A 3D Printed Passive Demagnetiser using Neodymium magnets

I saw a recent post on the HomeMadeTools.net site from Tony Foale about using Neodymium magnets in a rotating holder to act as a demagnetiser. 

Tony made the holder from aluminium but from my point of view with Fusion and 3D printing facilities the idea lent itself to be run as a 3D print.  The finished device can be held in a lathe or drill press chuck using the central boss.  The boss does not have to be rigidly clamped as the magnets will grab and locate the assembly up to the chuck.   The magnets are very strong so be very careful as you bring the object to be demagnetised up to the lower surface or it will also get ‘grabbed’. 

Attached is a ZIP file containing the Fusion 360 file.   This is designed to take 10mm diameter magnets which will be a tight push into the mounting holes.   I used 10mm long magnets but smaller ones will probably work just as well. The magnet mounting holes have a 1mm thickness bottom surface.   The magnets need to be inserted with the alternating orientation as shown.  Tony made a circular ‘keeper’ for the bottom surface from a steel disc.  This reduces the attraction to swarf.   The ZIP file also contains a simple lid to fit over the top side to protect the holes from accumulating magnetic swarf.

Screen shot of the demagnetiser fusion file
Pictorial screenshot view from Fusion 360 of the demagnetiser 3D model

ZIP file download is on the link below and contains the body and lid as a Fusion file and as separate STEP files  – demagnetiser disc body and lid

A closing thought (which I haven’t tried …) but if all the magnets were in the disc the same way round would this act as a magnetiser to save having to stroke the item with a magnet ?

Similar or related subjects : –

3D printed Myford QCTP dial gauge holder

I bought three Kafer dial gauges in an EBay job lot with a view to making a dual gauge holder as per Clough42’s design.   

After some thought I realised that a single holder would suffice by just flipping the orientation of the dial gauge in the holder.  Rather than machining the holder I opted to 3D print as this would be sufficiently robust when gripped in the QCTP of the Myford.

Here is the Fusion image and a picture of the finished holder in place.  The gauge is gripped in place by two nylon screws.  A M5 cap head screw acts as the height adjuster in the QCTP.

dial gauge holder for Myford QCTP
Fusion 360 model of the dial gauge holder to mount in the Myford QCTP
Dial gauge holder mounted in the Myford QCTP
The dial gauge holder mounted in the Myford

The threaded holes are all M5 and 3D modelled in the print.  They just need a run through with a tap to clean then up.

The following link has a ZIP file containing the Fusion file and STEP file along with the dimensioning sketch for the QCTP geometry.

Single dial gauge mount ZIP file

Similar or related subjects : –

Repairs to an ancient Thwaites clock completed

I have mentioned my activity on the Thwaites clock in a couple of blog posts and I can now confirm the work is complete.

Thwaites clock as originally received prior to the work taking place
The Thwaites clock as received before work commenced

This has been an interesting challenge and I am pleased with how it has worked out.  Once again I am impressed by the way that modern techniques and technology can all play their part in achieving a result that once upon a time would have been impossible using traditional circumscribed knowledge.

There is a full write up here on the Thwaites Clock Activity for anyone interested.

Similar or related subjects : –

Fogbuster update on my Myford Super 7 lathe

Plan B Fogbuster Mounting on the Myford lathe

Of late there has been a long thread running about Fogbuster use on the MEW forum.   This set me thinking.  The forum debate centred on whether mist lubricant or flood coolant was more or less healthy.   For hobbyists the consensus seemed to favour the mist coolant.  This was with the proviso that the jet and coolant mix is carefully balanced.  An interesting point was made about ensuring the air stream was pointing away from the operator to avoid blowback.  If all is good you should not be able to smell the lubricant.   (N.B. I use QualiChem Xtreme Cut 250C at around 8% dilution).

The installation on my Tormach PCNC440 is fine with respect to blowback at the operator.  Both nozzles are on flexible mountings and can be easily directed towards the back of the mill.  (See prior post).

My installation just completed on my Myford Super 7 is not quite so perfect.   I was using a T slot at the back of the saddle as the nozzle mounting.  This meant the nozzle was playing on the back of the workpiece and towards the operator.  Perhaps with hindsight not the most healthy option.   OK so I don’t use lubricant on the lathe that much as most of my work is brass and aluminium so maybe less of a critical issue.   Because of the infrequent use I wanted the Fogbuster to be quickly demountable until the next steel job comes along, hence the T slot idea.

I have a Myford Quick Change Toolpost fitted on the Super 7 which has two tool holder positions at right angles to each other.  It struck me that the Fogbuster could be mounted in the QCTP unused slot.   This would allow the air jet and lubricant to point forwards towards the workpiece.  Normally I would have the empty slot on the far side face so a boring bar can be dropped into place.   By rotating the QCTP through 180 degrees the spare slot would sit nearest the operator and be ideal for the Fogbuster.  

I didn’t really want to dedicate a steel tool holder to the Fogbuster so I created a 3D printed version.   This picked up on the prior mounting holes I had modelled in the flexible clamp.

I needed to make sure my 3D printed profile was a good fit in the QCTP so after fully modelling it I moved the time line in Fusion back to the profile extrude and reduced this from 26mm to 5mm and ran a test print on just a 5mm depth version.   This allowed a quick print to be done which gave me feedback to do some minor edits.   The timeline then was dragged fully forward and a full size print run.   Try doing that as easily and quickly in steel ?

The pseudo toolholder 3D print ran in around 90 minutes and looked and fitted well.   To finish off, I turned up a small clamping button to match the normal clamping and height adjustment screw on the QCTP.

Hey presto a new Fogbuster forward facing mounting ready to go.

Close up of Fogbuster mounting using the Myford QCTP
Fogbuster mounting using the Myford QCTP
Overview of Fogbuster mounting on a Myford QCTP
Overview of Fogbuster mounting on a Myford QCTP

Similar or related subjects : –

Fogbuster update prompted by Clough42 and other projects

Fogbusters Everywhere

Apart from working on the Thwaites clock parts, I have also done an upgrade to the mounting of my Fogbuster coolant nozzle installation on my Tormach 440.  This was triggered after viewing and being impressed by Clough42’s idea.   The Fogbuster is a great way to clear swarf and apply coolant.  The Fogbuster is normally supplied with a magnetic mounting arm but James’ modification uses LocLine gooseneck components to provide a much more flexible ‘aiming’ capability.

Something to be aware of – James recommends a download from GrabCAD for the 3D files of the two halves of the nozzle holder.   These had been uploaded by contributor Br BRB.  These were apparently publicly available via GrabCAD.  James slightly modified these and was offering them as a free download from his Thingiverse folder.  He has since had to remove them for download due to commercial issues.   BrBRB has also removed the original files from GrabCAD and is seeking to sell these as finished items.  I was lucky to have downloaded the files before the politics cropped up.  I  still have the downloads.

James also advocates fitting a second identical nozzle to the Fogbuster to avoid coolant and air shadowing.   I contacted Fogbuster in California and a very helpful lady called Rachel organised an upgrade kit to provide a second feed from my existing coolant reservoir. 

Dual Fogbuster coolant nozzles on Tormach PCNC440
Dual Fogbuster coolant nozzles on Tormach PCNC440 using Clough 42 flexible nozzle idea

It turned out Rachel was from Bristol UK so it is a small world and we had a good chat.   I have fitted both nozzles to the Tormach.  With a pressure of around 10 to 15 psi, the reservoir feeds both nozzles very well and is a huge improvement in use. 

As I was facing a shipping charge from the US I figured I might as well top up the package so I have also splashed out on a baby version of the Fogbuster to fit to my Myford lathe.  This uses the same idea but with slightly different mounting that fits into the T Slot on the Myford saddle.   I already had the 3D model of the T Slot strip from the ‘bits tray’ installation.

UPDATE : – I went to a Plan B on the lathe mounting – see later post

Baby Fogbuster mounted on Myford Super 7 saddle
Baby Fogbuster mounted on my Myford Super 7 saddle based on the Clough 42 flexi nozzle idea

Another pair of incremental asset improvements successfully installed.  I suppose I had better get on and make something now. 

Back to ‘the clock’ …

UPDATE 2 : – The 3D printed ball joint kept working lose on both the milling machine fogbuster mouunts.  The more I tightened the screws to grip it tighter, the more the 3D components began to crack and give way.   The solution was to fit brass inserts into the 3D prints.  Problem solved.  Incidentally there is a good review of such inserts on CNC Kitchen.

Similar or related subjects : –