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Member postings for Dave S

Here is a list of all the postings Dave S has made in our forums. Click on a thread name to jump to the thread.

Thread: Stainless Watch case
28/07/2021 14:10:37

Will edit later at home - and pull the photos locally.

They all show for me - but then if they didn't I would have noticed...

Dave

28/07/2021 13:15:12

I originally planned to make the case and stem tube in one piece, but the rather large hole required a new plan.
I didn't have any stainless in about the right size, but I do have some brass. So brass stem tube / crown guards it is.
The colour will make an interesting contrast, it might even look like a design choice
I made a cutter to create the crown recess from silver steel:

I filed 4 'teeth' onto it.



Then having faced and drilled a piece of brass on my smaller lathe I setup to use it

The original crown and stem fit beautifully, Feels like the o-ring seals will be fine.

Of course its somewhat fiddly to get at the crown with it totally surrounded by a guard.
To the milling machine!

Flip and repeat for the other side

Ta Da! now its simpler to get to

The milling has left somewhat sharp lines on the guard.

I wanted to blend them, so with the help of a hot glue gun and a piece of carbide I made a radius filing jig.

My little assistant helps to illustrate the size of these things


Once radiused I can then use the same diameter endmill to cut the recess into the case to fit the crown for length (its amazing how these things work out )

Crown sorted now time to do the light pusher.
She was very adamant this still had to work.
Of course its another hole in the case but this one I didn't snap a drill in. You can see it just next the the crown guard in the previous photo.
The Light pusher has a pair of o rings, a spring, and is held on the inside of the case with a tiny tiny E clip.
Fortunately I had just finished making a grinding work holding spindle, so I pretended my surface grinder was a cylindrical grinder:

Then made a quite long, stepped and very thin thing. To turn this on the lathe would have been 'tricky', especially as the stock is already hardened.



Then "all" I had to do was put a groove in the end with a small diamond file

All the bits are made - time for some finishing. I surface ground the straight edges, of course scrapbinium is not magnetic, so I had to make a fixture to hold the case to the chuck. First I ground the sides and then I added some facets - to reduce the weighty look of what is admittedly a large is chunk of metal.

The end result came out ok I think.
Its not perfect, but I'm fairly sure she wont snap the lugs on this one:


Dave

28/07/2021 13:05:44

Afternoon all,
It seems that recently I have been stuck in a loop of building machines. However I have just finished a little bit of watch case making, thanks to my eldest daughter.

Couple of years ago Daughter picked up a cheap 'dive inspired' quartz watch. Not a bad thing, and for a couple of quid it was reasonably priced given it didn't appear to work.
Once I changed the battery (it had gone flat in the shop...) it was all good.
I think its a Seiko movement - no2 daughter has a Lorus with the same movement in it. They have 2 batteries - one for the movement and one for the EL face - a PITA to change the movement one of course.
Anyway this watch was worn a lot, and eventually the lug on the case snapped. Cue sad daughter, who asked if I could fix it (of course).
I had a look and decided that while I could glue it back together where's the fun in that? So I agreed to make a new case.

I started by bunging a bar of recently acquired stainless scrapbinium in the lathe and set to. (Anvil for Scale )

The stick out was a bit much, so I set up the steady in avoidance of wearing a 2" diameter chunk of steel

Faced the bar off to give me an idea of what I was working with,

and then chucked a hole at the middle - the movement is actually a lozenge shape, so I roughed out the movement hole and the step for the crystal and chapter ring.

That done I bevelled the front and parted off a roughly case sized ring.

The hacking out of the movement hole will come later - on the Milling machine.

Seems I didn't take any photos of the initial lug cutting, but now the round is more of a case blank shape

The movement actually sits pressed up against the back of the chapter ring, so my datum point was the recess that the chapter ring sits in. The back of the blank is not yet at a specific place, so I made a brass plug to sit on the chapter ring ledge and allow me to set up from the other side

These 2 mini slots define the ends of the lozengeish movement shape.

There followed a lot of strange angle milling - which I apparently took no photos of - but that's not too surprising as I had to concentrate a lot...

Then the movement fits!

You can see the odd shape in the plastic case here.
The case is still quite chunky for a ladies watch

Next up was to work out where the stem and light pusher holes needed to be, and what size.
This is a shot through my Toolmakers microscope - to measure what size the stem hole was, and where it was positioned.



Then it was onto the mill to drill some holes.

What you can't see in this picture is the snapped carbide drill bit inside the nearly completed hole

These things happen, but I was a little 'upset' about it.

Fortunately I've picked up a few machinists rescue methods...
Here's one I used this time - you can drill out a carbide drill if you are:
1 - careful,
2 - lucky, and
3 - have an enormous milling machine.
1 and 3 no problem, and as the option was to start from scratch or be lucky I gave it a go.

This is a single lip cutter - its ground out of a solid carbide bar and is a fair amount bigger that the hole I intended to make, but needs must - I can always sleeve it (shh - spoilers

I machined the round surface flat first, so I had a good starting point, and then pecking 1 thousandth of an inch at a time I proceeded to drill out the broken bit and the rest of the hole. Incidentally the plaster is in no way related to the watch case.

Now seemed like a good time to make it more watch case shaped, so I created some angled sides - Straight edges and curves are IMO a good design statement.

Whilst I had the case setup I put in the spring bar holes - I prefer drilled lugs as it makes strap changing much easier.

Part 2 to follow as the post is too long

Thread: Help with surface plates in Derby
27/07/2021 19:12:40

Eley metrology can probably recondition your plates, but I bet it is more cost effective to buy a new granite one.

My 4’x2’6” table has a planed finish. It’s flat (for some values of flatness - workshop grade and well out of certification. .
It makes an excellent stand for the 18” granite I actually use...

Dave

Thread: Lathe protection
16/07/2021 17:43:38

If your storing it get some boeshield on the machined surfaces.

Dave

Thread: Lathe cover
14/07/2021 19:13:13

My lathe ways get a good coverage of way oil during use, they don’t seem to rust when standing.

Same for the mill.
Both machines have a reservoir for the oil, I just keep it topped up.

No covers here.

Dave

Thread: Parting off problem
04/07/2021 12:45:40

End of tool is slightly not square, causing it to bend slightly would be my guess

Dave

Thread: Help with machining Titanium
04/07/2021 10:42:26

For a ring Grade 2 would be my choice - it’s reasonably available. I’d get a piece in bar form unless you can find a tube.
Tools need to be sharp and the cut made without hesitation.
Rubbing in the cut will work harden and then your done for.

Making a ring a swarf fire is unlikely, but be aware of heat buildup.

Dave

Thread: Is buying a custom ground tool my only option??
30/06/2021 18:30:34

Could you get away with a V groove? You’ll end up with a line contact on the balls, but that may be sufficient for your application. Grinding a V to suitable accuracy should be no harder than a threading tool.

Dave

Thread: Apkt size?
30/06/2021 15:46:30

Thanks.

e3de4751-310d-4d8f-8abf-58519593ee12.jpeg

they must be 1003 then.

Dave

30/06/2021 13:05:31

Afternoon all,

Last night I had a proper crash moment and my favourite insert endmill (16mm dia) is now less endmilly and more scrap.
I still have a load of apkt inserts, so a new body is all I need.
Should be simple however the insert size is a mystery. The only insert box I have with no label is the apkt one...

My google-fu is weak today and I haven’t managed to find a chart with measurements that would allow me to determine what I have.

I think they are 1604, but it seems all the bodies in the size I use take 1003.

Can anyone tell me what I need to measure to know?

Dave

Thread: Dressing / Truing a resin diamond wheel
29/06/2021 09:45:44

Morning all,

Im still building my tool grinder, but I have enough bits to do a few trial grinds to make sure that all the various angles and such work ok.

I have an alloy bodied resin diamond wheel that I am using - you can see it in this photo:

064e5434-7eec-48fc-9255-3c78dd8fd196.jpeg

I have had it for a while, and it’s been used on the previous iterations of this grinder.
As a result the face isn’t flat anymore.
What do I use to dress / make flat again?
I have single mounted diamond for my Surface Grinder, a number of scrap alox wheels, and a norbide dressing stick.

Dave

Thread: Re-making a centre hole in a small crackshaft
28/06/2021 12:16:44


Assuming a suitable sized lathe I would approach like this:

Given the bearing by the crank there is a reference surface there. Either remove the bearing, or use its outer race with some greedy soft jaws such as these:

182aa982-5e0e-4572-ae1c-6f90441f5114.jpeg


Bore in situ then you know that end is running true. Setup fixed steady on other true portion. If using outer race secure a drive to on of the jaws, and make sure the con rod isn’t flapping about.

Now if required can slap on some weld to build up if needed and then machine and remake centre.

Dave

Thread: 2D and 3D Cad Software Recommendations
22/06/2021 19:58:33

I tend to use LibreCAD for 2d for the laser cutter. Mostly like AutoCAD used to be and exports a DXF that the Laser understands - Fusion DXF is to new a version for the laser software.

Dave

Thread: So, you know about clocks!
22/06/2021 18:09:20

You could try Bernard Whitworth near Newark.
Afraid I can’t find his contact details, my google-fu seems weak today.

Dave

Thread: Locking Bearing preload nut
19/06/2021 22:15:24

Given the nut is pressing against a bearing that will spin freely it will have little tendency to unscrew.

As the bearings are "solid' the preload will not need to be continuously adjusted.

Simple solution, if it was me doing it, light or possibly medium threadlock.

Dave

Thread: Nickel Electroplating
18/06/2021 17:39:31

So if you stop at the right point you’ll end up with a nickel finish?

Might it depend on the voltage?

A different Dave

Thread: Securing workpiece for parting in lathe or 'left feed'
15/06/2021 21:42:39

I use centre support all the time on the CVA.

This is mystery steel, about 2" diameter:

e3yz0ccwuaawwuf.jpeg

Just remember to loosen it of as you get towards the actual cut off.

Dave

Thread: Can you recommend a UK supplier for good quality "mill board"?
15/06/2021 12:14:25

So there is an implicit symmetry in the stack up.
Fair enough.
can you get ~3mm board and mill the edge to the half thickness?

Thinking production you presumably will cut the parts from a larger sheet, so an additional op to thin the edges first saves a glue stack up op.

Dave

14/06/2021 21:25:52
Posted by John Smith 47 on 14/06/2021 14:33:48:
Posted by JasonB on 14/06/2021 13:25:55:

Can you make the core from one layer each of 1.0mm and 1.5mm which with the other items would give the total you desire.

Or if you want to make sure the structure is balanced then two of the 1.0mm with something 0.5mm in the middle of the sandwich.

Hmm... 1.0 +1.5mm isn't completely impossible, but it would mean fundamental changes to other parts of the design. Moreover if the product went into production the unwanted added complexity would add unwelcome cost.

So, yes, if all else fails... I'll guess I'll have to have another think about it but it would be must better to get two layers of mill board of the correct thickness!

J

Can you enlighten us about the fundamental changes that having an unbalanced 1+1.5 laminate would cause? In your stack up:

0.15 - Protective film (minimum)
0.05 - adhesive (guess)
1.50 - Gemimi Mill Board
0.05 - adhesive (guess)
1.50 - Gemimi Mill Board
0.05 - adhesive (guess)
0.15 - Protective film (minimum)

You make no mention of anything “in the middle”, and by your numbers it would add up to 2.9, just inside your sweet spot for thickness.

If you make it to production then presumably you’ll make an order for the right thickness of custom board, so no complexity there.

Dave

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