What Did You Do Today 2020

Yesterday; changed out a LED security floodlight that some LED's had decided to give up the ghost, kept the pir sensor, 'just in case', together with a sketch of the wiring...

George.

New toy day:

Tiny 55° partial profile carbide threading inserts. I've bought them for short internal 7/16" x 32 and 1/4" x 40 ME threads. I declined to buy the holders at about £100 each. Note the small holes as the tool shank goes to full diameter. These are for through coolant, which is probably why the holders are so expensive. I'll be machining brass so won't be using coolant, through or otherwise.

That's blown the discretionary budget for this month.

Andrew

Spent the past few days workshop time machining down a chunk of 1.5" dia "Swedish Iron" to make some polepieces for the next clock project. Apparently this material is virtually pure iron, not cast, no inclusions, no carbon, just solid iron, made for magnetic circuits. Horrible stuff to machine, even though not very hard it's very tough and takes a nasty burr. Just remains to take the L-shaped bit I've finally milled out down the centre line on the bandsaw, mill the cut edges square, and drill a few holes. These will mount around a neodymium magnet and concentrate the flux into a small airgap about 16mm long x 2mm wide x 2mm gap. Lots of horrible blue oily chips all over the place, I try to avoid using cutting oil but on this it's needed to get a good finish.

They look incredibly useful Andrew, I'm thinking of doing some CNC thread milling on my KX1 and they look like they would do the trick, maybe?

Two questions where did you get them from, and are they going break my meagre monthly budget!

IanJ

Key thing for thread milling is that the edge is on a plane through the shank axis when mounted in a collet. If so it should work fine. I got a cutter like this from JB and it worked very well.

Good program to generate thread milling g code here:

**LINK**

Sounds promising! It's something I've been meaning to do for a while now. I use Vectric Vcarve and they recently upgraded it to include thread milling, although its orientation is mainly towards wood work CNC I think it will work okay with metal.

I'll give JB tools a try, I usually get my carbide tips from them at trade shows, so I know they are good quality.

IanJ

Carried on with making a set of tool-holders for the Hemingway kit T&C Grinder.

I am making two sets, one metric, the other inch sizes as per drawing. Since that meant having to find extra steel I had to turn some oversize bar down, and for a roughing tool used a lozenge-shaped insert in a home-made holder that utilises the tip's obtuse angles. It left a rather poor surface, but the finishing tool soon put that right.

The roughness may have been by the tip, of unknown source and type, being for metals other than mild-steel of EN-Something grade. More likely from the geometry of the holder, or a small setting error. After all, the holder is only a bit of square bare with a filed step and a pan-head screw, to hold used tips salvaged from work years ago!

Today was its first use, and it proved its worth, allowing for its limits.

Frustration time came right at the end when I discovered I have either lost or had never bought, the 10mm reamer I needed, but I then found the (too-close) reaming pilot 9.9mm hole had finished an easy sliding fit anyway, on a milling-cutter I used as a gauge. Right on the "plus-tolerance", but just about acceptable.

A trivial thing for many, I know, but I successfully turned a 0 MT taper to fit my Flexispeed this evening. Much to my pleasant surpise, it seems to fit better than the original one which came with the machine.

James.

Here are two tools that I've used for thread milling successfully. Best is the internal threading tool from JB - this I think isn't actually listed on their site but Jenny produced it from under the stand at an exhibition. Shank is 8mm dia with 2 flats and the cutting edge is on centre. This is preferred since you can climb mill from the bottom of the hole which is a bit quieter. The other is an M8x1 tap with all but one row of teeth ground away, as well as the point. This works but has to be started at the top of the hole - if you try to climb mill from the bottom then all of the teeth are engaged at once which would be very trying! Also limited to 1mm pitch. There was some discussion on here about using taps and the significance of the lead angle, but as long as the hole is a bit bigger than the tap they are fine, an easy way to try it out.

They're made by Carmex, who are based in Israel. I bought online from the UK distributor ProTools, based in Kent.

ProTools

Total cost was a few pence over £50 including next day delivery by APC and a 10% new website discount. So not cheap cheap, but less than a proper thread mill.

Andrew

420 miles starting at 5 this morning 10 hrs driving, down M40,A34m, M23, M25,A1, M1, A5 and then home

Collect tyre for one friend, Bentley Dynamo and Dizzy for another, delivered magazines for another and collected a few bits for myself. All socially distanced. One journey saved four.

Quite pleased with my bits.

Castings for Alyn Foundry RLE engine

Castings for Rider-Ericcson Hot Air Pumping Engine

Jones and Shipman Sine Vice.

Colin

Edited By Colin Heseltine on 02/12/2020 17:43:19

Just looked at this to get the 100,000th view.

Found one of these lying around in the "never used bits" box yesterday:

and decided to convert it into something useful. In fact, I've been meaning to do this modification for years, but never did. Now COVID-enforced workshop time has given me the opportunity to do all those little jobs I thought I didn't have time for. Actually, I've just been putting them off.

Sawed off the mounting "ears" and milled the sides parallel then set to and made a pair of new and thicker jaws. Milled a central groove 1mm deep and popped them on the surface grinder and ground the faces parallel, too. Just to make them look pretty, not for any functional purpose.

I really ought to clean it up at least , if not re-paint it, shouldn't I?

By clamping it vertically, like this:

I can now use it on the band saw to hold small section pieces of stock and, more usefully, hold short ends of material without the faff of using a bolt or similar to stop the band saw vice jaws from canting over.

John

Now that's a good idea!

Based on a posting by Journeyman I made a pair of vice clamps for my Vertex VMV-15 toolmakers precision vice. I will be used primarily on my Cowells mill which has two 'T' slots on 24mm centres. I felt that a single point fixing on the small 'T' slots might overload the 'T' slot so opted for 2 bolt fixing on each side and a pair of pins into each side of the vice.

When I made 'T' nuts for my big mill I made some with 6mm threads so can move this to that machine if required.

Colin

If this is a machinist's Jack

Then surely, this is a Machinists' Jill

Being Engineers of course they are really productive and here is their immediate family

Unfortunately, only Jack's parents are still with us after an unfortunate incident with a steam hammer and a vat of acid...

And they've been put to work straight away. But much to their disgust the first pedestrian job is holding up their new home whilst the no-more-nails sets. Not what they were promised in the job interview!

Iain

Brilliant Ian, made me chuckle anyway

The horizontal and vertical spindle motors on my new mill have noisy electric fans fitted to cool them. Presumably, because the VFD does not guarantee sufficient revs to do the job.

Both going at the same time, all the time was annoying so I fitted 40 degC thermal switches to shut them up until they are needed. 15mm binder clips, with the wire levers removed, provide excellent thermal contact and you wouldn't see them if you didn't know it was there.

The horizontal needed the engine hoisting to fit it, but the silence is well worth the effort.

Ever since I was a nipper, I've always been into motor racing and hankered after designing my own sports car. Nearest I got was designing and building a sporting trials car - reasonably successfully. I've long harboured a desire to build a model of the GT40 replica I once owned and now I've made a start, of sorts. I've decided to make a scratch-built scale generic sports car, specifically so that no one can pick holes in its authenticity or dissimilarity to the actual car. I've started with the rear suspension and begun drawing it in Alibre Atom. Here's what I've done so far:

As I'm designing it on the fly, not only will it evolve as I progress but it could change dramatically while it does so.

I wonder if it will ever get finished? The rear upright would preferably be an aluminium casting, but, looking at the current 3D printing thread, I might be persuaded to invest in one of those and make them out of PLA, along with a few other parts.

John