Member postings for Dave S

Yes to photos. I can’t picture what you made. Sounds useful

Dave

Surely the point is to make things?

I don’t think a cylindrical square will work for what I think I’ll need - as with the parallel faces I can square vertically and with another square horizontally at the same time.
Still if it turns out I need one I do know I can turn to under a tenth over 20” or so because not that long ago I had to…

Dave

Im building a CNC mill, and I think Ill need a chunkier square when I eventually get to the aligning stage.

I came across a webpage sometime ago (can't find it now of course) that showed how to make one from a chunk of cast iron. Not having a lump of iron the right sort of shape I poke about and found some thick walled steel box section. Hurrah, that'll do to try the process at least, and might even work for the intended job

To start the long edges are made parallel. Fortunately I have a reasonable surface grinder, so I slapped the box onto the mag chuck and started making sparks:

The weld seam was something like 0,004 lower that the edges. Not too bad.

I planned to rough grind and then finish, so once both sides had cleaned up I checked it on the surface plate.

 Basically zero movement on a 0.0001" DTI.

I was well chuffed

Now the long edges parallel It was time to rough in the ends. I hacksawed them roughly square, whacked it in a known OK grinding vice and made some more sparks:

Then with parallel ends that should be close to square it was back to the surface plate to measure up:

DTI on a surface gage rocked left and right for the high reading. Turned out to be leaning by about 0.007". For the first round of squaring up it was back to the grinder with some feeler gages:

0.003" under one side and clean up one end, then flip and make parallel (without the feelers).

At this point I left it to sit for a couple of days, partially to let it move if it was going to, and partially cos I have other things to do...

It did move, and the long sides were slightly out, something like 4 tenths IIRC. So I did a light set of finish passes on them. This is the start of one ( the beautiful dark corner):

Ended up back to basically as good as I can measure

Then another round of measure the squareness. I couldn't easily get the round part of the surface gage to touch and have the DTI at the height I wanted due to the way the angles worked out. Fortunately the surface gage has a V in the front, so one bearing later I have a round bumper again and I could measure over pretty much the full height.:

This time I needed an offset with precision in the tenths region, so I made a pair of gage block stacks with the required offset ( IIRC it was 0.2 on one side and 0.2014 on the other). The square was supported on these on the grinder, mag'd and clamped so I didn't get any ideas about flying away and then a fresh dress and a light grind and I cleaned up the ends.

The finished square has come out OK:

Its roughly 90 degrees - I calculated it to 89.996 / 90.004 based on the measurements. Ill check it again in a few weeks to see if it moves, but even if it does it'll likely be close enough for what I need.

Dave

Edited By Dave S on 11/05/2022 21:36:28

I would probably TIG or braze up the holes - but I have a TIG set and like to use it
Given it’s an oil tank if you do fibreglass it make sure it’s ok for continuous submerging in hydraulic oil.

JB weld might also be an option

Dave

Yes indeed. I was hoping to get the seals before having to strip the machine.
Currently I’m in the middle of a project where the grinder is the best machine for the job. Id rather not have it out of action for a long time while stripping and then procuring seals.

Still if no one knows then I guess that’s how it’ll go.
Dave

All I have is a photo of the parts manual, which has a very general description:

Of course the part numbers are no use unless you can get them from the apparently defunct J&S.

Given the cost of the wheel head oil Id rather not run a total loss system...

Dave

My elderly 540 has decided to start leaking from its wheel head.

It’s the plain bearing, uses super thin oil model.
Does anyone have the spec of the seals, or a lead on where to buy them?

Andmar suggested a seal place, but the info in the parts manual is apparently not sufficient.

Dave

I would put it in a box with filtered forced air cooling.

doesn’t need to be fancy filters, just something to stop the brass - a panel filter for a car engine might be what I’d use as I have them available. Even a pair of tights from swmbo over a tube would work.

Dave

What are you making a spindle for?
Is it for the Hobbymat lathe or are you using that lathe to make the bearings for something else?

Dave

I would not worry about comments like don’t use the “cheap Chinese” movements.
I would carry on and learn on them.

Much like machine tools there is a significant section of society that believes cheap Chinese = terrible quality junk.

In my experience a working watch movement cannot be junk of that sort, although the finish might not be first class Swiss.

Tool’s however are a different matter. They are an extension of your hands, but with less integration.
That said my favourite tweezers are not expensive - something like £5 a pair ( Vetus no3 and 5 from here - **LINK** .

I also do surface mount prototyping and rework with the same tweezers :

That’s on a standard 0.1” piece of veroboard and I had to hand place and solder those connections…
Better magnification is more important than tweezers that cost 30 odd quid each - *provided* the tweezers you use are good enough.

Dave

A small amount of poking later : **LINK**

John was running D1-5 not 6, but the principal is the same

Dave

IIRC the late Sir John Stevenson of this parish used to run D1-6 with only 3 pins in it.

The pins pull the taper together. 3 is most likely sufficient for most uses.

Somewhere on the internet (might be the home shop machinist bbs site) there is a long discussion about this and how 3 pins are plenty enough based on the strength of them.

Dave

Good news and an interesting thing to file away for next time I have a blobby print

Dave

I’ve used DD haulage in the past to move my tools:

**LINK**

Dave

Looks like your retract setting is too low, so the filament oozes as the head is moving from one move to another.

Usually a setting in the slicer I think

Dave

And varies with collet clamping diameter as well as collet size.

Useful link to regofix doc: **LINK**

Dave

I’ve only skimmed the video, but it looks about right:

**LINK**

Dave

The rubbery mesh draw liner stuff is quite good. Stuff falls into the holes and doesn’t bounce back out.

If you are “pinging” out of tweezers I suggest you dress them and also practice manipulating small nuts and bolts - 12BA are cheap enough in a small packet to practice stacking, moving and rotating, with the bonus that they are none critical if they ping off.

Have a poke about at the watchmaking forum on WatchUSeek for more tips and stuff.

Dave

I suspect the increasing use of fibre tips is related to the cost of manufacture.
The use of any pen for precision drawing is obsolete.

Technically you should always use a raised edge for any “wet” lining.
Properly used Rotring pens are less prone to smudge that dip pens, and no more prone that fibre tips.

One thing with Isographs and other tube nib pens is that you must hold the pen consistently, and preferably at right angles to the page for the line to be correct. Fibre tips flex, but “tube” pens don’t

Managed to complete the second part without any mishaps  The “backing” is 30mm square, so hopefully adequately rigid.

The D bit technique is one I got from James Harvey’s Machine Shop Trade Secrets. It’s a good book of short tips and tricks. I misremembered it slightly - he uses a ball nose, which presumably is a better geometry. He also likes to make the cutters hexagonal rather than round for some reason.

The important bit tho I’m sure is having a rigid setup and pecking a thou at a time:

Mods - if there is any sort of copyright issue then feel free to remove the pictures- I think it’s ok for educational sharing.

I’ve used this truck a couple of times on taps, but also to rescue a watch case where I snapped a tiny carbide drill in 316 stainless. In that case the cutter was bigger and I sleeved the hole, but the D bit did the job, with the tiny drill shattering as the pecking happened.

Dave

Edited By Dave S on 18/04/2022 14:44:00