A Lazy Cable Clamp using 3D Printing

This is nothing magic but worth a mention.   Being fundamentally lazy I don’t like to assemble and solder electronic multi-way connectors.   There is never enough room to work on the contacts and the cables never lay up how you would like them to.  This could have course be a function of my eyesight ..

I am currently working on boxing and installing the Tormach USB Expansion Board which has a USB connector interface.   I wanted the cable to pass through some form of gland into the box but didn’t want to cut a standard USB cable and remake the connector at one end of the other.   

After some head scratching I came up with the following simple cable gland/cable grip.  It is nothing revolutionary but made life easy and the parts only took 20 minutes to design in Fusion 360 and then 3D print on the Sindoh 3DWOX.

It has two identical semicircular halves that hold the cable and there is a ring that pushes over these on the outside of the box.   A small flange holds these in place on the inside of the box. The hole in the box and the ring inside diameter are both 16mm to allow the USB connector largest dimension to pass through.   This is also one of the standard cut rings on a cone cut hole drill which makes cutting the hole in the box very straightforward.

The component parts (two halves and the retaining ring)
Inside view of the gland showing the retaining shoulder on the two halves
Outside view of the cable gland showing the retaining ring

Not rocket science but you never know it might come in useful and the dimensions can be tweaked to suit other cables and connectors. Similar or related subjects : –

Microset Clock Timing Instrument Upgrade

Mumford Microset Clock and Watch Timer

Some while ago I bought a Microset Timer from Bryan Mumford.   This is a lovely device that allows you to monitor all manner of parameters on clocks and watches.   It has an acoustic sensor to listen to the beat of the clock or watch and an optical sensor that creates and detects a beam of light that is chopped by the pendulum.   From these simple accessories all manner of diagnostics can be done on the clock under inspection.   If you want to know more I suggest you log into Bryan’s site.   Bryan also has some videos which you can find on YouTube.   You might also want to download and read a pdf collection of articles written by Chris McKay in the Horological Journal about using the Microset to fault find on Turret Clocks.

Microset Timer from Mumford Micro Systems

The Local Church Clock

If you are a regular reader of this blog you will know that I have got involved with the local church clock which is a Cooke of York movement.   I have been working with a fellow engineer in the village to try to bring the clock to time and we are slowly getting there.   Our last major breakthrough was finding the fly was lose on the gravity escapement arbor.   Since tightening the fly the clock has been much more reliable.

There is a weight tray on the pendulum which has an assortment of coins in it where someone historically has been fine tuning the pendulum swing. Because the clock has been running fast by a few seconds per day we have been slowly removing the coins one by one to bring it closer to time.   I think it is now at a point where we need to monitor it long term with the Microset.

Microset Upgrades

Bryan offers an upgrade to the Microset that allows a temperature sensor to be added to the recorded information.   There will almost certainly be temperature changes in the clock tower so it seemed like a good idea to upgrade with the temperature option.   This was ordered and duly arrived from Bryan and is now fitted.   There is also an upgrade to allow the Microset to record data into internal storage in the Microset rather than depending on having a PC connected.   I would be more comfortable leaving just the Microset in the church pendulum cupboard rather than my portable PC so I also ordered this upgrade.

It took me about an hour to do both upgrades on the Microset.   The memory upgrade involves a chip change inside the device and the temperature monitor needs an additional 3.5mm jack socket fitting and wiring to accept the new temperature sensor.   Neither is a difficult task but clearly need to be done carefully so as not to do any damage to the Microset.   Bryan’s instructions are well written and illustrated.

Since the upgrade I have been running the Microset on the bench with a Smith’s clock movement.  (It is actually the one I stripped down, cleaned and rebuilt on my ‘Clocks 1’ course at the BHI).   The new Microset facilities seem to work well and as expected.

Microset optical sensor monitoring a Smith’s clock mechanism

A New Sensor Needed – 1st Attempt

To implement measurements on the church clock the supplied optical sensor as shown in the picture above is not totally ideal.   It has a very narrow gap between the transmit light source and the receiver detector diode which on a turret clock is not  easy to use.   

It is possible to get round this my fitting a cocktail stick or similar to the pendulum bob and using this to break the beam but it is a bit messy. I had picked up a bag of laser diodes and detectors at a local ‘ham’ radio junk sale and I decided these might form the basis of a new sensor which might be more useful to a large pendulum assembly.   Bryan is a really helpful guy and although he does offer a larger laser sensor he was more than happy to help me with the required electronic interface to the Microset.  The one proviso is that the amount of current drained from the Microset 5V power supply must be kept below 30mA.

I set to and made the most elegant and over engineered solution for my laser sensor.   This is shown below.   The black mountings were designed in Fusion 360 and 3D printed on the Sindoh 3DWOX.

First ‘elegant’ laser detector for Microset timing instrument

The spacing between the emitter and detector is adjustable by sliding the transmitter along the steel rods.   The power to the laser is also carried down the steel rods.   A small DTC transistor provides the interface to the Microset and the 5V supply provided by the Microset is dropped via two diodes to power the laser.    It works really well ….. but … when I went round to the church to install it I realised I should have checked one or two things first.    The rating nut at the bottom end of the pendulum (used to make course adjustments to the pendulum length) was almost touching the floor of the pendulum cupboard.   My wonderfully elegant laser detector would not fit under the pendulum to monitor the swing.  A serious re-think was needed. The gap was so narrow that at best I will only be able to get a piece of 16 SWG aluminium sheet or PCB underneath the rating nut.

A New Sensor Needed – 2nd Attempt

I did say I had a bag of laser diodes and detectors so a new version would be possible and I could then save the posh one for more public facing activity.

As mentioned above I decided to use PCB as the base board.   This is shown below.

Mk11 Laser Detector Specific to local church clock with little clearance from rating nut to floor

This has the advantage that I can use the copper surface to mill tracking into it to aid the wiring.   The downside is that it is quite flexible and therefore possibly not stable enough to keep the laser aligned with the detector diode.    To resolve this I soldered strips of nickel silver (could have been more PCB) either side of the centre line as shown but leaving a gap for the pendulum swing.

I designed a common holder for the laser and detector diode in Fusion 360 and 3D printed two of these on the Sindoh 3DWOX.

The finished detector assembly still had a tendency to flex so I stuck some old pieces of credit card on the lower surface, one at each end before the mount and a large piece in the middle.   This seemed to cure the problem without adding significantly to the base thickness.

Microset Display

When plugged into the Microset all seemed to work well.   Here is a typical PC display of the Microset data.

Microset Data Display showing the data from a Smiths clock mechanism and also the green line showing the temperature

I now need to get it installed in the church tower.

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Golf Caddy Locks and Ring Lights

Golf Caddy Locks

We have a couple of rigid golf caddy cases that take a full golf bag plus whatever else you can squeeze in when going on a holiday trip.   Last trip to Hawaii this included lots of shoes, snorkels, flippers etc.   These have or at least had two cabinet style locks on them but not anymore.  Customs / security at Seattle decided they wanted to have a look inside and took the easy option and smashed the locks off, had a look inside and then Gaffa taped the case back up.  Lovely.

Everything arrived home safely with nothing missing but now the debate on how to replace the locks.  Clearly the idea of locking them does not go down well with baggage security teams.   I have knocked up a design in Fusion that only needs a single cable tie to make it secure.  I have 3D printed a concept model from the Fusion design and I have now run the finished items in aluminium using the Tormach CNC.   I used a combination of CNC and manual milling to get the results and this highlighted once again that the combination of a CNC and manual is incredibly useful.

Gold caddy with 3D printed trial lock in place

 

Close up of the prototype lock without the peripheral shaping

 

Fusion 360 representation of the lock design without the locating pins and hinge pin.

Replacement latches for golf caddy security

 

Ring Lights

have been receiving requests for my machine spindle illumination lights using car headlight ring light clusters and have got the process fairly slick. 

 I first of all edit the centre clearance hole in the boss in Fusion in preparation for printing.  I then 3D print the power supply box and lid and while putting this together I get the boss print underway.  The boss takes around 7 hours to print on standard quality.  .   Given the amount of interest being shown I think a formal write up would be useful for others with perhaps the Fusion file as a download.  Working on it and more to follow. 

New ring light off the production line. Note that the baking foil reflector is getting easier to do.

Update – the ring lights are available on Amazon at around GBP14 per pair and you can select diameter (and colour).  Buy the largest diameter you can so that there is reduced shadowing around the tool point in the mill or drill press.  They are cheaper to buy on EBay from China but there is a longer delivery time.

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Hawaii, Combine Harvesting and Alibre v Fusion 360

Hawaii Ironman and Seattle

Having got home from Chicago I had a few weeks at home before we left for Hawaii where my son was participating in the Ironman World Championships.  This is a crazy triathlon event in 30 degree heat and he finished in just over 9 hours.

We played a few rounds of golf on the Makalei course on Hawaii which is at 2500 feet above sea level. Sometimes in sunshine, sometimes cloud and sometimes hissing down with rain all of which made it challenging.   We also visited Pearl Harbour which was quite moving and this included visiting the Aviation Museum on Ford Field.

No visit to Hawaii by a Brit would be complete without a visit to the Captain Cook monument in Kealakekua Bay.  We completely misjudged the arduous terrain we would experience in getting down to the monument and nearly came to grief with dusk fast approaching.

Captain Cook Monument Inscription Plaque in Hawaii

On the way home from Hawaii we stopped over in Seattle for a few days which was a culture shock on body temperature.   We visited the Pacific Science Museum and the Space Needle plus a tour of the Boeing works as part of the stay.  The PSM is brilliant for kids (and OAPs).

All in all a good trip but will now be glad to get back in the workshop.

CAD & Farming

Being away home and more precisely away from the workshop, allowed me to do a few write ups that might be of interest and both of which were stimulated by reading forum posts on MEW.  My waffle would have been too long to post in the normal way.

The first write up is about CAD/CAM and my concern that there will probably be unfilled expectations from the news about Alibre doing a special deal for MEW readers.

To 3D CAD or Not

The second write up is about harvest time in North Yorkshire that is based on my younger days in a farming family.  This has been on the stocks for some time and the posting on the forum kicked me into finishing it off.

combines and harvest

Hope you enjoy these two missives and more proper stuff from the workshop soon.

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NYC CNC at MHUB Chicago

Rather than have the annual Open House at his factory in Zannesville, John Saunders at NYC CNC decided to have a joint event in Chicago at the MHUB facility under the banner of a Manufacturing Entrepreneurship Summit.

The format was for key presentations together with the attraction of having a tour of the MHUB setup which is a resource facility for product development.

John Grimsmo, a highly respected knife maker, told of his ups and downs prior to his current success.  This was followed by Jay Pierson telling his not dissimilar path to his company’s success in the machining work holding market.

After a break for a tour of the facilities there was an update from AutoDesk regarding developments on their wide portfolio of engineering software with particular interest in Fusion 360.   There was then a closing Q and A session.

The tour revealed the breadth and depth of the resources available to external organisations at MHUB to help get a product to market.   An extensive mechanical workshop, 3D printing, electronic workbenches and software development are just a few of the tools and resources available.   It was impressive.

The afternoon and evening passed quickly and it was good to see some familiar faces from my visit to last years Open House and the training course I attended in Zanesville.

John Saunders in checked shirt flanked by Jay Pierson, John Grimsmo

As I sat listening to Jay and John I could not help but identify with how they had got to where they are and the parallels with my business days.  We may be many years apart but we have all suffered the same ups and downs, long hours etc that are an essential part of getting to success.

An excellent event.

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