some Fusion 360 images and shots of the new valve and whistle mounted in place on my Polly V.

Here is a blow by blow description of the process as a PDF download.

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Noga Tool Christmas Present

Every workshop should have one

There was a recent thread on the MEW forum about Noga tools. It led me to download the Noga catalogue as a PDF. I am amazed at the technology that Noga produce to just remove burrs.

They are lovely tools and well worth the investment. I particularly like the external Rotodrive EX18 countersink. This is very handy for cleaning up the end of a newly threaded rod so the new thread will ‘take’. So quick and easy.

What really took my fancy in the catalogue on page 51 was this combination tool. That’s certainly one for my Christmas list.

No affiliation to Noga. I just like their technology.

“Better to have it and not need need it than to need it and not have it” – Jimmy Diresta.

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Edge Technology Lathe Tool Setter

A useful tool for setting lathe tools on centre

There are many ways to set a tool centre line on a lathe. The most basic is just to trap a 6″ rule between the workpiece and the tool edge and adjust so the rule is vertical.

One gizmo I picked up at a trade show from the Machine DRO booth is this very useful tool by Edge Technology.

Edge Technology Lathe Tool Alignment jig

It is simple but clever. You mount the rod in the lathe chuck and then rest the bubble anvil on the tool edge. Edge Technology also do a more refined version with a calibrated scale.

It is not something that you use every day but every now and then I have a session with it and go through all my QCTP tooling and tweak them.

(If it has been one of those ‘not settling to anything’ days you can at least switch the workshop lights off with a warm glow that you did something useful …)

In the UK they are marketed by Machine DRO

(I have no affiliation to Machine DRO or any other manufacturer or supplier I might mention in my write ups but I will mention any nice pieces of kit I come across or use).

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3D Printed Four Facet Sharpener

A Hybrid Version of John Moran’s Elegant Design

While investigating four facet drill sharpening, I came across John Moran’s website which detailed his design for a four facet drill sharpener.   Four facet sharpening is popular for providing more accurate starting of a hole, less drilling pressure, more accurate hole size and better retention of drill point sharpness. John’s design is intended for sharpening 2mm to 12mm drill bits.

I have a Quorn grinder but it is not something that I can quickly pull out from under the bench to sharpen the odd drill.   John’s design looked easy to set up and use and certainly easier to carry. I have been working with him to produce this hybrid version. I recommend that you read John’s write up before embarking on either his original design or my 3D printed hybrid version. He also presents a YouTube video on how to use the sharpener.

https://gadgetbuilder.com/DrillSharp.html#Facet4

Here is a picture of John’s finished design. Very nicely finished and presented.

Here is a picture (not quite so pretty …) of my 3D printed hybrid version. A new baseplate might be in order to smarten it up.

The concept of combining 3D printed components with essential metal parts works very well and the resulting sharpener appears to be stable and repeatable in its results. There is a huge advantage in combining technologies in this manner. All the ‘boring’ or ‘dreading to make / leave until tomorrow’ parts are easily produced on a 3D printer and the remaining metal parts are straightforward to produce with conventional resources and skills.

Rather than go into details as a blog post, below is a link to a ZIP file that contains my full write up, 2D PDF drawings of the metal parts, STEP files of the 3D printed files and the raw Fusion files for those wanting to tweak.

If you can’t work with STEP files then let me know and I will run STL versions. STEP files are more accurate than STLs and also have the advantage of being more easily editable than STLs.

I think you will be impressed with the end result of John’s design.

If this write up or my general waffle is of interest then please subscribe to receive notices of new posts. If you build the sharpener and it works let me know. If it doesn’t work and it’s my fault for not providing enough information than email me so I can correct things.

As an alternative to a 3D printed version you can watch Mark Presling on YouTube who has recently construct the same sharpener in metal.

UPDATE

I have already had some feedback on the 3D printed design so some of you are quick off the mark.

This feedback related to the friction of the collet holder shank in the block and also the print roughness against the depth setting screw.   Both of these will relate to the print quality from your printer.

As an experiment I ran a new version of the block with a larger bore and then lined it with an aluminium sleeve that was a smooth fit on the shank.   I also turned a flange on the end of this sleeve so that the adjuster nut had a smooth metal surface to ride against.

The addition of the sleeve looks promising in solving these two issues.  I admit it is going against the concept of a 3D printed set of parts but the sleeve is easy to turn up on the lathe and the new block in PLA is still much easier to produce that trying to make the block totally in metal.

You can download the edited write up, new collet chuch holder block STEP and the sleeve drawing in this add on ZIP file.

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Truncated Lock Levers

Restricted space modified lock levers

Each of the axis locks on my VMB mill uses two M8 cap head screws in association with a lock nut. This works OK if the hex driver is in reach …. but it never seemed to be …. so I decided to remove the cap head screws and fit lock levers instead. Lock levers come in male and female format and various thread sizes. The M8 versions all have 40 to 50mm long lever arms. This length doesn’t work comfortably in the space constraints on the VMB X and Y axis but is fine for the Z axis. Similarly I also had to reduce the length of the lever thread.

The obvious solution was to cut down the length of the lever arms. The trouble with this was the raw open end of the arm looked naff and did not sit easily with my usual perfectionist approach. The solution via Fusion 360 was to create some 3D printed end caps which I then bonded in place with Araldite. This finished the job properly.

Fusion 360 modelled end cap for the shortened lock lever arm open end

The Fusion 360 3D modelled end cap printed in under 4 minutes with a further 5 minutes for the Araldite to cure. I now have a much more elegant looking solution.

Full length lock lever and the truncated version with 3D printed end cap mounted on my VMB mill

All of which has led to a rethink the lock levers on my Quorn tool grinder. I get in a real mess with these clashing with each other. Where did I put the Araldite ? …..

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